Biscuit Jointer Disappoints - Any Suggesions?

[Jeff Wright]

I tried using my new Porter Cable biscuit jointer for the first time today and was disappointed with the results. I tried gluing up two milled pieces of mohagany and ended up with the glue joint poorly aligned top face to top face (See photo). Am I expecting too much? It seems to me that there is a lot of slop/play in the biscuit slots; the biscuits don't fit snugly, but instead at best lay loosely in the slots. I had thought that once I applied glue, inserted the biscuits and joined the two workpieces, the boards would clamp nice and even . . . at least that's what NORM promised me!!

I was careful to joint the boards square prior to cutting the slots. I also referenced the tops of each board with the jointer fence and made sure the base of the machine was not touching anything. I am confident in my technique.

Any suggestions?

[Rob Will]

Domino!
Rob

[Mike Heidrick]

Biscuits allow for some movement/play. How did you clamp the pieces together? Did you use cauls on the top and bottom to align/flatten the surfaces while gluing?

Biscuits are fresh as well correct?

[Jeff Wright]

Biscuits allow for some movement/play. How did you clamp the pieces together? Did you use cauls on the top and bottom to align/flatten the surfaces while gluing?

Biscuits are fresh as well correct?

Mike, yes I used my Bow Clamps while gluing. I attempted to align the two workpieces while gluing, but was unable to make a perfect alignment. I guess I was counting on the biscuits to align the pieces. But their way loose fit prevented their insuring a perfect alignment. I used my Bessey K clamps to bring the boards together.

[Jeff Wright]

Domino!
Rob

Yup, got one of those too.

[Mark Carlson]

Jeff,

Did you see this offset when dry fitting the boards together? If not you might want to use cauls to keep your boards flat during glueup. I would also suggest not using biscuits to join boards edge to edge. Its not necessary and can lead to offsets like your seeing if your biscuit joiner is misaligned. Many are.

~mark

[Phil Thien]

On occasion I've stumbled upon cheap biscuits that are loose, while name-brand ones often seem a little snug. I prefer the snugger ones.

[Carl Fox]

I don't use my biscuit cutter for this reason.:mad:

[Jeff Wright]

On occasion I've stumbled upon cheap biscuits that are loose, while name-brand ones often seem a little snug. I prefer the snugger ones.

Phil, I used Porter Cable biscuits. I assume they would fit in your category of name brands. They were real loose, just flopping in their slots. I may be spoiled by the tight fitting dominos I've experienced using my Domino.

[Jeff Wright]

Jeff,

Did you see this offset when dry fitting the boards together? If not you might want to use cauls to keep your boards flat during glueup. I would also suggest not using biscuits to join boards edge to edge. Its not necessary and can lead to offsets like your seeing if your biscuit joiner is misaligned. Many are.

~mark

Dry fit looked ok, using my Bow Clamps (cauls) and Bessey K clamps. But once glued, I was expecting the biscuits to do a good job of aligning the boards, and when they did not I had some trouble aligning the glued boards precisely as the glue began to fire off.

[David DeCristoforo]

If it ain't the biscuits, it's the blade. Or the machine itself. What brand (model) of joiner did you get? Are you rocking it at all when you are plunging the blade? If it's a cheapo or flawed unit, a bit of blade wobble would cause the slot to be cut a bit "fat". You should not have any mis-alignment in the faces unless the slot is too wide or the biscuits are too thin. One thing I can tell you is that the biscuits will shrink or swell seasonally. But even when they are bone dry, they should be a "snug slip fit" in the slots.

The only other thing I can think of is that you may not be placing them close enough to "pull out" any warp in the stock. How far apart are you placing the biscuits?

[Jeff Wright]

If it ain't the biscuits, it's the blade. Or the machine itself. What brand (model) of joiner did you get? Are you rocking it at all when you are plunging the blade? If it's a cheapo or flawed unit, a bit of blade wobble would cause the slot to be cut a bit "fat". You should not have any mis-alignment in the faces unless the slot is too wide or the biscuits are too thin. One thing I can tell you is that the biscuits will shrink or swell seasonally. But even when they are bone dry, they should be a "snug slip fit" in the slots.

The only other thing I can think of is that you may not be placing them close enough to "pull out" any warp in the stock. How far apart are you placing the biscuits?

I got the Porter Cable joiner (model 557) and am using their biscuits. I am not rocking the machine. I was very careful to hold the fence firmly on the workpiece and slowly/gently push the blade into the wood to make the cut (and carefully extract the blade on its way out as well). I put five slots on 36-inch boards, so the slots were about 7 inches apart from each other. I used the #10 biscuits.

If my machine and my technique are both ok, and this is the best a joiner can do, I think I will use either my Domino or get some edge gluing router bits in lieu of the joiner.

[Alan Tolchinsky]

Jeff, I think you get better accuracy without using the fence. If you register the base against something flat and the piece against the same, you should get better results. But I must admit that getting accuracy with a biscuit joiner has sometimes driven me nuts.

[Steve Rozmiarek]

Jeff, I've had the exact same thing happen recently with my Makita and lumber yard biscuits. The last glue up I did, I was really choosy about which biscuits I used out of the bag, and it really helped. Everything that had visible defects got tossed. I am waiting on the Lamello biscuits to get here, thinking that there will be a quality increase that will translate to better alignment.

[Bob Hallowell]

I sold my dewalt cause I tried and tried but never was happy with the results I got from it so it sat in it's case for a couple years.

Bob

[David DeCristoforo]

I don't know Jeff. It doesn't sound right. You should be getting a better fit "out of the box". How would you feel about exchanging for another machine? I have a sneaking hunch that either the machine or the blade is out of whack in some way.

[Mike Goetzke]

Jeff, I think you get better accuracy without using the fence. If you register the base against something flat and the piece against the same, you should get better results. But I must admit that getting accuracy with a biscuit joiner has sometimes driven me nuts.

I do this too.

Another thing, the moisture content of the biscuits is important. I have read some put them in the microwave to reduce the moisture and make them thinner. I suppose you could add moisture the same way by adding a few drops of water with a plastic cover then microwave. I usually just butter up the biscuit with glue and let it sit for a couple of minutes - they actually expand quite a bit.

If you have some calipers measure the slot thickness and I can check mine.

Mike

[John Thompson]

"If" you did not set the 557 up in advance with scrap and relied on the marking.. the center may be off slightly. "If" so.. "if you happened to not be paying attention when you made the cuts.. the matching board could have been cut upside down. At glue-up time that would translate to a mis-match.

But then again.. "if" the biscuits were loose, that should not have mattered. I don't use my 557 often as I prefer M&T's on about everything, but when I do.. I make my own biscuits and they fit snug.

Good luck...

Sarge..

[Alan Tolchinsky]

That sounds very interesting. Alan

[Ray Schafer]

I stopped using my biscuit joiner now that I got the Dowelmax. That is what I would recommend.

[Joe Jensen]

I used a biscuit jointer for years to add strength to joints. It was always a terrible way to align, basically worthlss. I never understood why the biscuits always fit so loose in the slots. I have a domino now, WAY different...joe

[Wayne Cannon]

I've experienced that a few times at first with different brands of plate jointers, but it was due to movement while cutting, not the biscuits or the jointer.

I really like the P-C plate jointer and have not had any problems with it at all after my first few learning attempts. I have occasionally found a thin biscuit, but it's been pretty rare.

BTW, I find the DeWalt cordless plate jointer very handy when doing a limited number of slots, which is most often the case. The P-C fence is more versatile, however, especially for inside and outside miters.

[Doug Shepard]

I'm with Alan. Skip the fence and use the base if possible. I'm also suspecting blade issues like maybe you got one machined a few thou too thick. I very often purposely plunge twice because the biscuit are so snug (also PC biscuits) that once you put some glue in the slots it's sometimes hard to even insert the biscuit. This is also with the PC 557.

[Hans Braul]

Yup, got one of those too.

Just curious, if you have a Domino, why bother with the biscuit joiner?

[Art Mulder]

I got the Porter Cable joiner (model 557) and am using their biscuits. I am not rocking the machine. I was very careful to hold the fence firmly on the workpiece and slowly/gently push the blade into the wood to make the cut


Jeff, I think you get better accuracy without using the fence. If you register the base against something flat and the piece against the same, you should get better results.

I would echo Alan. I try to NOT use the fence on my biscuit joiner. It is much easier, much more accurate, to hold the joiner down flat on a bench and plunge it into the workpiece.

Another, more humbling, possibility is user error. I have once or twice misaligned the board -- I registered off the TOP of one board and by accident off the BOTTOM of the other. The result was much like your photo.

I would suggest getting two short pieces of scrap, and cutting two or three slots in it as practise and see how it aligns -- This will help you double check your technique, your slots, and your biscuits.

[Jeff Wright]

I'm with Alan. Skip the fence and use the base if possible. I'm also suspecting blade issues like maybe you got one machined a few thou too thick. I very often purposely plunge twice because the biscuit are so snug (also PC biscuits) that once you put some glue in the slots it's sometimes hard to even insert the biscuit. This is also with the PC 557.

Doug, My first attempt was referencing over a flat surface for both the workpiece and the machine. Had the same results. That's the reason I tried using the fence this time.

[Jeff Booth]

I agree with the poster that suggested that your machine may be defective. In particular the loose fit is disconcerting, the poor alignment is possibly an out of parallel problem or maybe a technique problem. I would cut several test slots in various pieces of scrap and see if anything improves. Try a few different species to see if the fit improves. You may need to return it.

You also may need to lower your expectations of biscuit jointing as others have suggested.

I've got a Dewalt 682, it is slightly out of parallel, I could dissassemble and shim I suppose. However it will machine slots that grab biscuits tightly if I use good technique. All in all though it is a crude machine. And it is LOUD

I purchased a Domino, it is as everyone else has attested a much nicer machine for fit and finish, and in particular I like the long deep tenons over the wide shallow tenons (biscuits).

The biscuit jointer still has a slot in my tool bin, for joining thinner stock, there are some situations where the stock is too thin for a 5mm domino.

Jeff

[Jeff Wright]

Just curious, if you have a Domino, why bother with the biscuit joiner?

See Jeff Booth's reply below. In addition, I am a tool nut . . . one can never have too many!! :D

[Rod Sheridan]

It's interesting to see comments regarding alignment problems, I always thought it was just me.

Eventually I purchased a slotting cutter for the shaper and that cured my alignment problems, no wobble, the cutter is always the same height etc.

Now all I have to do is figure out how to use it as a handheld.

[Al Willits]

I have the 557 and it works just fine for me, couple things I remember when using it, it doesn't have to be centered, but just close, keep the boards in the same orientation that you cut them in. if the cut is slightly off centered and you flip the board over, they won't align.
I use the biscuits to help align, but don't rely on them, I made sure whatever I'm setting the boards on is flat as possible and as I tighten the clamps I use a dead blow hammer and a block of soft wood to fine tune the edge alignment.

I don't think you'd want to reduce the moisture content as wouldn't that decrease the thickness, not good if your wanting tighter biscuits, personally I'd think add a bit of water to them would make them tighter.

I don't have any problem with the fence, just be careful to not let the cutter waver while using it.

Al

[Thom Sturgill]

I only use the biscuits for face frames, they do not add significant strength when gluing long-grain to long-grain. That said, I suspect (as others have said) that there is probably a problem with the blade. Also I noticed when I used my BC that I needed to do a FAST plunge as there was too much chance of the machine creating too wide a slot (due to vibration?) if I went slow.

[J. Z. Guest]

I stopped using my biscuit joiner now that I got the Dowelmax. That is what I would recommend.

I'll post another vote for Dowelmax, since you're a tool nut.

The thing is that biscuits don't fit tightly until they swell from the glue. It is just not a precision tool like Dowelmax or Domino.

When you use any of these things, be sure to NOT put the dowels, biscuits or Dominoes too close to the ends of the boards. If you do, they're visible when you trim to length. Then, you'll have to do breadboard ends too. ;)

Oh, and return the biscuit joiner. That'll get you halfway to Dowelmax.

[Scott Vigder]

I find when cutting biscuits to place the edge of the board over the end of the workbench so I am resting the plate joiner on the workpiece, and make sure the face is square to the edge before plunging. I clamp the workpiece to the workbench top.

I had your same problem until I started using this method and have had no alignment problems since.

Are you using the correct biscuit size for the slot cut? Or, to put it in reverse, are you cutting the correct slot size for the biscuit your using?

I tend to stick with #20 biscuits for just about all my board joinery. I have the DeWalt but use the Porter Cable biscuits.

[William OConnell]

I use my biscut jointer to assisit in alignment not to count on it to perfectly align. If you expeect it to perfectly align the pieces then yes your asking to much. Also you are expecting to much whether it be MT, Domino, or biscuts to think that your going to join two boards and be finished with no further machine work ie: sander.
Heres a load bearing column I built using the PC biscut jointer several years ago It still looks the same.
The shoji screens were made using MT joints and 1/2 lap joints and also required futher sanding.

http://woodworkers.us/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=833&g2_GALLERYSID=1c3a68c208fb748abe4f9ae59c36de3f

I actually think I biscutted the plinth blocks to the fluted pilasters I made around the door if I recall.

http://woodworkers.us/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=839&g2_GALLERYSID=1c3a68c208fb748abe4f9ae59c36de3f

[Wayne Cannon]

I've had better results referencing from the fence and not the base. Referencing from the base adds the possibility of the work not being fully down against the reference surface (or moving) unless you clamp it -- and the extra work of clamping removes one of the nice benefits of biscuit joinery. When using the fence, you are forcing the tool directly against the work. The only time I reference from the base is when everything is held in a jig (a variant of this: http://www.woodhaven.com/pdf/catalog/25.pdf).

[JohnT Fitzgerald]

I knew zippo about Domino till I started to see it mentioned here on SMC. Looks like a way cool machine, but, I have to ask - is it seriously over $700?? Holy cow!!!

[John Thompson]

Good morning Alan.. Cutting biscuits is not all that interesting to me.. :)

Scrap stock... rip to width... slice and dice to thickness with my larger re-saw BS.. shape to anything you want with the smaller BS or vertical belt sander. A biscuit is nothhing more than a floating tenon with the exception the hole is severed to an elongated oval.

I don't have any problems on the rare occasions I use a biscuit joiner. Those occassions are limited as I do mostly large carcass work and I believe in over-killing joints.. so M&T's get the call. But.. I set the joiner up to dead center with scrap and I built a way to make sure it gets referenced with no movement as shown in the picture below.

Now.. building a round bar.. craps table.. etc. etc... that's interesting to me. ;)

Regards...

Sarge..

[Rye Crane]

Jeff,

I also have a PC 557 and the first time I used it two years ago I had the same result. I checked the arbor, very little run out but the blade is my culprit. It was way out. So the PC 557 is on a shelf gathering dust and I am saving for a DOMINATOR, whoops I mean a DOMINO.

Take care,
Rye Crane

[Paul Johnstone]

Any suggestions?

It's probably your technique.
Try again. If you have a flat surface like a bench, put the board on the bench. Put the bottom of the jointer on the bench and plunge. Repeat for the second board. Since both slots are indexed off the bench, they will line up.

If you use the top fence to register the cut, you need to be vary careful not to plunge at an angle.

Sorry to say this, but if the alignment is that bad, it might be error.

I have the same bisuit cutter and it works great.

[Paul Johnstone]

Phil, I used Porter Cable biscuits. I assume they would fit in your category of name brands. They were real loose, just flopping in their slots. I may be spoiled by the tight fitting dominos I've experienced using my Domino.

They should move side to side.. that's intentional. They should not move up and down. If they move up and down (in the thickness dimension), either you are moving the machine while it's cutting or maybe the blade isn't in right (wobbling).

[Paul Johnstone]

I'm with Alan. Skip the fence and use the base if possible. I'm also suspecting blade issues like maybe you got one machined a few thou too thick. I very often purposely plunge twice because the biscuit are so snug (also PC biscuits) that once you put some glue in the slots it's sometimes hard to even insert the biscuit. This is also with the PC 557.

Is it too snug on the side to side measurement? .. if so, there's an adjustment knob to cut the slot a hair deeper. That's what I did, makes fitting much easier. I don't mind the slop side to side because that's not the dimension biscuits are supposed to align.

[John Gornall]

I had some sloppy bisquits recently and realized the blade had done a lot of work. Installed a new blade and all is well again.

[charles anderson]

I use a Porter Cable biscuit joiner every week. I join about 200 pieces each time. They are two pieces 7" wide, and 20" long. I match the pieces up, then cut the slots as fast as I can push the cutter. I put glue in the slots, spread a thin layer over the edge, and clamp. I use Titebond II, and after a short time, I scrape the glue line, and let dry for the rest of the day. I run the pieces through my stroke sander, and it's ready for drilling holes, and routing. I am very pleased with the results with the Porter Cable. I make sure the depth of the cutter is correct, and use it on a flat surface. I use 3/4 ash. No problems.

[Yun-Fong Loh]

I use my biscut jointer to assisit in alignment not to count on it to perfectly align...

:eek: Very nice work!

[jason lambert]

Should do a better job, I was alwas happy with my dewalt. I would suggest checking the cutter agenst the biscuts maybe the biscuts are not tight enought as mentioned above. I also watch for that when I glue up I think I may have had similar issues and required a little tweaking during glue up with the biskets, can't really remember now. Something is up I doubt it is the cutter disk though.

If I where you the Domino is a better system and stronger. There is no reason at this point to even own a bisket joiner. I sold mind the day after I got the domino and haven't looked back since.

[Travis Gauger]

I have a 557 also and never had any issues like this. Some minor allignment issues where I slapped my forehead later after realizing what I did wrong. I also use PC Biscuits. I did run about 10 slots in a board once only to realize I was cutting #10 slots for a #20 biscuit. Maybe start to experiment a little and pull some measurements off of freshly cut slots to see where the error is coming from. Something isn't right. Blade, Machine, something. If the biscuits were loose, they shouldn't have had any bearing on your joint allignment. They would be loose! I think it would take a tight biscuit in a misaligned slot to throw off your edge alignment. Right?

One note for everyone, Take it or leave it, When someone asks about a problem they are having with a tool, why do half the respondants resort to offering up some other tool to fix their issue. I too have a domino and love it, but the question wasn't "What should I get to replace my Biscuit Jointer?" I have often asked for advice on A and gotten sales pitches on Z. Frustrating.

So back to the Biscuit Joiner, I would try to figure out what is out of whack and fix or replace. I would not recommend getting rid of it as there are still quite a few reasons to have one handy. I set mine on the shelf next to the domino and have pulled it out more for use more. That is just because of the projects that I have been on lately, but the point is, There is still a place for them in the shop. Just like there is still a place for grandpa's old saw bench.

[William OConnell]

One note for everyone, Take it or leave it, When someone asks about a problem they are having with a tool, why do half the respondants resort to offering up some other tool to fix their issue. I too have a domino and love it, but the question wasn't "What should I get to replace my Biscuit Jointer?" I have often asked for advice on A and gotten sales pitches on Z. Frustrating.

I agree you can throw all the money in the world at it but at the end of the day its joining two boards. Me personally sometimes I use biscuts sometimes just glue. The guy asked a question about his biscut jointer and may be convinced A) He needs a domino wich he doesn't B) His PC is a piece of garbage wich I'll bet it isn't. And C) If he gets a domino he doesn't have to check his methods of work wich is frankly I think just bad advice. He simply needs to work on flattening his glue ups on clamping from what I can see.
Either way Festool is a good sander for flattening that joint:D

[Travis Gauger]

I agree you can throw all the money in the world at it but at the end of the day its joining two boards. Me personally sometimes I use biscuts sometimes just glue. The guy asked a question about his biscut jointer and may be convinced A) He needs a domino wich he doesn't B) His PC is a piece of garbage wich I'll bet it isn't. And C) If he gets a domino he doesn't have to check his methods of work wich is frankly I think just bad advice. He simply needs to work on flattening his glue ups on clamping from what I can see.
Either way Festool is a good sander for flattening that joint:D



I couldn't agree more. I'm laughing really hard right now.

[David DeCristoforo]

"... why do half the respondants resort to offering up some other tool..."

Havta kinda agree, at least in this situation. "Decent" biscuit joiner.. what? $250? Domino $even or eight bills? I have used a biscuit joiner since 1975. A Virutex that I still have and use almost daily. PC biscuits. Nothing "special". But I consistently edge join veneered plywoods (and you know how little "wriggle room there is there!) using biscuits to align the surfaces. Trust me... something's wrong with either the machine, the blade or the "technique". Like I already said, seeing as this is a new machine, I would exchange it and see if another one performs better.

[Scott Vigder]

I agree you can throw all the money in the world at it but at the end of the day its joining two boards. Me personally sometimes I use biscuts sometimes just glue. The guy asked a question about his biscut jointer and may be convinced A) He needs a domino wich he doesn't B) His PC is a piece of garbage wich I'll bet it isn't. And C) If he gets a domino he doesn't have to check his methods of work wich is frankly I think just bad advice. He simply needs to work on flattening his glue ups on clamping from what I can see.
Either way Festool is a good sander for flattening that joint:D

And don't forget the Delta 50-760 DC system to suck away all those chips!

Great sense of humor, Bill!

[Jeff Wright]

They should move side to side.. that's intentional. They should not move up and down. If they move up and down (in the thickness dimension), either you are moving the machine while it's cutting or maybe the blade isn't in right (wobbling).

They are floppy up and down in the slot. No, I am not wobbling the machine while cutting. I went the additional step of clamping the workpieces down tightly so I could focus all my attention on stabilizing the machine while cutting.

[Jeff Wright]

If I where you the Domino is a better system and stronger. There is no reason at this point to even own a bisket joiner. I sold mind the day after I got the domino and haven't looked back since.

I am coming around to your camp Jason. While I just bought this joiner, I may put it up for sale and just use the Domino.

[Jeff Wright]

I find when cutting biscuits to place the edge of the board over the end of the workbench so I am resting the plate joiner on the workpiece, and make sure the face is square to the edge before plunging. I clamp the workpiece to the workbench top.

I had your same problem until I started using this method and have had no alignment problems since.

Are you using the correct biscuit size for the slot cut? Or, to put it in reverse, are you cutting the correct slot size for the biscuit your using?

I tend to stick with #20 biscuits for just about all my board joinery. I have the DeWalt but use the Porter Cable biscuits.

My machine came with a second blade, but it appears to be the same size as the one that came mounted on the joiner. I figured it was simply a backup. I imagine there is a separate sized cutter when using the FF size biscuits, but I am not using that size biscuit in my work.

[Jeff Wright]

I did run about 10 slots in a board once only to realize I was cutting #10 slots for a #20 biscuit. Maybe start to experiment a little and pull some measurements off of freshly cut slots to see where the error is coming from. Something isn't right. Blade, Machine, something. If the biscuits were loose, they shouldn't have had any bearing on your joint allignment. They would be loose! I think it would take a tight biscuit in a misaligned slot to throw off your edge alignment. Right?

Travis, the second cutter that came with the machine appears to be the same size as the one that came mounted on the joiner. Should my kit have more than one size cutter? I figured the same size cutter handled both the #10 and #20 biscuits, just adjust the depth of cut. I don't recall the owners manual saying anything about changing cutters for different sized biscuits (except for the tiny FF biscuits which I do not use).

[Richard M. Wolfe]

I don't know why but the Porter-Cable biscuits are the 'cheapies'. I stocked up on them some time ago....as I recall I bought about six boxes of 20's and paid about twenty bucks a box. for what I do they work OK but sometimes they fit pretty loose but for what I got mostly the fit is really tight.

[Rick Levine]

Jeff,

I also have the 557 and the second cutter is a 2" blade and it uses the FF mark on the tool. Also, make sure you don't have the depth setting as 20 or MAX for a #10 biscuit. It would make the cut much deeper and wider.

[Jeff Wright]

I agree you can throw all the money in the world at it but at the end of the day its joining two boards. Me personally sometimes I use biscuts sometimes just glue. The guy asked a question about his biscut jointer and may be convinced A) He needs a domino wich he doesn't B) His PC is a piece of garbage wich I'll bet it isn't. And C) If he gets a domino he doesn't have to check his methods of work wich is frankly I think just bad advice. He simply needs to work on flattening his glue ups on clamping from what I can see.
Either way Festool is a good sander for flattening that joint:D

Bill . . . in answer to (A), I already own a Domino, (B) No, I don't necessarily think the PC is a piece of junk (but certainly not up to the standards of the Domino), but I am convinced there is a problem (or limitation) inherent with the tool more than my technique - but I could be proven to be wrong, which is fine as long as it leads to a solution, or perhaps a tempering of what were higher expectations of performance from the machine, and (C) See (A), plus I continually check my methods of work. Afterall, that is why I initiated this thread!

Yes, I think I could improve on my glue-up techniques, but I still don't believe that is the root cause. If it were, I would forego using biscuits in edge board glue-ups since I am not deriving any edge-alignment benefits from the use now.

I suspect we're all laughing now! :)

[Johnny Fischer]

Throw your biscuit cutter in that pile of stuff labled FOR SALE and stick with your DOMINO cutter.

[Matt Bickford]

Jeff, the problem is most likely user error. Possible mistakes are (1) referencing off the wrong face, (2) unsteady hand, (3) things not being tight and square. I'm sure there are a few others.

I have no question that the Domino is universally better, but a biscuit jointer is a very good tool for the this job. Anybody telling a person that currently owns one or is looking to perform the specific job that you are doing that the tool is irrelevant is completely off base.

If something doesn't line up before glue up it won't line up after. You should have checked your performance with this very capable machine prior to using it on your glue-up.

[Dale Lesak]

Jeff, in the instructions that came with my PC jointer #7 states "Release trigger switch to stop machine and remove machine from work" which tell me you should only be cutting on the in stroke. When I run it in and out mine are sloppy too. In off and out makes them a lot tighter. Dale

[Jeff Wright]

Jeff, the problem is most likely user error. Possible mistakes are (1) referencing off the wrong face, (2) unsteady hand, (3) things not being tight and square. I'm sure there are a few others.

I have no question that the Domino is universally better, but a biscuit jointer is a very good tool for the this job. Anybody telling a person that currently owns one or is looking to perform the specific job that you are doing that the tool is irrelevant is completely off base.

If something doesn't line up before glue up it won't line up after. You should have checked your performance with this very capable machine prior to using it on your glue-up.

Thanks for your suggestions Matt, but as I have indicated in other posts in this thread, I am certain that I referenced off the correct surfaces, hands were steady like a surgeon's, pieces were properly milled, and workpieces were clamped tight prior to cutting the slots. Cutting these pieces was in effect my checking the machine's performance as I knew I had enough thickness in the pieces to allow me to joint/plane any mismatch out of the joined pieces once glued up. The pieces were able to be aligned fine during the dry fit, but then with so much slop in the cuts, that was no surprise. It was only in the glue up that I think I relied too much on the biscuits doing the task of perfect alignment. Maybe glue joint bits on the shaper is a better way to go in the future.

I re-read the manual and it repeatedly says to plunge the cut and stop the machine prior to removing the bit. I don't think I stopped the machine prior to carefully extracting the bit out of the wood. Perhaps I somehow enlarged the slots by withdrawing the bit while still running, however I was extremely careful to keep things aligned and pressed against the reference surfaces as I withdrew the cutter from its slotted hole.

[Jeff Wright]

Jeff,

I also have the 557 and the second cutter is a 2" blade and it uses the FF mark on the tool. Also, make sure you don't have the depth setting as 20 or MAX for a #10 biscuit. It would make the cut much deeper and wider.

Thanks Rick . . . the machine was set to the #10 for use with the #10 biscuits.

Do you stop the machine while the cutter is plunged into the piece, i.e., do you plunge the bit to make the cut, and then release the trigger to shut the machine off in order to extract the plunged bit so you don't mess up the freshly but slot? The manual seems to suggest that is the proper way to do it. I did not. I withdrew the still rotating bit, but did so very carefully. I am thinking maybe I enlarged the slot by allowing the bit to continue to spin on the withdraw.

[Peter Quinn]

I use an old cheap makita biscuit jointer, it gets the job done. The fence isn't much to speak of but the rest of it works well. I don't trust the fence on most plate jointers for precise work (unless you want to throw down for a Lamello).

I've noticed that PC biscuits themselves are all over the place thickness wise. Try checking the thickness with calipers on a few dozen and see where their at. I've hit some containers worse than others. I hear Lamello biscuits are made to tighter tolerances than others and may try those myself.

When things go well I can join two boards with mine that can be leveled with a few passes of the card scraper, or plywood with thin veneers edge to edge.

[Greg Cuetara]

I typically align my joiner then get it up to speed...plunge in and let go of the trigger...then pull out. The first few hundred biscuits I installed things were not aligned perfectly. I got better over time. You need to make sure the biscuits are tight going into the joint. If the buscuits are at all loose then move onto the next biscuit. If a majority of the biscuits are loose then I would check the machine and if the machine is perfect....keep practicing and you will get better.

I had problems with my joiner a while back and traced it back to a bad batch of biscuits. Once I figured that out my joints were a lot better. You need to make sure that the biscuits stay in an airtight container or nearto that so that they don't swell etc. from the moisture in the air. If you are real serious about using the biscuit joiner I would take each biscuit with calipers and measure them down to the thousands of an inch.

If you are looking for festool quality out of a PC biscuit Joiner I wouldn't get too excited. If you want the cadillac of biscuit joiners then go out and get a lamello and buy lamello biscuits but I would think you could get a domino for the same price and it would give you many more options.

Greg

[jim gossage]

ended up with the glue joint poorly aligned top face to top face (See photo). the biscuits don't fit snugly, but instead at best lay loosely in the slots. I had thought that once I applied glue, inserted the biscuits and joined the two workpieces, the boards would clamp nice and even . . . at least that's what NORM promised me!!

Any suggestions?

i don't quite understand the problem. if you are using the bow clamps and spacing them every 12 to 18 inches, and starting out with boards that are flat and of equal thickness, the edges should line up pretty well. loose biscuits should not result in misalignment, unless the slots are themselves misaligned along the thickness of the boards relative to each other; in this case, the bow clamps will not be able to flatten the table with or without glue in place. rather than try to postulate in what way the BJ is misjointing or what you might be doing wrong, i recommend a stepwise analysis. this has helped me immensely in many other shop debacles.

1. start with a stack of 3 or 4 boards to edge glue, and make sure that none of them wobble on a perfectly flat surface, and that no light can be seen between the edges when 2 boards are pressed against each other by hand and held up to the light. a pass here indicates that your stock is flat and the edges are straight, and that your problems are related to slot cutting, gluing, or clamping.
2. cut your slots using whatever method you like.
3. without biscuit or glue, arrange the boards for glue up and clamp them exactly as you normally would if they were being glued. if there are gaps here, there is a problem with one of these three steps, most likely step 3 if the other 2 truly passed inspection. if this test passes, then your clamping techinque is good.
4. add slightly wet biscuits (with water) and repeat #3, agian without glue. if there are gaps here, then most likely the slots are misaligned or the clamping pressure is inadequate.
5. add glue and repeat #4. if there are gaps here, the glue is somehow screwing things up (e.g. by slipping, or expanding wood, etc). if it works, then you're screwed, becasue you won't know why it worked, and therefore can't prevent the next cluster! good luck!!

[Alan Tolchinsky]

Good morning Alan.. Cutting biscuits is not all that interesting to me.. :)

Scrap stock... rip to width... slice and dice to thickness with my larger re-saw BS.. shape to anything you want with the smaller BS or vertical belt sander. A biscuit is nothhing more than a floating tenon with the exception the hole is severed to an elongated oval.

I don't have any problems on the rare occasions I use a biscuit joiner. Those occassions are limited as I do mostly large carcass work and I believe in over-killing joints.. so M&T's get the call. But.. I set the joiner up to dead center with scrap and I built a way to make sure it gets referenced with no movement as shown in the picture below.

Now.. building a round bar.. craps table.. etc. etc... that's interesting to me. ;)

Regards...

Sarge..

Hi John,

That looks like a nice set up for doing biscuit joining. I've got to get away from doing biscuits as they cause me ulcers I think. So I just pop a couple of Tums and biscuit away. Alan

[Rick Levine]

Jeff,

I operate the jointer pretty much like Greg does. I squeeze the trigger, let it come up to speed, push the jointer in, release the trigger and let the tool's spring pull it out of the joint. I don't always wait for the motor to stop completely but I do keep my hand tightly on the fence, pushing down to prevent any sideway movement. I haven’t had any problems so far. I learned my technique watching Norm.

[Stephen Edwards]

Phil, I used Porter Cable biscuits. I assume they would fit in your category of name brands. They were real loose, just flopping in their slots. I may be spoiled by the tight fitting dominos I've experienced using my Domino.

I have a 12 year old makita biscuit jointer that's still working perfectly. If I use their biscuits they're always snug and boards align nearly perfectly. Not so with off brand biscuits or even biscuits from other well known brands.

[Jason Scott]

Ok, I didn't read all the replies b/c there were too many LOL, anyway I have the PC 556, the predecessor to your model, I get the same thing. At first I thought it was a warped blade but it is not, this is just the way a biscuit jointer is I have been told. Biscuits are designed to expand when glue is put on them, but they do not do it enough right away to help with alignment, which I have also been told a biscuit cutter should not be used for, however that is why I bought mine. So, nothing is wrong with your 557, and that is a nice machine, especially for someone like me that is not going to spend 700 on a domino, I have the money, but just can not justify the cost vs. use thing. Anyway here is the trick I have found if you want to get your biscuits to help the alignment, which from your post sounds like you do. First take the top off the biscuits. I know everyone on here says to keep them in a XXXXXXX dry area clamped in a fort knox style vault with 0.0000000 humidity, but that keeps the biscuits as small as they can be which makes your semi loose fitting biscuits, absolutely sloppy fitting biscuits. I keep mine out in the garage with the top off, so they are expanded about as much as possible, so when I go to put them in, they fit much tighter and the alignment is much better. This is my opinion, it works, and made me glad I bought the joiner. If you are not going to expand the biscuits as much as possible, I agree you should sell the joiner if you want it as an alignment aid, b/c it will not do anything with bone dry biscuits. Good luck.

jason

[Jeff Wright]

I keep [my biscuits] out in the garage with the top off, so they are expanded about as much as possible, so when I go to put them in, they fit much tighter and the alignment is much better. This is my opinion, it works, and made me glad I bought the joiner. If you are not going to expand the biscuits as much as possible, I agree you should sell the joiner if you want it as an alignment aid, b/c it will not do anything with bone dry biscuits. Good luck.

jason

Thanks Jason . . . I'll give that a try. I appreciate your helpful idea.

[David DeCristoforo]

"...this is just the way a biscuit jointer is I have been told...they do not do it enough right away to help with alignment, which I have also been told a biscuit cutter should not be used for..."

I would have to completely disagree with this. Whoever told you that? It is true that the fit of the biscuits in the slot can vary but my experience has always been that they, if anything, are a bit too tight if it's humid. As I mentioned before, I use biscuits to align veneered plywood faces. I have done this often enough over a long enough period of time to pretty safely rule out the possibility that I just "got lucky" on a few occasions.

[William OConnell]

"...this is just the way a biscuit jointer is I have been told...they do not do it enough right away to help with alignment, which I have also been told a biscuit cutter should not be used for..."

I would have to completely disagree with this. Whoever told you that? It is true that the fit of the biscuits in the slot can vary but my experience has always been that they, if anything, are a bit too tight if it's humid. As I mentioned before, I use biscuits to align veneered plywood faces. I have done this often enough over a long enough period of time to pretty safely rule out the possibility that I just "got lucky" on a few occasions.

I agree Ive been doing this for a living for a pretty long time and whatever stength biscuts add is secondary to me I use it to help me get my alignment in the ballpark. However its not auto pilot from there. I use my handi dandi ever shrinking shop made poplar mallet quite often for persuassion.
I did just that, aligned plywood pieces on this job using a PC557 biscut jointer and some taps with the mallet.
http://woodworkers.us/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=44&g2_serialNumber=2&g2_GALLERYSID=1c3a68c208fb748abe4f9ae59c36de3f

[David DeCristoforo]

Ahh, yes. The big mallet. We just might have something in common there....

[Travis Gauger]

Travis, the second cutter that came with the machine appears to be the same size as the one that came mounted on the joiner. Should my kit have more than one size cutter? I figured the same size cutter handled both the #10 and #20 biscuits, just adjust the depth of cut. I don't recall the owners manual saying anything about changing cutters for different sized biscuits (except for the tiny FF biscuits which I do not use).

You should have two different sized blades. A big one and a small one. The small one is for the FF biscuits. The #10 and #20 slots are cut by adjusting the machine to cut the proper depth. You are absolutely correct. It's just a bad deal though when you cut a bunch of #10 slots, put # 20 biscuits in them and then try to put your two boards together. My mistake, not the machines. the real problem is when you try to re-cut those slots to the deeper setting. Then you end up with sloppy biscuit fit. My technique is like this...
I never use the fence. I place whatever piece that needs biscuits on my tablesaw. Working from the left side of the saw and facing the fence, I push the piece to be cut against the fence and down onto the table. the fence is just there to hold the board from sliding back and allows me to concentrate on keeping the board flat and the machine from moving side to side while cutting. I then line the biscuit joiner up to my mark, fire the trigger and wait for it to hit speed. Then I plunge in and release the trigger. I don't think that I have ever waited for the cutter to quit spinning before pulling it out but it's not under power.
I have noticed that the Bosch brand biscuits seem a little better finish to them than the PC's do. This could be just my perception though, they probably all come out of the same factory in china somewhere. I got a biscuit once that had a flattened bug in it. I still used it and now someone has it in the middle of their desk top somewhere. ;) I have found that there is a large amount of variation in the biscuits. I haven't tried any of the premium ones to compare to. I hope you figure it out.
Someone mentioned that you should go return it for a different one. Good call. Where did you purchase from? If it was a woodcraft or something you can probably take it in and have one of those guys use it to test it out. There may be something out of whack in the machine itself that they will notice. Or they are going to cut a perfect slot and you may see what was done wrong on your trials. I have to lean towards a machine defect vs technique as there isn't all that much technique to using a biscuit joiiner. Just keep it flat and true to the board. I have had my 10 yr old son out there running that thing with decent results. You should see his technique. It's about as gracefull as a ... I don't know, but it's not good.

[Jason Scott]

"...this is just the way a biscuit jointer is I have been told...they do not do it enough right away to help with alignment, which I have also been told a biscuit cutter should not be used for..."

I would have to completely disagree with this. Whoever told you that? It is true that the fit of the biscuits in the slot can vary but my experience has always been that they, if anything, are a bit too tight if it's humid. As I mentioned before, I use biscuits to align veneered plywood faces. I have done this often enough over a long enough period of time to pretty safely rule out the possibility that I just "got lucky" on a few occasions.

Well, maybe I have been given bad info., but my 556 was all but brand new and it has done this since day one, unless I "swell" the biscuits outside in more humid weather. Now with that said, it may just be the PC biscuits I bought from HD, maybe their quality is not the best? Is there other biscuits you would recommend that might solve our problem of too loose a fit?

[Will Blick]

I have a PC 557 and a Dowelmax. I always figured the two provided tremendous versatility. The biscuits used when boards are thin.... since I never used a Domino, I never paid much attention to it.... but, the small domino is 5mm thick vs. 4mm thick for the biscuit.... much closer than I had originally thought. Interesting.

As for your problem..... you seem way to knowledgeable for user error....biscuits are quite fool proof... as suggested earlier, you probably have mechanical problems, either one, or mix of, blade wobble, blade thickness, biscuit thickness...

With a loose fit, I don't see how this would mis align the boards considering you used cauls?

BTW, you do mean the full length of the boards are mis-aligned, not just the areas where the biscuits were located? Some people experience biscuit swelling, causing the biscuits to rise and force the board up. Of course, if you used enough biscuits, this could have disguised itself as total board mis alignment....just a thought...

[Fred Voorhees]

I have been following this thread with great interest and with a bit of amusement. I have to say that I have the 557 and have really never had a problem with it. For the most part, I have experienced the biscuits fitting on the tight side. As someone else mentioned....if you are expecting the biscuits to alleviate any kind of further finishing of the surface, you will be disappointed. I have gotten into the habit of leaving the material just a bit over final thickness dimension and then, after edge gluing with the biscuits, I then run it through the planer down to final dimension and have a great surface which I then only lightly sand with my ROS.

I find that the biscuit jointer has a place in woodworking. I have found it indispensible when creating shadow box style picture frames to help in preventing shearing of the joints. I usually use FF biscuits for them. I have used the PC 557 in a number of instances and not just for edge gluing. Also, I find that I usually hold my left hand down on the fence to keep it right on the surface of the wood that I am plunging into. I also do not allow the blade to stop while still in the slot. In fact, I have sometimes used the button that keeps the on button depressed and gone from one biscuit slot to another with the blade at full song. I will "sometimes" get a biscuit slot that seems to be loose, though I am thinking that the biscuits are at fault there instead of the plunging technique.

[Chris Padilla]

I haven't seen it mentioned but you should always sort your biscuits, testing them in the slots, to see which ones are too tight, too loose, or just right. They aren't all a uniform thickness. Thick ones can be compressed in a vise. Thin ones might have a use in a joint that may need slight adjustment during glue up.

If ALL your biscuits are too loose, then as has been said a myriad of times, there may be something wrong with your tool.

I use my 557 for mitered joints all the time and only operator error gives me bad results. :)

Get some cheap wood/MDF/scrap/what-have-you and do test cuts to see what is up. Is there a wobble to your blade? Is the blade worn? Is there a bad tooth on the blade? Is the fence or face not square. Spend some time staring at it if you are convinced it ain't operator error. :)

[David DeCristoforo]

"...there may be something wrong with your tool..."

And as we all know...that's a bad thing.....

:)

[Will Blick]

I am wondering now, if Lamello biscuits might be worth their premium price.... assuming they are built to tighter tolerances....

Question: Since dominoes are also made from compressed wood, do they also force the board surface upwards like the biscuits do? I would assume they should?

[Chris Padilla]

Question: Since dominoes are also made from compressed wood, do they also force the board surface upwards like the biscuits do? I would assume they should?

Even *if* biscuits or dominos swell when glued, I don't understand how they can move the joint unless the joint itslef is misaligned in the first place. They swell to within the wood space they are inserted.

If anything, due to the copious amount and concentration of glue, the moisture from that might swell around the biscuit or domino area.

This is one reason why you should let the board dry for a couple of days so that the moisture from the biscuits/dominos escapes and the swelling goes down. If you sand to soon...you may find slight divots across all your joint...mysteriously seeming to line up with where you put biscuits/dowels. :)

[Michael Hammers]

I cannot tell from the picture if the "offset" is the same all across the board. Looks like its sticking up what a 1/16" ?
I have the same machine and have not any issues like you are having. I believe your technique is sound, it very well could be some "wobble" in the blade, either way PC will make it right I am sure.
I have noticed that some of the adjustment knobs could work loose, did perhaps the fence move abit and throw you off? I know I was a little disapointed with the way the fence locked at a 90 degree angle, I even double checked with a square because it looked so funky.
Also you said it was solid Mahogany, did the would move perhaps after you worked it? Is the moisture content right? Not questioning your ablilities just digging, but are you sure the boards were dead flat?
Just some thoughts as to what may be causing this.
Try some cheap practice scraps maybe to see if it does it again, good luck!

[Harry Niemann]

I've found a thickness difference between brands. Also if they are stored in a low humidity environment, they will shrink. Keep them in a closed container with a drop or two of water.

[Jeff Wright]

I tried soaking the biscuits in water prior to trying them in another test cut. I took the biscuits out of the water and allowed them to thoroughly dry. I made careful cuts using good technique. The test workpieces were precisely milled in the jointer and planer. I then inserted the biscuits in the grooves and laid the two workpieces on my workbench's flat work surface. The two pieces aligned fine (without glue at this point), however the biscuits STILL had a good bit of wiggle room between them and the sides of the slots. It is this slop that has caused me to conclude that the biscuit joiner is not a tool I would want to use for fine mating of pieces where precision is desired. For edge gluing I think I will instead either use simple edge gluing or buy a set of edge glue router or shaper bits (I have both a router table and a shaper with 1.25 inch spindle). Or, I'll use the Domino. So I am unsure to what use I would put the biscuit joiner. Firstly, they do not do a precise enough job for me for alignment, and secondly, they don't likely add much strength to the resulting joint.

It looks like we beat this subject to death. Thanks for all your great responses and suggestions.

BTW, my original mohogany test piece is a foot rest I fabricated, varnished and intalled in my Grady White boat in place of the factory star board footrest. It looks great!

[Quesne Ouaques]

Hi Jeff:

I'll chime in here even though most of what I have to offer may have already been said (and beaten to death :-)

Once the dimensions are set, your only job is to hold both fences tightly against the board and push the bit in to the wood. Period. If you are concerned that the bit may be moving off-track when you are backing out, then you may not be holding both fences tightly enough against the wood.

I always leave the bit spinning as it comes out simply because I don't like to shift my grip during a cut. Still, that should not make a big difference. Even if you simply enlarged one or two slots slightly, it would not throw the two work pieces out of alignment.

That said, my gut feeling is that your technique is probably fine, but the bit or the fence must be off kilter. It's very, very hard to screw up a cut made by a good quality, properly set biscuit joiner. Here is my reason for saying so:

I have used several nice biscuit joiners over the years (none of them mine) but the one I finally bought for emergencies is the cheapest little POS you can imagine. A "Professional Woodworker" brand I bought for $20 at one of those traveling Homier shows. Not proud of this fact, to be sure, but I had a very limited budget and it was only a "just-in-case" purchase.

It is an absolute abomination of a tool -- seriously -- but it works perfectly every time I use it (maybe 150 plunge cuts, to date). The reason it works perfectly is simple. As long as: 1) the face of the joiner fence is parallel to the face of the board; 2) the blade rotation axis is parallel to the top fence, and; 3) the two fences are held tightly to the board when plunging....then absolutely nothing can go wrong!

Even if the plunge depth is wrong (#10 vs #20) the boards will still line up. And even if the top fence's depth setting is wrong the boards will still line up. As long as the tool is set up correctly and you hold the fences tight against the board, nothing can go wrong.

If you are sure you are holding both fences securely against the board and not shifting them, then I think there may be something wrong with the fence adjustment, or perhaps the bit is not properly aligned. There's not much else that can go wrong!

[Chris Padilla]

So I am unsure to what use I would put the biscuit joiner. Firstly, they do not do a precise enough job for me for alignment, and secondly, they don't likely add much strength to the resulting joint.

I think they work fantastic for mitered joints. I used them for door casings (I glue up door casings on the floor and then nail them up) and frames of all kinds. I just think you need to look more carefully at the tool...something ain't right. My 557 works great. Good Luck to you whatever you end up doing but give that 557 a close inspection before giving up on it.

[glenn bradley]

Biscuits are designed to swell with the glue and some are a bit undersized for the PC (including their own brand). I found Bosch biscuits to work best with my 557 as far as providing a snug initial fit. I could even use them dry for face frame alignment etc.

[Harry Goodwin]

I guess use of a plate joiner is whatever floats your boat but I have an older PC and a foreign jointer and love them every time. I use 20 biscuits
on your type glue up without any problems and keep biscuits in that fancy PC jar. Harry

[Dan Lee]

I am wondering now, if Lamello biscuits might be worth their premium price.... assuming they are built to tighter tolerances....

Question: Since dominoes are also made from compressed wood, do they also force the board surface upwards like the biscuits do? I would assume they should?

Dominoes are not made from compressed wood. Solid beech

[Brian Dormer]

Jeff, the problem is most likely user error. Possible mistakes are (1) referencing off the wrong face, (2) unsteady hand, (3) things not being tight and square. I'm sure there are a few others.

I have no question that the Domino is universally better, but a biscuit jointer is a very good tool for the this job. Anybody telling a person that currently owns one or is looking to perform the specific job that you are doing that the tool is irrelevant is completely off base.

If something doesn't line up before glue up it won't line up after. You should have checked your performance with this very capable machine prior to using it on your glue-up.

PC makes a good tool - unless you got a lemon, it's probably "a loose nut holding the tool". :eek:

You may have tipped the biscuit joiner when you plunged it (it's easy to do if you don't have some experience). If you have enough width - re-rip the joint and re-do it. Also, make sure you get the biscuits 1/2 or more from the show face. If the biscuit slot is shallow, you will sometimes get a ghosting effect on the show face.

[Ron Bontz]

I just cut some biscuit joints tonight with my 557 plate jointer. No problems. I pull the trigger, plunge in and out, then release the trigger. I actually lay my hand on top of the fence slightly to make sure nothing moves. The motion of the hands can cause an ever so slight movement of the tool. I use name brand biscuits also. Another thing I do is to cut a joint on scrap and pop in a biscuit to see how well it lines up making sure I have the cutter adjusted deep enough and not to deep as well as checking for play in the biscuit. Hope this helps. Best of luck.:)

[Jeff Wright]

I just cut some biscuit joints tonight with my 557 plate jointer. No problems. I pull the trigger, plunge in and out, then release the trigger. I actually lay my hand on top of the fence slightly to make sure nothing moves. The motion of the hands can cause an ever so slight movement of the tool. I use name brand biscuits also. Another thing I do is to cut a joint on scrap and pop in a biscuit to see how well it lines up making sure I have the cutter adjusted deep enough and not to deep as well as checking for play in the biscuit. Hope this helps. Best of luck.:)

Ron. I use the same technique as you describe. I am not having an issue with slots being cut with variable spacing between the slot and the referenced surface. If I were to take a caliper, they all measure the same DOWN from the reference surface to the cut of the slot. I believe my techique is not the problem. My issue is that the slop in the slots themselves is enough to allow the two pieces to become misaligned . . . there is a lot of play up and down, not side-to-side in the slots. I have even tried pre-soaking the biscuits in water to swell them prior to using, but with little success. They are STILL not tight fitting in the slots. I had hoped to use the joiner as a means of aligning mating pieces for glue up, but because the biscuits fit so loosely, I would not be able to achieve the consistent alignment I require in my work.

I will call PC on Monday to see if they can suggest a solution. Perhaps the cutter is cutting a slot too wide, or there is some wobble in the shaft.

BTW, the pic below is the result of the test piece. I rebuilt the foot rest on my Grady White boat. The factory original is on the left, a star board material. Mine is the one on the right made of mohogany. I was able to plane out the misalignment and all ended well. But next time I'll use either routed glue joints or the Domino.

[JohnT Fitzgerald]

Jeff - how about making some test cuts on some scrap, and then measuring how dimensions of the cut - depth, width, height. if the cut is bigger than the thickness of the blade, then maybe you have a warped blade or some wobble.