dowel pins too tight (follow up on Jessem dowel jig)

[Paulh Tremblay]

On the suggestion of members of this forum, I bought the Jessem doweling jig. It seems a nice tool, but I won't know until I make some successful dowel joints.

I tested it tonight by drilling 9 holes for edge joining two scrap pieces. I never got to actually observe the fit of the dowels, because the 3/8'' dowel pins would not fit in the holes. To be clear, I do not mean that the holes did not align. (In fact, as far as I could tell, they did align.) I mean that I could not push the dowels into the holes with my hand.

I could have used a mallet to hammer the joint together, but I don't believe you should fit dowel joints together that way. The videos for Jessem and Dowelmax show the joints going together easily with the push of a hand.

So I think I have bad dowel pins. The 3/8'' pins seem exactly that width--3/8''. You can only fit a 3/8'' dowel into a 3/8'' hole with force. Shouldn't the dowels be a bit smaller? I used the bit that came with the Jessem jig. I either need to use a slightly larger big (25/64""?) or get different pins. Where should I buy my pins? Should I try a different bit?

[Mike Henderson]

You can make a dowel plate or buy one. You make it out of steel and drill a hole the size you want. Then you pound your dowels through the holes. LN makes a dowel plate (http://www.lie-nielsen.com/dowel-plates/dowel-plate/).

Mike

[Loren Woirhaye]

Take a big coffee can and fill the bottom with dowels. Put a 75+ watt incandescent light with the bulb inside the can. This is a "shop oven". You can also shrink dowels with a toaster oven or a microwave. After they are shrunk you can encourage them not to expand by putting them in an airtight container with a dessicant packet... those little packages that come in all sorts of things. I think the blue crystal cat litter will work as well.

I bought big bags of dowels from McFeeleys. In Los Angeles I don't have many problems with oversized dowels but it's pretty dry here in general.

[Paulh Tremblay]

This thread actually throws some light on my problem:

http://www.sawmillcreek.org/showthread.php?127646-Dowels-how-tight-is-tight

The drill bit should be larger than the actual dowel pin. I believe Jessem's drill bit is larger; I probably just have bad dowel pins. (I did microwave them.)

I ordered more pins, and will test again when they arrive. I also emailed Jessem.

[Loren Woirhaye]

Jessem's drill bit works fine with the McFeeley's dowels. For me anyway. Sometimes in dry fitting I have to pull a dowel out with pliers. Sometimes a dowel gets chewed up and I throw it away. The glue does provide some lubrication. I use the dowels with the long grooves in the sides, not spiral ones. I also have another 3/8" drill I use with another collar since I use two different dowel lengths with the Jessem. Both bits work fine for the dowels I use.

[mreza Salav]

The original (bigger) Jessem jig came with 9.7mm drill bit which is larger than 3/8", in fact I think too large as the dowel fit would be too loose. The newer (cheaper) version that they have comes with 3/8" drill bit which causes this very snug fit with dowels. You can try 9.6mm drill bit or the V-drill bit that are just slightly larger than 3/8" and they work fine.
You might have to enlarge the jig holes a little too to ge those bits in ( a smaller dowel with a sand paper rolled around them and sand it down a few strokes).

[Paulh Tremblay]

Late last night I tried fitting a 25/64'' bit into the Jessem. It would not fit. I then got the idea to fit a 3/8'' dowel into the same hole, but the diameter of the pins wouldn't allow to put them through. In other words, my pins are much too wide.

What exactly is a V bit? I gather from the other thread it is one size bigger than 3/8''. But where does one get one?

[Bill Huber]

Late last night I tried fitting a 25/64'' bit into the Jessem. It would not fit. I then got the idea to fit a 3/8'' dowel into the same hole, but the diameter of the pins wouldn't allow to put them through. In other words, my pins are much too wide.

What exactly is a V bit? I gather from the other thread it is one size bigger than 3/8''. But where does one get one?

This chart will show you the different drill bit sizes. http://www.csgnetwork.com/drillsizeconvert.html

To answer your question a V bit is a letter bit (.3770 in.), there are 26 of them, A-Z there are also number bits that go from 1 to 80.

As I stated in that linked thread I use a 9.7mm bit and I get all my dowels from Lee Valley.

[mreza Salav]

As that chart (linked by Bill) shows V bit is 0.377 inch (vs 0.375=3/8), so it is oversize by 0.002".
9.7mm=0.381" which is oversize by 0.006". I find 9.7mm bits too big for 3/8" dowels. You can try 9.6mm=0.378" which is oversize by 0.003".
You can get the V bit from LV and probably from other suppliers.

[Von Bickley]

Paulh,
When I ordered my Jessem Jig, I also ordered these dowels and they fit perfectly.

http://www.thetoolstore.ca/viewItem.asp?idProduct=16725

[Paulh Tremblay]

I received dowel pins from Woodcraft, and they fit. I drilled 9 holes with the jig in 2 feet of wood, and the joint fit together just like the video. I also ordered the pins that Jessem makes but have not gotten them yet.

I learned a good trick in the process: push the pins through the bushing on the jig. If they don't fit through the bushings (as my original ones did not), they certainly won't fit in the drilled holes.

[Von Bickley]

I received dowel pins from Woodcraft, and they fit. I drilled 9 holes with the jig in 2 feet of wood, and the joint fit together just like the video. I also ordered the pins that Jessem makes but have not gotten them yet.

I learned a good trick in the process: push the pins through the bushing on the jig. If they don't fit through the bushings (as my original ones did not), they certainly won't fit in the drilled holes.

Which jig did you go with?

[pat warner]

The hole and the dowel diameters have to be attended to for every session. Dowels should be sized through a steel plate before use and some material should be shaved away to verify the sizing.
Then the hole has to match the dowel, less ~.002"-.003" max.
It may take a reamer to hit that dowel slop/fit. Drill diameters are good guesses; they're not meant to = their stated diameters. They can be big or small. Reamers are to tenths, very reliable.
Testing is essential. Blow one assembly with a frozen dowel and and you could ruin the whole megillah.
**************************
Hole diameter sentence ambiguous. Hole should be .002" - .003"max larger than the dowel. Hole = the dowel diameter, will jam the dowel.
Cheap reamers = a dime a dozen. Machine tool houses behind every rock.

[Paulh Tremblay]

The hole and the dowel diameters have to be attended to for every session. Dowels should be sized through a steel plate before use and some material should be shaved away to verify the sizing.
Then the hole has to match the dowel, less ~.002"-.003" max.
It may take a reamer to hit that dowel slop/fit. Drill diameters are good guesses; they're not meant to = their stated diameters. They can be big or small. Reamers are to tenths, very reliable.
Testing is essential. Blow one assembly with a frozen dowel and and you could ruin the whole megillah.

I've looked for reamers but have actually never found one for sale.

[Paulh Tremblay]

I went with the Jessem Paralign jig.

[Bill Huber]

The hole and the dowel diameters have to be attended to for every session. Dowels should be sized through a steel plate before use and some material should be shaved away to verify the sizing.


I will have to disagree on that point if you are using expandable dowels, they should fit the hole and once in the hole with glue they will expand to the point you can not get them out.

In fact if you put an expandable dowel in a hole with no glue and just let it set there for a while and there is some humidity in the air it will expand to the point it is hard to get out.

If you shave off the outer part of the expandable dowels then there is no place for the glue to come up as you push the dowel into the hole and can form an air lock at the bottom of the hole and you can not get the dowel to set to the bottom.

[Paulh Tremblay]

Can you tell me if I have aligned the Jessem jig correctly?

I make an X on each of the reference pieces. I then make an X on the surfaces that will receive the dowels. I put a check mark on the faces of the pieces.

When I drill the edge, I make sure the face (with the check mark) is flush against the alignment bar. I align the edge of the Jessem jig to the edge of the piece with the X.

When I drill the face, I make sure I drill the surface that does not have the face. I align the Jessem jig to the edge nearest the X.

I made a test box and did not align the alignment bar to the face of my piece when doing he edge drilling; hence the joint was not completely flush.

What surprises me (and the reason I ask about alignment) is that you you don't always use the same bushing when drilling the face as you do with the edge. Lets say you start with the left most bushing when you drill your edge. When you start with the face, you sometimes use the bushing furthest to the right. Only because of the exact precession of the jig do the holes line up. I thought I was doing something wrong, that surely you have to use the same hole when starting each piece, but I just can't see how that is possible. In other words, I might drill from left to right when drilling the edge piece, but then have to drill right to left for the face piece.

[Bill Huber]

Paulh, I am not sure if I understand all you are saying and asking.
Here is a thing I was working on that may help and get us going in the right direction about your questions.
The main thing is you ALWAYS use the same reference face and the same reference edge.

Here are 2 things I have done to the jig.

http://www.sawmillcreek.org/showthread.php?150851-Jessem-doweling-jig-flat-work-adapter&highlight=Jessem+doweling

http://www.sawmillcreek.org/showthread.php?212510-New-Jessem-Paralign-Doweling-jig-mod&highlight=Jessem+doweling

293503 293504 293505 293506

293507 293508 293509

[Paulh Tremblay]

293586293587

The first picture shows me drilling for the edge. I am making a box. You can see the tape that marks the reference edge. I have the guide block against the face of the board.

The second picture shows me drilling the face. You can no longer see the tape. The tape is on the other side of the jig. I cannot possible use the original reference edge for the face joint. The only way I could use the same reference edge is if I flipped the board over and drilled on the wrong side.

[Loren Woirhaye]

The jigs is made to insane tolerances. The offset from the edge is identical for woodworking purposes. The middle hole is dead middle and all the holes are evenly spaced. You can index off either edge and it will be the same. The edge of the inside face of the perpendicular fence part represents the plane of the outside edge of the board, generally.

What you're dealing with is however understandable. It took me awhile to model the way the jig works in my brain.

[Paulh Tremblay]

I concluded the same thing after seeing my edges perfectly aligned. (The faces were not, because I didn't align the face to the reference block, and of course 3/8'' is not exactly one half of a 19mm piece of MDF.) I just wanted to make sure I wasn't doing something wrong.

[Loren Woirhaye]

If you drill wrong, fill with half-dowels and glue and start over. I've done that a few times. Good reason to acquire a flush cut saw.

[Paulh Tremblay]

I just got the 9.7 mm replacement bit from Dowelmax, and it won't fit in the jig. The bit that accompanied the Jessem jig is 3/8'', which explains why the dowel pins fit so tight.

I drilled two holes with each bit (obviously, not using the Jessem jig). I tested several different dowel pins, and got interesting results.

In some cases, the pins fit nicely into the 9.7 mm hole, but would not go into the 3/8'' hole without excessive force. In some cases, the dowel pins fit nicely into the 3/8'' hole, but were too loose for the 9.7 mm hole. Millscraft worked very nice with the 3/8'' bit. Some pins from Woodcraft worked good, but others from the same package were too tight.

I am a bit disconcerted about getting pins to fit, especially since I don't have the option to use a slightly bigger bit.

[Paulh Tremblay]

I just did a test fit with 10 dowels using Jessem's own dowels.

http://www.thetoolstore.ca/viewItem.asp?idProduct=16725

I had to use a clamp to dry fit the pieces because the dowels fit so tight. The joint split in several places.

I had to use pliers to remove the pins, and one pin wouldn't come out without my having to bust it out. I measured the pins with a caliper and noted that they tended to be 1/128 inch larger than 3/8''.

I then tried other dowel pins. The only dowels that fit easily are the ones made in China, dowels that are probably technically undersized.

Next, I used Dowelmax's bit to drill a hole. All pins fit easily in this hole.

I can't fathom why Jessem changed their bushing so the 9.7 mm dowelmax drill bit no longer fits.

[Ole Anderson]

I made my own dowel plate using a chunk of 1/4" steel plate and the same size bit as used to drill the dowel holes and it worked fine. Finger push fit. As stated, just drive the dowel through the steel plate to resize. Just be sure to leave sharp edges in the plate, you want to shave the dowel, not compress it.

But if you want a slightly undersize dowel, get a reamer and enlarge an undersize hole in the plate as much as you want. Here is the catalog I used to use: http://kbctools.com/usa/Navigation/NavPDF.cfm go to page 80 for decimal reamers. Navigate to page on the upper left. To do this correctly, you need a drill press.

[David Winer]

I could have used a mallet to hammer the joint together, but I don't believe you should fit dowel joints together that way. The videos for Jessem and Dowelmax show the joints going together easily with the push of a hand.


Has anyone experience with the dowel pins sold by Jessum? I would expect their pins to match quite well with their own jig. Seems better to me than the various re-sizing schemes discussed in this thread. I haven't yet ordered them but plan to give them a try.

The company describes their pins:

Our pins absorb some of the glue moisture and expand to take up the space left by the shrinking glue, creating an excellent mechanical and chemical bond.

Our Expansible Dowel Pins are milled round and slightly oversize, then grooves are impressed into them creating an accurate, strong, joinery element.

[Bill Huber]

Has anyone experience with the dowel pins sold by Jessum? I would expect their pins to match quite well with their own jig. Seems better to me than the various re-sizing schemes discussed in this thread. I haven't yet ordered them but plan to give them a try.

The company describes their pins:

Our pins absorb some of the glue moisture and expand to take up the space left by the shrinking glue, creating an excellent mechanical and chemical bond.

Our Expansible Dowel Pins are milled round and slightly oversize, then grooves are impressed into them creating an accurate, strong, joinery element.

Jessem, DowelMax and Lee Valley all get their dowels from the same supplier.
Those dowels work great with the 9.7mm guides and bit but are just a little oversize for a 3/8" bit.

[Paulh Tremblay]

I did two tests with these dowels. In the first, I used the dowels out of the bag. The dry fit was so tight I actually had to break a dowel to remove it. I did not even try a glue up.

In the second test I microwaved the dowels for 2 minutes. They fit nicely during the dry fit. When I glued the joint together, I needed 4 clamps for a 16'' piece. I just checked a minute ago and saw the test piece had developed a crack because of the excessive pressure. I may have used too much glue.

[David Winer]

I did two tests with these dowels. In the first, I used the dowels out of the bag. The dry fit was so tight I actually had to break a dowel to remove it. I did not even try a glue up.

In the second test I microwaved the dowels for 2 minutes. They fit nicely during the dry fit. When I glued the joint together, I needed 4 clamps for a 16'' piece. I just checked a minute ago and saw the test piece had developed a crack because of the excessive pressure. I may have used too much glue.

Paulh, from Bill Huber's comment about two sizes of drill bit it seem important to know which size you used. Your results indicate a mismatch in your test. You didn't specify which dowels you used in the test but presumably they were Jessum, right?

What we need to know from someone's experience is: whether the Jessum dowels work without complications in the Jessum jig with what drill bit?

[Paulh Tremblay]

Paulh, from Bill Huber's comment about two sizes of drill bit it seem important to know which size you used. Your results indicate a mismatch in your test. You didn't specify which dowels you used in the test but presumably they were Jessum, right?

What we need to know from someone's experience is: whether the Jessum dowels work without complications in the Jessum jig with what drill bit?

They don't. The dowels I used in both tests were Jessem's dowels. I used the bit supplied by Jessem, the 3/8'' size. A Jessem rep has informed me that there is a flaw in the Jessem Jig design, and suggested I return the jig.

[Cary Falk]

They don't. The dowels I used in both tests were Jessem's dowels. I used the bit supplied by Jessem, the 3/8'' size. A Jessem rep has informed me that there is a flaw in the Jessem Jig design, and suggested I return the jig.
I am getting confused in both of these threads. According to Jessem the "flaw" is not having the 9.7mm drill bit and bushings? So all jigs that were shipped with an actual 3/8" bit and bushings is flawed and should be returned? You should return it even though Bill said that JessEm is offering the 9.7mm by the end of the month? Why did JessEm switch from the 9.7mm to the 3/8"(which I have).?

[Phil Thien]

I am getting confused in both of these threads. According to Jessem the "flaw" is not having the 9.7mm drill bit and bushings? So all jigs that were shipped with an actual 3/8" bit and bushings is flawed and should be returned? You should return it even though Bill said that JessEm is offering the 9.7mm by the end of the month? Why did JessEm switch from the 9.7mm to the 3/8"(which I have).?

Here is my take:

The difference between 9.7mm and 3/8" is .006" (two sheets of rather thin paper). And most people with 9.7mm bushings said 9.7 is too sloppy (and I concur), so many are using 9.6mm bits w/ the 9.7mm bushings. The difference between 9.6mm and 3/8" is .003" (now one sheet of rather thin paper).

Now, there are a couple of complicating factors, first: Hard vs. soft wood. If you're trying to shove a slightly oversized dowel into a 3/8" hole in hard maple, it is going to be a challenge. Now multiply that because you're creating a joint with several slightly oversized dowels in 3/8" holes, adding glue, ugh.

But softwood is different. I can tap a slightly oversized dowel into a 3/8" hole no problem-o. Do it in fir and pine all the time.

And there is a second complicating factor: The dowels themselves. They may be a bit oversized, they may be a bit undersized.

So as much as people want a guarantee that the holes will always be the perfect size for the dowels, there is really no way you're going to get that. Perhaps if you have a single source of dowels with very high quality control standards, and you can control your own shop environment perfectly, and you only use all hardwood or all softwood, maybe you could do it.

But if anything changes, like you now want to switch from hard to softwood for a project, or you want to use dowels from a new vendor, well, you're going to have some issues.

My point is, as soon as you think you have hit the magic combination, one variable can change and you're right back at the starting line.

So the advice to in these threads to make a dowel-sizing plate from a scrap of steel is (IMHO) the right approach. Sometimes I sand my dowels, it is cathartic. I'm not a production shop, I can fit my dowels. I can take some time and shrink dowels in the microwave or via dowel plate or via sanding. If the dowels on hand are a little small I simply go through the batch to find those at the opposite end of the tolerance spectrum. If I don't have enough, I order more dowels.

[John Gornall]

I had some issues with dowel fit but seem to have it in hand now.

The bits are standard twist drill bits designed for drilling rigid materials like metal. When drilling in wood they don't cut cleanly at the outer edge and push the wood which springs back. So you end up with a small hole which varies with wood species. Try a quality brad point bit designed to cut wood - often solves the problem.

The dowels are compressed and grow a little after manufacture. Try them in the jig bushing and if they are tight push them through a dowel plate. I use the Lee Valley plate inserts - don't have the plate, just the inserts which fit in a dog hole in my bench. Pushing each dowel through takes off a few thou and gets them to the size they're supposed to be.

[Paulh Tremblay]

I am getting confused in both of these threads. According to Jessem the "flaw" is not having the 9.7mm drill bit and bushings? So all jigs that were shipped with an actual 3/8" bit and bushings is flawed and should be returned? You should return it even though Bill said that JessEm is offering the 9.7mm by the end of the month? Why did JessEm switch from the 9.7mm to the 3/8"(which I have).?

I don't know why Jessem switched from 9.7 mm to 3/8''--that is a very good question several of us would like to know.

[Edit] I am deleting faulty information I had included about Jessem.

[Paulh Tremblay]

I had some issues with dowel fit but seem to have it in hand now.

The bits are standard twist drill bits designed for drilling rigid materials like metal. When drilling in wood they don't cut cleanly at the outer edge and push the wood which springs back. So you end up with a small hole which varies with wood species. Try a quality brad point bit designed to cut wood - often solves the problem.

The dowels are compressed and grow a little after manufacture. Try them in the jig bushing and if they are tight push them through a dowel plate. I use the Lee Valley plate inserts - don't have the plate, just the inserts which fit in a dog hole in my bench. Pushing each dowel through takes off a few thou and gets them to the size they're supposed to be.


[Edit Getting rid of wrong information about Jessem]

I can't get a dowel plate and as Bill Huber points out, that is a bad idea, because dowel pins are made with grooves in the side for absorbing the glue, and a dowel plate will get rid of the grooves.

[Paulh Tremblay]

[Edit: getting rid of faulty information about Jessem.] Sanding dowel pins, or pushing them through a dowel plate reduces their main feature, the grooves in their sides, so I am not going to do that.

[John Gornall]

My jig works just fine with 3/8 dowels using a 3/8 drill bit. The dowel plate is shaving at max a couple of thou - it doesn't remove the grooves.

Sometimes I have to do a little adjusting of dowel and/or hole - that's woodworking. A dowel with a kerf and a little strip of sandpaper makes a small flap sander to clean a hole. Lots of simple, quick solutions.

Using high precision drill bits, reamers, and precision dowel pins is metalworking.

[John Gornall]

If the dowel holes are full of glue with no air space it will take a lot of force for the clamps to pull the joint together and the wood will split from the hydraulic pressure.

Don't need much glue - just a surface wipe in the hole and on the dowel.

[John Gornall]

When I got my Jessem dowel jig a couple of months ago it happened that we were renovating at my shop. Needed sink and 3 upper cabinets in the lunch room. I usually rabbet, glue, and staple cabinets but decided to use dowels. Cut the panels, edge taped them, laid out the dowels, drilled with the jig, and glued them up. Perfect, no thoughts about drill or dowel sizes. Dowels from Lee Valley. If I had assembly problems I would have adjusted the dowel size - dowel plate - sanding - squeeze in vise whatever. Chasing drill size just makes it hard. Just do some woodworking. MDF may be your problem - try some real wood.

[Paulh Tremblay]

I found two good sources on how dowel pins should fit. They sources actually contradict each other, but still shed light on the problem.

First, this from an interview with Jim Lindsey, the maker of Dowelmax:


The 1×6 had six dowels in it and i pushed it together without glue and it is still together and that was 12 years ago. It would not come apart. I would have to have broken the wood to get it apart and that’s when I realized I had a problem. I did some research after that and discovered that a 9.7mm drill ...But as we went on through the years, what we found is the dowel sizes vary from company to company. You know, they give you all sorts of excuses that they can only go 5 thou, plus or minus 5 thou which is of course 10 thou and that can be problematic so Mike and I started looking at it again and did some research and thought that possibly the 9.6 might have been better rather than the 9.7 because it was more of a median size.

http://thewoodworkersnews.ca/2014/05/interview-with-jim-lindsay-designer-of-the-dowelmax/

And this from Laurier, a maker of dowels:


The dowel pin should be the same size as the drill used to make the hole. It is normal to use clamp pressure or a dead blow hammer to assemble a joint. In a properly fitted joint 2 to 3 dowel pins per joint is normal.

http://www.laurierwoodcraft.com/3648/sizing

[Ole Anderson]

[Edit Getting rid of wrong information about Jessem]

I can't get a dowel plate and as Bill Huber points out, that is a bad idea, because dowel pins are made with grooves in the side for absorbing the glue, and a dowel plate will get rid of the grooves.
A dowel plate only shaves a few thousandths off the pin, not nearly enough to remove the grooves. And the grooves serve two purposes: primarily they allow excess glue or air to escape, avoiding a hydraulic lock as the pin is driven home, and secondarily they give the dowel wood somewhere to go when it expands from the glue's moisture.

[Paulh Tremblay]

I found this interesting article on glue strength:

http://www.oldbrownglue.com/images/articles/HowStrongisYourGlue_FWW.pdf

An important point is that a slightly loose fitting joint is only slightly weaker than a snug or tight one. That fact explains why a 9.7 mm drill bit will produce strong joints.

[John Gornall]

The compressed dowel people - dowels for 9.7 mm drill and smaller dowels for 3/8" drill - read their "Helpful Information" page -

http://www.justjoinery.ca/

[Paulh Tremblay]

I found this interesting article on glue strength:

http://www.oldbrownglue.com/images/articles/HowStrongisYourGlue_FWW.pdf

An important point is that a slightly loose fitting joint is only slightly weaker than a snug or tight one. That fact explains why a 9.7 mm drill bit will produce strong joints.


Very interesting. The company offers dowel pins for 3/8'' bushings and 9.7 mm bushings. The information on the fitting is the same exact I quoted above, about using a dead blow hammer or clamps. I do wonder if using a dead blow hammer would split joints made from MDF.

Thanks for the info.

[Jack Clay]

Could the 3/8 inch Jessem guides be drilled out to 9.7 mm?

[Paulh Tremblay]

Could the 3/8 inch Jessem guides be drilled out to 9.7 mm?

No. The bushings are hardened steel.

[mreza Salav]

No. The bushings are hardened steel.

I guess I am repeating myself multiple times. Just slightly enlarge your bushings with a sand paper wrapped around a 1/4" dowel rod and rob the bushing all around. You just need to take about 0.001" or 0.002" from each side. Then use 9.6mm or the V-drill bit which are between 3/8" and 9.7mm. You won't have all these problems anymore....
sigh...

I have both versions of Jessem jigs and have drilled thousands of dowels with them.

[Paulh Tremblay]

I contacted Jessem, and the rep informed me I should just put the dowel pins in the microwave. I put 20 pins in the microwave for 2 minutes, and it made a complete difference. My joint came together during a dry fit with just hand pressure. For my first glue up, I needed tremendous force with clamps, and an edge developed a slight crack. For my next glue up I coated the dowels with a very thin coat, and the joint came together with normal clamping pressure.

I am a bit concerned I cooked the dowels too long. Some came out of the microwave with brown specks. I asked Jessem, and was told that you can in fact heat dowels too much, but didn't get any more direction than that.

[Ole Anderson]

I will make the argument that no matter how you pick bushings and drills, variability in dowels, just like biscuits, really suggest the use of a dowel plate to resize them just before insertion in your joint. Remember the toy we had as little kids where we used to pound the peg through the hole? Same idea. Everything really important we learned in kindergarten. Just Google dowel plate. And you don't need to buy the $55 Lie-Neilson one either, you are better off making your own. Step into metal working, it is fun too.

[John Gornall]

I use this dowel plate but just the inserts which fit in a dog hole:

http://www.leevalley.com/en/wood/page.aspx?p=70555&cat=1,42524

[Paulh Tremblay]

Got new dowels direct from Jessem. They were the same as I ordered from a third party, Just Joinery. They recommend:

"If you find your joints too tight, our Expansible Dowel Pins can shrink about .002” by putting them in a warm oven at 200°F or 93°C for 20 minutes on a clean cookie sheet. Warm the oven then shut it off before putting the pins in."

I did exactly this. The dowel pins fit a bit tight, and during dry fit I needed a pair of pliers to remove them. But glue up presented no problems. I made sure to use to rub my finger over the dowel to remove the excess glue and leave just a very thin layer.

[Adrian Anguiano]

I have the new style Jessem Jig, and I noticed I had issues with the 1/4" Dowels being too tight. I got the dowels from LV, and they are .005 oversized (They say this on package). My Jessem Drill bit they provided was .002 less than 1/4". This makes it tight enough where I have to get a mallet to pound in the dowels, and I have to use some major clamping pressure to close the joint.

First time i used it I split the wood cause the joints were so tight.

Im not sure either what I should do

[David Eisenhauer]

Same answer for all dowel sizes - either dry the pins out in an oven/microwave, or drive the pins through a sizing plate prior to use. Sizing plate seems easier to me, but either way. I don't see how any brand of dowels ordered from any source could be guaranteed to be of any exact diameter 100% of the time.

David

[Adrian Anguiano]

Yea, but the dowels are exactly what they said they are supposed to be. Which makes me wonder if something else is going on