Another handcut DT question

[Doug Shepard]

It's been years since I've tried any handcut DT's. The results were usable but not pretty. So I'm getting ready to clamp one of the end pieces on this benchtop to trace the big pins with a knife and pencil. Somebody remind me - am I supposed to leave the line, split the line, or cut the line when I saw out the sockets??
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[Brian Kent]

Leave the line, then pare up to the line as you check the fit.

[Randy Klein]

knife and pencil. Somebody remind me - am I supposed to leave the line, split the line, or cut the line when I saw out the sockets??


Remember that the line you scribe, be it knife or pencil, is on the part (pin or tail) that will be kept. So if you scribe with a double knife, you split the line (since it forms a v-cut scribe line). If you scribe with a single bevel knife, you leave the line (since it forms half a v-cut). If you use a pencil, actually I don't know since I've never used a pencil but I would guess leave it.

Of course, I could be completely wrong but this is the picture that's in my head...

[Wilbur Pan]

The best way is to do some practice runs on scrap using each method, then use the one that works best for you. A lot depends on your sawing, and I'm not talking about skill level -- I'm talking about the same sort of intangible that affects your golf game.

I usually go for splitting the line, but there are some days where I find that leaving the line just works better. And then I'll be able to go back to splitting the line again.

[harry strasil]

just as a matter of habit from making mistakes while demoing to the public and my mind getting side tracked from questions being asked, I still use a pencil to put an "x" on the part that is going to be removed. Keeps me cutting on the waste side of the line and chopping out the waste part. Working in the quiet and solitude of your own shop and demonstrating to the public are two very different worlds. Being able to concentrate completely on the task at hand while trying to answer questions or give a running commentary while you are actually working is something that is kinda hard at times. Especially when you are attempting to answer questions about something completely different than the task at hand.

The worst part is when someone comes up to you with a very elderly person, usually a man, sometimes in a wheelchair and asks if it alright if they can leave the person to watch you work and tells you or the elderly person asks if its ok to stay and watch and then you are told that the person was a Cabinet maker or whose occupation was WWing for 60 or 70 years or more, yes more. At one place I demoed the person who was watching was the person whose shop and tools were donated to the Living History Museum and whose shop I was set up in demoing with extroidinary pieces of their work on display in a seperate area. This gentleman was as I remember, 104 years old and he was a 3rd or 4th generation WWer. His mind was clear as a bell. As standard precedure, I offered him a chair to set in, and stated that if I was doing anything wrong to please set me straight. He just set there with a big smile on his face and occasionally asked to see a specific tool, usually one of my homemade ones. I learned some real neat procedures and tips that day and was flabbergasted when he asked he could draw out one of my tools. I usually get nervous as a cat in a room full of rocking chairs when something like this happens.

The funniest thing that happened like this was when an elderly couple both sat and watched me for about 5 hours while the rest of the family was cruising the other sites at the event, and the lady commented when I was cutting dovetails, "Pa, he is a real Cut Up, just like you were!" I like to died laughing, and had to stop and set down I laughed so hard.

FWIW: I have also learned from experience when hand cutting dovetails to mark both pieces with either a number, a letter or the old way with just marks, /, //, ///, ////, as each corner is unique to themselves and do not often interchange. I also use the marking system when laying out boards for edge joining the same way across the joint, (technique learned from an old WWer who was my mentor). Also learned from him that the final edge prep is by clamping the boards with the marks together and doing one final shooting with a long jointer so they will match perfectly when glueing.

Like most WWers, my hand tool WWing knowledge is an accumulation of knowledge gained from reading old books I find, tips and procedures learned from other WWers and my own experience. And compared to the Old Time WWers I am just an APPRENTICE.

I got sidetracked again, as to the original question, I always mark the dovetails with a swan tail marking knife sharpened on only one side. The only thing a pencil is used for is to mark the boards as to their place in the assembly.

Thanks for listening to me ramble on.

[Jake Darvall]

The best way is to do some practice runs on scrap using each method, then use the one that works best for you. A lot depends on your sawing, and I'm not talking about skill level -- I'm talking about the same sort of intangible that affects your golf game.

.

Can relate to that.

If I'm cutting the tails into thin timber (like draws), I'll leave the line and drop the saw right on. No chiseling. Nice jap pull saw. Squint real hard :D

Cause the timbers thin I get good results that way. Nice and tight joints straight off the saw.

If the timbers soft, I leave the slightest of gaps between my saw kerf and the line. Will bite more with a nicer looking fit (consumes gaps more)

But if its thick timber, like what your doing there in that picture, its too hard for me to get a good fit straight from the saw reliably. I'd do what was previously mentioned....saw down say 1/2mm off ( whats that in imperial) leaving the line ,and chisel up.

[Doug Shepard]

Thanks everybody. Doing a couple of practice ones first is a great idea. One that I thought about weeks ago, but needed reminding of. I think it's about time I put a set of R/L single bevel marking knives on my Christmas list too.

[Wiley Horne]

Doug,

Good approach, especially the practice. On the marking knife, you can also get or make a spear point, or diamond point, with bevel on one side only, and use the one knife to do all the marking, by flipping it over as you mark left side, right side, etc.

Wiley

[Doug Shepard]

Wiley
I was looking about at knives this morning. I'm basing what I think I want on my marking yesterday and today in a tight space with the double bevel knife (I think it's actually a chip carving knife). So far I guess I've pretty much just used it straight down on a piece. I quickly regretted not having a flat blade with no handle and thought that a right/left pair was probably the way to go and something on the shorter side. So far these ones at GW look pretty good http://www.garrettwade.com/shopping/product/detailmain.jsp?itemID=106300&itemType=PRODUCT&iMainCat=12395&iSubCat=13551&iProductID=106300

Japan WW also has some but doesn't list the lengths so ???
But I think I've spotted some shorter diamond points too. Other than the one-knife convenience is there any other advantage? Seems like the longer narrower point on the singles would come in handy for some things.

[Wiley Horne]

Doug,

Well, you're going about it the right way, looking at everything and getting ideas. Cause there's no such thing as 'one size fits all' in marking knives. It's what fits you.

For me, the only advantage of the diamond point is that I'm dealing with one knife, and not looking around or reaching for the other one.

One other thing, I like a little more obtuse point, rather than a longer pointier point. First, because I am looking for a real positive registration against the side wall of the tail I'm marking from. Second, because it's ergonomically simpler with the broader point to leave a good mark on the edge where you're terminating, so that you can pick up that mark and go down the other face. This is true for marking the pins board, or for marking tenons. If the knife has a longer narrower point, I'm almost having to bend my knees to get the correct angle on carrying the mark into the edge.

I have also had to find a pretty thin-bladed knife, as my pin entries keep getting smaller. Blue Spruce's diamond point is thin enough for me.

However, I don't want to sound knowitall or dogmatic, because marking knives are way personal. To the extent, lots of folks will make their own (cue Derek).

Wiley

[harry strasil]

if you want narrow and strong, carefully grind the teeth off of all 3 sides of a 3 cornered file, square the end up and then grind a taper similar to a chisel edge on it, cut off the tang, slide a piece of clear plastic or rubber hose on for a handle. Walla you have a nice cheap marking knife, just put one of the flat sides with the sharp tip down against what you want to mark and pull, to do the other side put the other flat side against it pull.

[Pam Niedermayer]

A hint for accurate marking with knives, direct from Jeff Gorman: put the bevel up against the straight edge and mark, so the R/L designation will be reversed.

Pam

[Doug Shepard]

I'll have to do some more thinking on the sharp pointy vs diamond type. Admittedly I'm basing my thinking on what would have come in handy for reaching in around these big pins with the end piece clamped across them where the point would have given a bit more reach. Laying an unhandled blade right along the pin would have been nice and I dont think not having a handle for more normal work would be a detriment.

But Pam, can you elaborate on the bevel up against the straight edge? In my case would that mean bevel against the pin sides? Not sure I grasp why that would make it more accurate. Seems like since the bevel has such a smaller surface to ride on that it would be harder to keep the line straight, but I'm probably missing something.

[Pam Niedermayer]

Here's Jeff's take on it, he explains it much better. I know that it works, and intuitively that I end up with a mark closer to the straight edge.

http://www.amgron.clara.net/markingout/thebevel/bevelaspects.htm

You may not have room for this approach when marking from pins/tails.

Pam

PS Jeff has piles of good, reliable info starting at http://www.amgron.clara.net/

[Don Dorn]

Doug,

Good approach, especially the practice. On the marking knife, you can also get or make a spear point, or diamond point, with bevel on one side only, and use the one knife to do all the marking, by flipping it over as you mark left side, right side, etc.

Wiley

I'm a pencil pusher on DTs. I leave the line with hardwood and with softer wood, I leave just a touch between the cut an the line. Practice is definately the way. I think it was Frank Klausz who said "Start with four four foot pieces and start cutting dovetails. By the time you have it down, you'll have a nice little box for your shoe polish".

Take or leave it, but I married a little bit between Klausz and Marc Adams. I don't use any measuring ala Klausz, but I use the bandsaw to make the tail cuts ala Adams. I started with a bunch of poplar and made single tail into two pins, then three, and so on. Doing a couple every day, I had it down in about three weeks. The practice pays off because I very rarely have to make a repair nowdays.

[Derek Cohen]

Assuming you wish to remove the waste exactly (i.e. go from saw cut to saw cut).....

If you mark a pin from a tail with a pencil, then you must remove all the pencil line since it lies in the waste.

This assume that there will be no compression in the wood, such as joining two hardwoods. If, for example, you join a hard- and a softwood, then you could leave a tad of pencil line.

A knifed line is far more exact than a pencil line. If you knife the pins from the tails, then you aim to saw up against the resulting thin line.

Knifing the lines ....

http://i13.photobucket.com/albums/a262/Derek50/Joints/Dovetails%20Make%20Easy/Knifingthepins.jpg

My ideal dovetail marking knife has a thin double bevelled blade. I mark all the sides in one direction, then flip the knife and do the other side.

The blade of this knife must be thin to fit into the narrow gap of skinny dovetails.

The knives I make are very similar to those made by others, such as

Dave Anderson (Chester Toolworks) http://www.chestertoolworks.com/index.htm

and Dave Jeske (Blue Spruce) http://www.bluesprucetoolworks.com/tools/toolstore.htm

Here are my favourites:

http://i13.photobucket.com/albums/a262/Derek50/Marking%20and%20Measuring/Markingknifeset2.jpg

Here are the completed dovetails from the above example ..

http://i13.photobucket.com/albums/a262/Derek50/Furniture/Ladder%20to%20Bookcase/Laddertobookcasedovetails1.jpg

Regards from Perth

Derek

[Don Dorn]

Your explanation indicates a tails first approach and I'm just the opposite. Therefore, I want to leave the line since its actually on the part I want to save. I cut to the waste side of the line. In fact, I still make a scribble on the waste areas when removing the template (pins) just to be sure. Nice looking joints btw -

[Doug Shepard]

The pencil marking (using a 0.5mm pencil) was just insurance in case I missed getting a knife line somewhere as I traced the pins. I didn't end up needing it as I managed to get a knife line all the way around them. But it turns out that I'm having to take the knife line anyway. I think due to the tight space, a handled knife that couldn't be laid flat against the pin sides, and the double bevel, that I ended up with the knife line in the crease instead of EXACTLY even with the edges of the pin. I'm still working on my practice one. Still needs more chisel work to get the socket walls squared up. I've got about 7/16" (of a 1-7/8" thickness) going on nice and snug with no gaps then it stops. The fun part is that my knife lines are on the non-show side. No layout lines for paring from the good side. So I'm taking it slow sneaking up on the fit. In the meantime, the LV chisels I got last fall are getting their first serious workout (not much call for them on a DC installation). They're so much nicer than my Marples ones, although I need to take care of glueing the handles on so they stay, and take a buffing wheel or something to smooth out the sharp edges on the back edges. Got loads of little paper-cut type slices from them plus the little purpleheart (porcupine wood) splinters. I'll post a pic once I get the practice one in place.

[Doug Shepard]

OK. Here's the first stab at this. No gaps anywhere but I'm going to have to do my best to lay out a knife line on the show side so's I can pare from that side too. Got some tearout that I'm sure I can do better on the next one.
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[Wiley Horne]

Doug,

Looks good.

You definitely want to be doing your paring from the show side. Why are you paring from the other side--are you concerned about having a scribe line showing on the finished work? If so, this can be handled in a coupla ways. The most direct is to gauge the scribe line only where you'll be paring--at the bottom of where the socket will be--and not across the tails themselves.

Incidentally, the main cause of tearout of the kind you're showing is where the backing is getting chewed up, and the chisel is exiting the tails board into thin air. If you will keep moving your backing plywood underneath the tails board, so that the socket always has sound backing, then you should not be getting tearout. If you are, the chisel is not sharp.

You're doing well.

Wiley

[Doug Shepard]

It's just that the pins already exist. Didn't want to try and deal with cutting those by hand after they were glued onto the benchtop. So I cut those on the bandsaw and left the shoulders about 1/4" long then trimmed them up to the top after they were glued on. So now the only way to get the sockets sized to match is to clamp the piece across the pins and mark them which means marking on the hidden side. I'll have to take some careful measurements from that and get a line knifed on the good side to avoid the tearout issue.

[Wiley Horne]

Doug,

Sorry, I've been confused. Living in a 'tails first'-centric world.

Hopefully someone who goes pins first can help here, but I'm under the impression that the typical way that the pin pattern is transferred to the tails is direct--you put the tails board down flat on the bench, then clamp the pins board down onto it at right angles, using long clamps, then trace the pin trapezoid directly onto the tails board. Maybe I dreamed that, but thought I saw it done in FWW a few years back.

Wiley....having a head-slapping do-h-h-h moment

[Doug Shepard]

OK - yet another question. Made another practice piece that came out a skosh better, then dove in and did the real one. It's looking good from a gap standpoint, and I got one very minor tearout that will sand or plane out. But I got to thinking about the snugness of the fit and whether I should loosen this up a bit for glue. Right now I can seat the piece about halfway by smacking it with the heel of my hand. After that it's light/moderate tapping with a medium dead blow mallet, alternating from side to side. I'm using epoxy to glue this on which wont swell the wood like PVA but I'm wondering once the pieces have a coat of glue whether I'm going to have trouble getting these together. Think I should keep shaving here and there until I can smack the thing completely home by hand?

[Michael Schwartz]

They should fit pretty easily dry, you should only need light taps from a deadblow. You can always go in and undercut (slightly hollow) any tight spots that are not visible. If they fit properly you should be able to assemble them with yellow glue with no problems.

I cut mine tails first, and then scribe the pins. With this method layout the tails, cut them, and pare them so they are 90 degrees across with a flat face. Then cut the pins and pare them so they are 90 degrees across from the refrence face (scribe line) and they should fit very nicely.

I use a Lie Neilson dovetail saw, but for smaller dovetails I have been using a $10.00 model makers razor saw. The razor saws are about 25tpi with rip teeth, cut on the pull stroke and leave a really smooth cut and have a kerf thinner than that of a Japanese pull saw.

If your dovetails are perfect you are probaly entitled to an honorary degree from the College of the Redwoods.

If they are not don't be afraid to cover your tracks, as it is all part of the process. You can go in with a backsaw and cut a kerf nd fill it with veneer. fill larger gaps with wedges, and fill the slightest gaps with sawdust and yellow glue, or ca glue.

[Doug Shepard]

I think under normal circumstances I would have done the Tails-First approach. I had serious doubts on trying to do the pins by hand after the long edging was glued on though. No way to really hold this monstrously heavy top in a position I'd feel confident I could saw a straight line from. I'd have been in a kneeling position with my head angled over. Sounded too much like a recipe for a cut that was anything but straight. So I did them on the BS before attaching them to the top and left the shoulders long for trimming up after gluing. So I'm stuck with marking the sockets from the pins.

[Wiley Horne]

Doug,

It's good right now. Don't loosen the joint. Maybe it's too late, but I suggest you not use epoxy. Use PVA. Reason: cleaning up PVA squeeze-out is tough, but doable; trying to clean up epoxy squeeze-out would be impossible (for me at least!). Incidentally, this is why hide glue is so good for dovetails--easy cleanup and doesn't mess up the finish.

Not to worry about the fibers expanding from PVA--it'll just have that growed-together look. And

I think you have it set up perfect. The glue will not interfere with the joint going together. It has a slight lubricating effect when first applied; just don't give it three minutes to start setting up. Even then, a sharp mallet blow will break it loose.

Wiley

[Doug Shepard]

Wiley
Thanks but you're too late.:eek: At least for the 2 long sides that are already on. Actually the epoxy squeeze doesn't seem to be any worse than PVA squeeze out. It's more brittle but actually seems to come off easier without tearing wood fibers along with it. Nothing that cant be popped off with a sharp chisel anyway. I'll post pics after I get this end done and trimmed up. Then I need to lather/rinse/repeat for the other end which is also the back jaw for the twinscrew vise.

[Pam Niedermayer]

I wouldn't recommend epoxy, but of course it will work. As to positioning the work piece so you stand a chance of sawing in some controlled manner, you can alway put the piece with the edge to be dovetailed hanging over the top of your main bench. Then to saw the dovetails, kneel down so your head's more or less level with the piece. In this position you can saw with no problems if you're using a pull saw. One more reason to love Japanese saws. :)

Pam

[Doug Shepard]

Well they aint perfect but they'll do. There was another thread about not dry-fitting DT's as the fit was never as good as the first time. Here's proof. Unfortunately I discovered about a 6" gap on the end of the bench when I first clamped this on. I could hold a flashlight underneath and see about 2 paper thicknesses of gap near the center. So in the process of planing, chiseling, rasping, and sanding on the end of the bench and DT shoulders and dry fitting about a dozen times to check that gap, I ended up with a few minor gaps on the shoulders and face. I'll have to see if I can tuck some veneer into them or if not, some epoxy and purpleheart dust. Still have a bit more scraping and sanding to do but I'm moving on to the other end for now.
Although I like the longer epoxy open time, I didn't really need it for this. But the other plus is that you can add enough thickener so that it doesn't try to drip off a vertical surface while you're getting the piece tapped on and clamped. I know there's the thicker PVA for moldings but I already had the epoxy, so just used that.

Back Left corner - gaps on shoulders
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Front Left corner - gaps on face
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