I’ve recently acquired what is supposed to be a dovetail saw, but I have a couple questions, as usual.
First, the tooth count is a little shy at only 13PPI. I believe it’s recommended you have closer to 20 with 16 being about the least. Will the count make that much difference? Also the set seems to be more than I’d think from what I’ve read. From the sound of things, there should be no real ‘set’ to the teeth but these teeth have a definite set to them… to the tune of nearly 1/16″. If this is all just going to result in more cleanup time with the chisels, then so be it but if it’s going to be a serious detriment to the end result then I’d like to know before I stop practicing and start cutting dovetails for real.
Second, I’m using a machinist’s protractor for layout and just want to double check that the “traditional” soft and hardwood angles are about 9 & 7 degrees respectively. I’m not that worried about it from a strength standpoint, as too much or too little slope presents it’s pitfalls readily, I’m just looking for a start line.
Third and finally, and this question is in regards to all joints in general. How “pretty” should the mating joint faces be? Should I expend the effort to sand each pin and tail or will I eventually become skilled enough to fit the joint right from the chisel?
Anyhow, gotta go play with the new toys. Maybe I’ll try cutting the tails on the T-saw as per the article by Steve Latta. Then I’ll only have to throw out the bad pin members thereby saving vast quantities of lumber.
Replies
Broad,
I'm only going to answer one of your questions. How pretty should the joint surfaces be? They should be as good as you can make them. Glue surfaces should be straight and true and cleanly sliced. No, DON'T sand them. You will degrade the gluing surface from that produced by the saw and chisels.
Now I'm going to recommend something that may seem contradictory and offend "purists." I highly recommend the table saw technique of cutting dovetails. In fact I recommend it above any other technique, including hand made. (Whoa!)
But first, you must learn to cut by hand. It's NOT hard to master. I mean that. Use either the pins first or tails first methods. Follow the instructions that have been repeated in many issues of FWW, other books and numerous web sites. Learning to cut by hand enhances your skills.
Now, why do I recommend the TS method? It uses exactly the same skills that you use in hand cutting, but substitutes the accuracy and dependability of the TS and the magnificent blades that we have available for that machine for the free-hand sawing. And that's good.
TS dovetails are nothing like router cut dovetails. They are as flexible in layout and design as hand cut. And once you master the method, they are as fast. The cuts are potentially as "perfect" as the TS is capable of delivering.
I'm sure this will result in howls from some. But who here recommends crosscutting or ripping by hand vs using the TS. Think of all the advice that gets posted here about precision crosscut sleds, adjusting the blade parallel to the miter slots, the importance of a high-quality rip fence and the legions that line up on one side or another about the type of fence? The TS is our primary precision tool in the shop. Use it.
There is absolutely no reason to apologize for using technology. Who here would insist that a craftsman fine trim a board with a hand saw? (a shooting board and plane, yes - but that's another implementation of technology to improve on complete free-hand methods). Who here could produce a saw cut by hand, using ANY saw as good as one on the TS? No one.
I'm glad you are aware of Latta's method. Try it. I think it produces work superior to anything done by hand.
In fact, once you learn to use Latta's method, the freedom from the drudgery of hand cutting gives you motivation and energy to do more than otherwise.
You can have a carbide-tipped blade ground by Forest (or others) to the angle you need. And you can still use that blade for general work. But here's another tip: get a non-carbide blade and file the teeth to the correct angle using a jig with the blade on the saw. Use this blade dedicated only for this task. Even a non-carbide blade will last for years used this way before needing sharpening (or replacement - it's cheaper) used this way.
VL
I have two dovetail saws. One has 10 PPI, and the other has 15 PPI. Both have about .007" total set. That is, the thickness along the teeth measures about .007 larger than the thickness of the blade itself. Teeth are filed straight across.
The 15 PPI has a better handle, but I like the 10 PPI better. I can cut one side of a dovetail with about two firm strokes. The 15 PPI cuts fine, too, just slower, and each time you take a stroke is just another chance to wander off line. I certainly wouldn't want to go any finer. I took the 10 PPI saw to Woodcraft to compare it to a Lie-Nielsen, and everybody who tried it liked my saw better - of course, it was freshly sharpened, and that makes a big difference. I paid less than $30 for the saw nearly 20 years ago.
Do not try to sand joints to fit. It doesn't work. Saw as close as you can, and pare to fit with a sharp chisel. With practice you will be able to cut a clean fitting joint with very little paring.
The angles are fine.
Cutting dovetails is about on the same level as cutting M&T joints. Really, just basic joinery, so don't be intimidated. Anyone with decent eyesight and basic motor skills can do fine. When you can make a shield-back chair by hand, or dual radius casements - now you are starting to get good (or at least better than me!)
Michael R.
15 Broad,
I'll take a shot at some of your questions.
The set of the teeth should have no impact on quality...
A 1 to 6 or 1 to 8 ratio on the slope of the dovetail should translate to 16 degree or 12 degree about ...
Pretty mating faces....absolutely, but there are some tricks. If the faces don't mate perfectly...what did you do wrong...you need to identify and attempt to correct. Eddie here rates his students cuts and provides feedback. Everyone can have weaknesses and applying some wiggle room gives you some back up..just in case. Ian Kirby suggests a routine that helps....he squares his stock and flattens his face side (the face side is on the inside of the joint)...He does not plane the outside till the end. Ian also saws out the waste with a coping saw and pares to the base line...nice and clean....and planing the outside at the end makes everything look even tighter...
Ian also suggests you start with two pieces of stock about 18" long by 6" wide...makes a joint, cut it off and start again...he suggested mahogany...
Thank you Venecia and Woodwiz for the help. BG, your input on tooth set and the translation of the angles is appreciated. Unfortunately, the remainder of your response came off a bit sharp, but I may have misunderstood what was not written. Obviously one must cut many joints and see what went wrong if they don't fit, but if the equipment is totally wrong for the job it's impossible to know what to blame... technique or technology.
FWIW I'm trying to apply what I've read soon after reading it because I retain best that way and apologize if that bothers you.
15 Broad,
Gosh, it was not my intention to come off sharp. I was trying to share some of Ian Kirby's suggestions and kinda say perfectly mating faces while desireable may not be always achievable...and give yourself some wiggle room for at least acceptable outcomes.. sorry if it came off wrong, was not my intention..
Thanks.
Thanks for the kind words, BG.
15broad,
Any saw should do the job - as the price goes up, the inbuilt inaccuracy due to the tool decreases, but practice is the key.
a couple of links on technique below:
http://www.popularwoodworking.com/features/fea12.html
http://www.wood-workers.com/users/charlieb/DovetailDrawer0.html
Hope that this helps - good luck and let us know how you get on.
eddie
edit
Re: slope of 9 or 7 degrees in your original post, I was trained to cut any visible dovetail at a slope of 1:8 (7*) and carcase work at 1:6 (9*)
Edited 1/17/2004 9:43:53 PM ET by eddie (aust)
eddie -
Thank you so much. The PW article is fantastic! Seeing the process done by human hands makes a lot of things clearer. The detail of the other article will sure come in handy when the time comes to do it for real.
Anyhow, more time typing = less time playing so I'll sign off and get to work.
Mario Rodriguez did an article on dovetail saws in FWW some years ago. He said most saws sold as dovetail saws have too many teeth. He described taking a fine pitch saw such as you describe and refiling it to 9PPI.
He also said that since dovetails are very shallow cuts in seasoned wood, a dovetail saw should need very little set, if any at all.
15Broad,
This is only a month too late but I wish you could watch Rob Cosman, Canadian rep. for Lie-Nielsen cut a set of triple hounds tooth dovetails by hand with only a 15 tpi handsaw and a few chisels.
Ken
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