Dovetail Technique Question

[Mark Stutz]

I'm currently working on a cherry chimney cupboard. It's in 2 sections. I'm working on the bottom section now. I'm dovetailing the sub-top to the sides. My question has to do with the end grain tearout you can see in the picture. The end tail socket is pretty good, but others have lots of tear out. Is this the result of A) I need to learn to sharpen better, B) I'm wailing away with too heavy a blow...go easier, C) This is normal for Cherry, or D) some reason I haven't thought of.

I know it won't make any difference in the strength of the joint, but I just wanted to know if I should be doing something differently.

[Mike K Wenzloff]

Hi Mark,

I would reckon A + B, or simply B. But as I am not there, it could be other factors as well.

In general, ripping out the end grain is due to crushing the fibers instead of severing them. If you want to chop DTs, I would:

[1] Make sure I started with freshly sharpened chisels.
[2] Make sure I stopped and honed between sections. But I'm talking just a quick swipe or two across the stone.
[3] Observe the end grain.
[4] Stop chopping before reaching the baselines and pare--with freshly honed chisels.

Take care, Mike

[David Carroll]

Hi Mark,

I agree with Mike for the most part. I typically chop about an eighth of an inch away from the scribed line to do the heavy wasting and then a second lighter chop on the line. It seems to cut down on the tearing out. Certainly paring as Mike suggests would work too.

Incidentally, chopping dovetails ala Frank Klaus is all the rage now, but some years ago we were being taught to waste out with a coping saw and then light chopping or paring to finish. I'm not sure which I prefer. I guess in soft (ish) woods I chop, but in hardwoods I still saw out the waste. It makes me a girly-man I know, but dang they come out nice!

David C

[Steve Wargo]

Like Mike said... A + B. I run in this from time to time. Poplar always seems to magnify this problem for me. Good luck

[Ruston Hughes]

Are you chopping from both sides? (i.e. chop halfway through from one side and then flip the board and finish from the other)
I've had tearout problems at times when doing this and have read that the waste being unsupported after the flip makes it easier for tearout to occur.

[Mark Stutz]

Thanks to all. I sorta figured that was the problem. Ruston, I have no problem with the first side...nice clean cut. It's the other side that tends to tear out on me.

Mark

[Mark Singer]

Mark
The tear out is pretty typical to some degree. It will have little effct on the joints strength. I undecut slightly anyway to insure the outer surface touch. I would take smaller cuts.....that is usually not a problem with dovetails and if you check the pics of mine there may even be a little of the same.http://www.sawmillcreek.org/attachment.php?attachmentid=57059&d=1170690677

[Alan Turner]

Mark, If you are a chopper and not a sawyer, then you might try, on the first side, chopping, but removing waste in a "v" pattern instead of from the end grain, leaving the waste in place at the end of the board. Go half way, then flip it over to finish. The end of the board will then support the waste as you chop the second side, and should lessen the tear out. Just a thought.

[Mark Singer]

Mark, If you are a chopper and not a sawyer, then you might try, on the first side, chopping, but removing waste in a "v" pattern instead of from the end grain, leaving the waste in place at the end of the board. Go half way, then flip it over to finish. The end of the board will then support the waste as you chop the second side, and should lessen the tear out. Just a thought.

Alan
That is what I do . I go half way and flip over...

[Michael Keating]

Mark, If you are a chopper and not a sawyer, then you might try, on the first side, chopping, but removing waste in a "v" pattern instead of from the end grain, leaving the waste in place at the end of the board. Go half way, then flip it over to finish. The end of the board will then support the waste as you chop the second side, and should lessen the tear out. Just a thought.

That is the way I was taught . . . I wonder where I got this from?

[Tony Zaffuto]

Mark,

I had identical results to what you are showing and cured mine almost entirely by changing from chopping to sawing. I would suggest getting a good coping saw--Tools for Working Wood (no affiliation) has an excellent one (Olson???) for about $12.00 and blades for the same. Saw out most of the waste and pare out the remaining.

I picked up most of my technique from the Ian Kirby book "The Complete Dovetail", and (at least for me) the technique worked wonders. I got to also add, though, that every once in a while you come across a "bad" piece of cherry, particularly on those days when you just "can't hold your tongue right", that no matter what you do, you're better off doing something else!

T.Z.

[James Owen]

I'm currently working on a cherry chimney cupboard. It's in 2 sections. I'm working on the bottom section now. I'm dovetailing the sub-top to the sides. My question has to do with the end grain tearout you can see in the picture. The end tail socket is pretty good, but others have lots of tear out. Is this the result of A) I need to learn to sharpen better, B) I'm wailing away with too heavy a blow...go easier, C) This is normal for Cherry, or D) some reason I haven't thought of.

I know it won't make any difference in the strength of the joint, but I just wanted to know if I should be doing something differently.

Mark,

I usually use a variant of "saw and pare." First, I make the side cuts for the tails/pins as usual. Second, I drill a small hole -- a wee bit larger than the height of the coping saw blade (about 1/8th inch diameter for mine) -- just a hair above the shoulder line in the horizontal center of the waste. Third, I cut a vertical kerf (with the dovetail saw) from the edge to the hole, insert the coping saw and cut out the waste just above the shoulder line; the waste comes out in two pieces. I've found that I can get more precision removing the waste in two smaller pieces rather than trying to cut the whole thing out in one larger piece. To finish up, I pare the remaining waste to flatten and square up the interior edge.

However, if you prefer chopping, I've found that this technique significantly reduces the kind of tear out shown in your photo: take a shallow, light vertical chop at the shoulder line (about 1/8th or so inch deep) and then pare it at approximately the same depth from the edge in. It works sorta like riving, but with a "stop cut" at the shoulder line. Repeat as necessary to remove about half of the thickness of the waste and then flip the piece over to to work from the other side to remove the rest. After removing all of the waste, a little paring flattens and squares up the edge, and Bob's Yer Uncle. This technique almost always results in a smooth interior edge, but it is pretty time-consuming. Very sharp chisels are essential for this work cleanly.

Hope that this may be of some use to you.

[James Mittlefehldt]

That is the way I was taught . . . I wonder where I got this from?

I use what I guess is a hybridyzed method, with bits of Ian Kirby, Rob Cosman, Franz Klaus and Lonnie Bird.

Michael That is the way that Franz Klaus chops out his waste using the v and then turning the board over, and repeating till the waste comes out. I like that myself and I find it does not take me any longer than sawing first then paring what's left.

[Mark Singer]

I use what I guess is a hybridyzed method, with bits of Ian Kirby, Rob Cosman, Franz Klaus and Lonnie Bird.

Michael That is the way that Franz Klaus chops out his waste using the v and then turning the board over, and repeating till the waste comes out. I like that myself and I find it does not take me any longer than sawing first then paring what's left.

Its faster!

[Mark Stutz]

Thanks to all. Looks like I'll need to get this project done, so I can try again soon!

[Michael Keating]

I use what I guess is a hybridyzed method, with bits of Ian Kirby, Rob Cosman, Franz Klaus and Lonnie Bird.

Michael That is the way that Franz Klaus chops out his waste using the v and then turning the board over, and repeating till the waste comes out. I like that myself and I find it does not take me any longer than sawing first then paring what's left.

Hi James,

I was actually taught by Alan Turner to do dovetails by hand. It was a bit tongue in cheek.

Mike