Dove tail question

New to making dovetails...using bandsaw (yes, cheating). Directions for dovetails, bandsaw or not, is they are cut at an angle to the face.
Is the purpose of this so the joint locks together or just for looks? Seems like a 90 degree cut, for both pins and tails, would be fine for a "low load, light stress" situation...
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Dovetails are cut the way they are for strength reasons. The sort of joint you describe is commonly called a box joint. It is almost as strong but many people think it is not as attractive.

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A dovetail is just that-- been used for many years. If cut properly, they lock together quite nicely with a minimum of glue. "like a 90 degree cut, for both pins and tails, would be fine for a "low load, light stress" situation..." The description above is for box joints -- easy to do on the TS with a simple jig don't bother with the bandsaw on these. Either will work, dovetails are more elegant. For a low load light stress situation you can use simple rabbets & glue with nails- particularly if you don't care what they look like & have a lot to make. You could also look at the drawer lock mitering bit for routers (never used one), but the result looks interesting in the catalogs.
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A dirty little secret is that with modern glue, butt joints are all you need. Anything more sophisticated is purely for looks and the builder's satisfaction.
Don't believe it? Make some butt joints, let them dry for 48 hours, and try to break them apart. The wood will tear out before the joint fails. Okay, other joints may be even stronger, but so what; isn't that adequate?
That said, on a recent project I mismeasured and didn't have enough wood for anything but a butt joint (I pocket screwed them because the inside wasn't visible) Everytime I pass it (a dog food station) I get a little upset at how ugly it is. The only thing stopping me from rebuilding it is that no one else sees the problem.
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toller wrote:

Just because the wood might tear out before the glue doesn't mean the joint is just as strong. When a butt joint tears out, it tears out on the piece with the end grain showing, and the tear is with the grain.
If you make a box or dovetail jig, the ONLY way to break the joint is to break it against the grain. It is MUCH strong.
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stronger. Its just that a butt joint is often strong enough.
Addressing the OP's issue, it would be unusual to fine a situation where box joints were not strong enough. I just made some box-jointed boxes out of 3/8" wood and, just for fun, found I could stand on the setup pieces without breaking. Yes, a dovetail is stronger still, but usually the only reason for using it is appearance.
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The glue is not the problem. It is the weakness of the wood that you are trying to over come in a stronger joint.
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Leon wrote:
snip

You use GLUE to hold things together? What if you want to take the thing apart later? GLUE!?
Seriously, aside from the mechanical strength of a dovetailed joint, through & half blinds are self squaring, something you don't get with box/finger joints. That keeps things from racking.
I've made a seven overlay drawer unit under my drill press. Half blinds on the front, throughs on the back - no glue. Been using those drawers for a couple of years and they work fine - without ANY glue.
Have also made a handful of chisel racks, some with box/ finger joints and some with through dovetails. By not gluing them, it's easy to modify them as my chisel collection/obsession grows.
charlie b
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: New to making dovetails...using bandsaw (yes, cheating). Directions for : dovetails, bandsaw or not, is they are cut at an angle to the face. : : Is the purpose of this so the joint locks together or just for looks? Seems : like a 90 degree cut, for both pins and tails, would be fine for a "low : load, light stress" situation...
The chief value of the interlocking feature of dovetails is that it greatly assists assembly at glueing up time.
For information about the strength in relation to the splay angle, please look at my web site - Dovetailing Detailed - Dovetail Angles.
Jeff G
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It looks good. It also provides strength without requiring glue. Over time, glues (especially old ones) weaken.
Dovetails are very good for drawers, because it resists coming apart when something heavy hits the back wall.

Yup. Many old "practical" boxes use the machine-cut box joints.
But old drawers with box joints come apart.
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