Finger joints vs. screw and glue

[PRNDL]

I'm in the process of making my first guitar amp and am having a lot of difficulty with finger joints. After two failed attempts, I found an internet site that shows how to make a jig.
http://www.popularwoodworking.com/fe...le.asp?id=1030

Even with this new jig, I'm considering switching to gluing and screwing the pieces instead of finger joints (wood does get expensive if you keep making mistakes).

Are the extra strength of finger joints worth the extra work and hassle for a beginner?

After all, I could have been done earlier today had I chosen the easy way - instead, I spent all day and have to get another piece of wood to begin again tomorrow!

[Cal Weldon]

If finger jointing is causing you grief, you can use glue, screws and an inside chamfer or square block. This increases the strength considerably. You can install the inside block with finish nails and glue. Depending on the intended finish, you can remove the outside screws when the glue has dried. They are only really acting as clamps and it's easier to fill the empty hole than it is to cover over a screw head. That's what I do anyway.

[Curly Woods]

Predrill you holes and counter sink your screw heads. This is very strong, just not as "handcrafted" as finger joints would be. You could also add a small strip of wood on the inside seams (clamped and glued will be fine) if you want to make the joints a little stronger.

[Cal Weldon]

Curly, I'm guessing you were typing when I responded.

[HollowState]

Yes, I do almost what Cal does. But I don't like screws on the outside. I like to use ¾ inch square "baluster" strips from the lumber yard or those big box stores on the inside corners. Pine is the best, but poplar works too except it's hard to nail into. So I don't nail.

I predrill holes in the strips 90º opposite and screw them in with 8x1¼ inch wood screws from the inside along with carpenter's wood glue. This makes a nice strong joint even though you sacrifice a little corner area.

Finger (or dovetail) joints are nice if you have a good router, a jig and experience in using them.

Victor

[Curly Woods]

Originally posted by Cal Weldon
Curly, I'm guessing you were typing when I responded.

Great minds think alike

[Cal Weldon]

Michael,

I would like to look at your site but it won't open for me.

[PRNDL]

Thanks!

There's a local tube guru that uses finger joints in his replicas of Fender amps. He's very skilled, which is something I'd like to emulate.

[Sherman]

Originally posted by PRNDL
Thanks!

There's a local tube guru that uses finger joints in his replicas of Fender amps. He's very skilled, which is something I'd like to emulate.

If you like the look I would go with the finger joints (also called box joints). It is almost always worth the effort to do something well. I personally prefer finger joints for anything that requires strength and where a dovetail isn't necessary. Finger joints are extremely strong with lots of glue surface (dovetails are stronger but only in one direction).

If you have a table saw and dado blade making box joints is easy once you have made the jig. Tthere are also blades specifically for cutting box joints in 1/8 inch and 1/4 inch. If you don't have a dado set the box joint blades can be less expensive.

One thing I would recommend when making a jig is to make the vertical 'fence' your workpiece is held against relatively tall. Many jigs indicate a height of 3 1/2 inches. Something like 6 inches or even more makes holding larger pieces securely much easier than a short fence.

[PRNDL]

I have a vintage craftsman table saw (it weighs a ton) that came with a dado blade (an off-center one).

I made the jig out of two pieces of 1x8 nailed together.
I'm thinking of tacking on a 2x4 at a right angle, which will be held against the fence. It's not really necessary.

I do like making cuts with the table - the edges come out square and both pieces are exactly the same length. It's much better than a hand saw.


I'm more confident after making all those mistakes and might try making the box joints tomorrow.