HI. I AM GOING TO SPLICE 3/16TH X 3/4 BALSA STICKS FOR FUSELAGE STRINGERS. DO ANY OF YOU BUILDERS OUT THERE HAVE A GOOD WAY OF DOING THIS IN A WAY TO PRODUCE A GOOD STRONG SPLICE, WITH OUT GETTING TO BULKY. THANKS FOR ANY AND ALL SUGGESTIONS

I would lay one stringer over the other stringer with about a 2 to 2 1/2 inch overlap. Pinning this all down so that all of this assembly is in a straight line would be good. Then I would take a razor saw and cut a diagonal cut (the length of the cut would match that material that is overlapped) all of the way through. This will give you a lot of gluing area for a strong joint. There would be no extra bulk at all unless you wanted to wrap the joint with fiberglass, but that is probably not necessary.

Gary's idea makes a lot of sense

Do what Gary says.

I have been doing that since the 50s with no problem. on a long angle splice the wood will fail before the glue in the splice area gives up.

THANKS YOU GUYS, LOOKS LIKE IM GOING TO GO THIS ROUTE. ONE MORE QUESTION CA OR EPOXY,FOR THE GLUING OF THE JOINT

Probably a matter of personal preference, Whenever I splice two pieces together I always use thin CA because it penetrates the wood the best.

Heck, you could always do a couple test runs with CA & epoxy & see which one seems stronger.

Either one will be stronger than the surrounding wood.

By the way, the longer the scarf joint, the stronger (cut the angled part as long as practical).

If you have one, a disk sander with a miter gauge makes the best scarf joints.

Dave

A scarf joint 12 times as long as the wood is thick is said to be as strong as unjoined wood. I never make them that long.

And any length scarf joint that is glued with CA is going to be stronger than original wood with no CA in it.

Woodworkers recommend a scarf joint 6 times longer than the thickness. I agree this would be excessive with balsa.

One thing to consider regarding the length of the scarf; if you have to bend the stringers, as in following the curve of a fuse, the scarfed area will not be as flexible, because of the glue, so you get a small "flat spot" in the arc of the curve. The sharper the bend, and the longer the scarf, the more noticeable it is. Twice the diameter is plenty with balsa, no point in making the joint stronger than the rest of the piece.

I have done the above mentioned angle cut joint several times. It works very well. I worried about the strength a little so I cut this strips of CA type hinges to use as a doubler on the bottom of the joint. I don't know if the joint needed it but I felt better.

David