Fitting pieces together

[DC]

Sometimes you have to fit two odds shapes together. Like the long curve when doing a patch in a limb or maybe a tighter curve in the handle. How do you get a nice glue line? I've seen violin makers using chalk and rubbing the pieces together and others using graphite(pencil) the same way. Not sure if I'd trust a glue joint that was coated with graphite. Any YouTube links? Any hints? I've searched YouTube but I don't think I've gotten the right search criteria.

[Pat B]

DC, with handle splices you can boil both pieces, clamp them together and let them dry. This will help to match the glue surfaces for better glue lines. Whether this will work for other splices I can only imagine it will.

[DC]

Thanks Pat. The one I'm working on right now is a repair so one side already has some glue joints that I wouldn't want to steam. It just occurred to me that there is no reason not to steam or boil one piece and clamp it to the other though. Good idea. May not work that well with thicker pieces though.

[Eric Krewson]

I saw a neat trick on a flintlock site where a guy used carbon paper between to pieces of wood to mark the high spots to get a perfect fit.

I shine a light behind the pieces and look for light coming through to see the high spots. This only works if your added piece goes all the way through the wood.

I eyeballed this patch on a badly cut precarve flintlock lock panel, it took me hours to get what I thought was a perfect fit, and it was. I am pretty sure I shined a bright led light inside the mortise and looked for gaps on the outside. As you can see, the lower glue surface was snaky, not straight.

[Eric Krewson]

done

[DC]

My camping headlamp has a high intensity LED. I'll try shining that on it somehow. Have you tried to find carbon paper lately?

[mmattockx]

Have you tried to find carbon paper lately?

Amazon has piles of it. The art/scrapbooking people use it these days.


Mark

[Eric Krewson]

Back when I carved duck decoys 36 years ago I bought a pack of carbon paper to trace patterns, I still have that same pack and have only used a few sheets of it.

Here is my latest use of the carbon paper, making a cardboard gun pattern from a full sized plan.This is an old picture, I am old and gray now.

[DC]

I had a thought last night. Not sleeping well gives you time to think. Assuming the curve is only in one plane could I use double side tape and stick sandpaper to one piece and wiggle it across the curve of the other. Depending on the thickness of the sandpaper the radii of the two will be slightly different but there is usually some flex in the parts. Anyone tried this? I'm going to give it a shot today.

PS It works well. Doesn't take as long as I thought either. I used 120 grit paper.

[stuckinthemud]

Carbon paper is greasy and can badly affect your glue-up.  I use water as a tell-tale for finessing joints, its much more effective than carbon or chalk, and I have tried both, and leaves no residue to clean off.

[DC]

I've glued up the joints I did with the sandpaper. This is the worst side. I think the joint is actually better than it looks because I'm using old 205 hardener and it darkens with age. I'm pleased with the result.

When you use water do you just wet down one surface and rub them together?

[stuckinthemud]

Just wet one surface and press them together, no need to rub, the water transfers with the lightest of touches