Fixing bumpy bending curves

[Stray Feathers]

I had issues when bending the sides for this Australian Blackwood dreadnought; I mentioned it in another thread. I got bumps across the grain in the lower bout. I tried to coax them into a smooth curve first with the bending iron (no luck) then heating the insides of the curves with the bending iron while I heated the outside with an iron (no luck) and then finally I put the sides back in the Fox bender I use (otherwise successfully) misted with Windex etc. and making sure the affected lower bouts were well heated. The bumps would not budge. So I tried putting cleats vertically across the sides on the inside of the lower bout where the offending bumps were on the outside. They are not subtle - about 7/8" wide, and they look like "what the heck was he doing there?" But I have to say that they have helped a lot to flatten the bumps, so much so that I think some sanding will give me fair curves in the end. And if the sides get thinned a little in the process, there is some reinforcement behind them. Interestingly, the bumps are in nearly the same locations, two on each side, on the bookmatched sides, so I am wondering if it was something in the wood that caused it. It's an unorthodox fix for sure, but at least it is buried deep in the lower bout, and I am happy that I may get a decent guitar out of this nice tonewood. Bruce W.

[tippie53]

can you post pics of the area, so how thick was it?
you may be able to get them down

[jread]

Interesting. I had the bumps like that once on Rosewood sized. I assumed it was uneven grain and didn't fuss with it too much and it looked ok when finished. Thanks for your post. It'll give me something to try next time it happens.

[Stray Feathers]

John, the sides were .085" to start, and after some sanding about .081" generally. In the photo you can see a thin spot along the edge of the side - that's when I started to think I'd better reconsider this. At that thin spot, at the lower edge of the kerfing it is .075", and probably less under the thickest part of the kerfing. I didn't want to end up with thin patches across the grain. So with the cleats on the inside I think I can take a little more off in the levelling process, as well as sanding bindings - the binding will be a little proud at that thin spot already. I am using a wide rigid sanding block and also a rolling pin sander, at slow speed and carefully. Bruce W.