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I am building my first guitar (classic) and I just received my material from a supplier. I thought I would use the suppliers side bending service since I don't have the tools or experience for this, the cost was reasonable and the service included sanding to the correct thickness. The wood for the sides is Indian rosewood.

My question is what quality of bending should I have expected. One of the bends has a 'kink' to it and the vertical sides in spots is cupped. Is this typical of the bending and can this be corrected during assembly?

Any help would be greatly appreciated - Thanks

John

Hi John;
A picture would be helpful, if you are able to post one.
Cupping is fairly common after bending & as long as it is not extreme, you can usually sand it out. How thick are the sides?
The "kink" is a bit worrying, though. It might be an indication that the wood has fractured.
Without actually seeing & feeling the side, it's hard to tell if it really is a problem.
Is there any sign of a crack at the kink? Do you have a bending iron? You could try to straighten out the kink & re-bend the curve, but check with the supplier first in case there is a crack & you end up breaking the side.
Good luck... Dan

In my opinion (which ain't worth much), if you are paying someone to bend the sides, they should be pretty smooth or have just the tiniest ripples that will easily sand out.

Kevin Looker

_________________
I'm not a luthier.
I'm just a guy who builds guitars in his basement.
It's better than playing golf.

Based on your description, I would send them back.

I have attached some photos of the side bending. The cupping shows up very well and I was able to measure the depth of the cupping at just about 3mm which is almost 50% more thne the wood thickness. The poor bend profile was hard to capture in a photo but when you run your hand over the bend it is very obvious.

Thanks to those who replied.

looks like a pretty nasty clamp mark there, but depending on where you cut it down it may not show up, except I bet it's already cut down to final taper. Sometimes cupping and dings can be ironed out with a wet rag, but not so easily on a curved area of course. Anyhow it looks minimal to me. If you'd bent it yourself it wouldn't be so bad because these are areas that won't affect the sound or playability really IMHO. I would at least send pics back to the supplier. I wonder how much they charged. If cheap then not such a big deal. Wood is not perfect anyway. If you don't want it send it to me.

_________________
"Preoccupation with an effect gives it power and enhances the error"
from "Your Owner's Manual" by Burt Hotchkiss.

Send it back.

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Ken Franklin
clumsy yet persistent
https://www.kenfranklinukulele.com

It is commun and normal that wood moves, cup or warp, especially after wetting and heating it. Also, sides spring back after bending, so you can't expect a perfectly bent pair of sides when somebody do it for you, then send it to you, but in that case, it really looks like a poor bend.
Send it back.

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Francis Richer, Montréal
Les Guitares F&M Guitars

Ouch - definitely send back, especially if it stays that way at 45% RH.
Any decent piece of rosewood should not cup that much if properly bent.

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.