Official Luthiers Forum!

Ok so I'm pretty sure my current bandsaw setup can handle a small amount of resawing, which will, if I do it right, save me a lot of money, plus I'll have more access to lumber from local mills. The only thing is a lot of the wood a typical mill sells is flatsawn. I don't see backs being a problem to join, being flatsawn as I've had to do those a few times, but what considerations should I have before attempting to bend flatsawn wood? Just trying to find the best way to keep that piece intact.

I really try to stay away from flatsawn on guitars, and for ribs I don't use it at all.

I've had problems with flat sawn wood cupping whilst bending and then I over sanded it trying to compensate opening another bunch of problems!

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Formerly JJH

I learn more from my mistakes than my successes

I use laminated sides and if you really wanted to go this route you can always laminate it to a nice q/s interior side.

I have used a number of quilted materials with no problem (flat sawn) but in general I try to especially make sure the sides are nicely qs.

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

Ian-
I usually avoid flat-sawn wood, even for backs. I'd much rather do a 4-piece back with quartered wood than use flat-sawn. The notable exceptions to this would be for quilted and birdseye maple.
Most small mills just cut the logs 'though-and-though' (work from one side of the log to the other) so there will be a board or two out of each log that is close to quartered.
If the woodpile has been around the yard for a while, those boards will probably be gone.
So, it does pay to go through the piles of wood (be sure to re-stack or you won't be popular) to find something quartered, or close to quartered. Think of it as a trip to the gym! Most of the poor-quality wood tends to migrate to the top of the pile, unfortunately, since people unstack and pull the good stuff, then re-stack the rejects.
Chatting with the management and yard hands to find somebody interested in guitar building sometimes will get more co-operation, I hear. I've also known people to offer a premium to the management if they will pull boards of better quality. This may all lead to buying much more wood than you need, though....

Cheers
John

Ian: Folks have mentioned not using flat sawn for sides because of possible rippling problems on bending and rightly so. John has mentioned not using it for backs also. I'm not fussy about using it for sides or backs just due to the different shrinkage rates for radial[quarter sawn] and tangential [flat sawn]. The flat sawn is approximately twice as much as the quarter sawn. For me this raises a red flag for the possibility of cracks especially on backs because of the large size and the constricting cross braces. That aside ,there have been lots of guitars built with flat sawn wood. Guitars that are held in a narrow band of RH limits will most likely not have a problem. Here in Nova Scotia there is too much variation unless controlled by air conditioning. Have fun and good luck if you take it on.
Tom

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A person who has never made a mistake has never made anything!!!

I recently built a Koa OM for a guy that supplied me with basically flat sawn stuff he got in Hawaii years ago. I laminated the sides but did the back as usual. I think it will live in a pretty stable environment but I'm a little worried about the back. Looked nice. That's the extent of my experience. What's the T/R of Koa Todd?

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It's not what you don't know that hurts you, it's what you do know that's wrong.

In my thinking the T/R ratio was only mentioned to make the point that the tangential was greater than the radial. The real problem is the tangential shrinkage of the individual wood that is to be used. Mahogany has one of the smallest ratios and this along with it's low shrinkage rates is why is is so stable. Ian,you will have to take into consideration the rates of the proposed woods.
Tom

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A person who has never made a mistake has never made anything!!!

Okay I'll just stick to quartersawn/radial sawn wood for now, and maybe if I come up with some tricks to combat the above mentioned problems I'll try out flatsawn wood.

Just wondering...

The thorie behind all this (QS wood being more stable than flatsawn) makes a lot of sens, but how many builders actually has had a bad experiences using flatsawn wood on their guitars? Birdseye maple, as we know, is always flatsawn and there are a bunch of birdseye maple guitars out there.

I'm not trying to contradict what's been said here, I'm really just inquiring...

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

The only time I've ever had a guitar back 'turn inverted' -ie overpower the bracing and go 'concave' was with a flat-sawn walnut back. (cheap resawn lumberyard wood) .Luckily, the back was just hanging up, not on the guitar, so I took off the braces, checked the humidity and re-did the bracing and glued the back on the guitar.
That was a bit of an eye-opener for me.

But I'm pretty conservative in these things- I still consider sapwood to be something to be trimmed off before building a guitar with a piece of wood.

Cheers
John