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Need the help of those of you that have seen it all. I bought these three sets of Macassar Ebony B&S over a year ago. The wood was extremely wet and I was aware of that but didn't plan on using it for a couple of years and got great deal on it. I stickered these for about six months until it seemed dry and I was running out of space. I had these lying flat under 50 lbs of other tonewood for past six months but not stickered. I pulled them out tonight and all three back sets twisted immediately just like you see them now but sides are straight as an arrow. Can these be straightened or are they a lost cause. They are beautiful sets and I hate to lose them. I appreciate any help I can get. Thank you guys in advance.

http://i1195.photobucket.com/albums/aa3 ... 0_1349.jpg
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http://i1195.photobucket.com/albums/aa3 ... 0_1348.jpg

All three sets were cut from same billet at same time and they all three twist in exactly the same way. These are severe twists. Using substantial force or alot of weight I can flatten them out but as soon as I let go or remove the weight the backs immediately spring back into this severe twist. These are some really beautifully figured sets and I hate to think that they are gonners. Because all three sets twist exactly the same I almost think it is memory in the wood fibers itself but I am as new to this as anyone. I really want to flatten out and use thes backs to make some really eye candy classicals. The wood is definitely "zoot" material. Please help with any advice except tp burn them. Thanks again.
Anthony

Not seeing how bad it is twisted, it's hard to tell. Sometimes iron it with a clothes iron. If you have two heating blankets, you can lay them down on a flat surface and set up like to bend sides, but just leave the set up flat and weighted.

PS Never heat wood with wax on the ends. The wax will liquify and run into the wood just like water, and never come out.

Links to photos are now working . Thanks

Bend a set and see what happens. I had a set of flatsawn Birdseye maple that did the same thing, I bent it in my side bender, let it "cook" at 275 degrees F for a half hour per Todd Stock, let it cool overnight before removing from the machine, it's still the correct shape with no twist. I use the John Hall "slat, wood, slat, bending blanket" method, so the wood is supported on both sides by the steel slats.

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Old growth, shmold growth!

I have used wood like that before. Thin it as much as possible before joining. Clamp it between two flat boards (like plywood) to joint the edges.
Gluing the back braces on at full height will help.

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John

That is so twisted, it's going to be next to impossible to thin it.

It's always a judgement call but you have 2 large strikes against this wood, maybe three. One is that it appears to be reaction wood. Two is that it appears to go from rift to flat to rift. Three is that ebony tends to be less dimensionally stable than most other back/side woods.

From appearances, I would not use it.

If you want to try anyway, I have had success flattening wood with a heat press. Clamp it between two flat pieces of metal, one piece at a time, heat it to 275 F or so and let it cool slowly. Repeat. If it stays flat after 2-3 cycles, it may be OK.

Give it a few weeks to acclimate before bracing if you go that route.

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http://www.chassonguitars.com

No way.
Sorry....

Sometimes the wood will relax if it is cut down the middle or near the middle of the flatsawn section and rejoined with the rift sections glued together. The new flat sides can then be joined to make a four piece back.

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

As an example of how well heating might work, I fixed a fingerboard blank 30 years ago. It was about 3/8" think, irregular thickness and corkscrewed a bit. I clamped it between hot steel plates and then continued to heat it in the oven for a long time and then let it cool for a few days. I don't think the exact way to heat it matters, as long as you have a way to press it and get it hot all the way through. Clamps rusted a bit, but are still usable. The board came out dead flat. Thicker areas were squeezed down and then bulged out the sides. After the process, I left the board laying on the bench for a few months. It never showed any sign of twisting. I used the board and I still have the guitar. The fingerboard never showed any sign of bulging all these years and the neck never warped.

For your backs, I think you wil find that proper heating and pressing will affect the fibers the same way as proper heat bending of sides. The natural fiber system will melt and then conform to whatever shape you hold it while it cools.

Thanks for all the advice guys. This wood is too pretty for me not to at least give it a shot. I'll post after pics

If you want to try flattening it one more time before heating, spritz both sides well with a 50/50 mixture of water and glycerin (you can buy it at a drugstore), sticker it for a day, then repeat the process over several days. Once you get it flat, join, thickness, and bend immediately.

I haven't tried this with wood that thick, but for years I have used a similar process to flatten unruly veneer.

Ken

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http://www.casperguitar.com

One more approach that is a combination of other posts.

I bought a set of BRW that had been left unstickered. The backs were a full 1/4" and badly warped. They could not be flattened by pressure--they would not bend. I was going to set up to try to flatten them. I threw them in a sink of water while I was preparing but then I procastinated. After a a couple of days they were still warped and stiff. After about a week in the water, they returned dead flat and I stickered them and weighted them, and they seem to be OK. You said that yours were intitially flat after drying, but warped even under weight after additional drying. Perhaps you could soak them a week or so to get them to return to flat. Then sticker them as you did before until they reach a reasonalbe dryness, as you did before. Now thin them to finish thickness--maybe join them first. At finish thinckness, I think you will find that they will be flexible enough to lay flat under weights until you are ready to use them. Even if they spring when you eventually use them, at finsih thickness, they will be flexible enough to brace and the braces will stop the flex. An advantage to this approach is that if you have wax on the wood, you will not melt it into the interior grain. Also, if you do not have a heat press, you can try this.

I have on more than one occasion straightened thick walnut by complete submersion in water. The pieces I had actually straightened while under water for a week or so. It probably would not tske but a few hours underwater to completely rehydrate(but I would leave it a week or two-checking daily for condition), then maybe sticker a few days to halfish dry, add some heat(heat with moisture), I think you can considerably improve those pcs. It is hard to have an exact recipe, maybe you could try one set at a time-
wish they didnt look so flat sawn, kind scared on end checking on rehydrate/dry-
I have also clamped across width on end when I saw a check starting to form- might not hurt to preload the ends the 1st week of redrying because of the flatsaw
If its finally flattish, let it sit for a year or so and see how it behaves-

It is all waste it you don't build with it!

I have received several soaking wet sets in the past, and one thing I did was to immediately sticker and weight them and more important wrap the entire pile in plastic (save a few small holes to allow for a tiny bit of air exchange) for several months. They all came out dead flat. They were so wet that letting them in the open air would produce a continuous crackling noise when putting the ear on the wood. Several months later they were like 5mm narrower.

Yesterday I received another relatively wet set and it took me a while to get to stickering it. I left it around the dry shop for a few hours and it turned into a propeller too. I can flatten it with not that much hand pressure (it is both large and thin) but I am quite upset as the wood is superb. So far I wiped it with a damp cloth and stickered it wrapped in plastic. I might add more water in the following days then wait for a few weeks and see what happens.

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Build log

I have used wood much more twisted than that. Once thicknessed and braced then put on a guitar it will hole the postion . You can heat it before joining the plates and bracing to help "bend" it flat . Wood does funny things sometimes

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Well I heated the sets individually between two heating blankets and a press for 20 minutes. I let them cool completely before I removed them from the press. All strait as an arrow right now and holding. Will sticker and weight them and hope that they are still straight a month from now. I appreciate all the advice and will let you know what they look like in a month.
Anthony

Good news!

That's what I've been thinking right along but I don't have the experience to confirm it. Thanks for that tid bit.

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Hutch

Get the heck off the couch and go build a guitar!!!!