# Acoustic Build: Tonewood Issue??



## Antz_Marchin (Mar 31, 2006)

I'm a little concerned with my Walnut back that I recently purchased and thought I'd ask if it's a big deal. 

The wood is beautiful with great figure and a hint of sapwood showing at the seam. The only issue that I have is that the 2 plates are slightly bent from end to end which isn't a big deal, but they are bent in opposing directions. So, for example when I lay them on top of each other with both "outside" faces facing upwards, I get a shape like this --> )( where my spruce top is very nice and flat and stacks perfectly flat --> || 

I tried clamping the plates on my gobar deck + with cam clamps for 24 hours with no luck. I just worry that when I go to glue the plates together, they will really resist and I will have a difficult time making contact at the seam as the right plate curves in a slight "U" shape while the left plate is slightly curved downwards in the same shape. 

I'm just wondering if this is going to be an issue as I've generally only seen very flat tonewoods for building. Thanks for any advice.


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## Mooh (Mar 7, 2007)

Why not bend them with steam, hot water, wet towels, bending iron, whatever, then use the go-bar deck?

Peace, Mooh.


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## Lab123 (May 27, 2007)

I have glued together boards as you have described....Don't worry about it. I prepare the edges and glue them together and clamp them to a piece of plywood with waxed paper separating the glued edge from the plywood. It should come out ok.....When you install the bracing you will never know it was warped.....Before you glue on the bars test clamp them on and see if it will be ok.....If you are not satisified go to plan B.....You can always break the glued joint after and reglue it .....I have found that when you steam or even wet these boards you might not like the results..... and you might......Lab


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## Antz_Marchin (Mar 31, 2006)

Thanks guys. I've got them sitting flat under a bunch of gobars and I'm gonna leave them there for 48 hours then hopefully joint them right away. Yeah I don't mind bending sides obviously with heat/steam but I don't like the idea of steaming my back plates.......could get kind messy.


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## WarrenG (Feb 3, 2006)

Throw 'em in the oven between two pieces of flat stoneware...


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## Antz_Marchin (Mar 31, 2006)

WarrenG said:


> Throw 'em in the oven between two pieces of flat stoneware...


Really?? Cool, thanks.

Any time/temp guidelines to follow?


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## WarrenG (Feb 3, 2006)

Antz_Marchin said:


> Really?? Cool, thanks.
> 
> Any time/temp guidelines to follow?


I watched Sergei de Jonge do this. I suspect that 150-200 F will do the trick because any higher will probably scorch the wood. Try leaving it for 1 hour and then turn off the oven to let it cool down naturally. I would spritz the wood with water too as the oven will dry it out and shrink it a bit.

Alternatively, if you have a bare, flat concrete floor, spritz the concave side and place it down on the floor with a weight on top. Leave overnight. Should be flat by the morning. 

Try the latter method first, if you can.


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