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Thickness of sides - electric body

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tv1
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When you make an acoustic, or hollowbody, the sides are really thin - maybe 2mm-3mm.  I guess because you're bending veneers, the strength of the wood is still there because the fibres of the wood are still as long as they were - you've not cut them at all.

When you make an electric, but hollow out some/all of the body, how thick do you need to leave the side walls to retain sufficient strength in the wood? 

My thinking is that, as you cut out the body, you've cut across the fibres of the wood, so there are lots of shorter lengths rather than long, bent, lengths, so the sides need to be thicker to have the same strength.  Or am I over-thinking it?

 

Thoughts please, O wise ones ...

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Robin
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@tv101

When you make an electric, but hollow out some/all of the body, how thick do you need to leave the side walls to retain sufficient strength in the wood? 

I've left about 10mm on this one, I'll let you know what its like if I ever finish it. I'm fairly sure that its strong enough though. I was more concerned about having surface area to glue the top onto.

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Koendb
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I think, the thickness of the sides is probably more important during routing, due to the risk of tear out. Once you managed to route it , the thickness does not matter too much anymore, I think.

Glue area is also almost a non issue; I am currently following a lute building course and we have to glue the back and front onto 1.3mm thin sides with hide glue, without kerfed lining. But that is a very delicate, super light weight little instrument. It means you can get away with a lot of margin.
Have you looked at plans of other hollow bodies to see what dimensions have been used there?

The Gibson CS-356 plan on Electric Heralds' site also  seems to use 1 cm for the sides.

 


   
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tv1
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Posted by: @koendb

Have you looked at plans of other hollow bodies to see what dimensions have been used there?

The Gibson CS-356 plan on Electric Heralds' site also  seems to use 1 cm for the sides.

That's a good suggestion - thanks @koendb

 

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tv1
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Posted by: @robin

I've left about 10mm on this one, I'll let you know what its like if I ever finish it. I'm fairly sure that its strong enough though. I was more concerned about having surface area to glue the top onto.

 

That certainly looks like it should be solid enough @Robin.  Lots of routering to hollow that out!

 

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swepri
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@robin Maybe I worry too much, but is the middle part wide enough to fit the studs for the bridge/tailpiece? If a tune 'o matic bridge is used, that is.


   
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Robin
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@swepri 

@robinMaybe I worry too much, but is the middle part wide enough to fit the studs for the bridge/tailpiece? If a tune 'o matic bridge is used, that is.

I've taken more out of the middle since that photo, but don't worry, no bridge studs on this one, it'll be having fakesby.

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Robin
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@tv101 

My thinking is that, as you cut out the body, you've cut across the fibres of the wood, so there are lots of shorter lengths rather than long, bent, lengths, so the sides need to be thicker to have the same strength.  Or am I over-thinking it?

You're not over-thinking it, you're absolutely correct.

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🙁   @robin

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Rocknroller912
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@tv101

My thinking is that, as you cut out the body, you've cut across the fibres of the wood, so there are lots of shorter lengths rather than long, bent, lengths, so the sides need to be thicker to have the same strength.  Or am I over-thinking it?

I’m just catching up with some topics after being off the forum for a while. You’re not over thinking in my opinion and cutting across wood fibres is a concern. More for long term stability than construction I think. There is a commercial wood hardener that you could paint on the inside create more stability, or you could do a thin layer of glue. My main concern would be the inside drying out causing cracking. For electric I don’t think sealing the inside will affect the sound. 

 

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Robin
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@rocknroller912 

My main concern would be the inside drying out causing cracking. For electric I don’t think sealing the inside will affect the sound. 

I sealed the inside of this before I glued it together. I hadn't thought of it as stopping it from drying out, my thinking was that I was stopping dampness getting in.

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@robin 

Ive found that it’s hard to get moisture into wood unless you soak it totally for a while, and even then some oily woods are impervious to moisture.

Wood turners use Poly Ethylene Glycol PEG to work with green timber, and soak the wood in a 30% solution for about 2 weeks. It replaces moisture at cellular level and stops cracking dur to drying. It’s not used for acoustic tonewoods but should be ok for electrics.

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slot777b06
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