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 Post subject: Internal spreader?
PostPosted: Sat Feb 06, 2016 3:56 pm 
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Koa
Koa

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Working on my first ukulele. How do you spread the sides in the form when attaching the top and back, so that you can get the spreader out later?


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 Post subject: Re: Internal spreader?
PostPosted: Sat Feb 06, 2016 4:18 pm 
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Old Growth Brazilian Rosewood
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I have no clue and have never done this.

But it seems to me that with a uke you could use miniature, conventional guitar spreaders, install the linings of a thickness and stiffness to lock the rim in the proper shape, let dry, remove spreaders completely and then install the top or back depending on your preferred order.

Just guessing though.

I'm interested in an answer from someone who has done this though - great question.



These users thanked the author Hesh for the post: wbergman (Sat Feb 06, 2016 4:52 pm)
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 Post subject: Re: Internal spreader?
PostPosted: Sat Feb 06, 2016 4:55 pm 
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Koa
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I already installed laminated linings that did not spring back until installed on properly spread sides, and not there is a little spring back. Maybe not enough to matter, but I prefer not to have it.

I am leaning towards using a stick wedged in with a little wedge and have a stout string tied around the stick. After all done, yank the string to pull it loose. But, I have never done this before.


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 Post subject: Re: Internal spreader?
PostPosted: Sun Feb 07, 2016 11:55 am 
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Cocobolo
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I recently assembled a kit guitar whose instructions said to make up a solid square spreader stick and make a pair of offset cuts top and bottom more than halfway through, one on the top, the other on the bottom. When the spreader is no longer needed, reach inside the sound hole and flex the stick towards the open space inside and it will break between the cuts, and remove the two pieces. Worked just fine.

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These users thanked the author phavriluk for the post (total 2): pkdz (Thu Aug 04, 2016 12:32 pm) • wbergman (Sun Feb 07, 2016 12:59 pm)
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 Post subject: Re: Internal spreader?
PostPosted: Sun Feb 07, 2016 3:18 pm 
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Old Growth Brazilian Rosewood
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I'm going to be talking to Herb David the guy who introduced Dan Earlewine to Lutherie tomorrow. Herb is a good friend and kind of like family to Dave and I and I will ask him what he did. He built hundreds of ukes along with guitars and we still have all of his molds and forms in our shop.

More to come.



These users thanked the author Hesh for the post: wbergman (Sun Feb 07, 2016 3:19 pm)
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 Post subject: Re: Internal spreader?
PostPosted: Sun Feb 07, 2016 5:56 pm 
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Koa
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My question is: Why would you need to attach top and back at the same time? Given the potential difficulty of removing spreaders, why not just use them with the sides in the external mold to attach the top. Then remove from the mold and attach the back without the use of internal spreaders?



These users thanked the author cphanna for the post: wbergman (Sun Feb 07, 2016 8:24 pm)
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 Post subject: Re: Internal spreader?
PostPosted: Sun Feb 07, 2016 8:24 pm 
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Koa
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I was anticipating that if I attach the top with a spreader in the mold, then when I remove it, the sides would splay in a little towards the back before I attach the back. I think it is no different than a guitar--just smaller. But I might be worrying too much.


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 Post subject: Re: Internal spreader?
PostPosted: Mon Feb 08, 2016 12:24 am 
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Cocobolo
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Without going into detail on the "why" (it'll be the same reason for guitars - keep the sides square), I use turnbuckles (marine supply) for the spreaders. They're inserted in grooves in the cauls, so they can be "pulled" out of the soundhole. Why turnbuckles? Its how I was taught. And it works, even in the lower bout.

FTR - I also run them heelblock to tailblock. It gets pretty crowded in there. . .



These users thanked the author Aaron O for the post: wbergman (Mon Feb 08, 2016 6:21 am)
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 Post subject: Re: Internal spreader?
PostPosted: Mon Feb 08, 2016 2:01 am 
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Contributing Member
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Just scrap sticks stiff enough to hold with a little flex and light enough to break out work fine.



These users thanked the author Pmaj7 for the post: wbergman (Mon Feb 08, 2016 6:21 am)
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 Post subject: Re: Internal spreader?
PostPosted: Tue Feb 09, 2016 12:59 pm 
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Koa
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I use a small turnbuckle and two wood blocks at the ends. The blocks are shaped to fit the side curve and have a hole drilled in so the turnbuckle won't slip out. Just be sure the blocks will fit through your sound hole and you can reach inside to loosen it



These users thanked the author Quine for the post: wbergman (Tue Feb 09, 2016 1:46 pm)
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