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Private member DiscussionAcoustic Builds

Hide Glue Working Time

I'm using hide glue on this 1st build. So far I've glued up the kerfing, back braces, and the top "X" brace. I'm using the 190 grade glue. Working time is short at best. I heated the top "X" brace surfaces (brace & top) with a blow dryer and that seemed to help, a little. How can I get enough working time to glue the top, and then later the back, without having to rush and creating a real mess in the process? Suggestions and reco…

24 replies
24 replies
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Private member
I make a "hot hut" out of my go-bar deck by draping a large piece of vapor barrier plastic over it. Use clothes pins, or spring clamps to clamp areas shut around it. I then place a small space heate…
Private member DiscussionAcoustic Builds

Back Braces Shape

So the first real "full build" I'm doing is a Stewmac 000 kit. I was wondering about the back brace shape. I'll was planning to taper the ends at the side joint to about 1.5mm. Should I do some scalloping of the braces? Suggestions and comments are welcomed and appreciated. Regards, Gerry Images

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9 replies
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Private member
There's nothing "wrong" with what you have pictured but it lacks some finesse. There are soooo many variables in play to worry about for a first build. If you want to practice some skills in this st…
Private member DiscussionAcoustic Builds

Using Maple for Back Inside Center Seam

I just read a small note in a new OM plan (GenOne) I'm using that suggested maple as an alternate wood for the inside center strip between the back braces. Wondering what would be the downside of that (passive back). A curly maple strip would certainly be attractive, and the mass/ stiffness difference is virtually negligible for a passive back. Thoughts? I'm cutting braces this week...

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5 replies
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Private member
Flat sawn maple is what all the old Gibsons used for a center strip from the 1920's to the 1970's at least. They are something like .900in wide and .040in thick. It had to have been offcuts of their m…
Private member DiscussionAcoustic Builds

Steam Box Idea... What's wrong with this idea?

Speaking of Trevor Gore... I've started using falcate bracing on my ukuleles and in making the braces, 3 strips of .0625" spruce are bent and then put in a bent lamination glue up rig using epoxy. Bending spruce is no fun on a hot pipe. It's slow, fussy, the fibers want to delaminate. I have been thinking about building a small dedicated steam box. Pulling all 3 of the strips out at once and bending them over a form with a metal back…

7 replies
7 replies
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Ian Davlin
I tried it once for trying to bend mandolin sides. This was in 2006, back when the internet wasn't nearly as useful as it is today, so the attempt was pretty incomplete I think. If I remember correctl…
Private member DiscussionDesign and Testing

Raising resonant frequencies of a new build

Initial frequency analysis of this D28 copy (done with a temporary 35g bolt-on bridge and the back plate taped on) is VERY LOW. Main air resonance 83.5hz and top monopole 156.6. It's standard Martin scalloped X-bracing with a torrefied Adirondack top. Since I can still easily access the bracing, I'm thinking of going in and laminating wood on top of the X brace to stiffen it. Other options would be a very light bridge, though I'm not…

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Update: Turns out it's not impossible to raise the frequencies. Removing the 35g temporary bridge raised the air resonance 2.1 hz and top monopole 2.6 hz, so a lighter bridge could help a bit. Fill…
Private member DiscussionDesign and Testing

Tips for measuring and drawing plans?

Hi dear luthiers, I want to build a copy of a vintage Gibson acoustic. Therefore I need to draw a good plan. Do you have good tips of how to measure the guitar, especially the interieur like braces or the back+side thickness? Do you have a certain schedule, that you follow? For the position of the braces I will use magnets. But the height, thickness and profile, how do you adress this? Thanks a lot in advance!

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Thanks a lot fir the links :-)