Stewmac OM kit - Issue

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phavriluk
Posts: 665
Joined: Mon Jul 09, 2012 9:49 pm

Re: Stewmac OM kit - Issue

Post by phavriluk »

Kevin Sjostrand wrote: Thu Jan 15, 2026 11:11 pm Make your mold. Strace the outline of one half of the pattern and make a template on some 1/8 or 1/4 MDF or plywood. Use that to make your pieces for the mold. If you have a router table you can make pretty quick and accurate work of it.
You make one piece and make it as perfect as you can to the shape. cut the other pieces a tiny bit outside the line (oversize)
Attach your perfect piece to the others and use a flush cut bearing router bit to make them all the same. if no router then you have more hand work to do but it can be done.
you won't be sorry making and using a mold. if you purchase a mold it may not match your bent sides anyway. Not all OM shapes are the same.
there are different ways to make the 2 halves of the mold fit together, as it needs to be able to separate.

I just made this Jumbo mold from scraps of particle board and pine planks. I have other molds I've made from plywood and mdf.
They all work.
Make yours 3 or 4 layers tall. either will work.
Go for it you can do it you will be much happier with the result than trying to use that inside cardboard form . I know I tried it on my first build, a kit and promptly made an outside form!!!
So what to copy to generate the shape of a mold? The pre-bent pieces are very likely not precisely bent and would need to be clamped into a mold in order to conform to the as-designed shape - - - which is what? Perhaps the S-M cardboard cutouts could be the source.
peter havriluk
Kevin Sjostrand
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Location: Visalia, CA

Re: Stewmac OM kit - Issue

Post by Kevin Sjostrand »

Well in his picture the sides are pretty close to the plan profile.
I'd use the plans
jread
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Re: Stewmac OM kit - Issue

Post by jread »

I've always used a mold. I made my 1st ones but found that John's from Blues Creek Guitars were a lot better than mine. My only other comment is that I don't think it matters all that much if the line of your sides doesn't match the intended mold exactly. Sure, that's the goal but I've had all sorts of issues where the sides were a bit off from the mold and the guitars all look and play great. Of course, you don't want it to lean over or look skewed just saying that it's not critical for that to match the plans exactly all the way around.

If that were my build, I'd say that was great and close enough to the line. Nice job.
phavriluk
Posts: 665
Joined: Mon Jul 09, 2012 9:49 pm

Re: Stewmac OM kit - Issue

Post by phavriluk »

Kevin Sjostrand wrote: Sat Jan 17, 2026 9:48 am Well in his picture the sides are pretty close to the plan profile.
I'd use the plans
Thanks, Kevin. I forgot that part about there being plans.
peter havriluk
JLT
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Location: Sacramento, CA USA

Re: Stewmac OM kit - Issue

Post by JLT »

The only issue I see with not conforming to the pans is if you're going to shop for a guitar case. A guitar with thicker waists might not fit an off-the-shelf case.

But before you pull the trigger and buying or making a mold, and if you live close to another hobbyist, you might be able to borrow one. And if you decide that building guitars isn't for you, you won't have that money and time invested. I, for one, have several molds that might work for you. But I live in Sacramento, California, which might not be convenient for you.
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