MIMF

I picked up an East Indian Rosewood set on fleabay that was evidently a reject from Martin for a pretty good deal. But the sides are really thinned down, at about 1/16th of an inch....thus the very low price. Would these still be ok for an OM, or is that too risky? Alternatively I am planning a classical build down the road....and might try my hand at a harp-ukulele in the future. What do you think? Try it on the OM, hold for the classical...or use them for the harp-uke?

I guess it would depend on the sides. I've seen guitars ended up with sides that thin that were fine, but usually you end up taking same material off in the process. The kicker is, how much? If the sides are well quartered with no run out they should bend well and end up pretty flat, with no ripples. If there's significant stripe figure or they're skew cut you could end up having to take a fair amount off to make them smooth. Some customers will not put up with wavy sides, although others will.

My inclination would be to put those aside for a smaller box; an 0 or 1 size. The curvier shape will help minimize problems, and add a lot of stiffness.

I'm certainly no expert, but wasn't there a thread just a bit ago, talking about using veneer to thicken and stiffen the sides?
Would that add enough thickness?
That is an honest question by the way; as I said, I'm no expert.

Thanks guys for the responses.

I don't think I'll risk it on a steel string. I'm not experienced enough to manage outside of the normal parameters. I'll just order another set of sides only and try to match up as best to the back as I can.

But, do you think it would be ok for either a classical build, or potentially a harp-ukulele or a even a miniature harp guitar based off a sort of 3/4 size or 2/3 size version? Potential cupping issues aside during the bending process, is there a sort of linear correlation between the side thickness and the size of the box?

Incidentally, is anybody aware of someone who has built a mini harp guitar? I've always thought it would be fun to build one, but thinking a scaled down version might be fun to have around the house. The standard size just seems a bit unwieldy due to size. I was thinking maybe of taking a standard set of plans and just scaling to a smaller size.

A couple of years ago I built a small harp guitar, with the box based on my own version of a Martin 12-fret size 1. The lower bout is 13" wide. The customer wanted a guitar he could carry on, so it folds up to go into a 22" x 14" x 8" box. The construction was pretty complicated due to the need to fold it, and I doubt I'd do that again without a strong incentive ($$$). It worked out far better acoustically than I had expected. You can catch a video of it at Ken Bonfield's web site: the obvious URL. And, yes, it really does sound like that.

The sides on that are walnut, and quite thin, but it worked out fine even with the extra tension.

Pete, we require the use of full names on the MIMF. Can you go to your User Control Panel and make that change? Thank you.

There's a good book on classical guitar making in which the guy makes two veneers for the sides. The method would work for your situation.

http://www.jsbguitars.com/classical-guitar-making-book/

Amazon has the book much cheaper: https://www.amazon.com/Classical-Guitar ... 1402720602

Sorry Barry! I think I have it now!

Alan Carruth wrote:A couple of years ago I built a small harp guitar...

Very nice Alan! Sounds great...but to your point, looks like a pretty complicated build for sure! I'm thinking more along the lines of a Dyer style and using those existing plans to get me most of the way there.

It is a complicated build, but the extra soundboard and chamber really make a difference in the tone.

Alan, how does that harp guitar fold?

The neck of the harp guitar simply plugs in at the heel. There are a couple of locator pins at the top, and a bolt through the heel runs into a T-nut inside. The neck is held on by string pressure.

I use a secondary sound chamber at the top of the arm. The arm breaks just at the lower end of the secondary chamber. Again, there are pins to locate it, and an over center catch on the back side of the arm holds it against the string tension.

Because of the way the locators on the neck worked out those strings have to be slacked off to fold it. Once those are slacked off a bit a capo is put on the neck at the first fret to keep the strings from falling off to the side and getting mixed up. Similarly, there are sharping levers at the upper end of the sub-bases which hold the strings when engaged. A Velcro strap in put around the arm at the joint, and also at the base of the neck, also to hold the strings. The instrument is flipped over on it's face, the neck bolt is removed and the over center catch is flipped to release the arm. Then the instrument is turned upright again, and the neck and arm are folded up on top of the body. The whole unit is lifted up and placed in the box with the body on the bottom, the neck to one side in brackets, and the upper tone chamber fitted above the body. Note that the harp strings don't have to be slacked off to fold it, and they will be very close to in tune when it's reassembled. The over center catch has plenty of leverage to pull them up once it's engaged.