Acoustic Guitar Construction

Ken,

Thanks for clarifying your previous post regarding making the half-template to fit the sides as-is per their current "mis-shape." Whether this was caused by a poor bend or relaxing of the sides, I don't know.

And copy that with respect to your concerns about forcing the rims to fit the mold--I'm not crazy about this approach either. Not sure what potential problems will arise, but I'm sure there may be some.

To this end, I may reconsider my approach and either: 1. create the half-template to fit the sides as-is and adjust the mega mold accordingly or 2. have the sides bent again to fit the 000/OM shape exactly as I'd intended to build, as per the LMII template.

It's worth noting that I purchased the rims and back from a 3rd party off EBay who (allegedly) gets his kits from Martin, though I can't confirm this and have no way of knowing how long the sides might have been sitting freely without a mold after being bent before I received them.

If I were to re-bend the sides, do you have any suggestions or concerns with respect to increased fragility or other issues in re-heating and bending previously bent sides, or is it no different than if they were still flat?

Signed

Aspiring Luthier in Study Just Trying to Get it Right

Ah hah! That might explain my problem. I'm sure glad you're knowledgeable in all these matters. Let me circle back with the seller and see if I can confirm and clarify that the shape was bent at Martin -- I received no template from the seller, so purchased the LMI template after the fact. I'll also confirm which LMI template I did purchase and post both bits of info here to clarify and continue trying to move forward in the best manner. Thanks again.

-Kelly

Just wanted to follow up with my solution to this issue of the Martin OM sides not fitting in the mega-mold when I had it set-up using the LMI OM template--ie there were spaces between a number of the posts and I tried various ways to force the sides to fit before I came to my senses. As Ken correctly surmised, the LMI template is simply a different shape than the shape of the bent Martin OM sides.

So after trying to force the sides to conform by adding two additional spreaders to the mold, I took the better route and ditched the LMI template and then I did what I'd wanted to do all along in trying to build the earliest version of Martin's OM-28--I created a template and then a half-template using Robert Corwin's tracing of his early 1930 OM-28.

I pulled his tracings into photoshop, shaped it up per his dimensions on length and width of the bouts etc. (because it appeared that he'd taken a photo of the tracing and so it was slightly distorted), had the plan printed, then used spray adhesive to affix the plan to masonite, then jig-sawed it out and sanded it right down to the lines on the perimeter, halved it and used one half to re-set-up the Mega Mold. And wouldn't you know it, the sides fit in much, much better, with 90% of the rims flush to the posts with only a 1/16" of an inch or so between two of the posts on each side--which I'll adjust in equally on both sides--as I now proceed to glue in the neck and tail blocks.

I've attached a photo showing the sides cut to length and fitting better in the mold and a pic of the OM template affixed to and cut out of the masonite. I appreciate all of your input.