Official Luthiers Forum!

Im starting a new body mold for several reasons - I dont really like the solid MDF mold I ended up building in the first place. First off I dont think that the MDF I bought is as nice as the other MDF I see here in other photo essay's - mine seems rougher, w/larger chips and more prone to crumble that other boards Ive seen in photos here at the OLF.
I plan on keeping my solid bending form because I plan on sealing it
{ should I use high temp engine paint for this?} which should help quite a bit {whatever I decide} with crumble.
I plan on making the new mold from 2 x 3/4" baltic birch top and bottom, with hardwood spacers.
{Is hardwood necessary as a spacer block what do you use?}
Its the type I planned on originally after seeing them in J Kinkades book and I should have followed through on my intuition.

How tall do you guys generally make them incl the ply?
{if they are lying flat on a table say}
This will be for a Grand Concert size instrument, I would like to get some opinions because I unsure as to how much of the instrument should protrude etc - I didnt take any notes when I was reading through Kinkades book, which I should have.
If any of you guys had some photos that would be a great help also.

Thanks alot
Charliewood

I make mine almost as tall as the sides. I only have a little sticking out on each side. I also screw my end blocks into the mold during construction.

_________________
Brock Poling
Columbus, Ohio
http://www.polingguitars.com

Not a whole lot of experience here, but I've made mine about 3 inches high (4 layers of 3/4) and they seem to work. I've used solid ply or MDF or 'Medite'TM which we get up here in BC, or whatever is around the shop in the scrap pile from salvaged cheap office furniture, etc...

The 'spacer style' seems like a lot more work than necessary if you have a good bandsaw.

I also don't see the point of the 'big rectangle' style which is popular as well. The things are heavy enough as it is!

The cutouts can be stuck together to make the basis of a solid bending form- but you have that covered already.

I haven't seen a posting from the owners that the picture uploading is working, so the pics from me will have to wait for the future.

Cheers

John

I've made several molds but the one I like best is shown below. It sort of tapers to follow the body taper. It also has indexing holes for the top and back in it, some additional holes to loacte it in my rim sanding fixture and tapped holes for threaded studs for top/back clamping. The piece setting off to the side is my clamping caul.
This mold is a combo of baltic birch and MDF.

Like every else I can't seem to post the pic. If youd like I'd be happy to post it later.

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Jim Watts
http://jameswattsguitars.com

Im bumping this so hopefully we can get the photos posted - Id love to see some examples - Ive dug archives a bit but Im sure there are some exmaples Im missing.
John {or others} doesnt access to the sides come into play at all - as could be done with the spacer style mold?
Anyhow I hope we can get this picture thing sorted out so more ppl will put up guitar porn again!
Cheers
Charliewood

Mine are all three layers of 22mm MDF. Enough to hold the sides solidly while leaving space for sanding both rims in a dish without having to move the disk at all. A shot of mine, just missing a layer, a roundover treatment on the outside, and a bit of paint: