Building a mold?

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Telemaster
Posts: 6
Joined: Sun Mar 16, 2014 11:45 am

Building a mold?

Post by Telemaster »

This is the Jumbo kit that I purchased and am about to build.
http://www.martinguitar.com/guitar-make ... etail.html
I am fully aware that I should purchase a mold instead of building one, but I seriously can't afford that as of now and need to get the sides in the mold ASAP. My dad has experience in woodworking and he said he would help me. All I need is some dimensions, what tools to use, etc... Thank you!
JLT
Posts: 296
Joined: Wed Nov 02, 2011 9:13 pm
Location: Sacramento, CA USA

Re: Building a mold?

Post by JLT »

Here's what you need:

http://www.liutaiomottola.com/Tools/Mold.htm

There are many ways of building molds, and most of the better books on guitar-making have descriptions of how to build one.

It's not hard to do, if you have access to a bandsaw and a lot of plywood or particle board that you don't have any other use for.
tippie53
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Re: Building a mold?

Post by tippie53 »

I would advice that you use at least one ply of plywood , MDF will creep a good bit.
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
Telemaster
Posts: 6
Joined: Sun Mar 16, 2014 11:45 am

Re: Building a mold?

Post by Telemaster »

Is there a way to do it without a mold? Which do you recommend and what generally gives the best results? Thank you.
johnnparchem
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Re: Building a mold?

Post by johnnparchem »

The stewmac instruction show building without a mold. http://www.stewmac.com/shop/Kits/Acoust ... structions.

I have seen a lot of posts of kits built this way. You do need an accurate profile of the top, so that you can make a couple of cardboard cutouts.
tippie53
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Re: Building a mold?

Post by tippie53 »

I have issues with inside molds.
If you are experienced you may build without one but to the unskilled and untrained I have seen too many fail for a simple reason. The body geometry get out of whack.
The mold does a few things , 1 it holds the neck in proper position for the neck angle and set. If you never set a neck , having a neck block out of position will make this a nightmare and may kill the desire to build,
2 the symmetry is dependent on the mold. I won't build without one. I am approaching #180 and it is getting easier to hit the perfect set up. You are going to spend 100 hrs to make this guitar and you can make a simple mold to help assure success.
I would rather you make a mold of cardboard that can keep things set up till the neck and top are on. The better you control the details the better the end result. If you make one out of stacked cardboard and use duct tape to make it secure , you can cut this away at the end of the project you will be better off than free building.
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
justrfb
Posts: 217
Joined: Wed Aug 22, 2012 8:17 am
Location: North Jersey

Re: Building a mold?

Post by justrfb »

Hello.
I was in the same exact place a short time ago, saying the same things you are... I would strongly suggest you follow the advice of buy your mold from Blues Creek Guitars, John (he is supplier to Martin for their molds) and build your guitar. I did and it was probably the single smartest guitar building decision I ever made... It will save you in the long run. I can't think of a more important tool to have except maybe a set of nut files... Good luck, it is quite a journey and will more likely than not, be a life time of building for you.

Sincerely,
Rich
jusbroacoustic
Posts: 17
Joined: Mon Oct 17, 2016 10:47 am
Location: Orangevale, California

Re: Building a mold?

Post by jusbroacoustic »

I agree with John. I got a J-45 mold, and had the back and sides bent for me from another company. My sides had a lot of spring back. This became a problem. I had to use spreaders and clamps to make sure they are against the walls of the mold. If you have that problem with an inside mold, i believe it would be definitely change your chances for success.
tippie53
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Re: Building a mold?

Post by tippie53 »

the mold does 2 main things
A holds the shape
B controls the neck block

If you can't do these 2 things your success drops off dramatically
You can make one and if you bought this from Martin there is a side tracing in the box that you can use to make your mold from.
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
MaineGeezer
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Joined: Wed Aug 13, 2014 12:14 pm

Re: Building a mold?

Post by MaineGeezer »

I have built several molds for a guitar, a cittern, and three dulcimers. Getting the mold right makes a huge difference. Given the amount of work involved in building a good mold, John's molds look pretty cheap.
You can manage with a kludgey mold, but building a guitar is difficult enough without purposely adding to the misery.

If you do build your own mold, don't cut corners. Use good plywood, like Baltic birch, and. good clamps to hold it together. You can get toggle clamps from McMaster Carr.
Don't believe everything you know.
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
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