Mold Making Procedure?

[1968gtcs]

Ok, I'm getting closer to having my 1701-d 3D computer model to CNC a 6ft body buck and I'm wondering what the best procedure is to make a production mold that I could use to lay out clear gelcoat and fiberglass on. I saw the guy that did the voyager molds and wanted to know what you guys suggest......I have a lot of undercuts (biggest concern is rim section on the saucer) and was thinking that a straight up fiberglass mold wouldn't work. If I use the moldmax silicone method, I'm just afraid that its going to sink in the middle and warp the final product. Thanks for your time!

[erospawn]

The Undercuts are going to be the difficult part, depending on how deep they are. For something that big, you might be able to use the brush on rubber from Smooth-on.. I think something like Moldmax 30 might be good.. the brush on kind is thickened already.. Or you can get the liquid version and add Thyvex, a thickining agent.. But thats something you'll have to play around with. I'll leave the expert opinions to the guys who've done a lot of this...

[427 Cobra]

Fibreglas won't be the problem if you're making a two part mould. You just want to make sure that the mould has a jacket strong enough to hold the silicone weight when pouring the mould resin in. Use fibreglas for the shell of your model so that you won't have to pressurise your resins. This will allow you to make a model without having to buy all kinds of expensive equipment.

As for the undercuts, I suggest putting very thin styrene over them if you can, then cut them out after moulding. It depends on how many you have, but if this is not a production model, then I wouldn't worry about that as you'll only need to do it one time.

~ Cobra Chris

[JAWS]

Check out http://www.smoothon.com They have some great tutorials. You may see whats in your head.