Questions about fiberglass (hollow part construction)

bmagee · Post by **bmagee** » Mon Aug 21, 2006 7:08 am

I have had some folks recommend to me that when building a large model, to try and cast it using fiberglass and cloth to make the model lighter. I know (in a VERY basic sense) about the process but was wanting to know if anyone knew of a book or online tutorial out there that I can read or study before I attempt it. I know a master and rubber mold needs to be made first of course; but I do not know the process from there. Can any of you help?

DX-SFX · Post by **DX-SFX** » Mon Aug 21, 2006 8:17 am

It depends what you're making as to whether a rubber or rigid mould is required. Figure work can generally be done in rubber. Things that need to retain dimensional accuracy are usually done in rigid moulds. The latter need to be planned for a little more because of the usual problems with undercut and the item releasing from the mould.

Spacephrawg · Post by **Spacephrawg** » Mon Aug 21, 2006 9:21 am

Note: fiberglass is much more toxic. Mix the resin wrong and you get a smoke bomb. That being as it may, you will also need much more ventilation and special gloves, not to mention a resporator, even if you're working outside.

DX-SFX · Post by **DX-SFX** » Mon Aug 21, 2006 12:42 pm

..... unless you use epoxy laminating resin.

Polyester resin does stink and should be used in a well ventilated area, preferably outside. Fibreglass generally is one of those materials you either get on with or you don't. Again a lot depends on what shape you're trying to mould. Never mix up more resin than you're likely to use in one session as it can get hot as it catalyses particularly what's left in the pot. Pouring the excess into a shallow container or cooling the pot with water usually stops the smoking and fumes caused by the misuse of the resin that Spacephrawg was alluding to. There are many on line articles about using fibreglass which a quick search via Google will reveal.

Don't forget if it's a one off and a relatively simple shape, you can use plaster to make your female mould which is probably the quickest and cheapest route for a beginner.