ORIGINAL: avicom
To give you the idea. This is not a fuselage but the same principle is apply. This is my first attempt doing a mold. Not perfect but I'm happy with the results. There is much more info here. Do a search and you will find lots. In a whole rainy weekend with not much to do I decide to do it. This is the splash of an AW Hawk jet kit flap. I use the original flap as a plug and make a female mold of the LE in order to replicate the Flaps Vanes. Glass stick to the parting board even with 8 coats of wax and PVA. Next time I will use some clear tape or monokote in the parting board. For fuselages after the female molds are made is where it comes what Ed is describing. Wax, PVA, Paint, glass cloth, balsa core and another glass cloth. All this get in to vacuum bag.
Ed thanks for all your tips and posts.
Alex
Hello Alex I see you are having sticking problems. I sometimes only wax 1 time and it still comes apart. It's not really the number of times that you wax it that counts but it's what you do after that makes it stick. I spray paint the waxed part and never brush it with resin or gel coat. The secret is to get paint that dries in a few seconds seconds and dust it on. It can't stick this way. The longer the gel coat stays wet the more chance of it sticking and being rough with the brush doesn't help
If you use PVA properly it will always come apart but PVA "must be sprayed on" in a thick layer like a layer of plastic. Wiping it on is a waste of time.
Jim Fox