So, I've been asked to do a "how to" on GRP mould making... Well I'd seen an asking for under tins on the type 4s... now as I thought it turns out that there is more than 1 pair... looks like there is 3 pairs, Bus, 411/412, and Porka 914 might be more, but that looks to be it at the mo So I managed to loan 2 different sets (bus and 411) First off I started by stripping them back to bare metal Squirted on some primer Followed by some 2k black Once dried you give them several coats of a mould release wax, buffing between coats Mask up the holes and round the edges Next you use a bright gelcoat so you can see thin patches when you're applying gelcoat for the manufactured part Once the gelcoat has cured off to a tacky hardness, you can start applying the chopped strand matting I started with some 100g, nice and fine for the first layer Then some 300g I finished it with a layer of 100g to give it a good bonded layer curing off Then you leave it for 24hrs - longer for bigger parts... ideally you want to leave items about a week to fully cure off so they keep the parts shape... One mould - just needs trimming, polishing and waxing.... new moulds need around (I think) 15 coats of wax before you use them...
there's more than one type of type 4 van lower tin - depending on uk/us variant and the exchangers you have.
I thought that might be the case... FI exchangers are completely different Will have to keep my eyes open for some more parts to copy
yep the f.i ones with the afterburner multi section exchangers with the loads of joints and the "triangle" 3 bolt joins are a pain to get bits for, james - greenwesty off the site has them like me although he has the bottom tin in place unlike me - he is collecting euro spec parts to convert to that version as they are less complex.
i'm 99% sure i've secured a set of the correct california spec' lower tins today - just waiting pictures and i'm happy - i've got the flaps and now just need the thermostat and cable and we are all standard.
Hard to get hold of then?? Show us the pic when you get it Dash top - smoothed out the speaker holes In primer just needs a bit more fettling, and another coat of primer, and I'll chuck some top coat on ready for taking a mould from it!!
Hi Paul, I'm sure you have it covered but you might want to beef up your moulds a bit. It's recommended that they are at least three times the thickness of the finished part. This will add longevity to the mould if you plan to pull a few off. Also, another tip is to double gel the mould to give it a thicker surface as it takes a hammering when you use it over and over. Some folks like to use two contrasting gel colours so they can tell when they are getting wear on the mould as the contrasting colour begins to peak through. Nice job though, I know how much work it takes. I had thought about doing the same at some point as I use GRP a fair bit! Nick
Thanks for the tips dude I have done double thickness gel, but just in the one colour... shouldn't see much wear as they are a small part 8)
Well I'm currently waxing the moulds for the tins, so first parts aren't too far off!! 8) Dash top is on hold until I'm next spraying some primer as it needs a little fettling
