I have made a shape out of jablo, and I would like to use it as a mould in fibreglass, I know that the resin melts jablo, so can anyone tell me what I should use to make this shape?

maybe cover it with plaster? its what the book says...

Not entirely sure about Jablo - am i correct in assuming it is wood impregnated with resin? What resin does this system use? what resin are you using?

You could try spraying it with a barrier layer. Some automotive paints can work well, but test to see the effect on the paint first. Some more detail/photos might help..?

If you have used a styrene based product, then use polyester resin and vis versa if it is the other way around.

Appears that Jablo is expanded polystyrene - therefore not a good idea to use polyester resin as this will dissolve the polystyrene. Use epoxy resin or a barrier layer (sometines coating with pva can isolate (but as said already - check a test piece first).

Put the Jablo into some plaster then use petrol to melt it out and use the plaster as a mould?

ok guys so its like cover the jablo with some form of hardened material..... How about some car body filler? would that work? Photos up shortly...

i would guess car body filler would be much more expensive than ordinary plaster? you can get a tub of like 25L of plaster for £30.

Make your mould with epoxy as has already been said - after checking its ok.

It all depends upon what resin you are using. Car body filler is wonderful stuff (polyester based), and as long as you apply a good wax before moulding, most resin systems will release from it.

we were trying the same with our bonnet bulge car body filler will still melt the jablo so we covered the whole thing with some thick coats of water based varnish then covered then the resin will not melt material as long as you put about 4 coats of varnish on

thats a good one, but what do you use to fill in the small imperfections of the jablo? does the varnish do the job?

we used body filler over the whole thing then sanded back till we were happy did a good jod although we havent got the thing finished yet. after sading painted on some more varnish if we rubbed through anywhere