Hi,

So I am making some rather large car parts with vacuum infusion. Due to the shapes, the moulds are split into several pieces, bolted together.

What eludes me is what is the best way to achieve an airtight seal when assembling the mould ?

On my first try I used a fairly generous amount of silicone sealant on the flanges. This worked OK, airtight seal, but was a heck of a job to take apart again after, breaking the silicone was very hard. I had used 6 coats of easylease release agent all over, but the silicone stuck to it very strong.
On my second try, I used a rather less generous amount of silicone .. and I just could not get an airtight seal.

My third attempt is coming up soon and i'm looking for any advice from those that have done this before. Would PVA on the flanges where the silicone will go work ok ?  I've only really used easylease so not much experience with PVA.  Is there a better solutiuon than silicone ? The moulds are already made so I can't sink a trench for a proper rubber seal.

thanks in advance,