Do you use sealing tape directly on mould coated with PVA? Or mould surface where sealing tape will be bonded has to be without PVA coat?
Thanks,
Mike
It may work either way, but why risk it? I would always go for sticking the tape directly to the mould with no release agents for maximum air tightness!
so when spraying or brushing PVA at first cover tape areas with masking tape… I dont think I will be able to place the tape exactly on the border of PVA/non PVA surface. If the resin will come close to the tape it will stick to the non PVA surface right?
NEVER put release agent on the bagging tape area. That’s just asking for trouble, especially with infused parts or molds going into the autoclaves.
Mask the line the most accurate you can, then overlap your tape onto the PVA by just a small amount, at least then you will have some 75% of it on a good sound surface.
Thanks for info… I think this is why I always have some mysterious leaks.
Do you think this goes for semi-perms aswell? The tape seems to stick ok.
I get some too, It would be good to know some methods of tracing them eh? I’ve tried sealing the outside of the bag against the mould and the pleats with an extra gunable sealant on top of the tape and sealing the back of the mould, still losing vac though.
Semi-perm is a release agent. So, yes. The bagging tape will “slip” in any area that the bag pulls too tight.
I had found some nice bag tape … it is grey butyl tape for metal building panels. You can buy this tape for around $3 a roll and it works better than the black AT200.
But yes do not use mold release on the areas where the tape goes. I noticed the black sticky tape won’t stick at all to pva. don’t ask how i know 
it will stick to pva… but pva…won’t stay on the mold 
i spray pva everywhere, then wipe the perimeter around with a damp cloth. i thought about masking it instead, but since pva builds up a membrane, im afraid i might pull more than the tape…
I don’t understand.
Why would you pva before applying the bagging tape?
What is easiest is to place your tape down (leave the “paper” on it) then apply your release coating. The protective “paper” will prevent any pva or wax from getting on your tape. you can then do your layup and bag with no worries:)
Just my 2 cents
2capt.ken: that’s exactly what I’m going to use ;). I’m also ordering Frekote semi permanent release. I want to save time end work.
2aga: I think same. If the PVA is sprayed over tape and dried, it can be problem to untape it without damaging PVA layer.