Epoxy and cling film

[aitchem]

Hello,
Will expoxy resin stick to cling film..?
I am making a moulding from epoxy/filler, and no time to wait for the postie to bring me a pukka release agent.


thx
Howard

 

[Seajet]

I've never tried it but suspect it would stick; off the top of the head, would vaseline make a release agent ?

 

[earlybird]

Hello,
Will expoxy resin stick to cling film..?
I am making a moulding from epoxy/filler, and no time to wait for the postie to bring me a pukka release agent.


thx
Howard

Never tried cling-film, but parcel tape, the 2" wide brown stuff, works well to prevent epoxy sticking.

 

[gjgm]

Hello,
Will expoxy resin stick to cling film..?
I am making a moulding from epoxy/filler, and no time to wait for the postie to bring me a pukka release agent.


thx
Howard

It wont stick to plastic sheet, if that helps?
I think cling film is a bit too flimsy

 

[colingr]

A good coating of a hard car wax works.

 

[aitchem]

Excellent.!
I have that in the garage guys.
I will try Parcel tape coated in Carwax.

thx v much
Howard

 

[penfold]

I have used cling film to retain araldite; it does not stick, but is finicky to remove if you leave it on after the epoxy has reached the 'rubbery' stage, especially if it's wrinkly.

 

[electrosys]

Epoxy won't stick to Polythene sheet or Sellotape, if that'll help.

 

[flipper]

Hairspray works as a release agent. Got it out of the West manual. I kid you not.

 

[tom_sail]

All the realise agent is, is PVA glue. The mould will separate with the pva glue a bit like when you peel it from your hands. Polish of the pva glue from the finished product. Also mix some food colouring with the pva then you can see where you have missed.

 

[Lakesailor]

Excellent.!
I have that in the garage guys.
I will try Parcel tape coated in Carwax.

thx v much
Howard

No need for the wax. The shiny side of parcel tape is totally non-sticky with epoxy. Made moulds with it.

 

[Pye_End]

Cling film with vaseline works. Havn't tried it without the vaseline.

 

[rakaaw]

All the realise agent is, is PVA glue. The mould will separate with the pva glue a bit like when you peel it from your hands. Polish of the pva glue from the finished product. Also mix some food colouring with the pva then you can see where you have missed.

This is not correct. PVA adhesive is not a release agent.

 

[tom_sail]

This is not correct. PVA adhesive is not a release agent.

You can come and inspect a fibreglass tender I built at a professional boat building workshop if you like? Popped straight out the mould no troubles. The chap has been using pva for years since it's much cheaper then release agent.

Now I have never used cling film but 5 layers of bees wax then a thin even coat of pva has worked wonders for me every time.

 

[PuffTheMagicDragon]

PVA adhesive is polyvinyl acetate whereas PVA releasing agent is Polyvinyl alcohol. Not the same thing at all.

 

[Richardsix]

All the realise agent is, is PVA glue. The mould will separate with the pva glue a bit like when you peel it from your hands. Polish of the pva glue from the finished product. Also mix some food colouring with the pva then you can see where you have missed.

You will get a better finish if you water the PVA down, I generally use a 50/50 solution, has worked for me for the last twenty years and yes, a dash of food colouring works a treat. I only use PVA if the mould has a poor quality surface finish.
If you dont want to go this route, use a good quality wax, such as Simoniz service station pack or Mequires Mirror glaze, be sure to apply at least five coats, polish off and give time between coats for the wax to harden up, you can check easily when the mould is waxed enough with a small bit of sticky tape, lay it on the mould and pull it away, no resitance = ready.
Hope this helps a little, may get shot down in flames for my advice....just my opinion in over twenty years of working in composits.

 

[Richardsix]

PVA adhesive is polyvinyl acetate whereas PVA releasing agent is Polyvinyl alcohol. Not the same thing at all.

Agree, sorry should have said this!

 

[tom_sail]

PVA adhesive is polyvinyl acetate whereas PVA releasing agent is Polyvinyl alcohol. Not the same thing at all.

Worked wonders for me I remember buying a pot of it from the craft shop. We did also use bees wax maybe it was just that which made it pop out nicely. But this chap swore buy it and never had problems.

 

[Richardsix]

Worked wonders for me I remember buying a pot of it from the craft shop. We did also use bees wax maybe it was just that which made it pop out nicely. But this chap swore buy it and never had problems.

Knowing how PVA glue dries, I can see the theory in using it as a release agent as it would form a thin skin interface, the same as PVA release agent.
I will try a small test piece and report back.

 

[tom_sail]

Knowing how PVA glue dries, I can see the theory in using it as a release agent as it would form a thin skin interface, the same as PVA release agent.
I will try a small test piece and report back.

We did use bees wax as well! We did a test piece with no bee waxs and it wouldn't part, so made a small hole in the flange and inserted a syringe full of water. Left the mould for a few hours and the water dissolved the pva though capillary action.