Apply using a foam brush leve 20mins then spply gelcoat
http://www.ecfibreglasssupplies.co.uk/p-2191-blue-gloss-pva-release-agent.aspx
http://www.ecfibreglasssupplies.co.uk/c-1011-foam-brushes-jenny-brushes.aspx
You can get simular on eBay too
What sort of wax is it or what can i use for a large area. Thanks.
I've always had great results as a beginner using pva release agent loads quicker too!
Apply using a foam brush leve 20mins then spply gelcoat
http://www.ecfibreglasssupplies.co.uk/p-2191-blue-gloss-pva-release-agent.aspx
http://www.ecfibreglasssupplies.co.uk/c-1011-foam-brushes-jenny-brushes.aspx
You can get simular on eBay too
Google is your friend!
I always go for Meguiars waxes - they are the standard. How big is your 'large area'? I have applied wax to a mould for a 150' yacht
hull mould before, but it really is a horrible job on something that size! Otherwise, you could look at chemical (semi-permanent) release agents -
e.g. Freekote, Chemtrend etc.
I have always used duck tape over my mould. It seems to work ok for me.
If you want to do it properly, you want beeswax. The product is actually called beeswax and it's brilliant. Don't use PVA Release Agent if
you care at all about the quality of your gelcoat.
Remember to buff on - buff off quite a few times before you actually try anything.
Yep as said beeswax. you can get it from either toolstation or screwfix
One of the polish GRP manufacturers use - Neutral Kiwi Shoes Polish It contains Carnauba Wax like other premium waxes...
I know it's funny, but he's making GRP mainly for german market (bike fairings etc.) so can't be that bad...
What application are you thinking of?
If you have a relatively smooth non absorbent surface you want to take a part from, then a chemical release agent is great - it's dead easy to
apply and i've had fantastic releases with it. I use EasyLease from Easy Composites. They sell it in small quantities as well. You wipe on, leave
for a second or two and then just buff a little to remove the high spots.
PVA (poly vinyl ALCOHOL) can be ordered in shiny blue or matt finishes. If you spray it on (clean air and a cheap air paint gun) you will still get a
reasonable finish. If your surface is a good quality you can wipe it on with a rag and that'll do. It's not for showroom-quality epoxy-CF
finishes but it's still excellent. Put enough down and you could pull a part from a block of concrete. It also forms a physical barrier (you can
peel it off) and it is water soluable. When pulling parts from difficult moulds using it, you can start the separation and pour water in to dissolve
the PVA. you can sometimes actually hear the sounds as the part and mould separate.
I would use wax last of all - lots of effort and easy to miss a spot. With EasyLease it's on quick and sets quick. With PVA it's on blue so
you know where you are. Things have moved along a lot since wax.
For me, and I'm not saying this is the correct way, but it works, if I have a less than perfect mould/buck, I use wax. Usually whatever I have on the shelf. I made a buck for a dashboard out of MDF and filler. It got some random 'brushing wax' applied with a cloth. Several coats and left to dry between each one. The two parts practically fell apart. I knew I would have to spend some time finishing the components so the finish from the buck wasn't too critical. After I'd spent time finishing the mould and given it a couple of coats of paint to help me with the guide coat, it got a couple of fine mist coats of PVA release from a water squirty bottle. It took a bit more separating but came out with an excellent finish. Then I changed the clocks and chucked the lot in the bin, but that's a different story...
The key is always in the mould quality; the quality there is amplified to the eye when you look at the finished part. If you're only making one
part then time is best invested in fettling the part after the mould. If you're intending to pull more than one part then the time is best spent
on the mould quality.
I'm learning (thanks to CarbonMan) just how much of a slog it is getting a good mould made from scratch. It's A LOT easier if you're
copying a part.
I hadn't thought of misting PVA on with a plant squirter - I'd set up my spray gun ... the more I use PVA for some parts, the more respect I
have for it. For instance with my fuel tank I don't need a cosmetic finish so it's going to be a CSM/poly mould, PVA and then aramid for the
tank.
quote:
Originally posted by owelly
For me, and I'm not saying this is the correct way, but it works, if I have a less than perfect mould/buck, I use wax. Usually whatever I have on the shelf. I made a buck for a dashboard out of MDF and filler. It got some random 'brushing wax' applied with a cloth. Several coats and left to dry between each one. The two parts practically fell apart. I knew I would have to spend some time finishing the components so the finish from the buck wasn't too critical. After I'd spent time finishing the mould and given it a couple of coats of paint to help me with the guide coat, it got a couple of fine mist coats of PVA release from a water squirty bottle. It took a bit more separating but came out with an excellent finish. Then I changed the clocks and chucked the lot in the bin, but that's a different story...