Best epoxy resin for overlay

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#1

What would be the best epoxy resin for doing overlay? I’ve tried some epoxy, they pooled a lot in one area and some area leaves pin holes. For guys who’ve done overlay what epoxy do you like the most and easiest to work with?

#2

Sorry budski but the pooling isnt a problem with the resin, its a problem with the opperator. What is your process step by step? Include how many layers of resin you put on, how you adhere your fabric to the part, what tools and other materials you are using, and your enviornment.

Hope to help :).

#3

I usually do 4-5 coat of epoxy, I first adhere the fabric with epoxy wait till it harden then apply few coats, I’ve used polyester before for overlay and it does not pool as easily as epoxy unless I coat it very light but i’ll need to coat it 7-8 times to cover the fabric completely and leaves room for me to sand. I am thinking about thicken the epoxy but I am afraid more air bubbles will trap inside as it already did.

#4

Polyester has a different rheology, meaning it doesn’t flow the same way as epoxy. What epoxy do you use? What’s its viscosity?

#5

Try different epoxy resins. Pooling can be caused by blushing of the epoxy. Some resins are more prone to blushing than others.

Polyester does not blush, and the LSE additive that might be present will be solved by the next layer.

For overlays I like vinylester, for its high Tg at RT cure, and less prone to yellowing than epoxy. Also, there are special (polyester) gelcoats that are less prone to yellowing, specifically for carbon work. (Nord Composites)

#6

For your application sp320 would be the best choice for you or sp115.

#7

Are you putting on that many coats then sanding? Or sanding in between each coat or two?

#8

I use aeromarine epoxy viscosity is 600, I can’t use polyester anymore because of the smell, it stink up the whole house.

#9

I put on 4-5 coat then sand.

#10

I’m sure you’d have better success sanding in between each two coats? When I overlay parts, I put on two coats, sand, two more coats, sand, clear coat, sand, clear coat once more. Its down to a perfect routine.