surface coat cheat??

General Composites Discussions Composites Talk
#1

After my carbon fiber hand layup of two pieces cured, I wasn’t happy with the surface texture. It’s rough, and I am looking for that glass 3-D look. I was thinking of different ways to fix it, but what I came up with was to mix 1 oz of epoxy resin and just brushing it over the parts. I put it on thick enough that it flowed out flat. It looks pretty good, but it’s wet right now.

Is this typical? I know if I would have maybe vacuum bagged the part against glass or something it would have saved resin, but 1 oz seemed like a affordable alternative.

Thoughts? Thanks.

#2

Quite common to do. Many high gloss parts are either PU or epoxy coated. Think doming stickers, for example.

#3

It turned out well. It could use a buff to get out the tiny imperfections, but since this is a prototype, I think I’ll leave it as is.

#4

You can apply peel ply and sand only the texture away then follow with a clear coat or gel coat to get what your looking for.

#5

If you want a cheat, I’ll have one for you, but this is really poor craftsmanship (cheating…)

Sand it down, to about 220 grit, mix up some epoxy, add a lot of acetone and mix it up thin as water. apply wit a piece of cloth, watch out for drips.

No idea how long it stays glossy, but if you’re having a product presentation in hours, this might be the way :wink:

I’ll deny having ever used this, haha

#6

Also silicone spray makes things shiny (for a couple of days). Never use silicone spray in your workshop. Better use it across the street, where the air intake of the car painter’s spray booth is…

#7

This should all be deleted in a few days, or we get some manufacturers producing cheap garbage out-pricing us with crap. Hahaha. (although, those parts are now probably on 150k euro cars…It wasn’t me)

#8

Lol we call that method resin seal. Very streaky

#9

Pictures??

#10

I usually avoid epoxy coating parts for a few reasons that are, it’s very hard to sand, it has no UV protection, it runs too much so you get thin on top and drips elsewhere, and finally it is very sensitive to surface contamination so it also fisheyes.

I have found a polyester coating sprayed or brushed fills and sands easy. Then clear coat with a proper two pack paint system.

#11

spray PVA on ur molds

#12

Please, can you link to this type of polyester coating?

For lay up I usually apply epoxy resin, sand it and later apply 2K automotive varnish