Epoxy Gelcoat Suggestions?

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#1

Hi Everyone. Long time lurker picking up tips here and there, first time posting. I’ve done many searches on gelcoats to see if I can find the answer before posting yet another gelcoat post but no luck so here goes…

I’ve been looking for answers for a product to use as a gelcoat. I’ve been using Duratec VE Clear Topcoat for a while now with success but there are two factors that I’m not happy with: 1) there is no UV protection 2) It has a brown color and looks like Cocacola which affects the color of the product especially with lighter color fabrics.

After some test panels I’ve found out that a polyester gelcoat is out of the question. I’ve tried the Metalflake Clear and 249A and both do not have the properties that I’m looking to achieve.

I’ve tested the Aluzine 2:1 Epoxy that I use. Eventhough it’s crystal clear, UV protected, and my favoite to use while laying composite layers, it does not do well as a gelcoat. It doesn’t fisheye or alligator… it “groups” together and creates major crators in the surface.

I’m looking for an Epoxy resin which has UV protection and is able to roll out on a smooth surface using a foam roller with a film finish similar to Duratec VE Topcoat (no fisheyes or craters). Any suggestions would be greatly appreciated!!

#2

Sicomin Surf Clear

http://www.sicomin.com/products-epoxy-39.aspx

#3

You should just clear coat your parts with automotive clear coat and widen your variety of what you can use as gel coat. You really should clear coat your parts regardless if you don’t already.

If you use an automotive clear already, then don’t worry about a UV stabilized gel coat.

#4

Thanks but I make small pieces in mass production. I asked a local shop what they would suggest. They also said clearcoat them after the parts are made. So I asked how much they would charge to clearcoat 200 parts per week and told them the size…He didn’t really give me an answer. Just a look of “You got to be kidding me!” The labor alone to have someone clearcoat these parts would cost me to lose money.

Ric: I looked up Sicomin and couldn’t find a USA distributor. I’ll give them a call to see how much is shipping. Thanks.

#5

I was just thinking about trying the duratec clear top coat. Do you have pix of how its turning out after cure? It’s the first time hearing about this on this forum.

Let us know how the sicomin works out and where you got it from.

#6

Why would labor cost him?? How bad are the parts your makeing?

#7

REZCAR: Duratec produces a high gloss, pretty hard surface that looks good and is easy to buff to a class A finish. The down side is that it isn’t UV protected. If you are spraying it in mold in a thin layer the color will not be that noticable. For my particular situation I use a pretty thick surface coat that is why the color is a problem for me. I would definately recommend Duratec for a gel coat application to take care of porosity problems. It’s a great product but for my application I think that I need to try a different route since I’m not looking to spray post fabrication. I’ve posted a pic of the duratec finish below.

brainstorm: Labor cost would be high not because the surface quality is bad but the amount of items that will be made. I have over 200 different shapes with the smallest being smaller than a dime. The labor involved with 200 of these small parts a week while also fitting it in their regular work schedule is what causes the cost to be high.

#8

What is the stiffness, and is weight important? You could use a VE skin coat with a PE gelcoat. The surf clear epoxy’s are better than regular ones, but they’ll still yellow after some time

#9

Thanks for the pic. This whole time I thought the Duratec was UV resistant. Time for me to go looking for a solution too!

PS, I also don’t understand why the labor cost would be high. Just lay them out and spray them. You could pre-sand them, and he could wipe them down with wax/grease remover prior to spray…are you also asking him to color sand?

Spraying is not an option for me due to the chemicals. What about a rattle can automotive clear?

#10

yeah this is really the downside to Duratec clear topcoat… no uv protection as stated. I thought the same also… too amber colored right out of the can.

We have tried various epoxies for a smooth, clear surface coat. We have one that works ok now but in no way is it a polish and go finish out of the mold.

If your product is cosmetic or can utilize it you may try a vinylester resin with a low viscosity. This way you can spray clear gel coat into the mold prior to lay up.

My other thought is epoxy seems to degass well with heat. I bet if it was cured in mold- in oven you may obtain a better surface finish with clear epoxy. Just be sure to not overheat the epoxy or leave it in the oven too long * can cause yellowing*.