sticky epoxy

[micsk88]

I fiberglassed some boards friday and it was very cold.After I put all the board in my garage that was at 20 degrees celcius(68 degrees farenheit).After two days, the boards are all correct but there's a sticky film on the top of it.The epoxy is really hard but it sticky on top.What happenned and what can I do?

[RiRak]

I've only heard of that with polyurethane, never with epoxy... but i use a heat lamp to help cure my epoxy when its cold out so you may want to give that a try. It could also be the mixture wasnt quite correct

[SoloRider]

When you say sticky do you mean that your hand will actually stick to it, like fly paper? Or stick to it like it's a waxy surface?

I'm guessing you're talking about a waxy surface, that's called amine blush and it happens with all expoy to various degrees. Soap, water, and a scouring pad are a good way to get most of it, afterwards a good scuff sanding will get it ready for the next coat of whatever you're putting on your deck.

[Cann0n]

Wait til summer time and try again?

I live in FL. If I have to let anything dry over night, I bring it in my room because the moisture in the air really effects curing.

[Old Guy]

Epoxy doesn't dry; the two components react and harden. That's why it's good for filling gaps - no volume is lost through evaporation of a solvent. The chemical reaction needs some heat to get it started and 68* F is a little too cool. The package probably gives a temperature range for best results.

[bray]

I don't mean to hijack the thread, but this just happened to me, although it was with polyurethane, not epoxy. It was pretty humid here though, not cold. I'm certainly curios; what causes this? And what is the best way to resolve it? Darn stuff just clogs up whatever sand paper I use to try and sand it off.

[RiRak]

There is really no way to resolve it the stuff just never will fully cure, i've let a polyurethane patch on a sailboat sit for a whole summer and it still was pretty sticky. The stuff just sucks and its fumes = death. I stick with epoxy, west systems imparticular

[flannelman]

I don't mean to hijack the thread, but this just happened to me, although it was with polyurethane, not epoxy. It was pretty humid here though, not cold. I'm certainly curios; what causes this? And what is the best way to resolve it? Darn stuff just clogs up whatever sand paper I use to try and sand it off.

wet sanding is your friend. use some wet dry sandpaper and water. it will slurry instead of clog

[Old Guy]

There is really no way to resolve it the stuff just never will fully cure, i've let a polyurethane patch on a sailboat sit for a whole summer and it still was pretty sticky. The stuff just sucks and its fumes = death. I stick with epoxy, west systems imparticular

I see what you did there.

[piedogger]

What epoxy resin did you use? Almost all epoxy resin systems come with slow med and fast hardners. At 68 you are borderline between fast and med. I use system 3 and the fast hardner is good to 35* ferinheight. IF you mixed it properly you can add heat to help it cure.
Another solution if it is just blush, you can scrape the surface with a straight edge razor. This is like sanding it with 400 grit.

[micsk88]

thank you very much.I think that this is a blush.There is no sticky residue on my fingers after.The part under the waxy film is fully cured so I'll wash it and sand it a little.After, I'll just varnish it.What are the causes of the blush?

[k-9]

my experience, I use the epoxy resin in my cellar, each time she has become sticky when dry.
If I covered with a polyane film during stratification, it become perfect.
I think this is affecting by the temperature but also humidity.
(excuse my english, i only speak french)

[micsk88]

I'm also french so we're in the same situation.

[Cann0n]

The trick is to be patient.