View Full Version : Epoxy Work and Rain

03-28-2012, 08:59 AM
I hope to do some outdoor gluing today. There's a chance of showers this afternoon. If I epoxy dry peices and cover them with plastic, can rain ruin my job? Even with plastic over it might not remain completely dry. What effect will moisture have on uncured epoxy?

wizbang 13
03-28-2012, 10:16 AM
Different epoxies react differently I have found.
west clouds up very easily
sys 3 resists milking better
it's a crap shoot sometimes, on one hand , one wants the first coat to go off slowly to penetrate better, but in this case, one is tempted to use fast hardener, heat up the glue and heat up the job .

03-28-2012, 11:53 AM
Some epoxy hardeners like West System 205 and 206 are water soluble. Direct contact of water on mixed but uncured epoxy can wash out the hardener and leave a resin-rich, sticky surface.
Damp conditions and lower temperatures contribute to the formation of amine blush on the surface.

I'd want to keep all rain off any part of my glue-up and i'd be virtuous about cleaning the surface after it's cured.

03-28-2012, 03:42 PM
I got caught by an unexpected summer shower (how unexpected is a summer shower in the UK?) when building my strip plank canoe and have a lot of cloudiness as a result.
I managed to cover the area I was working on pretty quickly but the damage was done.
West system epoxy.

03-28-2012, 05:14 PM
I don't think that the cloudiness is very deep, so if you can sand it without doing much damage to the glass, you're OK.

03-28-2012, 05:19 PM
I think a concern will be the wood getting wet, and any swelling and joint wetting (from the wood)

- just cover it really well, tape it down etc and put some thing there that would take up moisture, sawdust or a blanket or something, and then make sure that that doesn't stay there wet

03-28-2012, 06:40 PM
When you sand to get rid of the cloudiness it will be difficult to see if it worked. spray the surface with water after sanding, you will be able to see what the epoxy looks like. Make sure you dry it off well later (of course) before you do anything else - another coat of epoxy or final finish.

Rich Jones
03-28-2012, 08:24 PM
What are you glueing up? Something for Wandering Star?

03-29-2012, 08:42 AM
Thank you all for sharing your experience. It rained sooner than I expected, so I didn't get to the glue stage.
Richard, I'm gluing up a bow transom for my dinghy. Last "spring" I built a new mizzen boom for WS. The glue dried quickly enough in the driveway, but the paint took five days to fully harden!

Jacob Reverb
03-29-2012, 09:51 PM
I know the hotter it is and the higher the humidity (especially the humidity) the faster that stuff kicks. Not sure about rain...I suspect once it's mixed good, rain won't do much except to the surface. (I'm sure others know better.) My experience is with West System and Raka resins.