Epoxy cure

I am about to do a delamination repair in my garage. Temps around here are mid 60s. During the day and mid 30’s at night. Using west systems. Wanted to use the slow hardner so it had plenty of time to get pumped in and find all the nooks and crannies it needs too, but I guess it’s too cold. If I use the fast, and it drops below 40, will it still cure if mixed properly?
Not sure about West Systems, but the epoxy I use from US Composites recommends minimum 80 degrees for the slow hardener, 55 degrees for medium hardener and 45 degrees for the fast hardener. I would expect West is probably similar. So probably not advised to do any epoxy work if the temp is dipping down to freezing and definitely not the slow hardener unless you want to wait until April for it to cure. If you only have a small area of delam to fix, you can use a heat lamp to warm the area up to speed up the cure. The other problem with working in the cold is that the epoxy will thicken as it cools down, so it won’t flow into the delaminated area as easily. Definitely keep the epoxy somewhere warm before doing the repair so viscosity stays low.

You also need to be careful storing resin in cold temperatures - it can crystalize at low temps.

I would wait a week for warmer weather
not worth it if it doesn't cure well

How much luck will I have tarping off my carport and using some space heaters? I hear cold concrete slabs really hurt these projects, but I really want to be ready to hit the water by March 1st
If u can work in a warm location u r fine
Tarps will have almost no insulation value

Just bring your cat into your bedroom like a normal cat sailor (jk)

I’d love to hear Sam’s input since he works with these products all the time but for me: if it’s worth fixing, it’s worth doing it right.
From what I hear - Epoxies continue to cure for days. The last thing u want is cold temps interfearing with it’s ability to flow into all the nooks and crannies so it can make strong mechanical bonds

If u r in fl ... it’s a safe bet we will have a string of warm days over winter. I’d personally wait (actually I am as I have work to do on my 5.5)
I'm in the same situation as you. While trying to figure out what to do I found this article: https://epoxyworks.com/index.php/cold-weather-bonding/
I'm using WEST System epoxy with the fast hardener. I keep them indoors where it's about 70 degrees and only work on days that will reach temps at least in the high 50's. I also wait for the warmest time of day (usually just after noon). I've been able to work like this 4 or maybe 5 days so far this winter and all my epoxy batches have gone off just fine, no issues.

It sucks to only be able to work so infrequently, but it's better than not working at all. I prefer WEST (I've tried others) because I find it is the easiest to work with. There may be better epoxies out there but I've yet to have an issue with any of my repairs or builds using WEST (and I've been using it for close to 20 years).

Edited by gobigkahuna on Jan 23, 2019 - 01:14 PM.
How big is the area? You can also put a heating blanket over it. Definitely use the fast stuff.
Oops, ziper is right. I wrote "slow" when I meant "fast" hardener. I corrected my earlier post above.
I do it for non-significant structural work (this would include basic hull delam) in accord with West recommendations (previous link and other link below). Get both the surface and epoxy up to temp (heaters, hair dryer and even heat gun on structure if necessary noting not to get too hot if working with heat gun). Note this also opens any pores on surfaces which improves bonding and you can also warm/heat as layup cures. If working on beams or complex structures with significant layup steps I wait for warm weather.