can you kick a hot coat too fast? (RR Epoxy)

can a hot coat kick too fast, if you have time to brush it out, cross stroke and walk out?

just did an 18oz, 10’6"x24" RR epoxy hot coat with the fast hardner in 95 degrees F. Had plenty of time to work it all out, but got me thinking can you kick it too hot?

If so what happens?

Note: not talking about kicking too fast to finish the job.

brushed it out in 10min w/ 3" brush.

Hey 4est,

I would think it is a good thing since the reaction goes to completion; and that means maximum strength. I get worried when a batch takes too long to go off and stays soft for a half day; that’s when you want a warmer room, so you know the finished strength will be good. As long as the mixture has time to flow out smooth, you should be okay.

I just did a batch today using the X-55 accelerator and it went off in just minutes. The stuff is great for small jobs and batches or slightly colder weather.

Good Luck,


i dont really understand that question cause if you want a faster cure you use a fast hardener or work in a higher temperature…

there is no advantage to a faster cure except faster turnaround times

it still takes the same amount of time (say a week)to achieve a full and thermally stable cure.

that is unless you post cure at an elevated temperature(as per manufacturers specs and temps).if you leave the resin in the bucket in a large mass it will heat up and kick but if you spread it out thin in a shallow tray it will have a lot longer pot life

i just dump it all and squeegee.

the term “Hot Coat”

is not relevant when using epoxy resins it is basically a "filler coat "

and should be applied before the first coat or "lam coat "is fully cured say after about 6 hours.

this ensures a strong chemical bond between the coats.

rather than a mechanical bond …

if you use too much hardener in a mix of epoxy (in a half assed attempt to get a faster cure)

it is a bad move

and will substantially weaken the final cure …

the longer the potlife available, usually the higher the post cure temperature required

Silly, Your right with epoxy it is a filler coat and the term hot coat is just a legacy poly term. There real question was (provided you have enough work time) can an epoxy filler coat go off too fast? and if so what are the problems?

Fast meaning using a fast hardner (but at the correct ratios) and in a hot room?

I used to heat the resin for hotcoats in a microwave in winter so it would kick almost when it hit the surface. I could only hotcoat two at a time and I’m really fast at hot coating. No disadvantage but increase additive F by 50% when the temps are over 90º. Makes everything work a bit better.