PSA - Watch that heat, folks.

natec

Tele-Meister
Silver Supporter
Joined
Mar 21, 2009
Posts
379
Location
Portland Oregon
It's been unusually warm in Portland (see multiple other threads) however yesterday it 'cooled down' to the point that the high at 5pm was only 94 degrees Fahrenheit.

I attempted to apply some west system 105/205 epoxy to a red cedar strip amp cabinet that I have built to rehome my blues jr. I've worked with west systems product for quite a long time (boats, canoes, kayaks) and have always paid attention to the lower temp limits (where it just won't set) but had not given much thought to the upper threshold.

I mixed 1oz hardener with 5oz resin, in a disposable 16oz cup just as I've done dozens of times before. However yesterday I experienced what West describes as an "uncontrolled cure".

Y'all probably already know that warmer epoxy cures faster. It's also true that faster curing epoxy generates more heat. Under ideal conditions this heat dissipates as you are working with it, and doesn't rise to a point to be a problem.

But if your ambient temperature is high enough, that cycle of heat -> cure faster -> more heat -> cure faster -> more heat will run out of control, hot enough to melt a cup and potentially start a fire. Also the fumes that come off of hot epoxy are incredibly toxic.

Fortunately I was in the middle of my backyard, the wind was blowing, and as soon as I felt the heat through my latex gloves I realized what was happening - so I sat the cup down on a flat rock and pulled up a chair 10' away while I watched it melt (garden hose at the ready).

This could have gone sideways and I consider myself lucky. Stay safe folks.

Nate

https://www.westsystem.com/safety/u...rolled cure, mixed resin,you heat it too much.
 

old wrench

Friend of Leo's
Joined
Feb 2, 2017
Posts
3,126
Location
corner of walk and don't walk
When the temperature hits 115* degrees plus in the shade, it'll cook more than just your epoxy :).

This is not a novelty - and it's also an inescapable fact that it's a self inflicted condition.

They say that if you stick your head in a hole in the sand, you can escape from the worst effects ;)

.
 

Freeman Keller

Poster Extraordinaire
Joined
Aug 22, 2018
Posts
8,895
Age
77
Location
Washington
Many of our finishing products, particularly catalyzed ones, have exothermic curing reactions - they get hot. I'm not surprised yours reached the thermal run away condition - it could have easily burst into flames. Glad there were no big problems other than melting the cup and a bit of a lesson.
 

DrASATele

Poster Extraordinaire
Joined
Jul 6, 2012
Posts
6,679
Location
North of Boston
I want a picture of the cup. Is that wrong?...lol
I agree with all of the above statement and will add that if you use solvent style paints, heat can be just as deadly. Stay safe out there!
 

Killing Floor

Poster Extraordinaire
Silver Supporter
Joined
Feb 3, 2021
Posts
7,917
Location
Austin, TX
We're up in Salt Lake City for a recruiting tournament and it's over 100F and high elevation and super low humidity. 6 hours in the sun today from 11-5. Not surprisingly all the teams from up here are gassed from the heat and the teams from Texas are 1st and 2nd place. The rest of the country is too hot. Back home it's just summer.
 




New Posts

Top