Just tried that new 'fast-cure' epoxy for filling voids in walnut. It kicked off in the pot in under 5 minutes and ruined a $90 batch.

I was working on a big slab table top and had a few small voids to fill. Saw this stuff advertised as a 10-minute working time. Mixed up a small batch like I always do, and it went from liquid to solid rock in the mixing cup before I could even get it to the slab. Ambient shop temp was only 72F. Totally wasted the material and had to spend an hour chiseling the hardened cup off my bench. Learned the hard way to always do a tiny test batch with any new adhesive, especially in a critical application. Anyone have a reliable, slower-setting epoxy they swear by for this kind of work?

3 comments

3 Comments

diana_kim661mo ago

A 10 minute working time claim at 72 degrees is just wild. My shop is about that temp and I've never had anything set that fast. Those advertised times must be from a lab in Antarctica or something.

the_brian1mo ago

Right? It feels like those times are from a perfect lab with zero humidity and a brand new batch. In the real world, the clock starts the second you open the container and the air hits it. My guess is they mix a tiny amount in perfect conditions just to get that number for the label.

sanchez.mary1mo ago

Yeah, the "perfect lab" thing is so true. I had a similar mess with a two part wood stain that was supposed to dry in 30 minutes. Left it in my garage overnight and it was still tacky. The can said 70 degrees, but my garage was maybe 68. That tiny difference totally ruined the finish on a set of shelves.