Red hardener painted blue.

Posted by Fish'n Jim On 2024/2/26 17:51:20

Like the old directions joke; go past the red house painted blue and turn left at the intersection. They switched colors on the body filler cream hardener across the board some time ago, and I didn't know of it. I don't use much filler, I like metal. I use more MEKP, clear stuff, as I do gelcoat work on the boat, fixing chips, etc. I bought some last year.
I had a few small weld imperfections to cover on an inner fender repair, so I got the old can out, no hardener. All fresh stuff is in the freezer and didn't want to wait on thaw.(BP loses 1% a month at room temp, prevent the filler from setting up) I didn't need much, so I go to the closest parts store down the street and all they got is blue. House brand filler too. I checked across the street, only more blue. I went to NAPA and all they had was blue. I see a pattern here! I bought blue. Conflicting store stories on whether it was the same. You can still get red, but they don't stock it. The chemist in me, decided to check, and it's the right peroxide/CAS. I used unknown tons of this peroxide, installed onsite storage, and we even made it at other locations. Looks like they did change the plasticizer though to ECHA. I suspect it's cheaper to get from China that way. It hardened, so no issue. Nothing worse than having to scrape off gooey sticky filler that didn't set up.
The internet "why" story is red bled through to top coat, but I've been using filler for nearly 60 years and never had any issue with bleed through. That's what primer is for. Could be artifact of water borne urethanes, but I don't use those, but doubt the story. More likely some body man messed up.
Plus it turned turquoise green, not blue, when I mixed it, so go figure? Maybe we'll have green next?