jfxberns

For future readers: I tried acetone, it cleaned the gunk on the channels, but it didn't soften the baked on crud at all. I ended up paying out mold maker to ream the channels.

We've removes the heat exchanger block itself, it's just a slab of aluminum at this stage. I was going to try to try acetone as I know it dissolves plastisol and PVC, but I was wondering about anyone's experience removing the burned stuff. Have you tried on burned plastisol?

We've been running the same heat exchanger on our soft plastic injection machine for a few years. We recently pulled it to refurbish (clean, replace heaters and thermocouples, re-run wiring etc.) and found there there was a lot of brown/black burnt (baked on) residue inside the heat exchanger. (Probably plastisol, but it could be from colorants or glitter.) It's pretty hard, I don't want to ream it out (I want to keep the plastisol channels smooth), so I was hoping someone here had some experience on how to soften the burnt plastisol so we can remove with a non-abrasive brush. Have you had a similar problem? How did you fix it?