taylor.brooke•13d agoMost Upvoted

Spent $180 on a mold release spray that saved my castings

I used to just use the cheap wd-40 trick for my sand molds. Figured it wasn't worth spending money on specialty stuff. Then a customer rejected a whole batch of aluminum parts because of surface pitting. Switched to a proper zirconium-based release agent from a foundry supply place near Toledo. Cost me $180 for a gallon but I haven't had a single bad pull since. Still cheaper than having to re-pour 30 pounds of metal. Has anyone else tried the cheap alternatives and regretted it?

3 comments

3 Comments

sanchez.julia13d ago

The WD-40 thing is honestly fine if you know what you're doing. I've been using it for years and never had pitting issues, sounds more like a technique problem or maybe your sand was too wet. $180 is crazy when you can get a can of Pam cooking spray for like $4 and it does the same thing for smaller pours. People act like you need all this specialized gear but half the time it's just marketing fluff. If you're doing high volume commercial work sure maybe, but for most hobby setups that's wasted money.

mason.drew13d ago

Hah, yeah I tried the Pam trick once. Ended up with a casting that looked like a golf ball. $180 beats re-melting pride I guess.

thomas.river13d ago

Wait, hold on. @sanchez.julia said you can use Pam cooking spray? For sand casting? Man, that's wild. I've seen what happens when people try that on anything hotter than a frying pan. You'd have to scrub your mold down after every single pour. WD-40 at least burns off clean, but Pam is basically just oil and lecithin. That stuff leaves a nasty residue that traps gas. Your castings must come out looking like a sponge. I'm not saying you need the expensive stuff, but there's a big gap between $4 can of Pam and a $180 gallon of zirconium release. There's got to be something in the middle that works better than cooking spray.