PSA: Ditch the fancy parting sand, just use plain ol' flour

I kept fighting with expensive ceramic parting sand lifting off my green sand molds until a 30-year vet at a shop in Cleveland told me to grab a shaker of all-purpose flour from the break room. Tried it on a batch of cast iron brackets last Tuesday and the flour held up through 6 pours without a single bit of crumble or sticking. Anyone else find a cheap substitute that worked way better than the high-buck stuff?

3 comments

3 Comments

wendysanchez1mo ago

Does the flour hold up just as well in humid conditions or does it start getting gummy on you?

miles_garcia1mo agoTop Commenter

Flour works because it's just fine particles filling gaps. Same reason I use cornstarch for my home shop molds. Big picture is most expensive hobby stuff is just regular things in fancy packaging. Bakers flour, construction sand, motor oil. Half the time you're paying for the label not the material.

the_xena1mo ago

Gotta say this reminds me of when my cousin tried using cake flour for his resin castings cause it's finer and he thought it'd work better. He ended up with this weird sticky mess that smelled like a bakery for weeks. Learned the hard way that not all fine powders are created equal. But your point about hobby stuff being overpriced common stuff is spot on. I've been using dollar store baby powder for my silicone mold release and it works just as good as the $15 stuff.