Showerthought: I started using a 2% borax wash on my greensand molds in Tacoma and it cut my scrap rate by a third.

We were getting a lot of surface defects on our iron castings, especially around the cope. An old timer at the shop said to try a light borax spray on the mold face before closing up. I mixed a 2% solution in a spray bottle and gave it a shot. The finish is way smoother now, but my foreman thinks it might mess with the sand reclamation system over time. Has anyone else run a borax wash in their sand system for more than a few months?

3 comments

3 Comments

hannahcraig20h ago

Okay so the gumming up worry is real. What's your sand reclamation setup like, is it a thermal system or just mechanical shakeout?

kelly.patricia21h ago

So the borax doesn't gum up the sand muller? That's my main worry with stuff like that.

sean_barnes2419h ago

Honestly it can if you just dump it in dry. What worked for me was making a weak borax water mix first, like a couple tablespoons in a spray bottle. You mist the sand while the muller is running so it spreads out instead of clumping. Tbh the key is not using too much, it's easy to overdo it thinking more is better. I had a batch turn into a brick once because I got lazy and poured it straight in.