My uncle swore by adding a bit of borax to the green sand mix

Honestly, I thought it was just an old timer's trick when he told me about it years ago. He said it helps with mold strength and reduces scabbing on the castings, especially with our local clay. I finally tried it on a batch of about 50 small gear blanks last month. Ngl, I was shocked. The surface finish was way cleaner and we had almost zero burn-in defects. I used maybe half a cup per 100 pounds of sand, just like he said. It made me wonder what other simple tips I've been ignoring. Has anyone else tried something similar with their sand additives?

3 comments

3 Comments

nathan_patel1mo ago

Nah, that sounds like a good way to mess up your whole mix. I've seen borax make the sand way too brittle.

noahs8212d ago

Ugh, tell me about it. I've been there more times than I care to count. You think you're being careful, following the recipe to the letter, and then bam, you crack open the mold and it's like handling a stale cracker. It's frustrating because you want that perfect balance, not something that crumbles the second you look at it. I've had to toss whole batches because I got a little heavy-handed trying to fix a texture issue. It's one of those things where a tiny bit makes a huge difference, and it's never in the direction you'd expect.

stone.evan1mo ago

Yeah, the "way too brittle" thing is such a classic over-correction. I mean, it happens with everything, like adding too much salt to food trying to fix it.