A different way to handle sand washout on big molds
Everyone at our shop in Toledo swears you need to pack the sand in layers with a rammer for any mold over 50 pounds. I had a huge core box giving me washout issues for weeks. Out of frustration, I tried vibrating the whole box for about 30 seconds with a palm sander before the final pack. It settled the sand way more evenly and cut my scrap rate on that part by half. Has anyone else found a weird trick that goes against the usual shop rules?
Check the moisture content in your sand mix before you try anything else. A lot of shops focus on packing methods but ignore that the sand itself might be off. Getting that balance right often solves washout without needing extra steps.