Used to pack my flask sand with a flat rammer, switched to a curved one after a casting at the Milwaukee shop came out with a weak spot.

4 comments

4 Comments

Curved rammers just make more sense for flask sand. The shape fits the mold better and gets into the corners a flat one can miss. That weak spot was probably from uneven packing pressure. A flat rammer can leave gaps along the edges. It's a small change that fixes a big problem in the final cast. Good call on making the switch.

rowan_wells302mo ago

Used to think a flat rammer was fine for most jobs. But seeing how a curved one just follows the flask shape changed my mind. It really does get that even pack you need.

bennett.harper8d ago

That third mold I packed last week with the curved rammer felt totally different. The sand went in smooth and I could feel it hitting every edge of the flask without having to angle my wrist weird. I was one of those guys who thought a flat rammer was good enough for everything, but watching the finished casting come out without those rough spots along the wall was what finally sold me.

spencer4002mo ago

Man, you're totally right. I've seen that exact thing happen. A flat rammer leaves those little pockets of loose sand right against the flask wall. Then when you pour, the metal finds it every single time. It's such a simple fix but it makes the whole mold feel so much more solid when you're packing it.