Shoutout to the old-timer who showed me why slow pours matter

I always figured pouring molten aluminum quick was the way to go, saves time and gets the job done. Last month, I was rushing a batch of parts and the casts came out with tons of air pockets and cold shuts. This old guy on the line, Joe, saw me struggling and pulled me aside. He had me watch him do a slow, steady pour into a similar mold. The difference was night and day, his piece came out smooth and solid. He explained that fast pours trap air and don't let the metal fill the mold right. Since then, I've switched to slower pours and my scrap rate has dropped big time. In my experience, taking that extra minute really pays off in quality.

2 comments

2 Comments

wren_scott391d ago

Thin molds do need a faster fill, but you gotta preheat them more. A cold thin mold will skin over no matter how fast you pour. We run a lot of sheet-like parts and that's the only way it works.

riverhunt1d ago

Wait, hold on... I get the idea but I've seen the exact opposite work fine. On our line, a quick pour is the only way to hit the temp window for some of the thinner molds. Letting it crawl in just lets it start to skin over. Maybe it depends on the alloy or the mold design, but a fast pour gets you a complete fill before any part of it starts to cool down. I've made plenty of good parts that way.