Got called out on my riser sleeve packing method last month

A senior molder at the Tacoma plant watched me pack a 4-inch riser and said I was leaving too much air gap. He told me, 'You're asking for shrinkage cavities with that loose fill.' I switched to a tighter, layered pack with a smaller rammer. The first pour after the change showed a 15% drop in our usual shrinkage defects on that pattern. It's a slower process, but the scrap rate doesn't lie. Anyone else find a small change to an old habit that made a big difference in casting quality?

2 comments

2 Comments

maxp681mo agoMost Upvoted

That's a solid result. We had a similar thing with our blind risers on steel castings. The foreman made us start using a vent rod to poke a channel down the center of the sand fill before we capped it. Lets the air escape better during the pour. It cut down on gas holes right under the riser neck. What rammer size did you switch to for that 4-inch?

angela_knight1mo ago

Oh man, the vent rod trick is a lifesaver. @maxp68, we tried that after fighting gas holes for weeks on some ductile iron jobs. Our guy used a bent welding rod to make the channel, real low-tech but it worked. Funny how the old-school fixes are sometimes the best. We still had to play with the sand mix a bit to keep it from collapsing, though.