Pro tip: Swapping from a standard 3-inch riser to a 1.5-inch on our main pour line cut our scrap rate from 8% to under 2% in a month.

The shorter drop reduced turbulence and air entrapment so much that our foreman said the X-ray results looked like a different shop's work, so has anyone else found a sweet spot for riser height on thin-wall ductile iron castings?

3 comments

3 Comments

claire9583mo ago

That's a huge drop, makes you wonder if the first setup was just way off to begin with. Hard to believe a couple inches makes that big a difference.

brookefox20d ago

A buddy of mine deals with lost foam castings and they had this nightmare where their aluminum parts kept coming out with cold shuts. They tried everything, changing alloys, preheating, venting, the whole nine. Eventually someone suggested trimming the sprue height by just over an inch and a half. Night and day difference, they went from a 30 percent scrap rate to maybe 2 percent. Funny how you can overthink something and the fix is just that small of a change.

jesse_west3mo ago

My buddy's shop had a similar thing happen with their risers on some pump housings. They kept fighting porosity until some old timer told them to try dropping the height by half. The change was so obvious they could see the difference in the castings before they even got to X-ray. It's wild how something that simple can fix a problem everyone was overthinking.