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Saw a MASSIVE difference in casting finish after switching to a new riser design last shift

I swapped from a blind riser to an open one on our ductile iron runs at the Cleveland plant and got way cleaner surfaces with almost no shrinkage defects, has anybody else tried this and seen similar results?
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3 Comments
grantschmidt
You're seeing cleaner surfaces with an open riser? Man, I've had the COMPLETE opposite experience on our ductile iron jobs. Blind risers have been my go-to for years and they cut down on dross by a LOT. The open risers let in too much air and we ended up with those nasty inclusion lines right near the casting surface, especially on the larger parts that took longer to solidify. We even ran a batch of valve bodies with open risers as a test and had to scrap nearly 20% of them from surface defects, then switched back to blind and the reject rate dropped to almost nothing. If your Cleveland setup is working great, more power to you, but I'd bet your shop has some specific gating or mold conditions that make the difference, not the riser type itself.
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holly_sanchez75
holly_sanchez751mo agoMost Upvoted
Oh man, I gotta respectfully disagree on this one. In my experience those open risers let in way too much oxygen for ductile iron and we saw more dross inclusions, not fewer defects. Your mileage may vary but I'd take a blind riser any day for consistent results.
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the_oscar
the_oscar1mo ago
Funny you say that @holly_sanchez75, I was on the blind riser train for years. But after trying open risers on a few recent pours, I'm starting to see your point.
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