1
Got fed up with core box vents clogging on our big gray iron castings
Every time we poured those 200-pound gear blanks, the vents would fill halfway and we'd get blowback. I tried something dumb and drilled a tiny 1/16 inch hole from the side of the vent into the main cavity, about an inch from the top. It gave the gas a second way out and the last batch poured clean, no spitting at all. Has anyone else tried a relief hole like that, or is there a better fix?
3 comments
Log in to join the discussion
Log In3 Comments
taylor.sean2d ago
You said you drilled from the side of the vent into the main cavity. That's actually a standard trick called a relief sprue! It's not dumb at all, it just gives that trapped gas a clean escape path before it blows back. Good job figuring it out on your own.
3
lopez.quinn2d ago
That relief sprue trick Sean mentioned is pretty common in old school foundries. But come on, how often does a tiny bit of back pressure really ruin a casting? It feels like we're overthinking a small fix that clearly works. Why make the core vent design way more complex when a simple side drill does the job. Sometimes a band-aid is all you need if the cut isn't that deep.
2
craig.mila2d ago
Sounds like a band-aid fix to me. You're just masking a core vent design problem that needs a real solution.
3