Hank Rearden
This is an image of a blower housing from an Otto Canedy forge blower that I'm restoring. After removing the oil film and years of crud that has accumulated on the casting I notice what appears to be a casting flaw. I would like some help from someone who has experience casting iron.

I think the flaw is from iron that started to set before the pour was complete. I'm not sure if I'm correct. The line is on both sides of the casting. It doesn't look like a crack. What are your thoughts?

Click image to expand
blower shell cast.jpg

Outside view

casting flaw 1.jpg 

Inside view

I think a crack would have held oil residue that would seep out and leave a film along the flaw line. Also the crack isn't a mirror image on both side. My last thought was that some of the crack line is fine while other parts of the line are wide with what looks like the edge missing material. No light show through.

Your opinion? Thanks 
Click image for larger version - Name: blower_shell.jpg, Views: 34, Size: 49.95 KB
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Flippabotamatic
Hey Hank, 
Just came across your forum and I've been reading through it. 

The miscasting on this piece is called cold shut. It's usually due to improper flow through a mold (as well as cold metal.) The metal has flowed from both directions and by the time it met itself it was too cold to fuse/mix. It's common for metal to to flow from a few directions inside of a mold and usually this shows up as a line if it shows up at all. You usually don't see this on such a small piece.

If there is evidence of a line that goes around the piece, then it could also be from a second pour. This probably isn't likely though, especially with iron. A pro foundry wouldn't take the risk of a miscasting, they would just scrap the mold.
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Hank Rearden
Thanks for you input. I had a similar flaw on the gear box as well. My first thought was to add a coat of epoxy after I cleaned the casting. I didn't do that though. I just cleaned then repaired a few parts and reassembled the unit. I used a light oil. Either tranny fluid or hydraulic fluid. I forget which. Anyway it's been hanging on a post and I haven't seen any oil drip  on the floor yet. It's been several months now.

You assessment seems to be correct. I appreciate you comments.

Thanks.

I will pick up a spare housing if I can find one on the cheap.
code[Maglio.gif]  Keep the fires burning hot!
2020 ABANA Conference in Sarasota New York. June 3rd. through June 6th. Plan now!
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