Had a core shift on a 300-pound casting last Thursday that scrapped the whole piece. Boss said it was the furnace temp, but I think the mold wash was too thick.

3 comments

3 Comments

We had a similar wash problem on a big gear housing last year. I always blamed the sand mix until our lead guy showed me the crust it left in the vents. Makes you wonder how many good castings we lost before someone actually checked.

jennifere181mo ago

Totally get what you mean, @jamesr75. Reminds me of a time we chased a porosity issue for weeks before finding a tiny blocked riser. Felt so obvious after.

the_linda1mo ago

Ever seen a mold wash so thick it basically glues the core in place? @jamesr75 is right about that crust in the vents. We had a batch last month where the wash looked like paste and it shifted every single core on a run of pump bodies. Boss kept saying it was a clamping force issue. Took us pulling a core box apart to show him the wash had set like concrete in the locator pins. Sometimes you just gotta prove it with the broken parts on the table.