Hi all, we had try to cast an impeller,attached the results. Can advise the causes and remedies? Material: bronze Thanks David
David, Can you please tell us what you were casting into ? Greensand, petrobond. I'm not a big greensand guy, but at first glance I'd guess the sand was a bit damp and maybe the bronze a bit cold.
Hi David, Pictures that show the mold and/or the impeller as-cast with the gating still on it might also be helpful, if you have any Jeff
Yes, using greensand mixed with sodium silicate, co2. Did not took any photos of the mold, but attached the sketches. During pouring, towards the end, there is a lot of bubbling like volcano eruption.
Hay Sus!! your sand was way too Wet. why in the world did anyone put that on the lathe??? Fix the sand! V/r HT1
If you were doing sand and Sodium silicate. you needed to bake those molds for a few hours. If the Sodium silicate isn't set you can get a reaction like that. You need it to harden fully.
I hope we are getting some language barrier issues Green sand includes clay SS or Co2 sand needs to be clean washed sand NO CLAY, the clay will just hold water , and bruce is absolutely right those molds need at the very least to have the mold faces heated enough to drive the moisture into the mold away from the molten metal JUST before pouring V/r HT1
Thanks guy, today we have recast the impeller, mold is heated up, the results seems good. Defects on gas porosity reduce almost 99%.
