Anyone ever break down or process alum. waterpumps so you can get clean cast rate on the housings? They have quite a bit of cast alum. on them. I've tried breaking them with a hammer but it's pretty hard. A friend said he was able to "press" the impeller and shaft apart and made it work but said it took awhile and wasn't worth it. I hate turning these into the yard as unclean cast 40% or whatever I get. There is more aluminum on them then iron IMO then 40% and the alum. is clean.