Projects 1st Alum Casting - What Went Wrong?

I’ve cut vertical and horizontal pours and never found any occlusions or obvious internal porosity. All of the porosity I have found has been on the surface of the casting. From what I read recently, 6061 aluminum (which I have been using exclusively) is not a good casting alloy. 3XX alloy being the best and commonly used in production castings. I have a cracked Detroit Diesel 3-53 blower housing that would be a good source of casting material. Just need to chop it up with a Sawsall.

Thanks!

 

I wack up aluminum rims. They are in the 3 series and pour nicely, plus they are everwhere.
To aid in the machining, when my castings have solidified, I'll shake out and dunk them in water. No more gumming up cutters.

 

I’ll have to give that a try with the 3xx alloy. The 6061 I was using would result in pretty poor machining qualities. “Gummy” being an excellent description!

 

This is the block in my avatar. It was poured from aluminum wheels and quenched. The machining was done on a CNC mill and here it is with the caps ready for final line boring and the flycutting operation to face the web and cap.

 

that is relatively HEAVY showing off-even if it is LIGHTWEIGHT--wow!!!

 

Dirt in the mold, poured too fast, too hot when pored, dirty old aluminum used. You'll soon get the hang of it.