I Didn't Like the Pulleys on My Drill Press

[Crusty]

There was some but it was widely separated small dots and to me didn't affect the integrity enough to be concerned about.

I first intended to use Light Salt to degas the AL but several videos I've watched since have convinced me that it doesn't work so I just poured the metal trying to keep impurities to a minimum. Apparently you need a costly bubbler rig to achieve significant degassing. I did use a smallish tapered sprue along with the Campbell pouring basin design which eliminates gulps of air while filling and there weren't any voids that I saw during machining. The foam outgassing as it vaporized left a terrible surface though.

That just reminded me that I forgot to take a picture of and mention that I made a fixture to turn wooden tapered sprue forms on my table saw.

Another metal casting tip that I forgot to mention: Plan all your moves in advance so that you can setup for the pour and make it with no improvising or adapting during.

[Saltfever]

. . . . Apparently you need a costly bubbler rig to achieve significant degassing. I did use a smallish tapered sprue along with the Campbell pouring basin design which eliminates gulps of air while filling and there weren't any voids that I saw during machining.

Years ago I remember using some cheap tablets to degas. Can't remember the chemical but I think chlorine was part of the mix. Supposedly, it combined with the hydrogen gas in the aluminum to out-gas hydrochloride or sumptin equally as toxic. The "bubbler" was just a simple, small, steel cup with holes I drilled in it and welded to the end of a steel rod. Drop the tablet on top of the molten aluminum and then plunge the cup and tablet to the bottom of the crucible holding it there while it dissolved creating a lot of gas that would bubble up to the top carrying impurities with it.