Problem with casting - pics included

Hi all,

First time ever having this problem on a casting. I’m hoping someone can help me figure out the cause.

It looks like the air bubbles didn’t come off the waxes during the investing process, but I’m not sure. We were pulling 30 inches of vacuum. Right before we poured the casting my temp gauge and controller began to vary wildly on temp readings and the actual oven temp were both varying between 500 and 1300 degrees within minutes. So, I really not know what the actual temp of the oven was during casting.

I’ve attached some pictures of the castings for your review. Any advice or input would be appreciated. Thanks in advance.

It looks like the investment started setting up before the vacuum was disengaged? Just cause the bubbles are really small. That would be my guess.