Craig Dabler - The DIY Castings Guy | Investing the Little Flasks - Video 3 @craigdabler-thediycastings7511 | Uploaded June 2022 | Updated October 2024, 1 hour ago.
In this video I show you how I invest two flasks at a time. You’ll also notice just how quickly this micro size system draws out the air. It is nearly instant so it doesn’t take anywhere near as long as a normal system.
The vacuum pump is just a Harbor Freight 3 CFM 2 stage as there is little need for anything stronger.

I allow the flasks to harden a minimum of two hours but often will wait overnight if it is getting too late in the day.