Hey Chris - that's a NICE stabilizing setup you've got there. Are you using Cactus Juice? OR something else? What wood are you doing now?
The big foaming bubbles don't usually last very long, but the tiny bubbles will last a long time. How long to run the vacuum pump depends to some extend on the type of work, whether it's open pore or tiny pore wood. Anywhere from 1 hour to 4 or 5 hours is usually enough to run the vacuum pump. BUT - be sure to let the container stand soaking up the resin for several hours, even up to 24 hours is good. When you get the wood cured and sanded clean, try putting a block in water to see if it floats or sinks. It should sink, or at least float with less than 10% of wood out of water, usually just level with water if you've got good penetration of resin.
Are you buying your resin by the gallon? That's the cheapest way if you've got lots to stabilize.