Even though this topic is posed as a question- it's not. I'm here to tell you guys definitively, and emphatically "YES"! For over a year I have struggled with the "Flex" line of casting resins. I tried everything under the sun to get the optimum cure, with about 30% success rate. Casting resins aren't cheap, so I was watching dollars being flushed down the drain. And in conjunction; since the curing and demolding time for the flex product takes hours (and requires patience- an attribute I lack at times), I found my frustration level exacerbated. I had several correspondences with Mike from Alumilite. He emphasized the temperament of the Flex line of resins, and the potential curing issues that could ensue when the product wasn't properly degassed. I did everything in my power to try to get the product to work without going down the route of buying or making a degassing chamber. I warmed the product to decrease it's viscosity so that air bubbles could more easily escape. I would shake the product vigorously and then let it sit in the warm cab of my truck for about 30 minutes to allow the bubbles to rise. Then I would very slowly measure and mix the two components being careful to stir and not whip air into the product. My castings were NEVER consistent. Sometimes it would work great, but more often than not the piece would be crumbly and soft. After a persuasive phone call with Mike, I finally buckled and decided to make one for myself. I know Alumilite sells degassing chambers, but I was able to make one for 1/4 of the cost with a vacuum pump and plumbing fittings from HF Tools, and $6 piece of 1/2" thick acrylic from Ridout Plastics.
The nice thing about using a vacuum chamber is you can mix the crap out of the product and not concern yourself with incorporating air. You're going to pull it all out anyways. So yesterday I mixed up 15 grams of A and B sides of Flex80. I stuck them in my vacuum chamber and degassed them for about 1 minute. That's all it took to get every bubble out of the resin. I poured it into a small measuring cup and let it cure in my toaster over for about 3 hours at 120 degrees. The product came out PERFECT! It's relatively indestructible! I could smash it with a hammer, and it would just bounce off of it.
So- I said all that to say this. If you have been wondering if you should invest in a vacuum chamber to degass you silicone or resins, the answer is YES! The final product absolutely, positively WILL be better than if you hadn't degassed it.
As far as storage, I transfer my resins into mason jars, and I label the jar and the lid with the product, and which component (A or B) is inside. You don't want to mix the lids and cross contaminate. I vacuum out the air after each use to ensure no contamination from moisture. The product will last way longer if you do this.
Mike sells degassing chambers on the Makelure and Alumilite websites. But you can also find numerous instructional videos of how to make your own on YouTube. If you guys are into fabricating lures from goop (like I am), it is worth the investment. After the first time you use it, you will be thankful you have it. Also, if you are into smoking meats (as I am), you can throw wood chinks into your degassing chamber with some water, and turn on the pump. You can saturate your wood chunks throughout in 5 minutes, as apposed to letting them soak overnight or over the course of several days.
Just my $.02.