I lined the top of the shroud with insulation tape and the table top as well. Once I clamp down the fans it will provide a nice air seal. I'll have to test to see if insulation will be required on the shroud. It may not be.

I initially tested the system for pressure differential. It didn't work out so well at first. The compressor check valve wasn't allowing for pressure differential to hold. However, after vacuuming, I applied pressure between cycles and two clicks. One was the solenoid valve, and the other must have been the internal compressor valve. The inline check valve clicked separately. I heard it. At that point, I was able to pressurize to 300 PSI on the high side and the low side held at lower pressure. No bleed over!

I protected myself (probably not well) behind a double thick sheet of MDF LOL. I wouldn't recommend it. I had my face shield on though. The nitrogen regulator started leaking at 300, so I couldn't go further.