Dan,
You only need enough air to take the squeeze off.
Unfortunately squeeze is a relative thing, theres squeeze thats bearable and theres squeeze that makes one a soprano.
Thinsulate is hydrophobic.
The underwear I have is Andys US 200. It is three layered, Tactile Ultrex Nylon, Thinsulate, and Polartec. When I went to the pool, I did not use the underwear as I thought I would die of heat exhaustion, the underwear is rated for 28 to 55 degrees and the pool is 84. In the pool with the standard backplate and a PST HP120 tank was neutral with no air in the BC in the shallow end with <300 psi and 10 pounds in the ACB, this is the same weighting as with my 2.5 mil wetsuit. I was also not wearing a hood or gloves.
At Mt. Storm where the temperature was in the fifties, I added a hood, 5-mil wet gloves, and the underwear. On the last dive, I had 26 pounds in the ACB pockets. At the safety stop with 1000 psi I had to hold onto the bottom to stay down. Im guessing that another four pounds would put me where I should be. However, it may be that my drysuit is over inflated.
The underwear is substantial; it looks like a snowmobile suit without a hood. At this point, Im not sure if the underwear requires that much additional weight, twenty pounds, to be added or am I over inflating.
I have no idea of your experience or how comfortable you are in the water, but new divers generally hold extra air in their lungs. They never seem to exhale completely. That changes over time as they get more comfortable.
If I was any more relaxed in the water I would be asleep. I just seem to be buoyant, with or without exposure protection and/or SCUBA.
Maybe you should post some specifics about your size, weight and body type and let someone who deals with a lot of different body types comment on your weighting.
In my admittedly limited experience, this is not something you can do over the Internet. In fact this is one of my pet peeves; I wish I had a dollar for every underweight diver Ive seen that was trying to impress people with how little weight they needed now that they were experienced, only to have to hold on to the anchor line to make a safety stop. Hey, your buoyancy is what it is and theres not much if anything you can do to change it. Whats important is to measure it and be properly weighted. Admittedly, when youre first learning to dive the feet and hands get going every which away which masks buoyancy and you tend to breath with full lungs but it doesnt take long to get past that.
btw, what was the original question?
The original question was
attempt putting the new parts (Fred-T plate and STA) together with the Pioneer wing for the first time. It looks simple enough, just bolt the STA to the plate with the supplied bolts with the bladder sandwiched in-between .. Is it that simple?
Did it last night and it was that simple.
Mike