Quote: (Originally Posted by
pwl4476)
I've never made any counterlungs but a critical aspect is obviously the material, as you've discussed. That being said, perhaps you can investigate the use of crushed (or compressed) neoprene as used in many neoprene drysuits. It's available in 2 and 4mm, that I'm aware of. It's tougher than typical neoprene, varies less in bouyancy at depth, seems to hold a seam/gluing better (in my experience), and still offers flexibility and stretch characteristics.
pwl4476
Crushed and compressed neoprene are two distinctly different materials.
Look here
Drysuits made from compressed vs. crushed neoprene
Genuine "crushed neo" is actually just slightly negative, and does not undergo any measurable change in buoyancy with respect to depth.
I'd be very surprised if there is any commercial source for true crushed Neoprene. Making such is not trivial, I know, I've done it.
Tobin