and it works! Followed Steve Evans instructions on www.suluk46.com and I got a a 36" pad (after making a mistake and having to re-cut about 1.5" off) out of it. Put it in a bathtub and didn't get any bubbles. Left weights on it overnight and wasn't able to detect any leakage. Heading up to Thousand Island Lake next week so I'll be able to field test it and I'll let everyone know how it goes.
I do have the other section (roughly 34") and I'd like to give it to someone on this site, if you think you can put it to good use. Just message me and I'll get it out as soon as I can.
Starting weight = 14oz
End weight = 7.6 oz