I would strongly advise against filling with water as a method of finding leaks in neoprenes. They stretch as you fill them and will take a huge weight of water you will rip the straps off, or severely stretch the neoprene, causeing more leaks. You will also get plenty of pressure at the feet but almost none at the crotch and this is exactly where they will be leaking. Additionally you will not be able to test the top few inches. Remember each litre of water weighs a kilogram, and if your waders are large or xl then you will have a couple of hundred ltr of water in there! If determined to use this method at least lay them on the ground or a diagonal table or similar. My advise is dont however.
But to answer your questions, do not glue on wet neoprene, the glue will not bond fully to the material, it should be dried and then cleaned with cotal 240. Then apply 2 thin coats of aquasure/stormsure/seam grip or whatever, thinned with cotal, withour this repairs are far weaker.
Our repairs cost £45 plus postage for neoprenes, and in 2 years we have never had a neoprene we have repaired come back to us leaking again. Neoprenes are repaired totally differently to breathables, they require a different sealant and have to be keyed properly so that the first 2 coats of sealant soaks into the seam. It is 3-5 mm thick afterall, so a floating patch will weap water in time. We then add 2-3 thicker seamseals to add strength. At retail prices we would have probably 8-10 tubes of aquasure on each wader, and it would cost way more than we charge to do what we do with 1oz tubes of glue - we make our own!
All our repairs come with a years guarantee and we are confident that once done our repair is the strongest part of the wader!
We also have a really good stock of warranty replacement waders in stock at the moment, including the snowbees you describe. Most are A1 condition, looking like they have never been outside, though some are clearly used. They are sold seamsealed and tested with a years guarantee with prices from £50 for neoprenes to £130 to top of the range zipped breathables.
Details at
DiverDave's Wader Repairs and feel free to contact me directly if you need any additional help in repairing your own waders, i am happy to help and advise
Dave