Doesn't look like you can buy it?
It's actually not easy to buy. But there is another product on the market that is a bit easier to get and is actually a better overall product.
Interestingly, after I built my first tank with this stuff I began working for the company distributing it. To make a very long story short. The company making Wetsuit is having some issues with the product and the company I work for is no longer a distributor of this product. We do however think this product has great potential so we have started manufacturing a similar (improved) product called Tritoflex. Once again this product is designed for the roofing industry but has many suitable applications including ponds and for waterproofing custom tanks. You can find info at Tritonwp.com although the website is still under construction. I know quite a bit about the product because I am the manufacturing facility manager and chemist that formulates the products we make.
Most of the improvements to this product would mean nothing to people building tanks but one in particular that would is the UV stability of the product. It has excellent UV stability. Most other improvements like fire ratings or low temp flexibility would have no relevance in a tank application.
If you are interested in using this product on a tank you will want the Tritotrowel brush/role grade. The standard Tritoflex product is a 2 component (liquid rubber product + chemical curing catalyst) spray application product that would just not work that good for tanks without the proper spray equipment, which is expensive. The trowel grade is a thick, single component product and can be brushed or rolled at a good heavy thickness without the need of special equipment. So is much more suited for the average Joe just looking to waterproof a big wood box.
Pricing is a bit high for small amounts but this is a superior product to anything similar on the market. I'm actually not sure about small quantity pricing but it's probably around $40/gal if I had to guess. We basically only sell very large quantities (hundreds to thousands of gallons at a time) but can do small amounts as well. It will cover about 18sqft at 80 mils (.08") thick per gallon. 80 mils is pretty thick so you could stretch it out a bit for this application if you wanted to.
I can probably answer any questions people may have and get more solid pricing if someone is interested. You can probably just deal with me in buying as well.
