On Rusty428cj, Tony, Elwood, Bob & Crashtech asked or stated: I used Raptor, SEM, SL&C and Qwik Liner cartridges also. I also had 2 spray-on lining, Line-X dealerships do work. One used stuff labeled SLC116SP (in a Spray-Lining & Coatings drum) instead of Line-X Ultra for 1/2 way up jeep + rocker panels. The SL&C stuff cost more than Line-X but was supposedly stronger. Price with that dealer was $16/ sq ft. I finally searched, "Comparison: Top DIY Spray on Truck Bedliner Kits Quality, Price, Coverage, Value". I got this verifiable report with all these brands. It turned out that duplicates of most or all manual mixes, or cartridges or whats called plural component proportioner polyurea via SLC or SL&C are just lower priced (I checked eBay, Amazon, online stores & parts stores too). On Rusty if you used one of those hoppers with SLC stuff, that happened with me also. I thinned it approx 10% with Lacquer thinner, used middle sized tip - perfect (see few pics- all with hopper or backpack deal). Cartridge was exactly same as Qwik Liner- I sold that ($450) gun for $275- it sucked. Static mixing tubes fail easily. they loaned me Backpack which worked great but hoppers are included which is less than over $2000 for backpack deal.