Ok. UPOLY tintable bed liner. I like the stuff, that said, I pretty much threw away the directions!!
Pic. 1 is the test box. Upper part is the shuts gun that came with it. No thank you. Even with the air pressure turned way down, it was fairly uncontrollable, a superior mess waiting to happen.
I went to Home Depot and bought a cheap $49.00 HVLP gun with a 1.4 tip and a 3/32 drill bit to fatten up the hole. I reamed out the tip best as I could, still having enough pin to seal at trigger off. See lower part of test box. I burned about 3/4 of a liter messing with this stuff before I got a mix that worked. The mix was 1 bottle Upoly, 2 oz. color, 3 oz. Med. Urethane reducer and an ounce or 2 more than the recommended amount of hardener.
The Upoly bottles will not hold the additional liquid so “Shake and shoot” is out. Also this stuff is so thick I had to put the top back on the bottle and pound it upside down to get the rest out. If you don’t do that you’ll lose about 15%. This stuff really likes to stick to a plastic paint cup and is a &itch to mix. If you mix your hardener, toner and reducer first and poor the Upoly second, it’s much easier and you won’t have to spend the time scraping the sides of the paint cup. It doesn’t mix real easily, stir it well 2 -3 times.
Shooting it out of the modified HVLP gun was pretty strait forward, 60 psi at the Air tank worked well. Sometimes the gun would spit a little and I kept the fan nearly closed. It’s slow to shoot because it’s so thick. I laid 3 really wet coats on. It builds well and doesn’t run or sag much, the air pressure will push it around if you go to thick. I gave the first coat an hour to flash and 30 minutes between the 2nd and 3rd. I gave it over night before pulling and re-taping . Use good quality tape and press your edges well to get a good line with the added air pressure.
You may be able to do a short box truck bed with one kit but I used 4+ liters on the pans and another almost 2 on the frame rails.
Total cost to do the undercarriage was around $350.00 ($125.00 a kit at Amazon) including toner and the HVLP gun. I like it well enough that I may do the interior sheet metal with it, not because it looks good, but because of the protective properties. It sealed the underside of that car up tighter than a ducks butt in January and 3 days later it’s hard as a rock but still flexible.
Do I recommend it? I don’t know, depends on your application. Good for a street Car. I wouldn’t use it out of the shuts gun in any event, but I want a smooth finish.