I bought this unit with the intentions of modifying it to use for spraying fluid film on my trucks...I read a bunch of other reviews and so far have found no issues with this unit..the pressure relief valve works properly and blows off a bit over 60 pounds.I keep the pot pressurized to 60 pounds and the spray wand,( Im not using the paint gun or hoses that came with the unit ) around 100 to 120 pounds of pressure,,,so the fluid film or whatever you want to use for undercoating gets pushed up to the spray wand even though it is thick like pudding, the warmer fluid film gets the thinner, so I put the paint bucket in the sun...what I use for a spray wand and it works great is the harbor freight air engine cleaner, I think you can buy one that looks the same from amazon..your choice, im sure either would work..you just have to modify the connections at the wand, and most important I put an inline shutoff maybe 10 inches from the wand on the pot side, so the undercoat doesnt keep pouring out, unlike the paint gun that shuts both paint and air, the engine cleaner does not...but easy to do and the angles and tight spots you can get into with the wand it is well worth it...and the paint bucket looks well built and should last a long time...air gauge was reading the correct pressure...