Doing Bodywork on my own car need some assistance. Please

My 1.4 sprayed epoxy fine. I don't think I'd try a 1.4 with a build primer. There was a number in the manual to call "for spare parts", but I didn't call it or try to get a different tip. I have another gun with a bigger tip anyway. The last time I used it was earlier last summer, but if I were to guess, I'd say I used it with 90 out of the tank and probably about 35-40 at the gun, but I could be remembering wrong. You'd just have to try it and adjust for your material.

As with any HF tools, I suggest inspecting in the store when possible before purchasing. I have come away with some missing parts sometimes when I haven't. I still have a bolt stuck in the crank of the engine stand I bought there because it was missing the pin when I got it home!