Harbor Freight #47016
I bought two of these guns because I clipped the coupon from the sales paper and needed something to spray primer with. I had been using the large gun from the 2 gun kit until it crapped out. I even bought extra 2.0 tips to spray 2K primer. I ran into the same problems with the RTV while cleaning. The seal on the bottom of the cup cracking. Didn't last 5 uses. I have tried the HF 66222, it works good enough for primer and base. You can't spray 2K primer either because they don't sell a larger tip than 1.4. But I would use my Devilbiss for the base anyway. It is what it is a cheap spray gun, use 1 time and throw away.