Steve81

This is my first try at painting and so far things are going pretty well. I sprayed the epoxy sealer then a couple of coats of 2K primer. While blocking it down, I when thru the primer & sealer to the glass and filler in some spots. I was going to re-spray them with the sealer. Problem is, I used it all (rookie mistake). I really don't want to spend another $200 on epoxy sealer & activator. The 2K primer I'm using is BASF RM Powerfil is pretty good stuff and the MSDS sheets says "Excellent adhesion and corrosion resistance on virtually any substrate such as galvanized, aluminum, aluminum alloys, steel, old paint, plastics, fiberglass, SMC and body filler." So I'm wondering if I even need to seal up these spots. (The guy at the supply house asked me why I was using both to begin with). So what do you think, seal it or just spray another coat of 2K?

JimiHendrix

I am not claiming to be an expert at painting. . . and I definitely am not. But in painting my Targa top, I did the same thing. I used 2k primer (dupont brand however) with no ill results. The primer itself is a good sealer and I;ve read where some experienced paint guys use it as a sealer because it is quite tough. What may be an issue however is if the epoxy sealer and the primer are drastically different colors. You may have to apply more base for consistent color.

Do a search on sealers. Anyway, I am not an expert . . . so this basically is a bump.

I believe that 2k sealer would be just fine. The primer itself acts as a sealer, although, it

Scott Marzahl

What coating does your RM system call for after the 2K primer? In some systems you need to apply epoxy thinned as a sealer and then apply your color. You may have to purchase more epoxy anyway??

Steve81

I went to the BASF website and they say if can be used as a Primer/Surfacer or a WOW tinted sealer if mixed 3:1:1:1 with a Tint Base, Reducer and Hardener. So I guess my question is does it need to be used wet on wet and mixed in these ratios in order to be an effective sealer?

crazywelder

Before you recoat anything, think about what happened. You sanded through to the body surface, which means those spots are high and if you were to topcoat now, they will stand out like a sore thumb. Nothing to be concerned about if your sanding technique is good, but simply an indication that you are not done block sanding if you want a smooth surface. Your next step should be applying more sanding primer and continue blocking until the high spots are smoothed out. You might consider a high build primer for your block sanding.

Steve81

Thanks ahoover. I will spray a couple more coats to smooth out the high spots, I was just unsure if I needed to seal it up or if I could just topcoat when done. My thinking was if on the last coat of surfacer, if I did not go thru, the spots that I sanded thru previously would just have a thin coat of surfacer on top of the glass/filler and no epoxy sealer between. Wasn't sure if that would cause problems later.

crazywelder

You did the right process. The epoxy adheres best to bare bodies, better than the 2k primers and you can apply filler where needed over the epoxy to fill the deep areas or repairs. Once the body is fairly straight, you fine tune with additional primer either 2k or a sandable epoxy and block sand until the high and low spots are gone. The amount of time you spend and material you spray at this point determines how straight and flat the body surfaces will be. No harm done if a few small areas are sanded through to the substrate as long as you follow proper cleaning procedures everytime before you respray additional primer. I submitted a post earlier this week describing how I use 2 colors of primer which is effective to find the highs and lows that you can't feel.

Steve81

That is some good info and nice work. Well, I sprayed, guided and block sanded a coat yesterday and I'm not completely satisfied I got all the imperfections out so I will head to the supply shop tomorrow to get a contrasting color primer. This may be a dumb question, but I used gray first and planning on painting the car silver. Since I'm getting more primer anyway, would either a lighter or darker primer make a better undercoat for silver?

crazywelder

No questions are dumb, we all continue to learn everyday. Imperfections you are looking for will be pits from filler and bodywork underneath, edges from bad feathering underneath, and surface waves. You need to judge how much sanding is needed. I'm not familiar with BASF products but you will want to use a sealer over the last coat of sanding primer just prior to applying your silver topcoats. That sealer should be a white or light gray for best coverage of silver. Silver doesn't have much color pigment since the flakes make up most of the color you see and the pigment is basically a tint. So to get the true color use the lightest sealer available. You should have a good quality gun and the nozzle and passages need to be very clean to shoot silver. Since this is your first job, I would recommend practicing the silver on a test panel such as an old body part to get the hang of sprying metallic color. You might be able to get an old panel from a body shop scrap pile for free. Just a thought.

Steve81

All of thee above. Actually, the body panels are straighter than I thought they would be, but another round of sanding can't hurt. I have to stop at the body shop Tues. anyway so I'll see if they have some scraps I can grab. Thanks again.