The Stovebolt Site Forums The Shop Area Paint and Body Shop sealer or no sealer?

Right now I'm just painting the cab (first time). This is where I'm at. Sanded to bare metal. Put on evercoat rage extreme body filler on metal where needed. Summit racing epoxy primer. More filler where I missed the first time. Another coat of epoxy primer. Filler where I missed the second time. Epoxy primer over the filler. Scuffed with 600 grit paper. PPG shop line 2k filler primer.

Next I'm going to sand. Now after that I can put on a sealer or skip the sealer and paint away. I was told that the benefit of a sealer is that everything is one color and I wont have shaded areas in the paint. I plan to use the maroon paint, which is pretty dark, so I don't see that being a problem. I'm leaning towards skipping it because I'm running out of cash and getting anxious to paint.

http://pic20.picturetrail.com/VOL1268/5055721/20931166/390609344.jpg

http://pic20.picturetrail.com/VOL1268/5055721/20931166/390609337.jpg

http://pic20.picturetrail.com/VOL1268/5055721/20931166/390609323.jpg

I would recommend one solid color for the sealer to make sure there are no contrast issues (light or darker shades) no matter how slight with your cover/top coat of paint. The base color can influence the topcoat color. A scuff coat of primer will help with adhesion of the paint as well. Good luck with your project!

If you want the top color to be the same, make the surface you paint over the same color.
Although hard to see with dark colors, there will be a slight shade difference in the top coat if surface you paint over is not the same color.
Usually seen in "just the right light".

Been there, done that !

Dan

Frankly, I see no point in sealer in your case. Your last coat before color can be primer. If you've blocked sanded everything properly you should be able to lay down a coat of primer and wet sand it smooth without cutting through.

Another thing is that "scuffing" with 600 grit isn't going to do anything. That grit is too fine. You should never sand without a block of some sort. Your final sand before top coat should be a thorough block sanding with 400 grit, wet, using a guide coat. If you do this, you will have a glass smooth surface with just enough "tooth" for good adhesion.

Remember that you top coat is only going to be as good as the work that went on under it.

IMO, of course.

Thanks for the replies. 600 grit sounded kind of fine to me, but the directions on the epoxy primer stated that if topcoatiing or puting another coat on after 4 days, then scuff with 600 grit, so I thought I better just fallow the manufacture directions.

400 grit on metallics is way too coarse, you will get sand scratches showing through.

On a metallic color 600 is good, I know painters using 800 grit on some colors.

If you went past the 4 day mark on the epoxy you need to sand or scuff it so you get paint adhesion. Personally, you are just scuffing it and then going to urethane primer for blocking, Id use a red scuff pad which is equal to about 400 grit. A red scuff pad just roughs up the surface so paint will stick.

By the way, most filler primers IF they are urethane based can be used as sealers if the mix ratio is changed. Look at the product tech sheets for the primer you have. Personally, I use sealers...Eric

I agree with Sevt-Chevelle. Im also in the collision industry, 400 grit will show sand scratches, espessially on silvers, but the use of sealer will eliminate sand scrathes.

In our shop(before it burned), we sanded everything with 400 & used sealer. Recently I realized that 600 works better, & you dont have to use sealer. Unless you have a color that doesn't cover well, then Id use a tinted sealer.

I wet sanded my doors with 400 grit and I can assure you that there are no sanding scratches in my top coat. Primer wet-sanded with 400 will actually have a bit of shine and I could not imagine how that smooth surface could have scratches in it deep enough to cause any problem. I don't know much about the current theories but I do have first-hand experience and an relaying my results.

Back in the day we used to paint show cars with metallics and translucent candy colors and the only time we ever used 600 grit was to color sand before rubbing and polishing. The final sand prior to paint was always 400 wet.

But, I'm not doing any fancy finish, just a single-stage, stock solid color. Perhaps if you are doing some show-quality basecoat/topcoat finish you would feel better using 600 or 800 grit, but for those guys reading this who want a stock color 400 wet is perfectly fine.

IMO, of course.

Not a show vehicle here, but it will be very nice. I bought some sealer...It wasn't very expensive. I put a couple more coats of filler primer on a few spots to fill. They are pretty level. I sanded down with 180, then 320. Its pretty smooth. I plan to go with 400 before putting the sealer on. And the sealer will be covering a couple of spots that are bare metal. They are definitely smaller than a quarter so that will be ok right? just want to make sure. These spots are about the size of the tip of a pen. Just a sliver. But I know they are there. Can't seem to get enough build to get it to go away. It's a never ending battle. But since it is a sunday driver vehicle, I'm going to call it good and sand things to 400 grit and apply the sealer.

Oh yeah. almost forgot this question. After the sealer do i need to sand or scuff? Or just sealer than paint?

Seal and paint it, sealer is a wet on wet application meaning you do NOT sand between coats. Seal it wait about 30 mins and apply paint...Eric

The finish that you get with 400 grit wet and 400 grit dry sand papers will be different. If you are finishing with single stage paint use 400 grit, if 2 stage (base coat- clear coat) use 600 grit. To get a uniform color and easy coverage when spraying a burgundy over a light colored primer such as grey try spraying on a light uniform coat of black first and then cover with the paint. All that you should need is a quart of black paint to put the first light coat on the entire truck. There is no need for sealer over a primer filler unless you burn through when sanding, make sure there is no bare metal.

I did burn through just a tad, about the size of the tip of a pen. So a sealer is planned. I may not be able to go with burgundy. The PPG store that I've been going to only has that code in 2 stage and its very expensive. I'd like to go with single stage. She said she could get close but not sure if I want to gamble with that color. I'd hate to have a pink or purple truck. I may go with transport blue or something close. Also what do you use to clean after sanding? The tack rag worked great when dry sanding, but the wet sanding it seams to leave some there. A clean damp rag?

You can purchase etch primer in a spray can to cover the bare metal for small areas such as you mentioned. After wet sanding wash it off with clean water and then blow dry. After sanding and washing try not to touch the surface with your bare hands before painting as oils from your skin may cause fisheyes. Use tack cloth just before beginning to spray. A clean well prepared surface is the key to a good finish as the paint seems to magnify any imperfections.