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Help please-sanded through base coat

8K views 11 replies 5 participants last post by  fastblueheeler 
#1 ·
As you can tell, I'm a beginner. Painted the car with Chev silver blue poly then clear coated it. Used Omni paint. Had some runs in the clear, so in attempting to sand them down I cut into and through the base to the primer. I sanded the spot with 600 and tried to put more base coat on. It blistered around the sanded area. Whats the best way to deal with this. And I'm finding out that metallic doesn't blend well. Is there a trick to applying it to get a consistent color or should I give up and go to a solid color. My base coat was pretty smooth but I had the areas where there is more blue than silver. I'm thinking metallic is beyond my skill level. Thanks
 
#2 ·
Metallic is a hard paint to learn how to paint with. even good painters sometimes have flow problems. The light and dark shades you have is called ghosting. the only way to fix that is repaint. Sand the clear off and seal with re coat sealer, then start over. You have to have the right air pressure and thinner to get the metallic to flow right(I like to use a little retarder to get flow out right). HTH.

Good Luck
Troy
 
#3 ·
You have yourself in a jam.

The RIGHT way to do it would be like Troy-Curt said. Strip the car back down, re-seal it, then start again.

You have other options that aren't as "correct", but are doable, and CAN produce a stable, lasting job.

Seeing as you have ghosting, you have almost no choice than to respray the basecoat. The question is whether you are planning on taking all of your paint back off or not first. If you feel that your original sealing job was adequate, there is no reason you cannot scuff the clear that you have on there now, reshoot your basecoat then reclear as long as you keep your thickness to a minimum.

No matter if you strip the car and reseal or shoot over your existing paint, shoot your metallic in 3-stages. Put it on "DRY". That is, turn up your air pressure and extra 3-5lbs, and give yourself an extra 2-4" of distance from the panel, and increase your spray speed about 15% (that is, how fast your moving down the panel as you spray). Put on two coats like this. Just get good coverage without the paint being very wet. The paint on the car should completely flash within 2-3 min. With metallics, I like to see it flash in the 1.5-2min range. After the paint has flashed, put on a second coat just like the first....dry! Then, the third coat, give yourself another 5-10" of distance, turn DOWN your airpressure to about 3-5lbs below normal, open your fan up about 20% and put on a light/medium coat that is over-reduced by about 5%.

What's going on is you are putting down a base coat with the first two coats....just to get the color of the paint there. You don't really care what the metallic pattern looks like, just so long as the layer of paint is uniform and there are no areas that are "pooled" or that are wet longer than the rest of the peice. The last coat is just to put a random pattern of the metallic on the color that you sprayed the first two coats. The last coat should be sprayed to where there is allot of over-spray or "Fog". The extra reducer helps the heaviest particles in the paint (the metallic particles) to stick when they hit the panel. Standing back furthur and opening your fan up helps keep you from developing streaks and makes the metallic pattern more random. The idea is to get a good solid flat color, with a random metallic pattern on the top.

Anyways, good luck, and post some pics when you get them!

The 'hopper
 
#5 ·
Thanks for the info guys. Just a couple of questions before I start:
So I can reshoot the base by either sanding off the clear and using a recoat sealer or scuffing the clear. What about the blistering on the areas where I sanded through the base into the primer. Is the new base getting under the edge of the old base and lifting it? Will a recoat sealer prevent this? Can I just spot prime those areas and feather it into to clear? Thanks for the metallic help hopper.
 
#6 · (Edited)
Check with your paint dealer, they should have a primer to level out the places you went through, tell them exactly what your doing, they should recommend what ever you need, for the brand of paint your using.

When I use a recoat sealer over uncured paint, I use Marten Senior. But go with there recommendations. HTH, Good Luck

You mentioned that you used omni paint, omni paint is not a very good paint. I think that`s what Macao uses. You might be able to wash it off with high pressure water.

Troy,:thumbup:
 
#7 ·
Troy....Omni is a lower-line paint, but it's manufactured as a cost-concious alternative to their DBU or DBC line...and in my opinion, besides the drier being cheap, the pigment and the base are just as good (if not the same thing as) PPG's regular lines. I feel that the pearls and metallics that the Omni line calls for are inadequate, but if your going for a easy-on-the-wallet paintjob, the Omni brand is okay. I sometimes bid out jobs in Omni when people portray that money is tight, but they don't want a single-stage paint.

As far as the paint blowing off, that may be true, but has very little to do with how expensive a paint is. It only comes into account when there is no mechanical bite (the underlaying paint or whatever isn't sanded properly) and the paint has little chemical bite (no chemical adhesion to underlying layers). The Omni job can be just as nice as a regular DBC or DBU job. Just my $0.02. Dont flame me too much.


The 'hopper
 
#11 ·
Troy I have used Omni for quite a while and so far no problems, but I have found that with Onmi metallics you need to use a gun with about a 1.5 tip, I have learned this from experience but if your careful you can get by with a 1.9 but must use a HVLP gun for it to flow out right and not get blotchy or create dark spots. Granted I have ever used Martin-Senor but have used DuPont, PPG, and I'm doing a Nova with Valspar and I think Omni is just as good as any of them but you must follow the mixing recommandations (as with any brand of paint) but as far as the blistering wet snd the entire car and seal and then reshoot.
 
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