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Discussion Starter #1
Hi! I need help again. I was wet sanding my clear coat lastnight and I noticed that saw small tiny bubbles in the clear and when I sanded to much down to the bubbles, the bubbles turned into white dots when I polished the paint. How do I fix this or do I have to put another coat of clear? THanks for any suggestions <img src="graemlins/sweat.gif" border="0" alt="[sweat]" />
 

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Sounds like you got trash from the gun, or the clear had some lumps of pigment that did not dessolve. I think you will have to sand them out,If you go through, you`ll have to reshoot the clear. Don`t get in a hurry,I think you can save it.Good Luck

Troy;
 

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Ive seen this before and more often with Dupont clear I have seen guys take mix up a small amount of clear and drop clear in the holes and wet sand it smooth
 

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It sounds to me like you have solvent popping.This happens for several reasons, some are the clear is to thick or your first coat of clear skimmed over from drying to long before applying your second coat or you used to fast of clear or activator.What happens is the solvent from your first coat escapes througha dried film of clear and the clear is to dry for it to flow over leaving real small pits.
 

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Thanks guys - so How do I fix this? I used PPG 2042 which has a very fast dry time and I think you guys are right about solvent popping. What happened was that we mixed a gallon of 2042 to paint a whole car and while we went through the first round, half the clear we had left started hardening. I was going to cry because that stuff was not cheap. Can I paint clear over the solvent popping or do I need to just put another coat of color and fresh clear after wet sanding. How do people fix this? - THanks again for your suggestions.

jon
 

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I`ve never seen solvent popping leave a white spot, just a pit when sanded. <img src="confused.gif" border="0">
 

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Man, how long did it take you to get around that car. I had no idea Clear would harden in the can in a matter of hours. In my experience, it takes a day or so. I would bet you are going to have to sand the problem out and and just reclear.

I think you will have to sand untill you are down to the first coat and the bubbles are gone. If you break through anywhere, you will have to recolor that area or it will show when you reclear. It will be time consuming and you will have to be very careful if you dont want to have to recoat everything.

Also, I would not try to polish it out from this point on. The polish will build up in the bubbles causing the white spots. If you get it all sanded out, the new coat of clear should fill any tiny pits that are left.

Chris
 

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Originally posted by troy-curt:
<strong>Sounds like you got trash from the gun, or the clear had some lumps of pigment that did not dessolve. I think you will have to sand them out,If you go through, you`ll have to reshoot the clear. Don`t get in a hurry,I think you can save it.Good Luck

Troy;</strong><hr></blockquote>

Have you got white dots or pits?

Turbo is right on the money.
Slow and easy. Troy;

[ June 06, 2003: Message edited by: troy-curt ]</p>
 

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Discussion Starter #9
Sorry for the confusion. They look like microscopic bubbles in the paint if I look at them carefully and can be seen as tiny white dots when I wet sand it with 1000 grit paper or polish it. I assume they are bubbles but after thinking about it, it could be trash. I really dont know. I do know that it will come out if I rubb it out hard enough, but I feel that I will be hitting color real fast.
 

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If you are taking of a lot of clear you should shoot a few more coats of clear just to be sure. I start with 1200 paper, then finish with 2000.

Recoat might depend on what kind of glaze or polish you are using.

Troy;
 

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Sounds to me like moisture in the line from the compressor and the white residue is polish left in the small pits.

Kevin
 
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I have to agree with Kevin. If they are bubbles and you wet sand them they will turn white from the powder that you create sanding. The bubbles are likely from moisture from the air source. If that sounds likeit came from experience, you're right! BEEN THERE, DONE THAT :eek:
 

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Yeah; I`ve been there and that is very possable. If you recoat the clear be sure all the bubbles are sanded out Good Luck

Troy;
 

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Discussion Starter #14
Repair / Blend

Ok, then I need a good advice on blending metallic color. I went ahead and sanded half the fender with 400 grit and got most but not all the tiny bubbles out. I plan on just blending in the new paint by painting color and then clear over the bubbled paint job. Will this be ok? Is ther anything I need to be careful about when blending metallic colors? Thanks
 

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You can`t hide the bubbles.
They have to be sanded out.
then reshoot the clear.
 
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Like Troy said. The bubbles will still be there. It would be well worth your time and effort to get rid of all of them. They will grab your attention every time you look at it. You will feel that every one of them is 10 times as bad as they really are. You'll also think everyone is looking right at them. It is alot of work to go back later and completely re-do it just because of that. BEEN THERE, DOING THAT.
 

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Bruce, what you have is solvent popping. The little white dot that you see after you wet sanded and polish is the wet sanding/polish residue. If you try to reclear over that, you will end up creating a fish eye if not properly cleaned. When this happens in my shop I tell my guys to sand it down completely to the base, blend the base and then reshoot the panel. To keep from getting solvent popping, take the temp of your booth (hopefully not your garage) and the temp of the surface of the car and get the appropriate reducer. With clear coat, always use a tack coat first. How you do this is a semi dry coat over the whole car and allow it to flash. The second coat will be a med wet coat. let it flash to a sticky but not stringy. Don't touch the wet paint but the paper to do this test. Third and so on coats will be the full wet, just remember the flash times.
 

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I have had this problem in my shop... Is it in just a few spots or is it all over the panel ??? If it is just little spots it is contamination (finger prints, residue from a tack rag or degreaser)... You must get all the bubbles out get it down to the base coat then blend that base coat out and reclear it... Also next time DONT harden all your clear at once. mix up a quart or less at a time..... BOBZ_RODZ
 

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I agree about the moisture in the air line. You can sand with 600 grit paper and re clear. If you need to blend from going through the clear just feather the paint out to blend it. Like everybody else said dont hurry follow directions with dry times.
Kevin
 

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tiny bubbles

hi bruce i've been busy this winter in the garage and am now getting to do some painting and last fall i had the same problem as your are with the 2042 i had to sand a complete down to base and reshoot and still had the same problem and to make matters worse it is black and they show up like baby powder when buffed they are trapped air in the clear and i even reduced by 2 and it did help in the lay down but still was getting some bubbles am trying less air pressure and going from a 1.4 to 1.3 and tring for a thinner coat your not alone on this one and i've been fighting it all winter
 
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