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Bad Paint?


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#1 danman6677

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Posted 16 June 2013 - 09:11 AM

These pics are an hour after I painted with duplicolor gm dark blue. I primed and sanded with duplicolor sandable primer. Washed my hands with fragrance free soap. warmed the can, shook for 5-6 minutes. Sprayed from 5-6 inches away. This is the second blue ive tried this happened to., the first was duplicolor Black sapphire. Any ideas what happened and what I have to do to get good non foggy coverage?

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#2 Bobdude

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Posted 16 June 2013 - 09:18 AM

How humid is/was it when you were painting? Weather effects lacquer more than people realize.



#3 danman6677

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Posted 16 June 2013 - 09:28 AM

didnt really feel to humid but ill crank on the dehumidifier



#4 Jantrix

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Posted 16 June 2013 - 09:35 AM

Yep. It looks like blush caused by humidity. The good news is, it can be polished out.

#5 danman6677

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Posted 16 June 2013 - 09:49 AM

oh really, i just put it in the purple bath 5 mins ago.



#6 Jantrix

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Posted 16 June 2013 - 10:48 AM

imagesCATOV0WZ.jpg



#7 danman6677

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Posted 16 June 2013 - 10:56 AM

I think I saved it, gave it a good wash then 2000 grit, another wash and good dry, Put the stand in front of the dehumidifier and sprayed, then brought the hood upstairs and it has a slight fogness on the side but its better than before.



#8 Art Anderson

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Posted 16 June 2013 - 11:10 AM

Automotive touchup paints are still a form of lacquer of some sort or another, and thus are subject to "blushing".  Blushing is that somewhat "pearly" look on the surface of lacquers, and some fast drying aerosol (rattle can) paints, caused by the paint droplets actually being rather cold as they come out of the nozzle under considerable pressure from the propellant (spray cans used to use Freon, a refrigerant which is now banned in most countries, so nowadays butane or propane is pretty common).  The propellant used in rattle can paints is under enough pressure in the can to force it to dissolve into the paint itself, and being under pressure at the same temperature as the ambient (surrounding) air where the can is being sprayed, and once you release that pressure by spraying, the temperature of the propellant, especially as it comes out of the nozzle, drops dramatically.  The rapidly chilled paint droplets actually will condense moisture from the air, for the same reason and by the same process that a cold can of beer or soda "sweats" with condensation on the outside surfaces.  The only way to avoid this is to either paint your model in an airconditioned or at least dehumidified atmosphere, but if that's not possible, Wait for the weather to cool down a bit, especially after a cold front passes by you--as that does drop the relative humidity quite a bit, and that will minimize paint blushing.

 

Having a brother and nephew who are in the cabinet-making/antique furniture restoration profession, they also gave me this piece of advice years ago:  When working indoors (their shop is a fully enclosed building), in Indiana which is well-known for frightful humidity much of the year (except on a bitter cold winter day when everything is hard frozen outside!).  They told me that in their experience (and they use clear acrylic lacquer (as in automotive clear acrylic lacquer) when it's pouring down rain, as in a thunderstorm, outside, the relative humidity in their shop drops dramatically, due to heavy rain actually sweeping water vapor out of the surrounding air--which does give them quite a "window of opportunity" for spraying lacquers (and they use both rattle cans and spray guns).  Since blushing is almost impossible to polish off a wood surface completely, their experience and knowledge is something I've taken to heart--they are both certified to several museums, including the Smithsonian Institution.  I've used their advice, and I can attest that it does work.

 

But, the good news is, blush can be removed, either by buffing out, or by laying on a clear coat of lacquer (or Duplicolor etc.) when the air dries out a bit.  No need to strip the part or body shell just to remove blush!

 

Art



#9 danman6677

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Posted 16 June 2013 - 12:49 PM

had the dehumidifier running all day and sprayed the body......yipppeee more blushing :blink: , Would going over it with Future help it?


Edited by danman6677, 16 June 2013 - 01:13 PM.


#10 Jantrix

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Posted 16 June 2013 - 02:54 PM

Like Art said, either polish it out or clear coat it.



#11 HNTR

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Posted 16 June 2013 - 03:00 PM

Polish it out.

This is a hood I just did and polished one side and left the other alone. 

DSCN2027_zps84e17800.jpg

DSCN2029_zpsa1cc0649.jpg

DSCN2028_zps01eaf2a7.jpg

 

That is what polishing will do for you.



#12 AzTom

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Posted 16 June 2013 - 06:37 PM

Isn't 5-6 inches a little close with a rattle can?