NO SHINE.

[65post]

I have had trouble in my shop for a very long time.The final coat of paint be it base - enamel or acrylic enamel within an hour starts to go hazy and lose the shine..The base is not as bad but it will still do it.I do not have a down draft booth but a very good home made job.99 % of the paint I spray with is base.I always put 3 coats of clear if I am not going to rub it out and an extra one if I am.I leave a 10 to 15 min flash time in between coats.Booth temp. is always between 70 - 80 degrees and the exhaust fan takes the fume out pretty fast. I like to spray with a shine behind the gun that leaves me with a flat wet finish. I have used R-M,PPG,RED LINE,TRAN STAR and they all do the same.I have had the paint reps from PPG and RM come by and told me to do alot of different things but I still have the same problem.The solid colors seem to be not as bad as the light met. colors.The wet look always returns with a little light scuffing with some 2000 paper and a buff but for the everyday car coming through the shop and having to go through this is not cost effective.The resto. jobs I do get rubbed out anyway so it is not a big deal.I have seen brand new light colored silver-pewter colored GM,FORD and euro cars and they look like they have the same problem NO SHINE.   HELP!

[mopar_madman]

what did the paint reps tell you? might eliminate some of our suggestions.

[65post]

The paint reps have told me the following.#1-To move the air around in the booth after I have finished spraying so the solvents in the air are not falling back down on the car.Tried it - no luck.#2-To have the body surface of the car the same temp. as inside the booth.No luck#3- To use a slower or faster drying hardner.No luck. #4 - Anything other than the big dollar clears will not hold a shine.Like I said before I have used the high end clears and I get the same result.#5 Not putting enough material on.- putting too much on.No luck#6 - too much humidity.Humidity is not a problem.#7 - Oil or water in the air line.No luck # 8 - ?

[Drop Top]

It must be something to do with the way you shoot your paint from the get go. I don't use a paint booth at all. Never had a problem with my cars not being glossy before I buffed them out. I the temp is right with the humidity and the reducers all matching. Thats the only thing left.
When I shoot paint. The first layer is as heavy as I can put it on without running the paint. Every layer is the same afterwords. Between coats I do the touch test. It may be ten mins or thirty mins between coats. When I'm done its the same story everytime. "Why are you going to colorsand and buff it? You can see yourself already." I did use a paint booth for the first time last Wedsday. The only diferance was the way the over spray disapeard afterwords. Other then that I saw no differance.

[bill440rt]

65post,
Sounds like it might be moisture in the air line. I've seen clears turn hazy because of moisture. Do you have enough water vapor separators in the lines? Have you tried using a "last chance filter" at the gun?
I remember painting a Monte Carlo AeroCoupe once, it was that dark maroon. I did it in DuPont base/clear, there were white lines in the hood from moisture being in the air line, I had to re-shoot the hood.
If you're only stating that the basecoat is losing it's shine, it's supposed to lose it's shine, it's the clear that provides the shine.

[parkerswede]

Try running a small job out of cylinder of dry, compressed air. If the problem clears up, then the air supply is your problem. Sometimes running too much air through your gun can cause the paint to look dry. Sounds like a systemic problem so look for something that affects everything.

[69chargeryeehaa]

i've had the same issue, and i can tell you it ended up being moisture in the air.  if your compressor is in the shop for example and your shooting in your home made booth, the compressor is keeping the water suspended in the compressed air under pressure, when you spray the air expands and cools, causing the water in the air to condense in the paint.  i know you've heard it all before, but if you look at what you've eliminated (ie: using different brands of paints, different reducers, hardeners, ect...) the only constant left is your air setup.  i'm a former industrial millwright, and used to service high end assembly equipment with pneumatic pick/place cylinders, and even with a oil-less screw drive 50HP compressor there was still a moisture in the air issue.  we eventually resolved it with a accumilator and several gravity and filter air/water seperators.  i'd bet my $ that it is a moisture or water in the air.  try a really high end filter/seperator, and run your system for like 1 hour continously with the gun hooked up dry with a elastic on the trigger, then paint.  you'd be supprised to see how long water comes out of the system that's in the lines ect... you can build your own gravity water trap by putting a "T" and haveing a regulator before it which kinda acts like a expansion valve and right after the regulator have a trap with a fitting you can remove to empty the water, and trust me there will be water even if you have a seperator.  the best test would be to run it dry for a few hours just before you paint and see if that eliminates the no shine issue, i'd bet it will. also after running your compressor for a long time like suggested empty the tank drain to get/see if there is any water in your tank.

[65post]

i've had the same issue, and i can tell you it ended up being moisture in the air.  if your compressor is in the shop for example and your shooting in your home made booth, the compressor is keeping the water suspended in the compressed air under pressure, when you spray the air expands and cools, causing the water in the air to condense in the paint.  i know you've heard it all before, but if you look at what you've eliminated (ie: using different brands of paints, different reducers, hardeners, ect...) the only constant left is your air setup.  i'm a former industrial millwright, and used to service high end assembly equipment with pneumatic pick/place cylinders, and even with a oil-less screw drive 50HP compressor there was still a moisture in the air issue.  we eventually resolved it with a accumilator and several gravity and filter air/water seperators.  i'd bet my $ that it is a moisture or water in the air.  try a really high end filter/seperator, and run your system for like 1 hour continously with the gun hooked up dry with a elastic on the trigger, then paint.  you'd be supprised to see how long water comes out of the system that's in the lines ect... you can build your own gravity water trap by putting a "T" and haveing a regulator before it which kinda acts like a expansion valve and right after the regulator have a trap with a fitting you can remove to empty the water, and trust me there will be water even if you have a seperator.  the best test would be to run it dry for a few hours just before you paint and see if that eliminates the no shine issue, i'd bet it will. also after running your compressor for a long time like suggested empty the tank drain to get/see if there is any water in your tank.

Going to give it a shot.I never see any moisture coming out of the gun when I am spraying but as you said it might be condensing in the paint.Sounds logical.I have a pick up I am going to be shooting shortly.I will post the results when its finished.

[69chargeryeehaa]

often the loss of shine and "milky" appearance in paint is attributed to moisture, or high humidity.  i think you'll find you have better results after running it dry for about 1 hour just before you paint, if you do you'll have to address the moisture with a better solution. good luck, let us know.

[65post]

69chargeryeehaa,May the good lord richly bless you.Your answer solved our 20+ year problem.Now I have been letting the compressor run with the drain open until I can see there is 0 ( moisture ) coming out ( before I was just getting the water out and not all the moisture ) and do the same  inside the booth at the separator before I paint and the results are fantastic! No more buffing.Again thanks a million.

[69chargeryeehaa]

69chargeryeehaa,May the good lord richly bless you.Your answer solved our 20+ year problem.Now I have been letting the compressor run with the drain open until I can see there is 0 ( moisture ) coming out ( before I was just getting the water out and not all the moisture ) and do the same  inside the booth at the separator before I paint and the results are fantastic! No more buffing.Again thanks a million.

your welcome.  i guess you have to have had the expirence to recognize moisture problems.  it's the most overlooked issue in painting.  did you make the trap i sugested?  making a "T" fitting, and just before it put a regulator, even if you regulate at the full supply, it acts like a expansion valve which seperates the water from the air, and then have a pipe going down with a cap?  then to empty it you just close the regulator, and bleed the air out of the system on the other side and take off the trap cap, lots of water will come out, cheap simple soloution.  glad to hear it solved your problem.