View Full Version : Paint Problems
04-17-2007, 04:03 PM
Ive been having paint problems and im at wits end trying to figure it out. I first started painting last year just a small project. I bought some OMNI AU black mettalic paint and already had a old craftsman touch up gun and old well used filter from my dad. Well I tried and after I got done there was tons of little bumps all over the paint job. It would be like sand paper about the size of a pin head all over it looked like shit. I opened up the filter and there was all this dried yellow water everywhere since it was so old and the paint gun was soooo old i thought this must be the problem.
So this year I bought a cheap Astro LVLP gun and a sharp filter and a central neumatic filter and a regulator at the gun all new hose and everything and it does the exact same thing. Ive tried everything from thinning the paint more to turning up the air pressure way past the max and it always does the same thing.
It just aluminum sprayed with SEM self ethching primer, wiped down with with thinner to clean and tack clothed, and painted with 4:1:1 OMNI AU and MK168, and of course thinner.
I dont know what to do Ive tried everything it looks terrible. I dont think its a water problem since my compresesor never even ran for a couple days since it was a small project it is cool and condensed.
Heres my setup
25ft of 3/8" ID ruuber hose to cn filter to sharp filter to regulator, 25ft of 3/8" ID tube to a regulator at gun. Any help would be great. Thanks, Dan
Sorry I tried to take pictures but I just cant catch it on my camera to show.
Are the spots small high spots or small low spots?
04-17-2007, 05:19 PM
small high spots like if you ran your hand across it they would be like tiny bumps. The gun lays down a real nice finish but all those bumps just plague it. But there evenly across the entire painted surface. Thanks, Dan
BTW Thanks for the excellent service I recived from u when I ordered len.
are you straining the paint?
04-18-2007, 10:30 AM
yeah i strain it into a cup and then strain it into the guns cup. But im not using the strainer that came wth the gun in the cup. Thanks, Dan
04-18-2007, 11:45 AM
too much pressure? what are the gun settings?
04-18-2007, 01:07 PM
Well I started out at the recommended 23psi at the gun and at the end i tried every setting posssible and it dont change a thing. Im actually starting to think theres a problem with the reducer and the OMNI AU paint cause I poured some on the painted surface and it has a reaction and makes tons of tiny bubbles just like i see when I paint for real.
Its the recommended reducer and mixture. I think Im gonna try without the reducer and jsut see what happens. It just seams strange to me how it looks when i put straight reducer over the paint and it looks almost identical to the finish im getting.
It just cant be a gun setting I tried two different guns a differnet filter system and its always the same. It has to be either the paint or something with the surface but I doubt the surface since I cleaned it a variety of ways and it never changes an ounce so it has to be something with the paint. What I dont know but im trying. Thanks, Dan
04-18-2007, 04:45 PM
i've had this exact problem with a gallon of chromabase before. Something happend in on the mixers end and the whole gallon was contaminated. He mixed me another gallon and it was perfect. I would try buying another pint of paint and see if the problem dissapears..then you know whatever paint you have there may be defective
04-18-2007, 04:47 PM
I tried decreasing the reducer with no success. Ive worked 2 years on my project and 100s of hours and this is how it ends.:( I never thought a can of spray paint would be better in the end.
Ive tried everything from adjusting the paint flow, spray distance, what I cleaned the surface with everything from a boughten prep spray cleaner to just tacked primer.Ive tried different guns, filters, and paint mixtures, primers. Ive had different people spray with the gun with the same results.
It is just like a window on a day with the lightest drizzle how you got thousands of little drops all over the finish. Looks like absolute garbage. Cant blame it on anything since of tried painting everything in all different climates differnt methods different settings different mixtures different guns. Absolutely everything and nothing has helped an ounce. Ive wasted probably a quart of paint and have nothing to show for it.
Im gonna try what the guy above said and get some different paint since thats the absolute only thing that has never changed. Thanks
04-18-2007, 05:06 PM
There's a term called "Seedy" paint. It can occur from old paint sitting in a can & reacting with the can seam solder or lining. Toners on a mixing bank can go bad too. If a seedy mixing toner was used in your mixed paint, then it's probably the problem. How long have you had the paint & when was it first opened. A lot of times seed paint will be small enough to go through the paper strainer but usually leaves a trace in the strainer. What does your jobber say?
04-18-2007, 05:13 PM
i bought the paint at finish master last year but i used it last year the day I got it and it was the same as it is to this day. Thats why I got new equipment thinking that was the problem but nothing changed. But I can tell u this place goes through very little paint and is always just hanging in there. Not a huge calling for it in the area.
04-19-2007, 12:21 AM
sounds like dust, or catamination from grease, oil, or wax. how clean is the area that you are painting in? did the car ever have wax? did anyone ever clean parts of the car with armorall( silicone)? is there any chance that oil was transfered while cleaning, or is there any chance your compressor is pumping oil( alot of wear) or water( condensation in the air lines, some filters won't catch it all) in i always use a water filter at the gun for a last stitch effort in getting rid of all problems.
04-19-2007, 09:30 AM
The area I paint in is in doors not a paint booth but inside where there isnt that much dust. Ive painted in several locations and it never changes. The surface is a piece of cleaned aluminum with a couple of layers of SEM self etching primer. There was no waxes or anything put on and im not painting over old paint. Ive cleaned the primer surfaces with prep solvent and several other cleaners but its always the same. And the compresor is a 60 gallon, sears oiless motor(its one of the loud ones:( ). I use double filters. So water is sa possbility but Ive shot so many times over and over agin with the same result im almost thinking its the paint. So im gonna try new paint and if that dont work ill be back and if it does ill tell my experience. Thanks, dan
It could be that the hardener is old. Hardener tends to create small bumps when it is opened then left on the shelf for a long time.
04-19-2007, 10:48 AM
Its actually unbroken brand new sealed hardner. I just opened it the day i used it. Had anyone worked with OMNI AU the cheap ppg stuff? I dont know if its good paint or not since ive never had the good stuff. Thanks, Dan
04-19-2007, 10:52 AM
Oh yeah BTW is there anything easy to get that I can buy for a prep solvent like at a menards or something. I just ran out of real prep solvent and the closest paint shop is like an hour and a half away. Im not sure what will remove grease and silicon but maybe someone here knows. Thanks, dan
04-19-2007, 11:03 AM
50/50 alcohol/water might work in a pinch. im really just guessing though
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