i dont know what all is in simple green but alot of times degrease like that contain differetn types of oils

 

Did you use a metal flake in your paint? If so could it be a run? When I painted my explorer I used flake and when it ran it looked like a hair due to the flake not settling properly. I lightly sanded down the spot and recoated over it.

 

Second on the FAQ idea. Sounds like bmaytum has been to this dance before. I never understood the idea of using a wax and grease remover before sanding off all the paint. Just didn't make sense - until I had to redo a job because I skipped this step.

Remeber guys automotive grade paints, any with a hardener, are very nasty chemicals. You really should use a supplied air system when applying them. Especially in a "home" shop that doesn't have the ventilation of a pro shop.

 

Another source of those dark lines could be contamination from within the gun. Even if you clean it out well by spraying solvent through the gun, paint can back up into the air passages because of leaking seals, momentary clogs that cause 'back blast' (jprobably not the official term) or gun lube on the needles getting loose. Later exposute to paint or solvent can mobilize the gunk with unpleasant results. Taking the wholde gun apart and cleaning everything, including the air passages, is the cure for all kinds of contamination.

"Three gallons of wax & grease remover is worth 20 hours of re-do". see "Finicky Prep Work" Sanitary Prep Pays Off from the 5-Star Paint site:
http://www.autobodypro.com/tektips/articles/prep_wrk.htm

Another possible source of contamination is rubber seals and o-rings that are not solvent compatible. Try wiping them with a white rag loaded with your solvent or paint and see if any dark color comes off. If it does, they are dissolving in the material and can cause problems.

The 5-Star Paint site has tons of great information, including their Tektips section and a free forum.. I use their clears and primers because they are very reasonable and work well. I don't have any financial or other interest in 5-Star, I just like the prices and the quality. You can search for dealers on their site: http://www.autobodybrands.com/

Painting Troubleshooting Guide:
http://www.autobodybrands.com/trblshtg_page.html

Their Tech Manual for the Pro Refinisher is a 48 page pdf with an excellent prep section at the beginning. http://www.autobodybrands.com/pdf/techmanual_july05.pdf

I have used: (with the fast activators)
#5185 XTREME ORIGINAL
CLEARCOAT 4.4 VOC

#5157 XTREME HI-VELOCITY
CLEARCOAT 4.2 VOC

I also like their Aerosol clear urthane--a great highgloss auto clear in a spraycan--great for quick touch-ups or small jobs that don't warrant suiting up and cleaning the air gun.

I tend not to paint whole cars at once so I like the speed of a panel paint. They make some that are useable for panel jobs to whole cars depending on the activator--see the manual

I hope this is useful.

Brian Maytum