Paint Spraying Problem...

[supersub14 1]

(First, if this is in the wrong section then please move it)

 

Ok, me and my mate have been spraying a few random bits and pieces for a while now but we keep having the same problem. When the top coat of paint goes on it becomes pitted with small dots all over it. Im at work here so ill throw some pics of a spolier i painted last night when i get home. Has anyone any ideas why this is?

 

We use a air compressor setup as below:

 

Procedure:

Before we start we drain all the condesation water that has built up in the compressor via the bleed valve on the bottom of its tank.

 

Using 2-pack primer mixed with 722 hardner, we spary a base coat onto the panel (Panel has been well sanded down and cleaned by the way).

 

Panel is left for 20mins or so to dry then the top coat of 2-pack paint is mixed with 722 hardner and sprayed onto it.

 

After 2 or 3 mins the imperfections in the paint occur. They werent in the base coat.

 

We are using a proper spray gun (worth £200) so its not it. Would it be the type of paint? Or is it moisture causing the problem? We originally only had 1 pneumatic filter in the line but i got a second one from my work but it hasn't made a difference. Its not dust either.

 

Any help greatly apprieciated...

 

 

John

[M@tt 77]

http://www.mig-welding.co.uk/paint-faults.htm

 

Sounds like fish eyes (scoll down near the bottom)

 

HTH

[miamichris 9]

sounds like silicone maybe!

 

* Just read matt's topic and it suggest silicone too, wherever it is you're spraying must have it in the air. Are you polishing stuff etc. in the same area? You want a really clean place to spray in and use polishes etc. that are silicone free (ie. no son of a gun, back to black sh*t etc!)

 

My dad talks about it like its some sort of plague Says that he had to stop spraying for 3 weeks one time when the spray area got contaminated and everything he sprayed got fish eyes. I think theres additives for the paint you can get that kill the silicone, don't know much about them though mate

Edited August 13, 2009 by miamichris

[supersub14 1]

Seems like yous were right about the silicon. We've just been spraying in the garage that we use for everything. ie. welding, grinding, servicing etc so theres a lot of contaimation in the air.

 

gonna have to look into using a seperate shed. Cheers for the help

[toddydal 1]

it could be anything mate,what size compressor you using,if its smaller than a 100ltr i would guess as its a water and oil issue,doe you have to drain your compressor all the time and when you do does a lot of water and oil come out have you got a picture of the problem,i had an issue with my 50ltr compressor with water and even with 2 traps on the airline it still happend and it always happend in the clearcoat,i bought a 100ltr compressor which when i drain ther is very little water in the tank and the 2 traps have no water in now so i know it was the 50ltr,i have done alot of jobs now and they have all been ok