Contaminated Alclad or just poor what?

[CANicoll]

Need some input from the smart people here.  I was attempting to spray Alclad on my F-4E last night started getting what looked like threads on the model.  Paint threads.  I was shooting Alclad Aluminum straight, at 8, 12 and 15psi.

Here is what it looked like on the F-4 tail:

And then on my test mule:

I know it LOOKS like actual cotton or wool thread, but it is paint. Also notice the coarse surface texture behind the gun muzzles.  I have a theory what caused this, but want to hear your thoughts before sharing.  Thanks!

[DocRob]

I had similar effects with Mr. Hobby GX-100 gloss clear, mixed with leveling thinner in a plastic jar. Seems the mix dissolved the plastic. 

Cheers Rob

[BlrwestSiR]

I think the paint is drying too quickly. This can happen with lacquer based paints if they're too thick or if the pressure is too high on the compressor. The first one would be odd with Alclad though as it's fairly thin. 

@ScottsGT would probably know best as he used to be a paint guy. 

 

 

[Peterpools]

Chris

I have to admit I've never seen this before and have no idea what may have caused it. Only possible explanation is contamination of the Alclad which caused the thread like finish in the air brush. 

 

[CANicoll]

Pretty strange, huh??  Thanks for the suggestions, gents.

Doc, I think you are on to something there - Carl, I did try it at various pressures down to 8 psi so you and I had similar thoughts.  Peter - I believe you nailed it.

I think I have narrowed the culprit down to a pipette I used to take the paint from the MRP bottle to my airbrush.  I have a tendency to re-use stuff and in this case, there was a white residue inside the pipette that I neglected to pay attention to.  I need to do another test, but I'm 95% certain that is the problem.  FWIW I even tried it with a different airbrush and got the same result.   So probably tomorrow I'll be able to do a test and am hopeful that will be the answer...

It is always something, huh? 

 

[Count0]

The paint is drying in the air. Likely you need to thin it, it's probably lost some of it's original thinner over time to evaporation.

[ScottsGT]

Modelers undercoating?  
 

Looks like paint that needs a lot of thinner added to it.  But as mentioned, could also be contaminated with something.  I’ve seen paint act this way from both issues.  
I’d try a fresh pipette and thinned out. 

[belugawhaleman]

That is odd. Reminds me of that Silly String stuff!

 

[CANicoll]

13 hours ago, ScottsGT said:

Modelers undercoating?  
 

Looks like paint that needs a lot of thinner added to it.  But as mentioned, could also be contaminated with something.  I’ve seen paint act this way from both issues.  
I’d try a fresh pipette and thinned out. 

I think it is contamination from the pipette.  I never have to thin Alclad and no matter what pressure I shot it at, including 8PSI Itried.  Hopefully this week I can run a test. Pissed that I was not more careful.  But at least I don't think the damage is major.

[ScottsGT]

Agreed. Alclad is pretty thin stuff.  

[BlrwestSiR]

If you have either Tamiya or Mr Color lacquer thinner, you can use either one to wipe the paint off. They're cool enough that they won't harm the plastic. 

Don't use their tool cleaner though as that will eat plastic. 

[CANicoll]

5 hours ago, BlrwestSiR said:

If you have either Tamiya or Mr Color lacquer thinner, you can use either one to wipe the paint off. They're cool enough that they won't harm the plastic. 

Don't use their tool cleaner though as that will eat plastic. 

Excellent!  Thanks!

[CANicoll]

Cleaned off the tail with Carl's suggested Mr Color and that worked very well.  Cheers!

Tried a test shot using a clean pipette and I have come to the conclusion that I have contaminated the bottle somehow.  Fortunately, am only wasting about 1/3 a bottle. I even tried thinning the Alclad with some MRColor and that didn't really have an effect.  Oh well!!!

If anyone wants a bottle of contaminated Alclad......  I have to tell you, the stringy effect is pretty cool.  No problem with clogging the airbrush, either.

[Peterpools]

Thaks Chris, what a guy