Attention Spray Painters!

[geodon]

I'm painting my Pug wheels & have struck a problem I've not had before.


The gun is a gravity feed unit.


Spraying grey primer with 10-20% GP thinners.


Air pressure 25-30psi.


With paint in the gun, no air, trigger depressed, paint comes out in a steady dribble under gravity.


Hook up to air, lovely full, wet coats for ~60 secs then the feed starts to falter. 60 sec more no feed. Air off, trigger depressed, no paint.


I tip out the paint, add thinners, swirl, depress trigger (no air), thinners comes out.


I start again with paint & get the same result.


It's almost as if the paint is prematurely going off in the gun with the air.


I've always used 25-30psi. Any more causes runs.


Comments?

[geodon]

Der! Sorry 'bout that!

[blue_mini]

Its not etch primer is it? Need to thin etch primer with acetone.

[geodon]

Yes, BM, it's etch primer & the paint shop said to use thinners GP

[Corgie Carrier]

I usually use 45-55psi and hold the gun about 30cm from the job. If you are getting runs you need to move faster or hold the gun further away.
If that doesn't work, I have no idea. the paint shouldn't go off in the gun unless it is old paint or the wrong thinners.

[blue_mini]

Reason i ask is I was having the same problems, paint would go off in the gun and clog up the filter. I have a gravity gun as well, probably running 50ish psi or so though.

That was with concept paints etch primer a few years old so went and bought a tin of dulux etch primer and read on the back to thin with acetone, did that and came out lovely. Wouldve been 6 months ago i did that over cold gal and the top coat hasnt shown any signs of anything bad.

[geodon]

I went up to 40psi with etch primer & got the same result!


After struggling through, I changed to colour (acrylic lacquer) diluted 50% with GP thinners & it went thru perfectly with good results.

[Corgie Carrier]

Like Blue mini said it sounds like the wrong thinners.

What does it say on the tin of etch primer you have?

[DoubleChevron]

I doubt it's the paint ... check your air breather on the cap and remove the stupid filter between the gun and pot. Just unscrew/remove the breather on top of the pot for starters (don't tilt the gun too fun an spill paint out) and I'm sure you'll find it works fine.

Get the feeling I've "been there and done that" many times :D

BTW: I'm NOT a painter, I'd just someone that tinkers in there shed.

seeya,
Shane L.

[geodon]

Like Blue mini said it sounds like the wrong thinners.

What does it say on the tin of etch primer you have?


The tin says: "Before starting refer to data sheet 426." Gee, thanks!


But I bought the primer & asked for the thinners. GP is what they sold me.


The weird thing is I used black etch primer for the Dauphine engine which is dark green & it worked fine with GP. The Pug is light green so I got grey etch primer & it didn't work.


I'll consult the guru Monday.

[geodon]

http://www.ppglic.com.au/uploads/tds/426%20Etchpro.pdf


Thinners is right but the air pressure is much higher than I was using.


Ah well! "When all else fails, read the instructions!"

[DoubleChevron]

The tin says: "Before starting refer to data sheet 426." Gee, thanks!


But I bought the primer & asked for the thinners. GP is what they sold me.


The weird thing is I used black etch primer for the Dauphine engine which is dark green & it worked fine with GP. The Pug is light green so I got grey etch primer & it didn't work.


I'll consult the guru Monday.

Check to see what needle/seat the spec sheet says you need. You might need a minimum of a 1.8 tip. Most will be 1.4. I would have thought it would still work if you hosed it on though :)

seeya,
Shane L.

[numpty]

I just play in the shed too and what I have success with is 50psi, thin etch primer with all purpose thinners at 30%. My gravity feed gun for this has 1.7 needle and I have another with 1.4 for top coat.

Seems to work so far :)