P60G2
As the title states, I've decided to use Sherwin Williams P60G2 primer with the Barney gun (Harbor Freight HVLP gun).
Any tips and or recommendations on surface prep, thinning, pressures, OAT's, etc.....? It would be appreciated. I plan on modifying the fus crate into a mini paint booth and will shoot the parts in a large hanger.
I've searched and read that a maroon scotch brite pad, solvent wipe and then a 1 part primer to a 2 part accelerator works best. But what about psi at the gun?
Also, best to have the parts hanging vertical or laying flat?
Thanks in advance.
Dan
Feel free to check out my blog. Lots of info on P60G2.
Here's my process.
Buy some rubberless syringes in 10, 20 and 60 ml. Handy for measuring.
Buy a good respirator.
A good mini regulator (RTI MR1 Micro Regulator) and water/oil filter is recommended. Regulator closest to the gun then filter then hose.
3M disposable paint cup system is awesome.
Process
Scotch brite maroon. Use a random orbital on big stuff. Faster.
Just before a spray session, scrub parts with Ajax or Comet and gray scotchbrite. Rinse thoroughly. Drip dry. The powdered cleansers are excellent for removing the aluminum oxide layer but it reforms within an hour so be ready to shoot. Nothing sticks to aluminum oxide very well and solvents don't remove it. Alumiprep will also remove it but it's phosphoric acid and powdered cleansers are really cheap.
While the parts are drying...
Open the primer and stir with a stick. Pull the solids off the bottom and stir till you get tired. Minimum 5 minutes for the first time use. Use the respirator. Wipe the primer off the stick with a popsicle stick.
Figure about 2 sq ft coverage per oz of mixed primer. It should get you close. No sense in wasting. Mix more if you run out.
1 part primer to 2 parts catalyst works well. It's pretty thin and sets up very fast so be prepared. If you stop more than a few minutes, pull the cup and shoot some lacquer thinner through the gun. Even swapping parts is enough time for primer to gum up the tip.
My DeVilbiss gun settings with 1.3 tip.
23 psi
1 turn out on the fan
1 turn out on paint
Spray only till you see a color change from aluminum to light green. It gets darker when it sets. You can always spray more but forget about removal if you spray too heavy.
Opinions vary but I like it thin. You can see markings through it. It sets to touch in about 5 minutes.
I usually make one pass then a second 90 degrees perpendicular.
It should go on very smooth. A sandy texture means too much paint or too little air pressure.
It's incredibly tolerant of temps and humidity. I've sprayed below 50 OAT with no problems.
Orientation is user preference. I don't like them swinging from the spray. I use a cheapo baby gate on two saw horses as a spray table.
