bgw67
Mar 17th, 08, 08:55 AM
Finally got to filler primer on all new sheet metal yesterday after almost three years of work. Up till now, I have only really shot a small amount of PPG DCC, the interior lacquer and a ton of DP epoxy. One of the habits I have got into is watching the volume of material in the paint cup on my gun so that I don't run out and spatter those last few squirts as it runs out. When it gets low, I just mix some more, add it to the cup and keep painting.
Yesterday, I laying down some nice PPG K38 catalyzed filler primer with this same approach and about 2 quarts in, I realize that I am just not laying down near the amount of paint I had been. I start readjusting mixture and fan pattern settings but can't get any real volume to come out. It is still atomizing nicely, so I am baffled. Finally, I decide to empty the cup and run some solvent through the gun. I tip it over, and then the gooey chunks start coming out.
That is when I remembered that the spec sheet mentioned a 3/4 to 1 hour pot life. Everything else I had shot with had a MUCH longer pot life than this. In hindsight, I realized that the remaining first batch was setting up in my gun with new paint on top still liquid, so when I looking in the cup, it all looked fine.
I was able to get all the goo out, thoroughly cleaned the gun, and hung it up for the night. I lost probably $35 in paint and wasted about an hour trying to shoot with a constricted gun, but this was a small price to pay at this stage. Going forward, I will run each batch out through the gun, run solvent through it, and then add the new paint.
I thought I would share so someone else does not make the same newbie mistake I did.
One good thing - my car is all one color!! This is the first time in probably 10 or 12 years. I still have work to do, but I can see the light!
Yesterday, I laying down some nice PPG K38 catalyzed filler primer with this same approach and about 2 quarts in, I realize that I am just not laying down near the amount of paint I had been. I start readjusting mixture and fan pattern settings but can't get any real volume to come out. It is still atomizing nicely, so I am baffled. Finally, I decide to empty the cup and run some solvent through the gun. I tip it over, and then the gooey chunks start coming out.
That is when I remembered that the spec sheet mentioned a 3/4 to 1 hour pot life. Everything else I had shot with had a MUCH longer pot life than this. In hindsight, I realized that the remaining first batch was setting up in my gun with new paint on top still liquid, so when I looking in the cup, it all looked fine.
I was able to get all the goo out, thoroughly cleaned the gun, and hung it up for the night. I lost probably $35 in paint and wasted about an hour trying to shoot with a constricted gun, but this was a small price to pay at this stage. Going forward, I will run each batch out through the gun, run solvent through it, and then add the new paint.
I thought I would share so someone else does not make the same newbie mistake I did.
One good thing - my car is all one color!! This is the first time in probably 10 or 12 years. I still have work to do, but I can see the light!