Could use some advice on gas tank painting

ckahleer

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Yesterday I painted my tank with rattle can DupliColor "Deep Cranberry Pearl". The texture of finished product was very rough. both visually and to the touch. I wet sanded it down again this morning, and will attempt to paint again tomorrow.
I have 2K clear coat on order. Should I have just left it alone, and the 2K would have smoothed it out?
The paint I used was unopened, but was sitting on a shelf in my workshop for at least 5 years.
I'm more familiar with Rustolium enamel type paints, Do DupiColor paints leave a smooth, shiny finish, the way an enamel would?
 
As paints ages in the can the finely dispersed particles can start to agglomerate to produce larger particles. The agglomerates can often be redispersed by shaking, but not always. So it is possible that your final texture is a result of storage conditions. Also, it is best to follow the temperature guidelines on the spray cans. If it says 20 - 25 Celsius then you will need to spray in a nice warm environment which is not always possible in the Winter. When the paint sprays it involves evaporation of solvent i.e. cooling. If you spray in damp/humid conditions the cooling can condense moisture out of the air and give a rough texture, you may actually see small globs of water on the freshly painted surface. I got caught out with this 2 years ago in November when the sky was blue, temperature was about 16 Celsius but the air felt damp.

Some people, including myself, preheat spray cans by standing them in approximately 25 Celsius water prior to and inbetween coatings. This will ensure the paint viscosity is well matched to the cans pressure and nozzle design. But it is still important that the environment temperature is also correct.

If you spray a clear coat when it is cool, 1K or 2K, you may see a milky appearance to the coating. This will usually go away after several minutes but it does indicate the temperature is too low for the paint application. Another reason for having the correct environment temperature is to ensure that you get the correct level of solvent flashoff between coatings. If too much solvent gets trapped in the layers of paint the coating can take a long time to harden and reach its optimum final film properties.

The 2K clear coats usually have quite a long application time once the two components have mixed. I have used ProXL 2K and it is rated at about 12 hours for application time. You have plenty of time to shake and shake for say 5 minutes to ensure thorough mixing. The downside to 2K is not mix thoroughly and this is usually the main reason for customer complaints of long cure times or the coating staying soft. So do not rush the mixing.
 
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Is the tank smooth?
What was the temperature of the tank when the paint hit it?
Have a piece of smooth material next to the tank and shoot some paint on it at the same time. If both materials end up with "rough" paint, then its the paint or climate. If just the tank, then its the tank.
 
The recommended temperature range stated on the can is 60 - 85 degrees F. The garage temperature was 62.
I will be picking up another can of the same paint tomorrow. I can run the garage heater and get the temperature up to the mid 70s.
I'll give that a try.
 
Really sounds like you were spraying too thin coats causing the paint to almost dry before it hit the surface. Spraying too far away from the object will do that too. Watch your paint hit the surface, travel at a speed that will lay down a WET coat of paint. Distance of about 10" is important to getting a WET coat of paint too.

That's Acrylic Lacquer, it will quickly dry in the air before it reaches the object, good choice but needs to be sprayed with more accuracy than slow drying enamel.

Scott
 
OK. Repainted today. Better results, but still not good enough.
Top of tank is smooth and acceptable. Sides are still rough and left side has weird lighter center.
Garage temperature was 72 degrees f. I had tank and paint in the garage at least 4 hours before painting.
I kept nozzle 6" - 8" from tank. Instructions said 8" - 12".
My first attempt, a few days ago, was 3 light coats 10 minutes apart.
Today's attempt was 2 heaver coats 10 minutes apart with the top of the tank on the 2nd coat extra heavy, to use up the paint.
I ordered another can of paint tonight, and will repaint using the entire 8oz can in one coat.
Although the instructions on the can recommend 2 or 3 light coats, from the results I got on the top of the tank, I'm thinking a very heavy single coat will work best.
On top of what I have on already, it should cover just fine.
I guess the trick will be keeping the paint from running.
Attached pics are of today's attempt.
Side panel is hanging there just to compare color.

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Im surprised the base was dry enough after only 1 hour, know ing you applied an entire can.

Did both the base and clear get applied while the tank hung from the rear mount like in the photo, no runs?
 
I screwed a 3' piece of 2x10 edge wise to a wood table and set the tank over it. So it was in its normal position.
When I say one coat, I mean I didn't stop spraying until the can was nearly empty.
Started on bottom right side, worked my way up, over the top, and down the left side of the tank. Then went back to the bottom right of the tank and repeated.
So I made 2 passes. Since it probably took a minute or two to complete each pass, the paint may have set up a little before being hit again.
No runs.
 
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