Mech is correct the days of sanding base between coats are long gone. The only time you would sand your base coat color is if you run it or a low flying elephant decides to land on your wet base coat color. lol Now if you do have to sand the base make sure you re-apply more base coat color in that spot.
The base should be applied as a medium light coat. Your gun fluid tip should be a 1.3mm to 1.4mm.
The general rule for base coat is 15 to 20 minutes flash time between the first and second coat. If it takes a third coat add another 5 minutes between your 2nd and 3rd coat if it takes a fourth add 10 more minutes to that. Spray the base coat color to achieve hiding.
The clear needs to be applied around 20 to 30 minutes after your last coat of base color. The key to this is not so much the time period but make sure the last coat of base coat is totally dry. On some painted part of masking paper you should be able to gently run your hand across the base coat and not have it string or stick. Its what we painters call "hand slick".
The clear is the same time between coats around 15 to 20 minutes flash time.
The first coat of clear should be applied medium wet. This is where it would look like what we call "spray to look" This means pretend its your one and only coat and you don't want any dry areas. The same "hand slick" rule applies for the clear coat between the two coats.
Now the number one major mistake people make when applying clear coat and all my staff is trained to talk the customer through this before they leave with the paint is... If you get a run or a major chunk of dirt in the first coat of clear, you need to
apply the second coat of clear no matter what!!!
If you only apply one coat of clear you will turn your paint job into a re-coat sensitive substrate. This means its very likely that the next time you go to add base coat or more clear over the top the paint will lift the existing job.
One coat of clear, is a very thin layer that doesn't have enough film build integrity to keep solvent from the next coat that goes over it from penetrating through. The solvent will go through the thin layer, the solvent then try's to come back to the surface. But when it does it lifts the paint job.
We hear this all the time when people first get into painting and have a lifting problem. So we will always ask them how many coats of clear did you apply??? The answer is always something like this
"will just one but, the air hose flipped up into the paint job and it looked really bad so I didn't want to put the second coat of clear down". Even though they remember us telling the importance of the second coat no matter what happens.
