Anybody have basecoat/clearcoat auto painting experience?

[MetroMPG]

I'm painting a stripe on a boat (above the waterline), and got some base/clear automotive paint. This will tell you how long ago I last used automotive paint: I've never used a 2-step paint system before. Last couple of cars I painted/touched up were just enamel with hardener.

I'm just curious about the basics:

1) How long should I wait between base coats? If I wait until it fully sets, do I need to wetsand it before the next layer? (I've already painted one coat of one portion of the boat, and it's fully set.)

2) How long should I wait to clear coat it? Same as above?

The info on the paint containers isn't very helpful.

I'm not expecting an auto quality finish. (I'm actually brushing the paint on one part of the boat!) But I'd like it not to flake off a year from now.

[War_Wagon]

Sadly my experience is mostly based on painting fenders on stacks of tires as a "paint booth" and painting my friends '72 Econoline camper while well into a 12 pack. However, we do manage to occasionally get a good finish out of it. Wet sanding the runs out of the base is something we do before the second coat of base. The smoother the base, the better obviously. We try to keep the base nice and thin, you only need enough base to have a solid colour that covers everything, the clear coat is going to do all the work. Time between coats depends on the temperature, how thick you sprayed on the last coat, etc. When it comes to the clear, I personally go for the 2 or 3 thin coats over 1 thick coat theory, as there is less chance for runs. Adding more is always easier than removing the runs without messing things up. If you aren't in a hurry, let stuff set overnight between coats, but we have done it with only a few hours in between and it hasn't fallen off yet ha ha

[user removed]

I would use a sponge roller if you don't want to use a spray gun. If the paint is a solid color without metallic as well as non metallic clear. I'll check with my buddy at his shop and get some first hand information. It won't happen tomorrow, wife has a minor surgery.

regards
Mech

[pgfpro]

What paint brand did you get? Every systems is a little different.

I should be able to answer your questions its what i do for a living. lol

I'm a certified PPG, Dupont/Axlata, BASF, Sikkens, Chem Spec painter.

[Xist]

Originally Posted by Old Mechanic

It won't happen tomorrow, wife has a minor surgery.

I hope that things go well for your wife.

I have looked into repainting Chorizo, but it may never happen, although my paint looks terrible, and black cars do not belong in Arizona!

[MetroMPG]

Thanks for the replies, guys.

War_Wagon: that sounds like my previous painting experience (though with enamel).

Old Mech: ditto, hope all goes well tomorrow.

I would have rolled/brushed all of this, but the base is metallic, so it doesn't work very well.

pgfpro: I'll go check the can right now, thanks. Back in a flash...

[MetroMPG]

I have...

NASON 3-NA354 Ful-Base 3.5 B/C

If you aren't in a hurry, let stuff set overnight between coats

And do you always wet sand between coats in that case? Even if no runs to fix?

[user removed]

I'm pretty sure my buddy does not sand between coats unless there is a fubar. The base coat goes on fairly flat looking and I think all the finish texture is in the clear. They usually never sand anything after preparation, only sanding imperfections in the final finish. pgfpro is the man as far as confirming my observations. I know on my Fiesta which had the front half repainted the new two-three stage paints are very durable.
Also very expensive.

regards
Mech

[pgfpro]

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.

[MetroMPG]

Thanks for that info, pgfpro!

This may be sacrilege, but the paint shop says they can put our paint into aerosol cans/spray bombs, where they mix our base & clear together.

Considering we're just doing a simple stripe, this sounds very convenient & appealing to me.

But will they also be able to put in the catalyst so it sets up with a hard finish? I realize this creates a can with a very short shelf life, but I'm ok with that if it'll work.