Spraying Clearcoat Technique

J

james.heider

I recently sprayed 4 coats of Universal clear on a 356 Porsche I am restoring. I am not a professional painter and have never had any lessons from anyone. I painted the car with acrylic enamel and then sprayed 4 coats of Universal clear giving it at least 30 min between coats. I only sprayed the top,hood doors and fenders in one direction not criss cross. I know that I put down a decent coat of material. there are many sections of the car that are very glossy and smooth and some that look dry.

A friend of mine came over today and was pointing out the dry looking sections I have in the clearcoat. He told me I would need to resand it and then spray another coat or 2 of clear in both directions. He said that the dry ares were an indication that I dont have enough clear on the car.

Is he correct? Do I need to spray more clear after having put down 4 coats of the Universal ?
Is a dry looking section an indication of not enough clear?

Sorry for all the questions but I am learning as I go and trying to teach myself how to do this..

Thanks
 
I think your friend is right about not enough clear but I'm not sure about the both directions thing...resand the car with 320 and recoat but try to smoothly spray the car with the gun only a few inches away from the surface (depending on the gun and pattern) with about a 50 to 75 percent overlap of the previous pass...The car you are doing is tricky and maybe a little harder than a "square, flat type body style" but you can do it...take your time with the first coat and look at it from all angles, hitting a dry looking area again before letting it flash...then carefully spray the second coat making it flow like you want it to look done...welcome to the world of painting, you will get better
 
4 coats is usually more than enough.
Using slower activator and reducer will help with the dry spots.
 
If the dry looking sections are from overspray not melting in you may have more than enough clear to sand and buff. If your not sure you held your gun properly over those areas you might need to spray again. The criss-crossing thing, no.
 
Rodman,

I think that the dryspots are from overspray not melting in. I did the 4 coats taking 1/2 hour between each coat and tried to hold the gun about 6 inches from the surface and get a good overlap, but I know on a couple of occasions I tilted the gun at an angle rather than being 90degrees to the surface.
 
It might be in your best interest to sand it down and have another go at it, like flynams said. Not only would sanding the car cut out the urethane wave and give you a nicer finish, but it would give you more experience.

As far as the clear being thin in areas, that's a tough one. None of us watched you spray it. How far were you holding the gun away from the car? How fast do you move the gun? How much do you overlap? Did you follow Barry's gun set up post? I think is unlikely that you have thin spots after 4 coats, but I wasn't there. What do you think?
 
If the clear was going on wet when you sprayed each panel this would confirm the amount of material going on was sufficient on each coat and the dryspray is a result of overspray- so scenerio would confirm the 4 coats would be plenty of material to colorsand and buff. What you want to look for when spraying the clear is the wettness of the panel surface within the spray pattern in the relfection of the panel as you move the gun.
 
Bob,
I believe that the dry sections are overspray.
Originally I sprayed 3 good coats of clear on the car but I was unhappy with a few runs and trash I got in it.
Wet sanded the entire car and removed all the trash and runs, then sprayed the 4 additional coats on the car.

I have order a Makita buffer/ polisher and until it arrives I plan to wet sand the car with 1500-4000. grit.
The buffing and polishing will be a new chapter in my painting experience since I have never run a buffer on a paint job.

Barry has offered to coach me through the process.

SPI is a really great product and the support from Barry is wonderful.
 
Bondoking;15270 said:
James with that much clear on there, you will be fine!!!!
Click to expand...

I agree....4 coats of clear the is no way all 4 coats you have dry spots in the same places all 4 times....dry spots equal not enough clear...usually...not always...but its a good rule. But if you have dry spots after 4 coats...don't sweat it dude...wet sand and buff and your golden...just stay off those edges and high spots.
 
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