Base coat issue need advise again

[MKH]

Sprayed 3 coats of motobase today and all was fine until I got to the roof on the last 3rd coat. It had a few whiteish looking dry spots. So I scuffed them with a gray pad and sprayed another coat of base but it looks no better. I think it got to hot by the time I sprayed the last coat. Using SPI slow reducer. I used up 2 gallons of rts and I am out of paint now. My question is when I scotch brighted the roof it looked much better until I sprayed another coat of base. So could I scotch brite the roof again and just spray clear over it? I plan to spray the clear in the morning.
Mike

 

[RenewAP]

No, the abrasion will leave a pattern in the base that will get magnified by the clear. It sounds like moisture blush, that may dry out of it if you leave it for a day in the sun. Then again it may not.

 

[MKH]

No, the abrasion will leave a pattern in the base that will get magnified by the clear. It sounds like moisture blush, that may dry out of it if you leave it for a day in the sun. Then again it may not.

No, the abrasion will leave a pattern in the base that will get magnified by the clear. It sounds like moisture blush, that may dry out of it if you leave it for a day in the sun. Then again it may not.

I’m pretty sure its the metallic not laying correct from spraying dry. I’m out of paint so I cant fix it the correct way at this point. I have to clear the whole car in the morning because I sprayed the base this morning.
Mike

 

[Chris_Hamilton]

I’m pretty sure its the metallic not laying correct from spraying dry. I’m out of paint so I cant fix it the correct way at this point. I have to clear the whole car in the morning because I sprayed the base this morning.
Mike

You have more than 24 hours. Disregard what manufacturers say about re-coat time. You can clear base literally days later with no harmful side effects. The solvent in the clear will bite into the base no problem.

 

[Lizer]

You have more than 24 hours. Disregard what manufacturers say about re-coat time. You can clear base literally days later with no harmful side effects. The solvent in the clear will bite into the base no problem.

I do this too, but I think the key point is that it's a good base that's using good polyols. A super cheap base I'd be afraid to.

 

[Chris_Hamilton]

I do this too, but I think the key point is that it's a good base that's using good polyols. A super cheap base I'd be afraid to.

I don't do it often, almost never but I would not be concerned doing it with any conventional base because the solvent in the clear will make it adhere.

Could you expand on why you would be afraid to do it with a cheap base? My thought is if a base (cheap or not) can be softened by solvent then applying clear days or even weeks later should not be a problem.

 

['68 Coronet R/T]

Can you post a picture of what you are looking at?

 

[RosharonRooster]

what grade of scotchbright pad?

 

[MKH]

Thanks for all the help everyone. I decided to sand the roof down with 1000 grit. Got it nice and smooth and scraped up about 6 ounces of paint by washing the gallon can with reducer. I had just enough to spray one good coat on the roof. It turned out great!

 

[Vanillagorilla]

I don't do it often, almost never but I would not be concerned doing it with any conventional base because the solvent in the clear will make it adhere.

Could you expand on why you would be afraid to do it with a cheap base? My thought is if a base (cheap or not) can be softened by solvent then applying clear days or even weeks later should not be a problem.

I probably shouldn't say this because I don't want to confuse people. I generally clear the same day. I like to get all my spraying done in one sitting if possible.
But..... the 1st car I ever painted when I was like 17 I had no idea what I was doing. I sprayed the base on, and was going to clear it a day or two later. I just happened to get injured at work before I could clear it. It was 2 months later that it finally got cleared. Drove the car for 3 years before I sold it. Never any issues with adhesion or delam. I don't recommend waiting that long. I wouldn't risk it again, myself.

 

[Chris_Hamilton]

Thanks for all the help everyone. I decided to sand the roof down with 1000 grit. Got it nice and smooth and scraped up about 6 ounces of paint by washing the gallon can with reducer. I had just enough to spray one good coat on the roof. It turned out great!

What model Z? Can't tell if it's a 240 or 260/280. I love first generation Z's. I have a 71 and 73.

 

[MKH]

What model Z? Can't tell if it's a 240 or 260/280. I love first generation Z's. I have a 71 and 73.

Chris, it’s 1978 5 speed. I am 60 years old now but had a early Z when I was around 20. Ran across this one and been working on it for the last year and a half. But it’s no longer stock! Putting early Z bumpers that I welded together so they are seamless and tucked in close to the body front and back. I really like the diamond pattern trans tunnel and strut covers on the early Z cars so I got all that in leather. BC adjustable coil overs so it sits really low. Fat tires and 15 in spider wheels etc. Excited to get the paint done and start putting it all back together. And thanks so much for all the advise you and everyone else has given me on the paint work.
Mike

 

[Lizer]

Could you expand on why you would be afraid to do it with a cheap base? My thought is if a base (cheap or not) can be softened by solvent then applying clear days or even weeks later should not be a problem.

I can tell you what Barry told me back in 2015. Base adhesion is driven by the polyols, and there are a lot of grades of polyol with wide variance in quality. Cheap bases use cheap polyol which can result in inferior adhesion of the clear the longer the base sits. I had that conversation when I was painting my Mustang and everything was blowing up on me. I think my car sat in Prospray base for a week, maybe two or longer, before I ever started squirting clear.

Which is why I tell people to not use cheap bases. You get more flexibility with a good product, which makes it MORE beginner friendly.