Hello

Today i sprayed my rooftop and pillars in a new color. It's a 3 stage paint: tone, base, clear.

Tone and base are both blue, second being metallic. I sprayed cross pattern with a gun 20 psi 2 turns out, checking for no dry spots and good coverage.

Then i started to spray clear, i did 3 coats of clear, last one or the one before last one a bit messy because i ran out of clear twice and had to refill. I also sprayed it outside with a garden tent above the car to limit sunlight and particles. It was also very hot today, started in the morning but noon caught me up.

The problem i'm encountering is those white stripes that i've noticed just short after finishing last coat of clear. I don't remember having tiger stripes after finishing spraying the metallic base.

They are mostly seen in shadow and artificial light, especially night, under sunlight they are barely visible.

I also took a close view and if i flash a light above them they disappear. The base beneath seems even, i don't see any white stuff.

I am considering sanding because of the orange peel but i'm not sure if im able to sand them away with 1500 or if they are embedded deep in clear or worse in the base and needs respray.

What do you think they are? Thank you!

Without seeing it, hard to know, But most likely, it is dry areas of clear, since you had to stop a couple times, and you report it was getting hot out. It couldn't hurt, in any case, to try and sand and buff the stripes out.
3 coats of clear is a bare minimum I spray, and I sand and buff everything I do. If you are careful, and the paint is not too rough, you should be fine. Personally, I would start with a light cut with 1000 grit, then do a lot of 1500, and 2000. Go easy with the buffer as well, as you don't want to remove too much clear. If you used a Euro style urethane clear, (high solids) you should do pretty well. If you used other, thinner clears, for a beginner, I would recommend sanding and putting a couple more coats on it.

Sorry, i forgot to add the photos.

Here are the two:


I used an HS clear thinned with 10% acrylic thinner.

You could just flatten the clear by wet sanding with a hard block and 800 grit (Some guys will go as low as 600) and then clean and spray 2 - 3 more coats of clear. It's called "flow coating" and the clear lays down much better over itself.

Another thing you want to watch out for is cutting the flash times short. You can trap solvent in the lower coasts which will try to escape causing little bubbles called Solvent Pop.

By flattening clear I mean lowering the orange peel to the level of the clear. Here is a picture of the process:


The shiny spots are where the sand paper has not made contact with the surface of the clear.
You want the surface to be flat and the hard block will make that happen by lowering the high spots only.

What clear did you use?
Was it lacquer, urethane or something else?
Also the thinner, lacquer, urethane ?

'68 Coronet R/T wrote:You could just flatten the clear by wet sanding with a hard block and 800 grit (Some guys will go as low as 600) and then clean and spray 2 - 3 more coats of clear. It's called "flow coating" and the clear lays down much better over itself.

Another thing you want to watch out for is cutting the flash times short. You can trap solvent in the lower coasts which will try to escape causing little bubbles called Solvent Pop.

By flattening clear I mean lowering the orange peel to the level of the clear. Here is a picture of the process:

Orange Peel 2.JPG

The shiny spots are where the sand paper has not made contact with the surface of the clear.
You want the surface to be flat and the hard block will make that happen by lowering the high spots only.

DM Removed 2.JPG

EXCILENT. it does look like dry spray from to much heat and flash time to fast.
Jay D.

JCCLARK wrote:What clear did you use?
Was it lacquer, urethane or something else?
Also the thinner, lacquer, urethane ?

YEP, COULD BE ANYTHING!!!
Jay D.

JCCLARK wrote:What clear did you use?
Was it lacquer, urethane or something else?
Also the thinner, lacquer, urethane ?

It's lacquer and i used acrylic thinner

Mr Meeseeks wrote:

JCCLARK wrote:What clear did you use?
Was it lacquer, urethane or something else?
Also the thinner, lacquer, urethane ?

It's lacquer and i used acrylic thinner

Then blushing is probably the culprit.
You probably got moisture in your air supply,
like your compressor got real hot air.
And being real humid outside makes things even worse.
This is fairly typical with lacquer.
You can add some universal retarder to your paint and it
will help a lot by slowing the drying down and releasing
the moisture. I run into the same problem when using lacquer
on my woodworking pieces.
Another fix is to use urethane reducer instead of lacquer thinner
for thinning. Lacquer thinners are to fast, use a slow urethane reducer
and you'll get a better finish too.