Calling on the painters: What happens if I get a run or dirt while spraying clear?

[Michael L.]

Guys,

I'm spraying some clear on something and wanted to know what I do if I get a run or dirt in the clear and need to sand it. I know when I spray color I can sand the imperfections and just put more paint on it, but if I try that with clear won't I get haze or fog in the clear where I've sanded? Thanks for the help.

Mike

[Leif A.]

Re: Calling on the painters: What happens if I get a run or dirt while spraying clear

Guys,

I'm spraying some clear on something and wanted to know what I do if I get a run or dirt in the clear and need to sand it. I know when I spray color I can sand the imperfections and just put more paint on it, but if I try that with clear won't I get haze or fog in the clear where I've sanded? Thanks for the help.

Mike

You will but you'll be cutting and buffing so the haze will disappear.

[Michael L.]

[Russ S.]

Re: Calling on the painters: What happens if I get a run or dirt while spraying clear

No you don't need to sand down all the way to the first coat even if the run is in the first coat. Just continue applying your clear coats and sand after last coat.
PS. If it is dirt than that changes things. In that case you would need to sand down until the dirt is gone.

[Michael L.]

Re: Calling on the painters: What happens if I get a run or dirt while spraying clear

Ok thanks. After spraying the first coat I noticed the clear is drying extremely fast, like even before it
has time to hit the surface. It is not going on wet. What is this a sign of and what can I do to slow the drying time?

[Russ S.]

Re: Calling on the painters: What happens if I get a run or dirt while spraying clear

Do you have a large enough nozzle so that you are getting enough product out? I would check with your supplier on correct nozzle size.

[Steve C.]

Re: Calling on the painters: What happens if I get a run or dirt while spraying clear

hi mike
without knowing what name brand material you are using it's hard to get too specific. but generally when spraying out here in hot southern arizona we would use a slower reducer so it wouldn't kick too fast. and then opposite if it was colder. i'll assume you are using a catalized clear. there are additives such as retarder and accelerator you can use for catalized products.
back in the day when i was painting learjets we'd mix one gallon of paint to one gallon of catalyst, reduce it with 732 reducer to 17seconds with a #2 zahn cup and go to it. loved alumigrip paint
steve

[Michael L.]

[Michael L.]

Re: Calling on the painters: What happens if I get a run or dirt while spraying clear

BTW, I also asked the rep and he said it's OK to sand clear and just shoot more clear over it. He said the chemical process results in dissolving the top few thousands of an inch of the prior layer of clear so the next layer can bond to it. This leads to "clearing" of any fog from sanding, I guess so long as the sanding paper is fine, probably above 600 grit I would think. No idea if this is correct or not but just thought I'd share it.

Mike