I am an amateur painter at best & I am very talented at running clear. This will be my first time spraying UC. Will be using a DV1 and can us either the 1.3 or 1.4. My question is in regards to the first coat. SPI says to spray the 1st coat to look like you want the final coat to look. I have seen a lot of guys spraying misc, clears that spray a light “tack” coat first. Anyone have an opinion on this for my situation? My intention is to follow the TDS unless I find solid info otherwise
Spraying UC for the 1st time,
- Thread starter CSG
- Start date
RenewAP
Promoted Users
TDS is correct, spray all coats like you want final finish. Give full 30 minutes to flash or you WILL have runs. best thing to do for new paint products is to mix a small amount and spray some old fender or whatever, you will get a feal for how it will spray without ruining a large job. I
Anyone who is spraying a high solids urethane or polyurethane clear with a mist coat on the first coat has texture in it that will not come out in the subsequent coats. Which is why you want to spray your first coat as slick as you can. Mist coat/tack coat advice is a holdover from the loooong ago days of spraying acrylic enamel. Enamels are "sticky" so to avoid runs it used to be advised to spray a tack coat to give the subsequent coats something to "stick to". This is completely irrelevent today. Never spray a mist or tack coat with Universal or other high solids clear.
How you want to spray is wet. Wet is not heavy though. Wetting is when you see the clear "filling in" as you are spraying. That is your goal when spraying clear. To get the clear to fill in and no more. More = Runs. Less = Orange Peel.
I don't spray with a DV1 so I'll just give you some general guidelines. First is air pressure. A high solids clear needs more air pressure. Don't be afraid to turn up your pressure. Fluid you want to find a balance between how fast you spray and how much fluid is coming out of the gun. Overlap is very important. Shoot for 75% overlap on your passes. Ultimately you want to adjust the gun to adapt to the speed of your passes and allow you to achieve wetting. I.E. seeing the clear fill in as you are spraying.