Messed up a paint job, but I think I know why.

I just wanted to run this past you guys as I am no paint expert. I know just enough to be dangerous for the most part!
We painted my sons 62 Comet yesterday. We were using Kirker Hot Rod black. It is a single stage eurathane. The sides came out rear nice but the horizontal surfaces look like SHIT!!! They are all tiger striped. We were painting outside in the sun and even though it was below 70 I think the panels got warm to the point that the paint kicked before it had a chance to flow out. I used the same technique on the whole car. Gun distance, 50% overlap ect.
Am I correct in my thinking that it was the heat generated from the direct sunlght? Thanks as always. Todd

 

If you don't mix your paint well enough or if your gun isn't completely parallel with the horizontal surface, you'll get tiger stripes. It happened to me with I use a single stage suede black on my 67. The roof and hood tiger striped like crazy. I ended up wet sanding it to give it some tooth and re shooting ah a bit higher PSI and making sure the gun was at the proper angle. After a couple coats, the striping was gone. I always mix my single stage paint, let it sit for 5 minutes then come back and mix it again. Some single stages have to be mixed pretty aggressively to get all the flattening agent and clear mixed into the rest of the paint

 

I'm thinking its both your thoughts about the heat and what dubie mentions. Take a IR thermometer and check the temps of a couple of cars that are in the sun on a 70 degree day and see how hot they really are. Repeated coats of black will increase the temp when in the sun. Respraying inside or in the shade with higher pressure and wider fan width should reduce the tiger stripes.

 

Just for the halibut I checked the hood on my dark red truck. Its 68 degrees outside, sunny and breezy. The hood and top temps were 116 and 118 degrees. Can only imagine black would be hotter.

 

Thanks fellas!!! I was pretty good on my gun technique. Thats always on my mind when I'm spraying. The reason I really think it was the temp was the sides came out very good the the hood, roof and trunk look like shit! Todd

 

clean your gun tip, and adjust the air pressure and dont forget to move your overlap pattern closer

 

Along with making sure your gun pattern is correct, change directions when you paint (i.e. across then up & down) Then if you still have the problem at least you could play checkers on it! LOL

 

You shouldn't be getting any tiger stripes on solid black ?

 

any thing with tits or hub caps and you got problems .

sounds like dry spots being a solid color and all .

if you have to paint when the surface is hot like that , use a sloooow thinner .

 

You are right that the sides facing the sun will react differently to fresh paint compared to those in the shade.

Might think about a slower drying reducer as well.

 

The paint does not use any reducer. It is just paint and activator. I know I can use reducer. I am considering using some slow reducer when I go to fix the bad spots. I am just trying to get it right next time. Todd

 

Shade is the answer.

 

I'm on board with that. Painting a car in the sunshine adds an interesting dimension to the possibility of failure.

Bob