Rough paint job

[Row Crop]

I painted my tractor Sunday with a good quality paint, low pressure, gravity feed gun. I sprayed 6-8 coats on the tin parts, but they turned out rough. It looks like it was powder coated. I painted it outside, and it was 92* out, hot sun, and high humidity. The tractor has very little shine to it. What can I do?

 

[glennster]

it was too hot and humid. did you use a high temp reducer? you will need to wet sand and buff the paint to get it smooth again.

 

[Brokengun]

I had a similar problem one time I determined in my case it was over-spray caused by holding the gun to far away from the job.

I also had the air/paint flow set to low where I got to small a mist of paint.

 

[TaylorMutts]

I suspect the high temps, humidity and the hot sun load are your main culprits. Make sure the paint is thinned enough to flow through your gun and that you are spraying about 8" from the gun to the body panel.

 

[Row Crop]

glenster..Wet sand the new paint? By hand, or use a sander? What grit? HELP,PLEASE!

 

[glennster]

when you said good quality paint, i will assume it is an automotive acrylic enamel or urethane. you will need to wet sand by hand, start with 1000 grit and then go to 1500. use plenty of warm water with a squirt of car wash soap in it. i use a sponge in one hand to keep a flow of soapy water, and keep dunking the sandpaper in the water so it does not cog up as quick. from there you can buff with a heavy compound on a coarse lambswool pad, then go to a fine pad with a finishing compound. yup, its a lot of work.

 

[GordoSD]

Are you assuming he can get this rough paint to a high gloss nice finish?
I guess you might as well try the 1000/1500/machine polish on a test section and see it you can smooth it out.

It sounds to me that it's bad enough that he needs to take it down with 400 grit and repaint And that will require at least a 30 day curing before he does that.

 

[glennster]

if he has 6 to 8 coats, there should be enough to work with. if it was catalyzed paint, it will be cured quickly in the high heat. if it will not wet sand and buff, he will have to re-shoot anyway. with the cost of material, i would opt for the wet sand and buff first.

 

[glennster]

here are some of the compounds and pads we use at the shop. the 3m perfect-it compounds are excellent, and the schlegel and presta are excellent buffing pads.

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[CNKS]

HVLP guns "low pressure" means 10 psi at the tip. You cannot measure that, Instead use the max pressure printed on the gun or in the instructions, measured with a gauge on the gun. IF you were using quality paint, meaning at least an acrylic enamel, better, urethane with hardener you do not need 6-8 coats. It should cover in three, no more than that should be needed. And you will never get a good job on hot metal at that temperature. Surface temp of the metal was probably 150+.

 

[Row Crop]

THANK YOU guys for your help. I'm gonna try and wet sand and buff. If it doesn't work, I'll wait till this heat wave gets over, like September.

 

[GordoSD]

Be sure and use a rubber pad and or soft block to prevent "finger marks".