Painting Help

[SevenCorners]

All,
I just painted my tractor using a HVLP spray gun. I used 3 coats of base and 3 coats of clear. The base turned out fine, when I sprayed the clear I got really bad orange peal. I tried to adjust the amount of material [less] but it got no better. What causes this? Am I using too much pressure, I had it set on 40 psi. How can I correct it, I thought about sanding it down and trying again. Is it just that I am inexperienced?
Thanks

 

[schmism]

clear is really hard to shoot.

I thought orange peal was an indication that your reducer amount wasnt right.

you can allways color sand it and buff it and youll never know.

 

[jmt1271]

was the base fully dry before you sprayed the clear? was there any contamination on the base?

 

[Soundguy]

Did you use a hardner in the base? A hardened base, once cured should be fine for clear.. the hardner is a catylizer..

My guess is it was a non hardened base.. and/or it wasn't cured, and the reducer int he clear lifted it..

Soundguy

 

[ScottAR]

What temp range reducer were you using?
What temp was it when painted?

A lot of orange peel or "dry spray" issues go back to improper temp ratings...
Too "cold" and it drys before it hits the surface, too "hot" and it literally runs off the surface. (if the surface is vertical)

 

[SevenCorners]

Let me see if I can answer all the questions,
I did not use a reducer, it came with a hardener, mixed it 4:1.

The base was fully dry, it was easy to tell due to no sheen, evident that it was dry, I waited around 15 minutes between base coats and probably 30 min before clear. I did not clean or wipe between coats, painted inside garage with minimum contaminates.

The base was premixed ant auto paint shop, I assume they knew what to do, I told them what I wanted and they went back and mixed up the base, it did not have any additive that I added, unlike the clear.

Scott that is a good question that I don't know the answer too, the clear was a fast dry, the outside temp was 90+, I was inside garge say 85'ish.
How do I find out the reducer range temp?

 

[alvanko]

What brand paint was it? Many times the guns "Nozzle" needs to be changed depanding on the viscosity of the paint. I have sprayed everything from Imron to Imron 5000 & 6000. Sherwin williams , PPG Deltron,Durathane, Delstar............etc..............
I used to paint semi's for a living. Each paint requires a different set up, depending on how you want the results to come out. The other guys suggestion for proper reducer for temperature are correct. Automotive paint is much more complicated then it used to be (EPA regulations). What paint did you use? What gun did you use. Some of the base coats will "lift" if you sand through the clear and recoat. Let it "cure" for a while and sand smoth and try again.

 

[ScottAR]

Most reducers and catalysts have the temp range in their part #. PPG and dupont do this anyway... PPG reducer for example is DT870, DT885, and DT895. The last two digits are the approximate ideal temp to use plus or minus a few degrees.

Some clears use reducers and some don't. Sounds like yours doesn't. In this case, usually the activator comes in different temp ranges. You might consult the activator can or the company web site if they have one.

FYI, Two stage (base/clear) typically doesn't use a hardner so all it probably well as far as the base application pre clear.

Single stage whereas clear is in the paint does use a hardner and is for another day.

I'm just a weekend hamfist and a counter boy during the week and am no means an expert, but as we sell "car" paint at my job, I've seen a few messups and orange peel is pretty typical in the summer. Unless it's especially bad, it could probably be wet sanded and then buffed out.

Pick up some 2000/1500/1000 grit paper, a good squirt bottle and a small squege (sp?) and use some elbow grease. If ya get her flat but dull, you done good. Get some buffing compound and mirror glaze and go to buffing.
HTH

 

[SevenCorners]

Scott,
I will go down to the paint shop and pick up the paper and compound, I have a machine buffer. I had no idea that painting was so complex. It does not appear that it is a good diy project. I did not want to spend the extra money just for my tractor.

Guys the brand of clear is dupont chromaclear hc-7600s fast flash and low overspray [haha] the activator is same but med temp, what ever that means.
My gun has a 1.4 mil tip the can doesn't say anything about tip size is this alright?

Thanks

 

[Soundguy]

Scott,
I had no idea that painting was so complex. It does not appear that it is a good diy project. I did not want to spend the extra money just for my tractor.

It can still be a decent DIY project. I've painted all of my tractors outside, with good results. Have only had to color sand one down due to weather that came out of no where, and On another tractor i had to repait a hood cowling that developed a significant slump.. this was a hanging piece and was pretty easy to buff the paint off and start over... No other major catastrophies.

I use a cheapy air compressor and an knock off 'binks' style chinese paint gun.

Heat is a problem.. cold under 40' is a problem, and excessive humidity is a problem.

Surface prep... 95% of how a paint job turns out is in the prep work prior to ever mixing the paint up.

Good luck. If you are lucky a color sand and buff or re-coat will solve your problems.

Soundguy

 

[ScottAR]

Looks like it was drying before it got to the surface. A high temp activator would be easier to use for those temps.

Your 1.4 mm tip is fine, very good atomization... Think of tip size like a shopping cart full of balls. A 1.4 would be golf balls, 1.6 baseballs, 1.8 soft balls, and 2.2 basket balls. Looking across the surface, the golf balls would be smoothest using base/clear materials. If you were shooting heavy rust primer or such, you'd want a bigger tip size.

As to the DIY part, your asking the right questions to become better at this.
Don't be too hard on yourself, Painting takes practice. knowledge of the chemicals does too.
If you saw a few of my customers, you'd feel a lot smarter...

 

[SevenCorners]

Scott,
Thanks for the advice, I went down to the paint shop this afternoon and showed the guy what happened. He advised I do a couple of things
1. sand it with 1000, clean body with rubbing alcohol and reshoot clear using high temp activator.
2. Shoot early in morning we are going to be in 100's next couple of days.
3. Open garage door about 2 ft, open back window, place fan in back window to get slight draft.
4. Shoot 3 coats, first coat light, second slightly heavier and third heavy.
I'll give it another try and report back.

 

[MrJimi]

Scott,
Thanks for the advice, I went down to the paint shop this afternoon and showed the guy what happened. He advised I do a couple of things
1. sand it with 1000, clean body with rubbing alcohol and reshoot clear using high temp activator.
2. Shoot early in morning we are going to be in 100's next couple of days.
3. Open garage door about 2 ft, open back window, place fan in back window to get slight draft.
4. Shoot 3 coats, first coat light, second slightly heavier and third heavy.
I'll give it another try and report back.

Wet yard in front of garage door to keep dust down and blow the whole inside of your shop with the machine out, and do this many times, rafters, lights and all surfaces. Then bring in machine and blow it real good about 3 times and you should have great results
Jim

 

[Jagmandave]

What about his air pressure? 40 psi seems high for an HVLP gun.......

 

[alvanko]

40 psi may be the inlet air. I thought the air pressure at the nozzle was to be no more then 10 psi (to be considered a true hvlp).