Freshly Painted with Orange Peel

[RobR93]

I am restoring a 1984 Mustang GT. I have painted it with a product that NAPA sold me….unfortunately, I didn’t do much homework on paint products……and took their advice. Anyways, it’s my first time painting a car in it’s entirety but it’s a winter project and Im in no hurry, other than I wanted to get it painted before snow flies.

First I did the body work and completely sanded down the car and removed all oils/waxes. I sanded the primer down with 600 grit sandpaper and it was very smooth. I wiped the entire car down with tack cloths before I sprayed color. The color, I painted it with Martin-Senour’s Brilliant Black Pearl and the LeMans stripes are their Galaxy Silver. I shot the first coat and it looked pretty good (so I thought how hard can this be….that was pretty easy), although I didn’t have complete coverage and had some runs……..so I sanded the runs down and shot it again with a little more air and more spread on the paint trying to avoid runs, and got a high degree of orange peel. The third coat actually looks better as I went for more paint and less air, and moved the gun faster to avoid runs which the fender picture you see is representative of where it stands now today with the third coat of black on it. It was the picture I had that you could best see the orange peel effect.


I have the time, and the patience, so what would you recommend I do to remove this orange peel? I do not own a rotary buffer but am willing to buy one to do it right, or do you recommend I just do it by hand by wet sanding? If you think it’s bad enough where I need a buffer, can you recommend a brand and where to get one? Thanks for any information you can provide to me. I have learned a lot from the forums and it has prompted me to stop and ask these questions before I do anything more.

[Blackthorn One]

If you have bad orange peel, wet sanding is about the only way to remove it. Part of the reason you are getting so much orange peel is that you are painting in cold weather. Paint atomizes best when it's very warm outside. When you paint a car, first, you must get a couple passes of the gun on the nooks and crannies, like the jambs and the rain gutters. This is because if you spray the rest first and THEN go for the nooks and crannies, you will put runs in the paint in the areas right next to the rain gutters. When you shoot the paint, you keep the gun pointing straight at the car, and at the same approximate distance the entire time, as you bend your wrist back and forth as you make quick passes across the car, each about 1 second each time you move your hand from side to side to full extension of your stroke. You will probably want to wet sand every 4 coats, just to make sure it stays smooth and flat, as you paint the full 15 coats on the car. You should be able to get complete and wet coverage in two overlapping quick strokes until you get each panel done. Any more paint than that at that point and you will risk runs. You could try one VERY light coat after that if you had to, after a few minutes, if you needed to even it out a little, provided it isn't too cold, and the paint atomizing nicely out of the gun. I assume that you are painting in a heated room, like a garage or a spray booth. Of course, you are also using a respirator, if painting in an enclosed space like that. I've been able to get orange peel free finishes using spray cans, and I've sprayed in various temperatures before, and I can tell you that temperature makes a big difference in how paint sprays. I would never paint a car in cold weather.

[RobR93]

If you have bad orange peel, wet sanding is about the only way to remove it. Part of the reason you are getting so much orange peel is that you are painting in cold weather. Paint atomizes best when it's very warm outside.

No.....it's been in the 70's this week....I shot it the past few days.....but at ambient air temperature in NY.......I was trying to get the paint on before it does start getting cold here. I don't have a paint booth or a way to heat to 120F. So I was hoping that in the summer I could get the paint on and hope for minimal sanding.......but I have some work to do. I have the time. Just want to know what the most mistake free path would be and if a rotary buffer is what I really need.

[RobR93]

PS- I do have a mustang fender in the barn that I can paint and practice on.....Ive read rotary buffers are something you want to practice with before putting one to your car.

[Mike Phillips]

Hi Rob,

Thanks for taking this topic to the forum. I have a meeting to go to so I don't want you to think I'm ignoring your post but I'll be offline for a few hours and then when I get back I'll chime back in.

Again, thank you for bringing this to the forum, I'll do my best to answer all your questions.


:)

[Blackthorn One]

No.....it's been in the 70's this week....I shot it the past few days.....but at ambient air temperature in NY.......I was trying to get the paint on before it does start getting cold here. I don't have a paint booth or a way to heat to 120F. So I was hoping that in the summer I could get the paint on and hope for minimal sanding.......but I have some work to do. I have the time. Just want to know what the most mistake free path would be and if a rotary buffer is what I really need.
After seeing that picture, you need to wet sand that out. You could use the buffer to get the sanding scratches out. Speaking of temperature, 70 degrees F is cold as paint is concerned. at least 80 degrees in ambient temp to get the paint spraying really nice. 90 degrees works well, but the paint dries a little quick in 90. I like 85 or 86 degrees, myself. You need to sand the orange peel out of this and then see how much paint is left on the car, and maybe re shoot one or two more coats. After you sand, you can buff. That is really bad orange peel there. In fact, it's about the worst I've ever seen. Don't even bother with a buffer for that. I would try 1000 grit paper, and if that doesn't cut quick enough, then go to 800 or even 600. You wouldn't need more than a minute per foot with 600, though.

[Blackthorn One]

PS- I do have a mustang fender in the barn that I can paint and practice on.....Ive read rotary buffers are something you want to practice with before putting one to your car.
I strongly suggest you do so. Painting is an art, and you should really get a decent hang of it before you try and paint your car and make a lot of extra work for yourself. You need to figure out how fast to move the gun, over a certain area, how far away to hold it, about 12-18 inches, depending upon the pressure, ect., and you need to figure out how much paint you can put on something before it runs. Now, once you know all that, you have to be able to adapt your technique to the temperature. If it's hotter, then the paint will spray more evenly and thinly. If it's colder, then the paint comes out a lot thicker. Great automotive painting is mostly an art, which only comes from experience. There IS such a thing as too much paint on a car, though. If you get too much paint on a car, built up over many coats, it can crack over time, looking like a dry riverbed. I doubt you will get that much paint on your car, though. But you might on your practice hood. :)

[RaskyR1]

After seeing that picture, you need to wet sand that out. You could use the buffer to get the sanding scratches out. Speaking of temperature, 70 degrees F is cold as paint is concerned. at least 80 degrees in ambient temp to get the paint spraying really nice. 90 degrees works well, but the paint dries a little quick in 90. I like 85 or 86 degrees, myself. You need to sand the orange peel out of this and then see how much paint is left on the car, and maybe re shoot one or two more coats. After you sand, you can buff. That is really bad orange peel there. In fact, it's about the worst I've ever seen. Don't even bother with a buffer for that. I would try 1000 grit paper, and if that doesn't cut quick enough, then go to 800 or even 600. You wouldn't need more than a minute per foot with 600, though.

I concur. I actually think repainting may be the best option...as long as you have the time and $$$ that is. Maybe get some test panels to dial in the gun and technique first.

What type of gun are you using?

[RobR93]

It's an HVLP gun. I have the time and energy to wet sand if that's what you think I should do. Im not afraid of a little elbow grease and doing what needs to be done panel by panel......or if reshooting is the best bet, I still have about a half a gallon of the paint left. do I sand out the paint on there now if I repaint?

[RaskyR1]

Maybe try sanding a section and see how it comes out. I've just never seen it that rough before so it's hard to say if it will safely come out or not.


I came across a good thread the other day on painting...let me see if I can find it again. ;)

[RobR93]

I'll try starting with the 1000 grit tonight. I believe I got good coverage of paint. So if Im careful, I won't get too for down......thanks for the tips and I'll be looking forward to Mikes response. do I wait for the one other 80 degree day we may get here in NY and try to reshoot? I have a wood stove in the garage, but am not keen on open flames and paint spraying.....and yes I have a respirator.....thanks for asking!!!! :)

PS.....Im learning as I go.....some mistakes will obviously cost me extra time/money/effort, but I will have learned something!!!!

[RaskyR1]

we are not supposed to post links so I'll just copy paste the post in the thread...PM me if you want the link. ;)


"Basics of Basics" Atomization and gun set up.
By Brian Martin

Being HVLP and low VOC products are the way the industry’s going I will be referring to them in this discussion on painting and paint guns. Most all basic issues dealing with HVLP can be applied to conventional guns, atomization is atomization. The HVLP just arrives at it differently.

The object of the spray gun is to break up the primer/sealer/paint/clear (I will call this “PSPC” from here out) into small particles and lay them in neat little rows on the panel being PSPRed. So the whole outcome rests on how well the gun is doing this. Picture the droplets of PSPC coming out of the fluid tip of the gun and then the air “slapping” them into smaller droplets.

You have two things that help you with this process, air and solvent. Solvent can mean something that is already in the PSPR from the manufacture or something the manufacture has told you to add to it. By the way, you should always mix in proper ratios as instructed in the tech sheet. The thinner (less viscosity) you get the PSPR or the more air you have at the fluid tip of the gun the more it will break up the PSPR. The target for you is getting the perfect balance needed. Too much solvent and the PSPR will have no body, fill, durability, etc. Too much air and you blow the PSPR everywhere but the car, poor adhesion, excessive texture, etc.

So, the answer is proper air supply and gun (and fluid tip) choice and how you adjust it.

With today’s high solids-low VOC (Volatile Organic Compound, you know the bad stuff that goes up into the air we breathe) products there is less solvent. And with HVLP guns there is less air at the cap to break up the PSPC, proper air supply and gun setup is more important than ever.

FIRST THINGS FIRST, your compressor and air supply.

An HVLP gun requires more VOLUME of air to operate (the V in HVLP, High Volume Low Pressure). Now you may notice that your HVLP gun is adjusted at maybe the same PSI as an old conventional gun, around 50 lbs at the gun (many HVLP guns are set at much lower though) so where is the “Low” in PSI they are talking about? It is at the actual air cap where the air and paint come out. An HVLP gun has only 10 lbs at the cap while a conventional has upwards of 50! So the VOLUME of air (CFM, Cubic Feet per Minute) is the key to proper atomization with an HVLP.

This 10 lbs I am mentioning is AT THE CAP where the air and paint comes out. It is not measurable without a special air cap that has a gauge built in to it. This air cap costs about $150.00 (and you would need a different one for every brand and model of gun you use) and is not needed to set up or tune your gun. Just looking at the droplet patterns will tell you everything you need. I only refer to it to make a point about HVLP operation.

If you have a gun that requires 15 CFM you will need a compressor and plumbing that will produce that at a very minimum. There are HVLP guns that need as little as 7.5 CFM so you can get good results even from a smaller compressor. Air supply is a complete subject by it’s self so lets assume that you have the air supply needed and move on to gun set up.

So atomization is the key, but why? Why can’t you just lay it out wet and let it “flow”, as an old painter will say. Picture a jar full of bb’s, they will represent well small, atomized droplets of PSPC. The gaps in between the bb’s is solvent. Now picture a jar filled with marbles, they will represent large, poorly atomized droplets of PSPC. The gaps in between are, you guessed it, solvent.

If you apply your PSPC in large poorly atomized droplets, what you will have is a film full of solvent. This can and will cause slow curing, shrinkage and dieback (the loss of gloss in the hours and days after application).

So, now that we have learned the need for gun set up, how do we do it? Lets start with the fluid tip choice. The newer high solids low VOC PSPC products need to be broken up more, so a smaller fluid tip is needed.
Basically you want the smallest fluid tip that will still allow you to PSPC the particular part you are PSPCing keeping the entire thing wet and in a fair amount of time. In other words a 1.0 tip would be beautiful for clearing one fender, but would be lousy to paint a complete. The application would be way to slow and the first panel would be way to flashed by the time you got around back to it. So you need to compromise, a 1.3 is a great all around tip, while a 1.5 though getting a little big, can get you by. If you read the tech sheet on the particular product you are shooting, it will have a recommendation for fluid tip size.
There are needs for other tips, for instance when shooting polyester primer you may need as big as a 2.3, but for urethanes and epoxies, the 1.3 or 1.4 will work great. If you plan on using a pressure pot or paint a bus, all bets are off and we would need to study a little bit more.

As an example of the use of a 1.3 tip I did a test once that proved the point well. I shot two panels of metal with a med solids urethane primer. One was shot with a 1.3 super high atomizing top of the line topcoat gun. The other was shot with a 1.5 (or a 1.7 I can’t remember) “hoser” primer gun. Three coats were applied and after a full cure (the one shot with the larger gun took MUCH longer to flash and cure by the way) the film thickness was measured. The one shot with the 1.3 tip was 2 tenths of a MIL thicker! The larger gun laid out the marble sized droplets full of solvent and when the solvent flashed the film shrank.

Air supply is a subject that could fill many pages by it’s self. So we are going to assume you have that covered and move on to gun set up.

You need to “tune” your gun EVERY TIME you use it just as you would tune a guitar before you perform. This is done with a very basic spray out pattern test. This very basic test tells you how your gun is atomizing and you adjust it to achieve the best atomization you can.

Lets do a spray pattern test:

Set the fan width as need (you don’t want to change it after you have “tuned” the gun). Turn out the material knob about 2 ½ turns. This is the “mixture” adjustment, kind of like the idle screw on a carburetor. The farther in it is screwed the lower the fluid to air ratio is and the smaller the droplets will be. The farther out it is, the higher the fluid to air ratio is and the larger the droplets.
Set the air pressure at the inlet to the gun to the manufactures specs. On an HVLP gun this spec is usually found on the gun and is the maximum PSI it can have while still maintaining the maximum 10 lb at the cap for legal HVLP transfer efficiency (68 %). You are now ready to do a test spray out.

Tape a piece of masking paper on the wall for the test. Hold the gun at a right angle to the wall, just as if you were going the wall. Hold the gun at a spread out hands distance (about 8” or 22cm). Pull the trigger to completely open for a split second and then close it. You want an ON-OFF wide open-completely closed in ONE movement. You should have a cigar shaped pattern with complete coverage in the center with fading coverage going away from the full coverage cigar shape in the center. The center should be fully covered without any runs. If you have runs, either you are holding the trigger too long, you are too close or the gun is simply applying too much material. In which case you need to screw in the material knob or turn the air pressure down. But most likely if you have turned the material knob out the 2 ½ turns and the air is set at the factory specs, you are just too close or holding the trigger open too long.

The droplets you see trailing off the center are what you will use to “tune” your gun.

Turn in the material knob to make the droplets smaller (and or raise the air pressure). The balance you need to attain is the smallest droplet size possible before you loose the coverage desired. In other words if you turn in the material knob too far, not enough material will be coming out to cover the panel!

Now, you’ll notice that I said, “raise the pressure to the gun”, while earlier I said to set it to manufactures specs. We are talking a very small adjustment. It is a fine balance in material to air ratio and a little more air than specified is okay. Even if it is an HVLP gun the inlet pressure recommended is to maintain the 10 lb limit at the cap. Well, about three quarters of the country has no regulations for HVLP use so if you go over the 10 lbs all it will do is atomize the material a little better. You may loose a little of the benefits of HVLP though. But remember you have a lot of control with the material adjustment knob.

After you are happy with the droplet size, DON’T TOUCH THE FAN CONTROL. It will change the PSI at the cap and will change the atomization you worked hard to get.
Do this spray out every time you spray as material change, temp, and humidity will necessitate a spray out droplet pattern test. Good luck!
Click here to see a sprayout pattern (http://members.aol.com/icantunderstand/hvlpdropletpatterns.jpg)

[Blackthorn One]

I'll try starting with the 1000 grit tonight. I believe I got good coverage of paint. So if Im careful, I won't get too for down......thanks for the tips and I'll be looking forward to Mikes response. do I wait for the one other 80 degree day we may get here in NY and try to reshoot? I have a wood stove in the garage, but am not keen on open flames and paint spraying.....and yes I have a respirator.....thanks for asking!!!! :)

PS.....Im learning as I go.....some mistakes will obviously cost me extra time/money/effort, but I will have learned something!!!!
A trick you can use to make your paint atomize better in cold weather is to put the paint can in a pot of very warm water before you shoot it, for about 10-15 minutes, to make sure it is completely warmed up. It really does improve your painting. Just be sure that the paint can is absolutely dry before you transfer paint from the can to the cup. You don't want any water to get in the paint. Practice a little on that hood first.

[Mike Phillips]

Here's the full size picture as it was attached...

http://www.autogeekonline.net/forum/attachments/wet-sanding-cutting-buffing/4624d1251911315-freshly-painted-orange-peel-coat3h.jpg


That's pretty bad, here's some bad orange peel,

http://www.nascarfool.com/Truck/op1.jpg



He sanded and then buffed and got it to here,
http://www.nascarfool.com/Truck/op2.jpg



But says he also buffed through a couple of places...


Like most already commented, the orange peel in the finish is pretty severe and you might be better off sanding and the re-shooting more clear and try find out where the orange peel problem is coming from in your process.

If you have a thick enough film-build of clear you could theoretically sand the paint flat and then buff out your sanding marks but keep in mind that sanding removes some paint and the compound and polishing steps both remove some paint so if there's not enough film build to work sooner or later you will buff through the clear and expose the color coat.

Even if you re-shoot the paint you're still going to need,


Rotary Buffer (http://www.autogeek.net/flex-l3403vrg-rotary-polisher.html) - It's possible to remove sanding marks with a DA Polisher or a Flex 3401 but the most EFFECTIVE method is with a direct drive rotary buffer.
Wool Cutting pad (http://www.autogeek.net/75inholodu10.html)
Foam Polishing Pad (http://www.autogeek.net/foam-polishing-pad.html)
Aggressive Compound (http://www.autogeek.net/meguiars-mirror-glaze-105-ultra-cut-compound.html)
Medium to light cutting polish (http://www.autogeek.net/meguiars-finishing-polish.html)
Sanding or Finishing Papers (http://www.autogeek.net/meguiars-sandpapers.html) - Finishing papers are a higher quality sandpaper
Backing pad (http://www.autogeek.net/meguiars-sanding-pad.html) for your sandpaper
Spur
That's a minimum of supplies. A wish list would include,

A pad washer (http://www.autogeek.net/grit-guard-universal-pad-washer.html) to clean your pad after buffing a section or two. You can clean your pad with a spur but a pad washer gets the pad so much cleaner.

A DA Sander - It's faster to sand with a DA sander and a heck of a lot faster to remove DA sanding marks than hand sanding marks.

The Mirka Abralon System (http://www.autogeekonline.net/gallery/data/738/AbralonSystem005.jpg) or the 3M Trizact system, both work great.

A DA Polisher (http://www.autogeek.net/hk7424.html)and some small foam pads for the final finish polishing to insure there's no swirls

Swirl Finder Light (http://www.showcargarage.com/gallery/files/1/Brinkman.jpg) is always handy to check your work.

Grit Guard (http://http://www.autogeek.net/gg1010.html) in a 5 gallon bucket to store your sanding papers and/or sanding discs

Painter's tape (http://www.autogeek.net/3m-masking-tape.html)

That's a partial list but a good start...

:)

[Mike Phillips]

I'll try starting with the 1000 grit tonight. I believe I got good coverage of paint. So if I'm careful, I won't get too for down......thanks for the tips and I'll be looking forward to Mikes response. do I wait for the one other 80 degree day we may get here in NY and try to re-shoot? I have a wood stove in the garage, but am not keen on open flames and paint spraying.....and yes I have a respirator.....thanks for asking!!!! :)

PS.....Im learning as I go.....some mistakes will obviously cost me extra time/money/effort, but I will have learned something!!!!

I posted a list of minimum tools required which includes a rotary buffer, if you don't own one you can probably rent one at your local tool rental store.

You can remove sanding marks by hand but it's a lot of work but also a good work out...

I would never usually recommend starting with grits lower than #1200 but the orange peel is so bad that you initial cut could be with #1000

Some will say even lower but I'll let you decide, #600 and #800 grit papers are pretty darn aggressive, I'd rather start at #1000 and then work my way up.

Let us know if you get the rotary buffer as you'll still need a backing plate and a wool cutting pad.


Take some good before and after shots...


:xyxthumbs: