What causes orange peel finish in painting?

[70 Challenger Lover]

I like doing things myself and learning new skills pertaining to car restoration. One area I have had trouble making improvements on is my skill at painting. I can shoots parts and large areas that generally don't require perfection but when it comes to a large surface like the topside of a hood, it will almost always have a slight orange peel effect, even on my best of days. Typically, I can color sand and buff it all out but I see guys lay down stuff like glass without having that happen.

So I'm wondering if I get this from air pressure too high or low, too wet or too dry, moving too fast across the panels, maybe lacking some thinner or additive during mixing.

Lately I've been spraying acrylic urethane single stage and it goes on very nice, just not perfect. My surface prep is good and I try to follow tech sheet directions to the letter. I use a $150 devilbiss starting line gun hvlp and for a while, I had good results at 30 psi. More recently, I've been shooting at 20 psi with slightly better results. Should I try even lower pressure?

I'd love some advice from guys who paint a lot and have worked past all these rookie issues.

[kawahonda]

Orange peel is completely normal. In-fact, orange peel is stock, even for new cars!

You can minimize it by experience, settings, pressure, faith, reducers, temp control, but it will always be there in some amounts. If there's any painter out there that can shoot a car with 0% orange peel anywhere then color me pleasantly surprised...I've never seen it.

This is why there's an additional step of "cut and buffing" that many opt for after picking up a car from a paint shop.

Orange peel is normal....it's not a rookie thing....unless it's really really coarse which is a sign of rookie-ness--usually something obviously wrong like poor pressure and bad technique.

btw, another Devilbiss user here...I've got the ol' Finishline 3 HVLP that I use for small topcoating jobs...but it's primarily a primer gun and it still rocks!

You should always follow the HVLP PSI range for your gun....never go above or below it or you will end up with bigger problems.

Some guys (like me) get to eye level on restorations...and what we look for has nothing to do with the top coating...it's the body work...I'm decently skilled in GOOD bodywork and I can tell what good blocking looks like....but for the "final spray day"...I leave that to the people with the big multi-million dollar paint booths and the expensive PPG mixer stations. Much better to have sound, straight, correct bodywork than it is for the paintwork to be free of orange peel...trust me!

[70 Challenger Lover]

Too dark to take a close up tonight but these were taken the other day couple hours after shooting it. If you zoom in, it's noticeable in my opinion though I am my own worst critic.

I've been tempted to cut and buff it just for practice. That seems to be another tricky process but the learning curve there has been much more forgiving to me than shooting the paint. The whole car needs painting and it's going up for sale but doing stuff like this hood was good practice and I had some leftover paint.

[kawahonda]

Pictures are too low-res to tell, but it looks good.

If it's going up for sell, I'd let the buyer cut and buff it. If you did it yourself (to learn) you may get yourself in a rat-hole. Practice on something else. Your efforts probably won't be paid nor returned back to you....and that's if you don't mess up....

btw, looks good. I'm sure some can go into the difference between one-part (single stage) vs 2 part (base + clear) in how the paint lays out....I'd assume 2 part may be more forgiving....but probably about the same in all honesty...

I'd be pretty pleased with what I see. I can send you photos of my 1965 Galaxie after a 2 part job was done, before cut and buffing. It didn't look like a mirror....it didn't look bad...it just looked kinda in between....shiny, but slightly dull without a lot of depth.

Cutting and buffing is a normal process of painting..

Regarding my Galaxie....trying to get a 20 foot land-yacht that had flat panels the entire way to look like a flat mirror all the way down had nothing to do with the paint work.....it took lots of determination and learning....and that's when I felt like I graduated and "had that eye" when I was 18....the paint shop was so impressed with my work that they admitted I did better than anyone around with the budget I had. I'm a bodyman...not a painter...but I've sprayed enough topcoats to at least provide somewhat of a response. I'm sure somewhere here will tell me I'm wrong.

[70 Challenger Lover]

Hahaha yeah I know you're right there. I've been in that rat hole several times now. One of my buddies keeps telling me to knock it off and just be done.

I think I will do that then. When the car gets painted someday, the hood will surely be redone as well. I'll just do the hood scoops and move on!

Thanks

Mike

[jimynick]

To answer your original question, "orangepeel" is caused by the product being sprayed on either too thick in reduction, too fast in reducers or too dry in application. The paint or clear hasn't had time to flow out and prematurely dries in the shape that it hit the panel in. There's a very fine line between putting enough product on to have it flow out smooth and creating runs that you won't enjoy removing. My personal opinion is that the cut and buff crown came to be as large as it is because of a inability of today's painters (some, not nearly all) to apply paint or clear in a proper fashion that doesn't generally need to be "cut and buffed" every time. I HAVE worked with painters who painted cars day in and day out without orangepeel in any significant amount, but that was in the days before "put lots of clear on, so we can cut and buff it to look right" Here endeth the sermon. 

[RUNCHARGER]

I am no pro but I have never buffed one of my paint jobs, (I have ran a few though). For what you're doing I think an orange peel job is just fine for this car.

[tparker]

I finished painting my car a couple months ago. I got a fair amount of orange peel. I sanded the primer (but didn't do a great job), and I sanded the clear coat. I should have taken a little more time and really checked my work since I got a couple runs here and there. I removed a lot of the orange peel through wet sanding up to 3000 grit followed by buffing. It looks 100% better afterwards. Not sure if you can get a paint job 100% without orange peel or not. But I have . heard that there are almost always some imperfections. Little bit of dust (nibs), occasional runs, etc, even for the pros. After all that time prepping and painting, might as well sand and buff it.

[MoparLeo]

Skill and quality materials. You need both to get a high quality job. Different paint types- enamels, lacquers, epoxy, base-clear etc... each require different adjustments and techniques. Let the chef's do the cooking.

[Marty]

It's a matter of gun control. Simple but not easy.

[JS29]

There is orange peel in factory paint jobs! practice, getting the right temperature additives, good equipment all make a difference. you can balance your temperature range by using a blend of slow, medium, fast additives to adjust to your conditions. there is a fine line between good flow and a run. the gun your using is an entry level gun, and that dose have a barring on the results. I would leave it bee, what you have now it a good base, if that was sanded with say 600 or 800 wet, the paint would flow out nice and be a plus for the new owner when the car gets a complete paint job .     

[70 Challenger Lover]

Appreciate the advice and opinions. The questions pertained to 'what could I do better for the next car I paint' rather than this one. I try to learn as I go and I could see doing more cars after I retire just as a hobby to keep me busy (plus I think it's fun). I completely agree that this RT needs help in other areas like the fenders long before I should worry about how perfect the hood is.

This hood was hung up and painted last week but I had runs everywhere. After sanding the runs out the following day (as well as lightly sanding the whole hood), I reshot it but did it flat instead of hanging. That made a world of difference but I got a couple tiny nubs. On the bulge areas where it might run, I moved the gun just a little bit faster and that seemed to help. The tech sheet did specify that I could add 5% reducer. I did that when it was hanging but after experiencing so many runs, I decided not to try it when I reshot it flat. Looking back, a touch of reducer might have helped it.

I guess the good thing to know then is I'm probably never going to lay it down perfect unless I get lots of practice every day. Even then, I could see the value in always using the same paint and having better equipment.

Thanks everyone.

[RUNCHARGER]

I agree with all. Temperatures, reducers etc. all play a big part. Initial coats should not be too heavy either as they are the most likely to run, once you have a few light coats stuck on you can go heavier overtop. If you finesse what you have it will make the contrast to the original paint even more obvious, best to leave it alone.

[70 Challenger Lover]

I agree with all. Temperatures, reducers etc. all play a big part. Initial coats should not be too heavy either as they are the most likely to run, once you have a few light coats stuck on you can go heavier overtop. If you finesse what you have it will make the contrast to the original paint even more obvious, best to leave it alone.

Glad you mentioned the initial coats. That might be another area I could work on next time I do a car. I put the first coat on just as wet as the last. So much that I had 90-95% coverage after the first coat. On the next project, I will try a couple light coats initially. I think the reason I hesitated on that idea before was I have it stuck in my head that a light coat will dry on contact and not flow out creating a sandpaper like base. Is there any possibility of that or am I just overthinking it?

And second, if I put down a couple light coats initially, should subsequent coats happen a little sooner to melt it all together and let it flatten out? Tech sheet said 10-15 minutes between coats but that just seems like a long time for the initial light coats. Am I looking at this all wrong?

[RUNCHARGER]

Other guys are more experienced than me but what used to work for me with single stage was: First coats were fine a little grainy, the last coat will fill in the grain and flow out flat. The 10-15 minutes between coats is best used as a minimum, a little longer is much better than too soon.
Like I say there are others here with more experience (especially with the newer products) but that always worked for me.