Paint spray guns/systems

[Zzz]

Broad topic here, but many of you guys talk flippantly about spraying paint here and there, maybe a 2-part epoxy primer. If it's not in a can, you're using a gun of some sort to apply it. I am embarrassed to admit that I only have a Wagner Power Painter and that my spraying experience is limited to household construction type stuff, and I'm magic with a rattle can. The world of HVLP is totally new to me though. For instance, I have some of the 2-part paint that Avipro paints their fuselages with, and I'd like to shoot some of that at some point for touch up on the tubes where I've welded or rubbed paint off. But then, say, shooting the fabric or wings is a level of magnitude beyond that.

Here are the options as I see them, please weigh in:

1) HVLP spray gun used with your own compressor of adequate pressure/volume.
2) HVLP standalone system, like this Fuji turbine. No compressor required.
3) Airless or air-assist system like the Graco Monark 23:1, which my dad has and has offer to let me borrow.

Naturally, the preparation of environment and subject are critical, but in terms of equipment, what are you guys using?

[Battson]

I think you'll still find, even in this day and age, that a lot of planes are still painted with the old-school HPLV guns, and oftens times a little 50 L compressor working overtime.

That's how I did it. I'm not saying it was the best - but it was cheap and available.
I bought a new mid-quality gun and kept it clean.
I tried to keep the air volume down as low as possible without getting an orange-peel finish, to avoid overspray. I always used a cardboard test piece EVERY time before approaching a real Bearhawk part with a fresh batch of paint, or a freshly cleaned gun (out of tune).
I only used a handful of screw-on air filters, and was sure to drain my compressor tank regularly.

Yes there was a fair bit of overspray at times. With large surfaces like fuselage and wings, most of the paint ends up on the part anyway - provided you keep the air volume tweaked down.

Ahh the joys of spray painting....
The most annoying thing is laying down a perfect base coat, then watching the paint slowly but steadily crawl away from a grain of silica you didn't manage to wipe off, or a fingerprint you missed. Like you say, preparation. Be prepared to let it dry a little while you paint something else, and come back again with the paint cleaner and a clean, non-shedding rag. Resist the temptation to lay more paint on a crawler...
I aimed for 90% is good enough, when it comes to painting, perfection is a road to nowhere.

[N942VT]

Don't be embarrassed, paint is a big deal and many folks seem to suggest you can open a Harbor Freight catalog and get great results - you won't, and it won't be the paint suppliers fault.
You cannot overdo your paint equipment, all depends on how much you can afford. I would never attempt a full spray job without the right tools of the trade. If you can't afford that plan to have your plane sprayed by a pro. Cheap guns are crap, not enough air will look like crap, a poor booth without proper exhaust and intake will produce crap. Paint is so expensive these days it's really a shame not to get a great product when finished. So with that I would say the minimum for a quality job would include -
60 gallon two stage compressor
Mid grade gravity feed gun (Devilbiss finishline is mid grade, not Harbor Freight or similar, don't go any lower grade)
Quality paint grade hose
Filters and Dryers are very important, you'll spend 3-5 hundred minimum on a good filter / dryer set up, don't skimp.
True HVLP is not really necessary, it requires HVLP hose, fittings, dryers, desiccant, gun etc. A good gravity feed gun and system is enough.
Many paints these days are $300 plus a gallon, spewing it on with a crap system just doesn't make sense. Can you, sure, but this is a pet peeve of mine considering we invest more into these planes than most anything other than our houses. For $1000 labor you can have a prepared plane sprayed in a booth by a pro and have a beautiful product, why spend the same $1000 on one time use crap. On the other hand if you are only going to spray this plane then why spend the 3-4 grand for a proper set up? If you are going to keep building it's good economy but if not get a pro to topcoat.
Now, some have done great work with less than what I've posted above but most won't. Shoot for perfection, everything you think is good enough won't be - in the end you'll end up at 90% and convinced that you could do it better next time.

For what it's worth the above is for topcoat finishing. For primers, fillers, UV blockers etc the lower quality set ups can work to prepare your plane for topcoat, just don't skimp when it comes to the finish.

[Zzz]

I wouldn't mind hiring a pro for the top coat... This is my lifetime dream airplane, so I can live with the shame of farming it out easily if it means a professional result. It seems like the aircraft industry guys who know both metal and fabric are few. If you've filled and primered and are at that stage, can you hand your Stewarts/Polytone/Airtech polyurethane or whatever your chosen poison off to an automotive paint pro and expect good results? Is being a pro with a certain system about knowing the particular product or the technique? Are guys who are good at shooting PPG on cars also good at aircraft fabric? I saw a fuselage the other day at a friend's shop that had been shot in Stewarts and the weave of the fabric was extremely visible with the top coat on. I wasn't too impressed, and I don't think it was the process at fault. Perhaps a rushed fill/primer job?

Dave, I hear you on not skimping on equipment, but as you the area in between low quality and high quality is a vast spectrum of value. Judging "mid grade" by price alone doesn't mean much. What exactly about that Devilbliss gun makes it attractive? How to qualify that?

[Battson]

This is my lifetime dream airplane

Like!
I am glad to hear you say that, the building process is such an investment of yourself into a machine. That is cool to hear you say.

[whee]

Z, sorry I keep jumping in on your threads.

Not everyone's definition of "crap" is the same. I'll never be able to shoot paint like a pro but I can do it good enough for my purposes with my 21gallon aircompressor and 150$ gun we bought 20yrs ago. The car I shot when I was 14 had quite a bit of orange peel but it was my first time and I was happy. The next car I did was a few years later and turned out better. Either one will be good enough for my plane. I asked a couple good automotive shops about painting and none of them would touch it. Still I hope I can find a pro to do it cuz I'm just not interested. If I can't I'll use the equipment I have and will work hard to do my best paint job yet. 50ft on a running horse...

[Battson]

If you're aiming at that "professional" level, why not farm out the whole job to a professional? It's going to be cost neutral... once you buy all that gear, and learn those skills to that high level. Devilbliss is top quality gear, I know more guys using a harbour freight system than a two stage compressor. I would say that aircraft paint and car paint are significantly different, so is spraying alloy vs composite vs fabric.

From my experiences painting my first aircraft, learning as I went, I don't think you would get the same professional quality if you farm out just the top coat. The base layers are where the mistakes can happen, which telegraph through to the top coat. Unless you looove spending days wet sanding. Teaching yourself from the first brush coat of filler, you do get skilled enough to do a fine job, but a professional job would look better - for about the first 15-20 flight hours.

With your comment about the weave showing - everything I have read from the Polyfiber and Stewarts manufacturers says "if you can't see the weave through the paint, there's WAY too much paint on the aircraft, which will lead to the paint cracking".

My paint wasn't perfect to start with, but you sure can't tell any difference now. The backcountry flying thing doesn't go easy on an aircraft's exterior. Nor is the Polyfiber 'easy to repair' Polytone top coat as strong or shiney as other finishes. But it is easy to repair and re-coat.

[Battson]

I had lengthy talks with my local paint shops before buying a gun. The message was - you only need professional quality if you're painting enough to wear gear out, i.e. dozens and dozens of big jobs. Apparently that is where the money goes on that top of the line gear. Making it last.
I was told that a well made, tight fitting, quality product from the middle of the range would be more than enough to complete just one major job. I am told that taking good care of the gear, is every bit as important as buying decent quality in the first place.

[Zzz]

I would tend to agree with this, philosophically, on the whole about most tools.

[N942VT]

With guns you get what you pay for, price will dictate quality, which means good atomization and spray patern. Devibiss Finishline does an OK job for the money if you have lots of air. Whee is right, everyone has a different tolerance for finish quality but you can't compare an 80K airplane to a kids first car, my greater point is that it takes a fair investment to get really good results but why not try.

[dedgemon]

Hmmmm, cost neutral between buying the gear and hiring a pro you say. Well I dont think so. Having painted a couple of Rv's now I have a really good idea of what materials and equipment cost. Figure $3000 in paint materials for a nice clearcoat job with some trim work. Maybe $1000 to $1500 in equipment. But if you take that same airplane to a real shop that paints airplanes, figure $10000 to $15000 depending on the complexity of the scheme. Call em and check, but I think the $4000 - $5000 paint job is a myth if you want quality work. Most of a paint job is labor. If can learn to weld and do the other stuff you can learn to paint, but it takes study and practice. Just like welding.

[Battson]

Well, not wanting to argue, but just to clarify what I meant - I said buying the gear and up-skilling yourself.
All that practice comes at considerable cost when using expensive modern coating systems, I certainly couldn't do a professional job after paint just one (or two) aircraft.

I agree it's cheaper if you just want a mediocre finish. I suspect the price to set up a full professional spray shop, with top quality gear is worth more than $1500. I spent nearly $1000 just on my half-baked setup, without a paint booth, extractor fan, quality accessories, personal air system, etc etc.

I agree it's probably about ten grand for a professional spray job. Several Bearhawk's have gone that way, interestingly.

[dedgemon]

You might be surprised at how quickly you can pick it up. It does take practice, but if yuor the type that can sucessfully teach themselves things (sheet metal, welding, etc) you can conquer it. I think a lot of folks are just intimidated, and it is a lot of bloody work. For the significant cost difference I thought it was worth trying, and now I rather enjoy it. not for eneryone though, for sure.

[Zzz]

I've always been of the opinion that experience is the most valuable piece of this equation, which is why I've tried to find people to shadow or apprentice in our area for fabric and painting, but without much luck. I imagine it's a drain on anyone who's trying to turn a buck to have someone asking them questions while they're working. I bet you could take an experienced aircraft painter and hand him a set of shitty tools and he would still make it look nice simply because he knows how to arrive at the nice result.

I'd be happy with a 90% result, but it will take some time to equip myself with the knowledge and experience to get there. That's why I like practicing on scraps. The main issue right now is that I won't be painting in my garage or on my property, unless I build some sort of temporary structure in my backyard. I do have a friend with a paint booth, but that requires transport of the aircraft, which is no small feat.

But I'm digressing from the equipment discussion...

[Mark Moyle]

Just finished my top coats. Using a 1.3 mm HVLP with a Mac label. Got it off Craig's list for a $110. Shot primer, top coat and metallic. Fought dirt and debris. Turned out it was from my filter set up and some bone head try's on my part. I have gobs of air.. Went with the moisture separator at the compressor and regulator to step the pressure down to 90 from 175 psi. Then a 50 foot loop to a large filter/drier. The triple clean air device is at the paint gun...one of the disposable filter/moisture separator. Pretty much rid my self of contamination. Cept today when I brushed against the fresh paint... I'm using Superflight system 7. Couldn't see the weave in the fabric after primer.


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[Mark Goldberg]

Mr. Mark Moyle - you are doing very nice work on that Piper. Really. However, I do look forward to seeing more pics of your progress on your Bearhawk. Mark G

[Mark Moyle]

Hey Marc..... Busting my butt getting the pre Bearhawk trainer done..... The rebuild wasn't planed...dang 64 year old right landing gear leg busted.... Was supposed to be finishing the Bearhawk....


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[Zzz]

Oh well, you'll end up with 2 nice airplanes. That Pacer looks great. Does Superflight use their own branded paint?

Anyone used Airtech? I've heard it's pretty easy to shoot by comparison to some other systems.

[dedgemon]

So what coatings are folks using. I'm used to PPG urethanes on. the aluminum, but havent shot enough fabric to have a preference. I'd like the gloss to be "similar" between the wings and the fuse if possible.

[Mark Moyle]

Yea....new urethane formula. More flexible for cold weather...not supposed to crack. No visible fabric weave. Epoxy Primer is easy to sand...both the fabric and the metal primers. Glue is super easy to clean off. Looks like Aerothane....but is easy to fix...same paint on fabric and metal...same same.... Requires almost equal parts paint to reducer. The primer is white...a pain to top coat with white. Must use a fresh air supply and full body protection...like a hazmat suit. The hood is a pain...the replaceable visor sheets like paint...coat good with Pledge....golden.


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