automotive paints, anyone?

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dwalker

Well-Known Member
I owned a paint and body shop for a while, so forgive me if I skew things.

First, if it is going to sit in the sun for any length of time, I would 100% clearcoat it. It is an easy thing to do and the benefits far outweigh any downsides.

I have used, on various race cars/motorcycles/parts- I will attach a picture or two- the Dupli-Color Paint Shop branded lacquer paints. They are pre-mixed and easy to use. However, they MUST be clearcoated for any durability at all. The paint tends to last and hold up just fine, and is relatively easy to sand off and refinish if needed. IMHO it is a very easy system to work with, holds up decently well, and is a very reasonable cost. As far as the clearcoat for this system, I personally would use PPG, but honestly any good automotive paint shop clearcoat- like SMART brand- will work fine.

If you absolutely must use a single stage, I STRONGLY suggest using a catalyzed system like an acrylic enamel (PPG OMNI) or acrylic urethane (Concept). These can of course be clear coated as needed, but are very durable systems and are forgiving to use.

All of the cars below are painted with Duplicolor Paint Shop paint with PPG clearcoat over usually PPG 2k primer.

The red/black/silver car is Dupli-color Performance Red with Jet Black and Brilliant Silver. The red and black are matte cleared for a more "hot rod" look.
The second car is Performance Red/Championship White/Deep Blue Metallic
The third car is is Brilliant Silver/Chrome Yellow/Deep Blue Metallic
The bike is done in Sublime Green Pearl, and in that picture has not as yet been cut/buffed.

Not sure how much help this info is, but be glad to answer any questions.

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wktaylor

Well-Known Member
I've been in Acft corrosion preventative finishes business for a while.

Aircraft ARE different from other vehicles... except maybe 'low-and-slow'... and steel... will be more like cars.

WHAT you are applying the paint system ONTO is an important variable of the picture.

Preparation of the surface for painting is ~75% of the job/value. Nothing sticks to dirty. Thin paint finishes reveal everything underneath: rough-flaky-dirt-poor cleaning, etc. Aluminum, composites, fabric, etc... all have unique preparation requirements.

One-part [1-part*] paint go's-on-wet-and-dries [solvent evaporation to form the paint film]. Modern multi-part [X-part*] paint coatings are mixed, applied, dry-to-touch [solvent evaporation], THEN chemically cure over-time [evolve> strength, toughness, durability, chemical resistance, etc... to form the paint film]. These coatings may be applied in multiple layers BUT[!!!]… generally speaking... never mix 1-part and X-part finishes... there are many incompatibilities. Of course there are exceptions to this rule [hard to explain].

*True paint thinners [solvents or water] don't count since they evaporate-away.

A few useful MIL-Spec/T.O./T.M.'s RE application of coatings. [emphasis]

https://quicksearch.dla.mil/qsSearch.aspx

MIL-DTL-5002 SURFACE TREATMENTS AND INORGANIC COATINGS FOR METAL SURFACES OF WEAPONS SYSTEMS
MIL-DTL-18264 FINISHES, ORGANIC, WEAPONS SYSTEMS, APPLICATION AND CONTROL OF
MIL-HDBK-509 CLEANING AND TREATMENT OF ALUMINUM PARTS PRIOR TO PAINTING
MIL-HDBK-803 GLASS REINFORCED PLASTICS - PREVENTIVE MAINTENANCE REPAIR
MIL-STD-7179 FINISHES, COATINGS, AND SEALANTS, FOR THE PROTECTION OF AEROSPACE WEAPONS SYSTEMS
TT-C-490 CHEMICAL CONVERSION COATINGS AND PRETREATMENTS FOR METALLIC SUBSTRATES (BASE FOR ORGANIC COATINGS)

Useful USAF T.O. painting and corrosion protection info. Technical Orders [etc]
1-1-8 APPLICATION AND REMOVAL OF ORGANIC COATINGS, AEROSPACE AND NON-AEROSPACE EQUIPMENT
1-1-686 DESERT STORAGE PRESERVATION AND PROCESS MANUAL FOR AIRCRAFT, AIRCRAFT ENGINES, AND AIRCRAFT AUXILIARY POWER UNIT ENGINES
1-1-691 CLEANING AND CORROSION PREVENTION AND CONTROL, AEROSPACE AND NON-AEROSPACE EQUIPMENT
1-1-700 CORROSION PREVENTION AND CONTROL, GROUND COMMUNICATION - ELECTRONIC EQUIPMENT
35-1-3 CORROSION PREVENTION AND CONTROL, CLEANING, PAINTING, AND MARKING OF USAF SUPPORT EQUIPMENT (SE)

US Army
TM 55-1500-345-23 PAINTING AND MARKING OF ARMY AIRCRAFT [Google]

Backtowerk.

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dwalker

Well-Known Member
dwalker,
If I diy the paint, I've wanted to avoid clearcoat because it seems like it'll be heavier, due to the extra coat of paint, more work, due to the extra coat of paint, and more expensive,due to... well, you get the idea. ;-) BUT, I'm certainly willing to be educated on the subject. 'I ain't dumb, but I are uneducated', when it comes to paint.

speedracer,
Got a link to your specific paint? I tried searching NAPA's site for 'probase paint', but it's not very navigation-friendly on paint products. I got hits for Martin-Seynour paints costing about $180/qt and up. You need two, maybe three coats of basecoatd to provide even coverage, then add two- three coats of clear, which gets wetlands and buffed. To get the same in a single stage you might only need three coats total, but the last two will be medium to heavy, because that is what you will sand and buff. Seems even/Steven right? No, not really. The single stage will oxidize and will have to be continuously buffed, so more paint "should" be applied to start with. Single stage will also need a lot of protection from the sun. It's going to have to be waxed, coated, whatever, far more than a clearcoat. Now the clearcoat is not without its fails as well. Without UV inhibitors- not all clears have them- the clear will have, crack, maybe peel. You might have seen this called "clear coat rot". In truly bad cases it will literally peel the basecoat like scotch tape. I understand value per dollar. I personally am painting my Dragonfly with Duplicolor Championship White with Sublime Green Pearl accents then using a specialty clearcoat over that. The Duplicolor paint should cost me maybe 200 bucks for all of it, the clear will cost me another 200 for the gallon I'll use. BBerson Light Plane Philosopher HBA Supporter TFF Well-Known Member If you are a crop duster or fly a Lear, those paints are made to handle ugly chemicals and extreme temperature changes quickly. Not really an issue with a normal GA plane. Now lots of planes use to be painted with Imron in 70s-80s for the gloss. Lovely stuff to paint. Pretty much single handily drove the paint industry into safety paints of today. It was a do all paint though. I know landing gear is painted with it still. I used PPG on this helicopter mainly for repair if needed. Yellow and white is new. Black needs attention and black stripes added. Needed to get it flying. My airplane on the metal has a$10 quart of Aerothane from the Oshkosh cheap parts tent and some good old fashioned nasty cheap paint from TCP Global. I’m doing garage style paint jobs. Not fancy ones.

Base clear is pretty light. Base goes on easy. Skill is in the clear. I talked a friend into painting his RV7. Decent enough paint job and he could have polished it more and made it look even better, but on the line at Oshkosh where 90 are pros, he had something that those guys didn’t have, which was guts to do it. The secret of base clear is as long as the clear is thick enough to color sand, you can make it look great with a cut and buff. Single stage is a little less flexible that way. Running the paint gun is the prize. Prep is where the work is.

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Fiberglassworker

Member
Many years ago I used to recover aircraft using the Stits Polyfiber process, at that time their STC stopped at the polyspray ( silver) process. For topcoat I used to use Acrylic enamel with flex additive ( Semflex), these finishes would last for 10 to 20 years without cracking. I did a few aircraft with Imron Polyurethane , which also did quite well. Now one thing I am finding is that most of the makers like PPG are making these single coatings obsolete, For example Delstar was replaced with Concept urethane and now that is obsolete. This all came to a screeching halt when Stits , (now Consolidated Coatings) , changed their STC to forbid any coating but theirs as a final coat.
at the same time I discovered that in a lot of cases the Stits coatings were a lower cost than some of the automotive coatings available today.
I have over the past 10 years switched to Stirling aircraft paint out of St Louis Missouri . for one main reason , you can roll and tip them , avoiding overspray. These paints are fiendishly expensive but they go much further resulting in lower overall cost. They require a special thinner for this which you have to get out of their marine paints division . However Done properly the final job looks like it was sprayed. If you try this, practice on something other than your airplane first, to avoid runs.

Pops

Well-Known Member
HBA Supporter
Log Member
Painting fabric is NOT the same as painting metal. Hard to find a paint that will do both well.
Clear coat over rivet heads and going to sand and polish, good luck.
Painting airplanes and painting autos is apples and oranges.
Love my HVLP turbine spray outfit.

Geraldc

Well-Known Member
PPG Autothane cv is good but I don't know if it is available worldwide.

dwalker

Well-Known Member
I had to re-read the posts and make sure we were discussing painting METAL and not FABRIC. Since the OP is painting metal, I am going to make a last comment about painting an aluminum structure with bolts/screws/rivets/etc. in it. For the most part, there is really only one way to do this, and that is to make SURE the last coat is even, wet, and mixed with with a bit of slow reducer so that it flows out, but does not run. Its a practiced thing for sure, but here's the thing...

Regardless of whether you are using single stage or base clear if you start sanding or in many cases even just buffing around rivet/bolts/etc., even those that are countersunk, you are very likely going to burn through. So take the time to nail that last coat!

Now yes. you CAN and I have, wetsand around the rivets, use a small buffer and work out a dry spot or a slight run or sag, but it is not a quick process, at all. If AT ALL POSSIBLE I want to just give the big surfaces a nice cut and buff and do a little as possible around rivets.

Now that I have said that, I would still use a base clear system, and would make sure your rivetheads are all flush and when you prime the panels make 100% sure you have etched the aluminum properly for good adhesion.

On your FG parts, if it is something that has some flex to it like a cowl or thin like a fairing, do yourself a favor and add a bit of flex additive to the paint and use an adhesion promoter like Bulldog or similar before you lay it down to reduce the risk of the paint cracking/lifting.

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Pops

Well-Known Member
HBA Supporter
Log Member
Very well said. With rivets, the last coat is what you get, so it better be right.

rv7charlie

Well-Known Member
You guys are really pushing me toward wrap. ;-)

It's an RV but with an alternative engine, so there's no sense in a paint job that costs 50% of what the plane will be worth flying. (I'm a pragmatist about that.)

Virtually all of an RV is flat wrapped except the wing/empannage tips, cowl & wheel pants. Maybe my pest path forward is to wrap everything that's flat wrapped and/or easy to stretch-wrap with the vinyl, and find a 'pro' to color match to the vinyl with paint on the pants & cowl, which take more abuse than the rest of the plane anyway.

dwalker

Well-Known Member
You guys are really pushing me toward wrap. ;-)

It's an RV but with an alternative engine, so there's no sense in a paint job that costs 50% of what the plane will be worth flying. (I'm a pragmatist about that.)

Virtually all of an RV is flat wrapped except the wing/empannage tips, cowl & wheel pants. Maybe my pest path forward is to wrap everything that's flat wrapped and/or easy to stretch-wrap with the vinyl, and find a 'pro' to color match to the vinyl with paint on the pants & cowl, which take more abuse than the rest of the plane anyway.

I've never found wrap to be less expensive than paint on new metal, and over time.

rv7charlie

Well-Known Member
I get your point, but I'm 70 now, and with the plane in a hangar, vinyl will almost certainly outlast my flying years. Running rough numbers, quality vinyl looks to cost about the same as some of the less expensive automotive paints for the materials required. I have no experience with vinyl, but after asking around, I'm confident that with a helper I can do at least the flat wrapped stuff & make it look a lot better than I can paint. I've sprayed one a/c, and it looks pretty good (about like traditional dope finishes), but it's a Kolb; almost all fabric & I sprayed acrylic house paint for the whole plane. Paint was so cheap compared to automotive that the learning curve and the \$10 Harbor Freight spray equipment didn't really cost anything. Multi-part automotive or a/c paints are a total unknown to me, except for the serious health risks with some of them.

If I had your skillset, we wouldn't be having this discussion. ;-)

rv7charlie

Well-Known Member
What about UV protection for fiberglass composite?
Obviously needed. But either finish will do the job. Paint wouldn't be an issue, and the quality vinyl wraps last for 5-7 years on commercial vehicles that never see the inside of a building if they're not being repaired. If the vinyl survives UV, what's under it will be fine, too.

dwalker

Well-Known Member
What about UV protection for fiberglass composite?
"Back in the day" until current times there is a primer that was "UV blocking", using IIRC carbon black. This paint was used as the base layer under the white paint. The problem was it often came unstuck from the substrate (composite skin) and bubbled, peeled, or flaked off the plane, leaving the epoxy completely exposed. The other issue is it works by absorbing the UV rays, which does not seem optimal. I would rather reflect the UV rays and avoid as much heat in the finish as possible.

The current base/clear systems as used with a epoxy primer/sealer are pretty good at blocking UV, but they MUST be applied to a specific thickness. I am not 100% sure but I feel like .2-3 coats of the base color was the "minimum". Now, that said, there ARE still clears out on the market that are not particularly UV resistant, and they will rot and peal right off the basecoat. Not sure that means a thing to the epoxy skin under the basecoat, at least until the basecoat flakes off.

Most catalyzed single stage paints are UV resistant, but not all and its worth asking the guys you get your paint from.

Note there is a difference between being "UV Stable" and being "UV resistant. A good even basecoat covered by a UV resistant clearcoat with a yearly ceramic coating done is the way I am going with my projects.

And here is the part where I remind you that while I seem smart, I am by no means an expert and you are a grown human and should make your own decisions

If you do not know if your existing finish is UV resistant, I very highly recommend having the paint sealed with a UV blocking ceramic coating, high end wax/sealant, or similar. If you do know the paint is UV resistant

TFF

Well-Known Member
I think painting is easier for the amateur. It’s not way easier, but it will be per results.

I used a harbor freight gun on the helicopter. Meh. A better gun is great, but you can get away with a lot with modern paint.

A friend flew his RV 8 in build aluminum for years, then he decided to paint it. Hasn’t flown since, and we are talking a long time. 95% done for years, but something always comes up to change. I figure he is at least one more avionics upgrade away. He is on number two right now. He has other planes. My friend with the RV7 who did it himself, used an old bottom cup gun borrowed from another friend. Respectable. The RV8 used something like pops uses.

I think I would mix mediums. I would probably leave most of the paint off, not polish, just leave it. Paint the fiberglass stuff and put on vinyl stripes and maybe leading edges, and fly. There is another friend with a beautiful 8A he had pained by one of the places known for RV painting. A couple of other RVfriends went suede and painted in toner epoxy primer done up military.