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Paint.

Discussion in 'Projects, mods, restoration' started by TWX, Feb 9, 2008.

  1. TWX

    TWX DO NOT FEED THE TROLLS!
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    Since almost all of our cars at some point will need paint, I figured I'd start a discussion that could become semipermanent if people want.

    I have two different vehicles that effectively require paint jobs, and another that theoretically could benefit from one. Two of these, the Stratus, and the Cordoba, are to be painted with a metallic-fleck paint. The Stratus was a metallic red from the factory, painted in a basecoat/clearcoat fashion, while the Cordoba was repainted at least once by the previous owner in a single stage process by a discount auto painter like a Maaco or something. The Cordoba oxidized and has started peeling like a bad late eighties OEM paint job and the Stratus is experiencing a complete breakdown of its clearcoat. The other vehicle, my white non-Mopar truck, is experiencing flaking off of its single-stage OEM paintjob and needs a significant amount of metal body repair in addition to a few outright new pieces of sheet metal.

    My biggest concern, overriding all of the processes, colors, and finish smoothness qualities is durability. I want each of the vehicles to look good when I'm done, and I would like to sun and weather protect vehicles as best I can, but they're cars, they're going to spend considerable amounts of time outdoors, and I want to paint them with the idea that they may never, ever be kept out of the elements. Being that I only have one covered spot at the moment available, it'll probably be the Cordoba that gets to be covered.

    I've heard of urethane acrylic paint, and I've heard of the basecoat/clearcoat process. The pickup doesn't need a clearcoat and would need only the most basic industrial white paint, but the other cars need to not oxidize, or suffer from a peeling clearcoat, or have a clearcoat that turns white, or have metallic paint that flat out dulls. I know that the paint won't last forever if it's outside, but it'd be nice to get fifteen to twenty years out of it, even if means spending more up front.

    I'm also curious as to what they changed in paint that so reduced the durability like we've seen in the last twenty years. I've seen plenty of cars made even as late as the early eighties that still have great looking OEM paint, and cars made only five years later that look terrible...
     
  2. Pacopcar

    Pacopcar Member

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    An all too common problem.

    Urethane paints require a finishing to them as they have to be brought to a shine. It is also a single stage paint so if it wears, you are down to the primer, or whatever is under it. It is a lower total cost to put down.

    Base/clear is the paint of choice these days. A well done job will outlast a single stage job and is more durable overall.

    There is a difference in quality between paints. It's best to stay with the professional brands. The reasons why clears separated was due to the lack of total paint sprayed and poor jobs doing them by the factories.

    Probably one of the biggest single issues on why paints don't lkast well is that not enough coats are put down. Factories and cut rate body shops put as little paint down as they can get away with. Another issue is how well the base is prepared before paint is applied.
     
  3. TWX

    TWX DO NOT FEED THE TROLLS!
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    Okay. I was watching a little bit of one of the "Power Block" shows on Spike TV today, and one of cars they've been with for a long time, "Project Blue Hair" early seventies Chevy Nova, got repainted with some new body parts, ending up with some kind of an isolator coat to prevent new paint from weakening and flaking (thus removing the above new layers), combined with an even priming, sealing, six layers of base coat, and something like four layers of clear. They did a lot of wet sanding of the basecoat between coats and between priming, and a lot of block sanding before they even applied the basecoat. What they didn't indicate was how much wet sanding, if any, they did on the clearcoat...
     
  4. Jeff2KPatriotBlue

    Jeff2KPatriotBlue Radioactive

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    This one is worth keeping at the top.

    [pinned]
     
  5. TWX

    TWX DO NOT FEED THE TROLLS!
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    I figure that, like building the engine that I'm working on, that research and prep will take 100 times longer than the actual act of applying coats to the car, at least if I want to understand the whole process from sandblasting to curing the paint...

    I found this:

    http://books.google.com/books?id=2QU9zRN-2...ary_s&cad=0

    Any opinions on this book or a recommendation on others? It's about five years old now, published in '03, but as the most advanced I've ever gotten was spraying some PPG K36 primer on a fender (and never even getting to painting a basecoat, let alone finishing it), so I'm still in the weighing the advantages and downsides of attempting to media blast back to bare metal and its associated costs and additional time. I actually have a set of fenders and a header panel, and I need a new hood (barely visible hail damage), so I could theoretically get a hood, set of doors, and a trunk lid and try out whatever I'm to do on those before even taking the car apart.

    Two non-metal areas that I'm wondering about are the fiberglass header panel and the rubbery-plastic bumper to body filler joints. The header panel isn't quite as much of a concern because it's relatively inflexible, but the bumper inserts worry me because I want to avoid chipping due to temperature changes or incidental flexing from air pressure. I've seen lots of repainted flexible parts that look terrible, so I really want to avoid that.

    At least this time I have a garage, so unlike the Magnum that I took apart last time, this one won't decay in the weather before I get done with it...
     
  6. TWX

    TWX DO NOT FEED THE TROLLS!
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    400 pages, when properly indexed isn't a big deal. Thanks!
     
  7. Pacopcar

    Pacopcar Member

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    Bob's right about the two very durable paints. Imron has been used on emergency vehicles like ambulances with success.

    The new EPA regs have been modified thanks to SEMA not to apply to hobbyists who paint two or less cars per year. The legalities of spraying at home don't really apply, therefore. Still and all, you do need to be very careful about physical exposure, especially respiratory,
     
  8. Dodgeboy49

    Dodgeboy49 Active Member

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    There are a lot of books and information out there that describe how to make a car look like new, but what about those that just want a rig to look, shall we say, less ugly? One of my projects is to put together a 1949 Dodge 1-ton to be an all-around work truck. I have all the parts to put it together, but when I am done, it will have a severely oxidized blue cab, orange hood, and fenders with peeling turquoise house paint. If I leave it this way, I'll be lucky if the police do not burn it rather than be seen impounding it.

    I've never painted a vehicle before, and basically want a relatively inexpensive, relatively durable, non-show quality paint job. If it comes out 20/20 (20 feet away by 20 miles per hour), I'd be tickled. I've got a cheap spray gun, and a good air compressor. What would be the advice for cheapskates like me?
     
  9. Bob ONeill

    Bob ONeill 325,000+ miles and counting...
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    I shot this car myself using Nason from DuPont. I used this brand because I was able to 'sign up' on the DuPont web site as a 'user' and was able to download all the instruction and information documents they had available. These included paints other than Nason but based on my needs I felt that Nason was the best for me at the time.

    This was a base coat/clear coat process. The base coat was applied over filler primer which was sanded smooth. The clear coat was sanded smooth then polished once it had cured.

    [​IMG]

    I'll be painting my black Turbo Z using the same process. I will of course take more care in the prep as black tends to be more unforgiving than a lighter color.
     
  10. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
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    Ah, it will still look better than when new, and like the base '86, the motor will be clean enough to eat off of. ;)
     
  11. Dodgeboy49

    Dodgeboy49 Active Member

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    Is acrylic enamel with hardener what is called "single-stage"? What are the advantages/disadvantages of single-stage over base/clear coat?
     
  12. TWX

    TWX DO NOT FEED THE TROLLS!
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    Well, here, sometimes the clearcoat peels off quickly due to temperature and exposure to the sun, while a single stage paint job won't have that happen. However, the 'wet look' is basically undoable without a clearcoat.
     
  13. Bob ONeill

    Bob ONeill 325,000+ miles and counting...
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    Properly applied you shouldn't have any issues with the clearcoat.
     
  14. Pacopcar

    Pacopcar Member

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    Bob is correct. The issue with clearcoat separation that was prevalent some years ago was due to poor application rather than the nature of the paints themselves. Preparation of the basecoat surface is important also before shooting the clear. It's no different than what is needed to insure good adhesion of any stage of primer, paint or dye.

    For example, I've gotten quite proficient at dying vinyl and plastic. Preparation turned out to be even more important than how you shoot the dye. Paints are no different. You can have issues with even any single stage paint if you don't take the time to do proper prep. Do it right, you'll have no problems. Do it wrong, you'll know it in time.
     
  15. Dodgeboy49

    Dodgeboy49 Active Member

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    The paint separation did have its advantages though. I have met people who actually believed that the paint peeled off as a result of excessive speed. I had one person temporarily convinced that my 1983 Plymouth had hit 175 mph, because "everyone knows that paint doesn't begin to detach until at least 150 mph!" Pretty impressive for a worn out 4-banger, eh? :lol:
     
  16. TWX

    TWX DO NOT FEED THE TROLLS!
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    Well, there are those who believe that they took, "gullible," out of the dictionary...
     
  17. Volunteer

    Volunteer Well-Known Member

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    Single stage is cheaper to do than base/clear because of less time and less material. But, unfortunately, so many of the 'newer generation' of painters do not like single-stage paints, especially metallics. It does take time and experience to get the metal flakes to 'lay-down' in an oriented fashion and many of the 'kid-painters' today don't care to absorb this talent.
    But, the time-tested acrylic/urethane enamals can still be shot over with clear. Again, not most painters' cup of tea. :(

    p.s. Being a 'traditionalist', I prefer to have a car repainted with the type of coating it originally came with. My (one-owner) '84 RX7 was base/clear but after the first 20 years there appears tons of 'spider-like' surface cracks no matter how often it was waxed, polished, sealed etc.
    If and when it's re-painted I will probably go with the same paint scheme, mainly to keep the originality.
     
  18. AC TC

    AC TC Well-Known Member

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    I´ve painted a few cars and found out a couple of things ower the years.
    - A base/hardener paint is easier than a "selfdrying"(dont know the word in english) paint to apply.They get glossier and have faster curetime between rounds.
    -Metallics arent all that difficult to spray and a "run" in the clearcoat is easily sanded out and resprayed.
    -It´s easy to get a "tiger" pattern with metallics, dim it lightly on the last round.
    -Dont use any spraycan products...read paint crackling.
    -Use a sandingprimer.
    -Dont be afraid to try, a 20/20 is an easy goal.

    NO SILICONE ON CAR EVER!
    USE A WATERSEPARATOR !
    WEAR A GASMASK(?) ALL THE TIME!
    FIRE HAZARD!

    Happy painting, its real fun spraying.
     
  19. TWX

    TWX DO NOT FEED THE TROLLS!
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    As an update to my original post that started this thread, I've tracked down or installed almost all of the parts that I need for my Non-mopar project (the pickup), and a friend is evaluating how much he'll charge to do the body work to remove a significant dent from the side of the extended cab and prime it. Since this truck is currently white it'll hide a lot of sins if I don't do the most spectacular job, and since it's not a show vehicle if it comes out looking only marginal it's not a problem.

    The new-to-me pickup bed that I've obtained needs minor amount of body filler. My friend suggested that the factory paint is durable enough that I might not need to re-prime areas that I don't need to fill though. He suggested scuffing the factory paint with 400 grit sandpaper, applying a sealer, and adding my white layer. I expect to need to prime it where I apply filler, but that shouldn't be a big deal.

    Right now I'm leaning strongly towards PPG's Nason line. The guy at work who paints all of the vehicles (be they white or be they yellow and black) likes the stuff as a good product for the price. Plus, a friend of mine has a Valiant that needs paint on the roof, and he's thinking about white, so we could do both vehicles easily enough.

    I'm planning on painting the bed off of the frame, and painting the cab while the bed's off, so I can get the backs of each, and so I can give the frame a good pressurewashing and to verify that there's nothing wrong with it. Costco has a 10' by 20' tent (for lack of a better description) that has zippered ends for getting vehicles in and out, and I'm planning on using that as my work area, ducting some air in and emitting it under the truck to slightly positively pressurize the inside. I'll get a decent enough face mask and eye protection too, and use ear plugs to keep the random airborne crap out. I'll strip off the easily removed stuff (bumper, grille, turn signal corners), probably pull off parts to paint separately like the front valence and cowl, pull the easily remove glass like the extended cab windows, and mask off everything else. I figure that any parts that will move in relation to the others (like the cowl, which isn't attached very well even when all fasteners are there) will cause paint chipping issues if they're painted on the truck, so that's why they'll come off and get installed once everything is dry.

    The one other thing that I haven't figure out yet is if I'm going to try to remove the old sprayed-in bedliner in the new bed or if I'm just going to leave it alone. I have an installable plastic bedliner that I may use, but if I strip the old sprayed in one then I can paint the bed inside. But, the installable bedliner will wear the paint in the bed if I use it.
     
  20. I did this once I would prefer to next time rip out my heart with a dull rusty spoon while puncturing my eardrum with a sawzall.
     

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