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Hot Rods New paint over old paint.

Discussion in 'The Hokey Ass Message Board' started by krylon32, May 10, 2019.

  1. krylon32
    Joined: Jan 29, 2006
    Posts: 5,928

    krylon32
    Alliance Vendor
    from Nebraska

    I'm not a painter and all the hot rods I've had painted started with a bare metal surface. I've looked at a Tan 40 Ford recently on Pews Place that has had new paint applied over sanded down original paint. How successful is this type of paint job and will it last? Paint looks good but it leaves you wondering.
     
  2. oliver westlund
    Joined: Dec 19, 2018
    Posts: 682

    oliver westlund
    Member

    if the original paint was lacquer and the new paint isnt lacquer, it wont last
     
  3. s55mercury66
    Joined: Jul 6, 2009
    Posts: 3,719

    s55mercury66
    Member
    from SW Wyoming

    It really all depends on the underlying paint. If it was in good shape then all will be good. Note that this applies to paint only, a lot of people confuse that with bubbling rust, or is that rusting bubbles? Anyhow, once an old paint job that was in good shape is painted over, it is essentially sealed under the new paint and will not deteriorate further. How to determine whether or not to do this? It takes years of experience, and a look at the vehicle, internet pics won't really do.
     
    427 sleeper likes this.
  4. lostone
    Joined: Oct 13, 2013
    Posts: 893

    lostone
    Member
    from kansas

    Yeah if the original paint was prepared properly shouldn't be a problem at all.

    Besides any idea how many repainted cars are done this way ? Just about every one of them. Stripping to bare metal isn't the norm it's the rarity.
     
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  5. anthony myrick
    Joined: Sep 4, 2009
    Posts: 4,578

    anthony myrick
    Member
    from al

    striping to bare metal is not necessary for every paint job
     
  6. Slopok
    Joined: Jan 30, 2012
    Posts: 2,319

    Slopok
    Member

    Factory paint in good condition is an excellent base.
     
  7. Pats55
    Joined: Apr 29, 2013
    Posts: 240

    Pats55
    Member
    from NJ

    I think part of the problem it's rusting from the inside out. Or he applied body filler over bare-metal.. Will have to wait and see what he has to say.The suspense is killing me
     
  8. tinsled
    Joined: Sep 7, 2007
    Posts: 608

    tinsled
    Member

    True. If in doubt, use sealer coat. Acc. to my experience the best, most reliable and most economical sealer is 2k epoxy. You can use inexpensive industrial epoxy. It also serves as primer, You can sand it and apply top coat right on.
    Nothing (exept rust *) goes through the epoxy - nothing from the old paint to new top coat, neither the solvents of the new top coat (or in between primer) to the old coat. Done it. Even sealed a lacquer paint by epoxy and laid acrylic on top of the epoxy. The lacquer was left under the epoxy and never boils out. I do have this car in my garage, it's 5 years back when I did the paint job. It's perfect like new today.

    EDIT: *) Epoxy seals also humidity and oxygen, thus is the best rust protection you can do, BUT what i mean is the underlying rust or rust from the back side of the panel - Of course there is NOTHING that would protect from such corrosion on top of your panel. The thing you need to do is make sure there is no underlying corrosion when you paint AND seal the panels also from back side - Epoxy is a good coat also in back side of body panels-
     
    Last edited: May 10, 2019
    rusty valley and j hansen like this.
  9. factory paint is your best base coat... Providing it wasn't lacquer..

    Being a 40 ford going out on a limb it has been painted at least once or even twice in its life time.

    If it was done lets say in the last 25 years it is going to be a catalyzed type of paint..

    Sand a area and see how many coats of build up you have (different colours) If there is more than one color NOT counting Primer STRIP IT !

    If there is just one color, sand it seal it shoot it...…….
     
  10. Squablow
    Joined: Apr 26, 2005
    Posts: 13,945

    Squablow
    Member

    I agree that old paint underneath is not an issue if the old paint was in good shape. Stripping to bare metal isn't necessary if you're just doing a color change or something like that. The only issue you might run into is the paint gets thick at the edges after multiple layers, which may make chipping easier, depending on how thick the paint underneath is. But that wouldn't keep me from doing it that way if the underlying base bodywork and paint was in good shape.
     
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  11. jimgoetz
    Joined: Sep 6, 2013
    Posts: 336

    jimgoetz
    Member

    As long as the body and old paint is sound it should be fine. I really think stripping to bare metal is a more restoration thing than a hot rod or custom thing. Some of those old rods were painted 1/2 dozen times just to change the color.
     
  12. BJR
    Joined: Mar 11, 2005
    Posts: 5,857

    BJR
    Member

    Body filler over bare metal is not a problem. Body shops have been doing that for over 50 years without any problems. Putting filler over epoxy is a recent thing, and many shops still do not do it that way. I have owned cars done that way for 30 years with no problems.
     
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  13. s55mercury66
    Joined: Jul 6, 2009
    Posts: 3,719

    s55mercury66
    Member
    from SW Wyoming

    Personally, I do not like to put filler over epoxy, due to the adhesion problems I have seen and had at the edges. Your results may differ, but I have had an adhesion issue over bare metal in 41 years. Remember, it is recommended that it not be applied over anything finer than 80 grit sandscratches, although it will adhere mightily to anything you get it on that you didn't want to.
     
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  14. Pats55
    Joined: Apr 29, 2013
    Posts: 240

    Pats55
    Member
    from NJ

    [​IMG] In 40 years I never let the body shop paint my cars. The kind of problem that were discussing is the reason I started my own paint line back in 1988. My biggest fear was to spend all this time and effort to paint the car and have turned to crap in no time. Automotive primers like DP 40 with 5 coats of color in 2 coats of clear will run anywhere from 500 to 1000 hours of 5% salt spray.The primer I have does 8000 and if you scratch it the rust won't travel beyond the scratch This truck is completely primed with my primer, body filler over it and another coat of my primer over the filler this ensures that no solvent, no moisture and no oxygen can penetrated it. Then comes a surfacing primer and a color. But body filler over bare-metal without an etch will probably bite you in the ass later. Everybody has their way of doing things and I know everybody thinks epoxy primer is the most powerful primer in the world.I've spent 30 years in the coatings business and I can tell you from fact that there are a lot of primers and paints out there that a body shop will never see.
     
  15. Ya know, I'm all for doing it right and using new technology is good. But really, I think there are a lot of old wives tales out there. For instance, all GM cars were lacquer for decades. Zillions got repainted and most were done in synthetic enamel until acrylic enamel was introduced. you didn't see cars back in the day with the paint flying off in a few years like you do today. I've painted a lot of cars with all sorts of paint and never took one down to bare metal. I've never had a paint failure from doing so. Unless this is a show car, I wouldn't worry too much about it as long as the existing paint is solid.
     
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  16. olscrounger
    Joined: Feb 23, 2008
    Posts: 3,505

    olscrounger
    ALLIANCE MEMBER

    Wifes 55 was painted over the orig paint in 79 (black over turquoise and white)then rescuffed and reshot again 85 with centari-It still looks great with no issues and had been driven many miles over the years as it was our main car for years. Had to reshoot the hood etc a few yrs ago for rock chips, etc.
    My black 57 fuely was also repainted over the orig black paint in 78. Was scuffed and redone in 2003-- it still looked good but had road wear, rock nicks chips etc.
     
  17. theHIGHLANDER
    Joined: Jun 3, 2005
    Posts: 7,779

    theHIGHLANDER
    Member

    Don't worry about it. That is unless you plan to drive it in mud, snow, salt, high speeds on gravel roads, sitting it the parking lot at work on steamy hot days for 40 hrs a week and, well, you know. What are the odds it'll be pampered and cared for once your tenure with it begins? My take is it'll be just fine. It'll still be nice when you have great grand children.

    As to etching primers under polyester fillers, BZZZZZTTT!! Makes an awesome release agent in most cases. All cases? Maybe not, but a good old fashioned mechanical bond for polyester fillers of any kind, be it good ol plain ol bondo or the current crop of poly primers is very hard to beat. I picked up a spray gun at age 12 when my dear departed Dad was active in the home shop. Shot my 1st complete at age 14 in Ditzler Alkyd Enamel, and now at 61 I still can't seem to avoid the craft. An ex employee used etch primer under polyester primer on a Duesenberg gas tank, against my direction not to. Well as I know it will all the edges and mounting areas let loose 1st, and essentially the majority of the tank delaminated. This a car worth nearly $2M (yes, million) and not something to experiment or take chances on. Yeah, he's gone and I'm eating a complete strip and refinish.

    But back to this 40, buy it. Don't sweat the petty stuff, better to pet the sweaty stuff. In the 40. Right away when it lands at home;)
     
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  18. These new primers and sealers make it possible to paint over nearly everything. I wouldn’t sweat it. If it looks fine it most likely is.
     
  19. F&J
    Joined: Apr 5, 2007
    Posts: 13,213

    F&J
    ALLIANCE MEMBER

    Hey!...careful now...


    last Saturday at a farm show ..not me,.... my son drove us there.. and 2 winters so far and some dirt roads too. Free PPG lacquer bench mixed color, that over lacquer primer, that over a light wash of alkyd enamel primer, over beat up old sandblasted tin. Yes, it is not mint anymore, but neither am I.
    32farm1.jpg 32farm2.jpg
    One guy there who liked it was the pinstriper that did the California Kid striping on the later restoration of that car.

    I guess I should have washed it a few days later... but I didn't.....it got into a couple of unplanned photo shoots for some college grads at UConn.
    DSCN2485.JPG DSCN2489.JPG DSCN2490.JPG DSCN2480.JPG DSCN2479.JPG
    They still wanted pics taken with it. "Don't waste a car by not using it". and don't worry if it's not as good as you hoped for, as nobody will seem to notice...

    .
     
  20. jimgoetz
    Joined: Sep 6, 2013
    Posts: 336

    jimgoetz
    Member

    Your probably right about that but I think we are talking about hot rods here not submarines or airplanes.
     
  21. Pats55
    Joined: Apr 29, 2013
    Posts: 240

    Pats55
    Member
    from NJ

    Okay nevermind
     
  22. rod1
    Joined: Jan 18, 2009
    Posts: 608

    rod1
    ALLIANCE MEMBER

    Don't go away...Tell us more.
     
  23. Pats55
    Joined: Apr 29, 2013
    Posts: 240

    Pats55
    Member
    from NJ

    Thank you for your interest. I became involved in industrial coatings in 1988. This BS about rust products and primers has been going on since the beginning of time. I was selling a well-known paint over rust product but it had failed and had inherent problems with sunlight, and adhesion. I did a show in New York State where I met the owner of the Sterling paint company he looked at my displays and told me this is similar to this primer that the MoBay chemical company has developed for bridges that did an incredible 8000 hours of salt spray. They sent him a sample formulation. He makes it he put in the back of his wife's car, the can burst and the entire trunk was painted. He never went near it again. I called Mobays tech department as asked them 1,000 questions . They hooked me up with a small company in Pennsylvania that was instrumental in helping them with this formulation and also formulated New York City subway anti-graffiti paint. These people were also car lovers and gave me a leg up selling these products. In the beginning we couldn't trademark Mastercoat. So we called it the Master series coating line,I did car shows every other week for 25 years so I could eat . I looked at the same faces year after year sold everything with a money back guarantee. I don't ever recall anyone embarrassing me for not telling it straight. You can't teach an old dog new tricks, you can't compete with people that spend thousands every month on ads.Rather than me rewrite the Bible just go to my site I'm writing a blog its more like the ramblings of a old man but it does have some good points
     
    Last edited: May 12, 2019
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  24. s55mercury66
    Joined: Jul 6, 2009
    Posts: 3,719

    s55mercury66
    Member
    from SW Wyoming

    Could you post a link to your site Pat?
     
  25. Pats55
    Joined: Apr 29, 2013
    Posts: 240

    Pats55
    Member
    from NJ

  26. Pats55
    Joined: Apr 29, 2013
    Posts: 240

    Pats55
    Member
    from NJ

     
  27. Pats55
    Joined: Apr 29, 2013
    Posts: 240

    Pats55
    Member
    from NJ

    1st misconception epoxy primer is airtight. Unless it contains a pigment that is a flake such as aluminum flake,matacious iron oxide, or Mica it does not cut off the oxygen.. Do an Internet search on oxygen depriving pigments. And you are right about that rusting from the inside out. It always amazed me to watch people try to fix rust from the outside Good rust work starts from the inside out

    They are now working on an epoxy that contains zinc powder and also zinc flake. It combines zinc powder which is sacrificial and the flake is used to cut off the oxygen. This is still in development. What happened to the guy with the mercury I'm anxious to see what the problem was there
     

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