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Technical Which primer to use?

Discussion in 'The Hokey Ass Message Board' started by evintho, Apr 28, 2021.

  1. evintho
    Joined: May 28, 2007
    Posts: 2,363

    evintho
    Member

    After minor bodywork I'll be priming and blocking my entire '54 Customline in preparation for final paint. I wanted to use hi-build primer so I could have some extra mils for blocking purposes however, every hi-build primer I see is polyester based and everything I've read says to only use polyester based primer on small repairs and NOT on complete paint jobs. So what type/brand of primer should I use to obtain my goals?
     
    dana barlow likes this.
  2. cavman
    Joined: Mar 23, 2005
    Posts: 669

    cavman
    Member

    There are so many choices, so wide a price range, but I like a 2K urethane in a lighter color. (just my choice) Mar-Hyde Ultimate is decent.
     
    jetnow1 likes this.
  3. squirrel
    Joined: Sep 23, 2004
    Posts: 55,931

    squirrel
    Member

    Is there a local auto paint store you can visit, and talk with the folks there about it?

    High build urethane primer is what you want, like he said, there's a wide variety available.
     
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  4. indyjps
    Joined: Feb 21, 2007
    Posts: 5,377

    indyjps
    Member

    If youre going over old paint, a sealer is a must in my opinion.

    Check out southern polyurethanes, they offer a 2K high build that doesnt require a separate sealer coat. Very good reviews for years on their products.

    https://www.southernpolyurethanes.com/products
     
    klleetrucking and 54chevkiwi like this.

  5. Hollywood-East
    Joined: Mar 13, 2008
    Posts: 1,993

    Hollywood-East
    Member

    Another for the Mar Hyde, Epoxy down first...
     

    Attached Files:

  6. HSF
    Joined: Oct 25, 2014
    Posts: 225

    HSF
    Member
    from Lodi CA

    House of kolor kD series. Can be mixed as high build, regular build and sealer. Comes in different colors too. Inexpensive for how good it is.
     
  7. Blake 27
    Joined: Apr 10, 2016
    Posts: 1,504

    Blake 27

    I totally agree. Because I planned to paint my car red, I used KD red primer and grey KD for guide coat.
    Any re-coating required would guarantee no issues with paint compatibility. The House of Kolor red base coat covered
    really well and the few rock chips that have happened are very inconspicuous. DSC05740.JPG
     
  8. More and more folks are switching to Tamco. This is the route I will probably go on my GMC
     
  9. Never heard of a polyester for small repairs only. It’s designed for large repairs.
    The question is make sure you use something that is direct to metal(DTM) at the start of the process.
    Meaning, the bare metal areas need a DTM primer for adhesion. An etch or epoxy are the main choices.
    Then a filler primer, either urethane or polyester.
    There are epoxies than can be used as primer fillers
    There are DTM urethanes and polyesters.
    Several options even old school lacquer.
    The key is to chose a system and follow the directions on the tech sheet. Unless the guy you buy your paint from uses the products he sells, don’t take it for granted that they know what they are talking about.
    I prefer an epoxy followed by a polyester.
    I will use epoxy an a sealer over the polly.
    Primer fillers are generally not designed to be directly painted over.
    Some guys use etch followed by a urethane.
    It’s a faster system. I generally allow epoxy 24 hours before topcoating. Epoxy dries slow. Trapping solvents can occur if you apply a polly primer too soon.
    My only issue with urethane is that it seems to shrink more than a polly will.
     
    deuceman32 likes this.
  10. 54chevkiwi
    Joined: Jun 28, 2020
    Posts: 346

    54chevkiwi

    Another one here for SPI
     
  11. Couldn't have said it any better. In some cases it's like taking advice from the kid at the parts counter.
     
    anthony myrick likes this.
  12. I’ll add this. Opinions on brand are numerous.
    Use whatever brand you like.
    Locate the tech sheet. They can be found online by googling the product name/number.
    There are lots of correct answers.
    You can spend a few hundred bucks or thousands.
    You will waste all of it if you don’t use it correctly.
    The tech sheet will tell you what it’s recommended to be sprayed on top of (the substrate)
    Bare metal needs a DTM product.
    All primers need a clean and properly prepped substrate.
    Each paint company has slightly different procedures/products.
    If you use brand X primer, research how to use it.
    Urethane vs Epoxy vs polyester vs etch bla bla bla all work when used correctly.
    No epoxy likes fresh etch under it.
    Some polyesters do not like etch under it, the ones that do, etch effects curing time.
    Urethane likes etch and epoxy under it.
    Most urethanes and polyesters are not DTM
    As far as I have experienced, epoxies like bare metal.
    epoxies can lift if topcoated too soon.
    etch cures/dries really fast.
    the process gets even more confusing if metal conditioners are used.
    some epoxies recommend a metal conditioner for large bare metal areas.
    etch replaced metal conditioners and aren’t used with them.
    I’m glad I could clear all this up.
     
  13. evintho
    Joined: May 28, 2007
    Posts: 2,363

    evintho
    Member

    Wow, things have changed since I worked in body shops in the early '70s! Lots of great advice but I'm still unclear on what to do. Original paint which I'll D/A with 80 grit then go over with 150. A few bare metal spots and some minor filler work to be done. Don't really want to shoot epoxy and then primer. I'll also be doing the color and clear and doing this in my garage. Not looking for show quality paint, it'll just be a clean, painted driver. I used Summit's 2K urethane primer when I painted my truck. Cheap and seemed to work well. Looking for something inexpensive that'll adhere to a little bare metal and prepped original paint that will build enough to be blocked so I can have fairly flat panels.

    today15.JPG
     
  14. chargin03
    Joined: Jan 8, 2013
    Posts: 516

    chargin03
    Member

    SPI for me good stuff.
     
    DeLuxe 32 and klleetrucking like this.
  15. The pics help.
    No need for 80 grit unless you are stripping to bare metal.
    A primer SURFACER will generally adhere to a 320 grit scratch (not for bare metal, large areas)
    A primer FILLER (the super thick stuff) is generally 220 at max sand scratch (not bare metal, large areas)
    You can get an epoxy surfacer.
    Or, etch the bare metal spots and prune with urethane. There is no need for grits bellow 180 for urethane to hold to original paint.
    I generally prime over 180-320 grit scratches depending on products used.
    Bare metal is different for large areas like entire panels and bodies. I will DA bare metal with 80-150 depending on products used.
     
    Last edited: Apr 30, 2021
    Tman and abe lugo like this.
  16. squirrel
    Joined: Sep 23, 2004
    Posts: 55,931

    squirrel
    Member

    I've only used urethane primer on the cars I've done over the past 25 years, and it's always been fine. Most of them were over bare metal. But I don't do it for a living, and I don't have to offer a warranty. I do drive them in weather, etc.
     
  17. Amen...

    Whenever i use self etching primer, i hit it with a scuff pad before i put anything on it. Personal preference, but the way i see it, it's made to adhere to bare metal, it's my job to make anything i use adhere to it.
     
  18. I will scuff over epoxy when it sits over night.
    Probably remove trash with 400-600 if using as a sealer.
    The “open” windows in the tech sheets are listed at a certain temp. Usually around 70 degrees. That window closes sharply at higher temps. Plus surface temp.
    If I can scuff it, I scuff it.
     
    Lloyd's paint & glass likes this.
  19. 1971BB427
    Joined: Mar 6, 2010
    Posts: 8,717

    1971BB427
    Member
    from Oregon

    I recently did my first complete paint job on my current project, and by the time I finished asking questions from various car forums, and a lot of other people, I was so rattled I didn't even want to try and paint my car. I was getting ready to go look for somebody else to paint it when I remembered one of my oldest friends has a son who is an ASE certified painter, and a Lincoln Tech grad about 30 years ago.
    I called up his son and after a short talk he told me he'd stop by after work to talk. I began telling him all the advice I'd gotten, and how it contradicted each other, and he chuckled. After about 10 minutes he went over enough options, and looked at all my various primers, sealers, and paint. Then told me what I could do, plus gave me options as to when and how I could do it.
    When the temps warmed up I shot the car, and it came out pretty nice for a 1st time job. It gets lots of attention and compliments, so I'm happy.
    I'd never again ask what to use, or how to paint on a forum. Just get so many different, and often contradicting answers, which may or may not be correct.
     
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  20. There are too many correct answers.
    It all boils down to correctly using the products.
     
  21. HSF
    Joined: Oct 25, 2014
    Posts: 225

    HSF
    Member
    from Lodi CA

    The only subject that gets more conflicting , confusing, contradictory answers than paint related questions are oil questions.
     
  22. What kind of oil do you use in your paint?
     
    anthony myrick likes this.
  23. Depends on the paint used. For old paint, I like high zinc oils like Royal Purple. It has enough zinc for older pigments to stay lubricated.
    I run Rotella in my latest paint job. No issues so far. I’m not a big fan of additives in my paint’s oil. I feel they just generally settle to the bottom of the paint job anyway.
     
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  24. Bill's Auto Works likes this.
  25. evintho
    Joined: May 28, 2007
    Posts: 2,363

    evintho
    Member

    I'm probably overthinking this (as usual)! I think I'll just go with basic 2K urethane primer, block it and call it a day.
     
  26. I'm using SPI products on my projects.....the guy who makes them is only a phone call away if you've got any questions.....that's customer service. They are high quality products, and well priced.

    Sent from my SM-G965F using The H.A.M.B. mobile app
     
    klleetrucking likes this.

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