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urethane clear over lacquer color coat?

Discussion in 'The Hokey Ass Message Board' started by 31Vicky with a hemi, Mar 7, 2013.

  1. rustang
    Joined: Sep 10, 2009
    Posts: 710

    rustang
    Member

    OK.....just thinking out loud here, have never done it over lacquer, but what about an Adhesion promoter/binder as a mid-coat between the lacquer and clear? You can get clear binders, and I have used Dupont 222s a couple of times with good results.
     
  2. metalman
    Joined: Dec 30, 2006
    Posts: 3,279

    metalman
    Member

    Back in the late 70's, early 80's I did literaly hundreds of paint jobs (production custom paint shop, lots of vans and bikes) using lacquer base, urathane clear. RM had a clear designed for it, worked well and held up fair, 5 years or so out in the NM sun, better then straight lacquer would. Even before that we were clearing the lacquer with Imron clear but we quit using Imron since it was too tough to buff and I though the sh-- would kill me sooner then later!. We never scuffed the lacquer first other the fixing minor issues, we let it flash a couple hours and go. I did the same thing with modern urathane clear a couple years ago on some art panels, not a good test for sun and road use but they came out fine. FWIW lacquer as a base is different then modern basecoat bases, they are more stable so you could get away with some light sanding without recoating. If you really would feel better by sanding first I'd throw some clear lacquer down first just to be safe if your dealing with a metallic base, solid color I wouldn't bother.
     
  3. Roger Walling
    Joined: Sep 26, 2010
    Posts: 1,145

    Roger Walling
    Member

    Quote,

    "Lacquer is stable under catalyzed products. I would definitely let it gas off first though."

    WRONG!!! Lacquer is not stable. the heat of the sun will reflow lacquere and eventually cause cracks under a catalyized product.

    Lacquere is an obselete product because of its inherent flaws.
    The new paints far out weigh it and can be made to have a luster almost like it. If you cover it, you will have a modern luster.

    (If you keep it inside for 15 years, you won't have that sun problem, your choise)
     
  4. theHIGHLANDER
    Joined: Jun 3, 2005
    Posts: 8,162

    theHIGHLANDER
    Member

    Ok, let's keep this quiet cuz you ain't supposed to say, but uncatalyzed BC is very similar to old lacquer formulas minus the gloss component. The solids are the same, the solvents are similar but not the same (a little slower and less "invasive"). Read the labels and be certain that there's compounds in each that match. You can also reduce a little bit of catalyst and add it to your lacquer to make it stable. I'll raise my right hand to the fact that putting this here will generate cries of "BULLSHIT!!" and "YOU'RE FULL OF SHIT!!"

    Well, I may be full of shit but not when it comes to paint. PPGs "Global" system was a flat lacquer-based product designed to go below catalyzed clear. PPG also used to make a basecoat lacquer (gold label). If you'd like to call bullshit on that, be prepared to wager something 1st. I'll win. The biggest danger in this whole idea isn't even the health hazards of the materials. IT'S OVER THINKING THE PROCESS. Sorry I raised my voice there, but 20min with a test panel and a modicum of logic applied will relieve all your woes about it. To quote a high-ranking PPG rep, "There's only so many types of "Japan", plastic crystals, catalysts, solvents, so much of this stuff is all the same materials with minor variants in the recipe here and there. You'd be surprised how many urethane clears are exactly the same, yet from different companies." After 40+yrs, I've found him to be right.

    In the end you get 2 bonds, chemical and mechanical. Get the best of both and forget the "worry wart" bullshit.
     
  5. MATTILAS
    Joined: Feb 9, 2008
    Posts: 51

    MATTILAS
    Member

    Be sure to spray the enamel first then the lacquer. NO DON"T just kidding!!!!!
     
  6. hobbyjp
    Joined: Mar 14, 2006
    Posts: 327

    hobbyjp
    Member
    from socal

    I think highlander has more experience than me after reading his posts over the years and Im on his side about base coat being lacquer. Im no pro but as far as I can tell base coat acts just like lacquer. I have painted both and have coated lacquer with urethane clear coat, if Im not mistaken I believe the tech sheet for some lacquer I have thats a few years old says to top coat with urethane clear. I would definitely scuff the lacquer before spraying clear as opposed to adding a fresh coat and then painting clear. I have used urethane clear over spray paint and one shot the only time theres a problem is when the underlining paint is to wet sometimes the clear will start thinning the underlining coat. to prevent this I usually put down fog coats at first and make sure they tack up before I start laying down the clear heavy. Hey the clear I have sprayed is still stuck to everything in my shop, work benches, stands wheels, hasnt peeled off anything yet!
     
  7. hobbyjp
    Joined: Mar 14, 2006
    Posts: 327

    hobbyjp
    Member
    from socal

    I'm sure theres a spot somewhere on the car probably a wheel well or the underneath of a valance that has some paint on it that you could test with some clear on it and see what it does, take a tiny container and mix up some clear and activator and paint some on with a small brush and youll get the proof you need.
     
  8. thanks Highlander!
    Does tge above sound like a reasonable approach ? Or would that be over thinking this. Sounds like I should just let the lacqure flash for a couple hrs and shoot the clear,
    & OK btw its about 5 coats of black tinted urethane clear


     
  9. jcmarz
    Joined: Jan 10, 2010
    Posts: 4,633

    jcmarz
    Member
    from Chino, Ca

    old farts tales.
     
  10. metalman
    Joined: Dec 30, 2006
    Posts: 3,279

    metalman
    Member

    I don't think anyone will argue that lacquer is "obselete" and I haven't heard anyone here claim it will last as long as a modern BC/CC system. Cleared or not we all know lacquer will break down when exposed to UV rays, always been the problem with it.
    When I say lacquer is more stable then basecoat look how stable basecoat is without clear, even dry you can scrap it off with your fingernail hince the reason you cannot ever sand it without recoating. Heck, I saw a paintjob the other day that the painter moved the metallic around (pulled it from a scallop onto the solid base color) with a tack rag!
    FWIW I've never seen a urathane clear come close to the look of a buffed lacquer. It will always have that "plastic" look to it. Modern paints can look killer, sure but never look like rubbed lacquer.
    Yeah, I miss lacquer.
     
  11. plodge55aqua
    Joined: Jan 4, 2009
    Posts: 1,710

    plodge55aqua
    Member
    from Alberta

    You can Urethane clear over Lacquer... But is might not last long... Lacquer Expands and contracts through weather changes... Clear urethane doesnt..

    It will in time let go... as for Basecoat.. No its not the same as Lacquer.. lacquer you can sand and polish to a shine... basecoats you cant.. Basecoat has to be cleared..unless you are matting the finish,, but it still wont last with out a Clear coat..

    from 1974 till now Ive worked with these.. Now waterborne enters the picture.. Yippeee...
     
  12. theHIGHLANDER
    Joined: Jun 3, 2005
    Posts: 8,162

    theHIGHLANDER
    Member

    I started wondering WTF is "tge"? It's Autorama weekend so I get a pass for not seeing it right away:cool:

    No matter what 'vick, do a test panel. The only thing worse than doing this work is doing it over. I see the term "gas out" which I assume refers to flash time, so my term will be flash.

    Get your lacquer down the way you like it. Here's a big clue in the whole process, and I'm not yelling, just emphasizing. THE SECRET TO FINISH LONGEVITY IS A MINIMUM OF FINAL MIL THICKNESS. So to that end you'll want to spray, surface, then final coat your lacquer for the right look. In certain colors and light conditions, sanded lacquer cleared over looks like, well, sanded lacquer cleared over. You'll see it through the clear. Not all, but some do. To that end give the final coat of lac a mechanical/chemical bond, let it flash out while you get the next phase ready and just check it for dry/hardness. If all's good start laying on your clear. It's solvents should not invade the base enough to disturb the look, but you want some "melt", so maybe 10-20% of a compatible urethane solvent in the clear will help in the 1st coat. This is where a test panel will save you time, $$$$, and most of all, labor. The "solvent fortified" clear will get a bite into the lacquer and give you enough of a foundation to go for the final coats. Just give that 1st coat enough flash time to avoid sags and such, and that solvent in that 1st clear will make it runny, so apply accordingly. Too much flash time removes the 1st bite that the clear needs, and even over compatible base coats it will delaminate if there's nothing to melt together or mechanically bond to.

    Did I mention a test panel?:cool: Good luck and have fun with it.


    To the rest, yeah, whatever. Do what works for you. All finishes move around with temperature change, some will move more times than others. Witness cracked OEM finishes. Figure out what happened and get back with us on that...or not.
     
  13. Well, to me flash time is measured minutes. 5,10,20,90
    Gas off period would be measured in hours or days .
     
  14. theHIGHLANDER
    Joined: Jun 3, 2005
    Posts: 8,162

    theHIGHLANDER
    Member

    Flash time is when enough solvents are gone to allow the next coat. A blending of all the solvents in the surface create a consistent finish from substrate to clear. They cure and become "one".



    I can and have made urethane look like lacquer. I have to when restoring 6 figure classics if I want to emulate the quality that was delivered to the customer in the 30s. It takes a lot of labor to pull it off, labor is hours, money, and few customers want to pay for it so the process is used only where a willing and informed customer is involved. While not revealing the whole process, let's just say that clear will not "fill" a surface as much as it will magnify it. Concave areas of bodies and fenders will show why it looks like it does worse than the rest of the car. Every layer of urethane "cellulite" is full of concave shapes. Step back from that mirror finish a good 20-40 feet. If it's reflections are as clear as they are when it's "in your face", you get a lacquer look. It's also time and material selection. "Show clear" products designed to look wet all the time are not appropriate for everything. They might make a modern pro touring, fuel injected, air bagged, 22" wheel car look fresh and exciting to some, but on a Packard or V-16 Cadillac, not so much. Surface quality vs shine? Surface quality wins every time.
     
  15. TR Waters
    Joined: Nov 18, 2006
    Posts: 1,439

    TR Waters
    Member
    from Vermont
    1. Early Hemi Tech

    So many experts.
     
  16. urethane "cellulite"

    That's a perfect way to describe everything I've never liked about its appearance.
     
  17. plodge55aqua
    Joined: Jan 4, 2009
    Posts: 1,710

    plodge55aqua
    Member
    from Alberta

    when you have worked with those products in the past and seen the effects years later on the same cars.. Its more just knowing.. I live in a 4 seasons a day climate.. Lacquer was a great product.. but it had its limits here.. in warmer areas it was alot better to use and lasted longer.
     
  18. stev8
    Joined: Jun 22, 2007
    Posts: 87

    stev8
    Member

    I have done 2 pack clear over lacquer many times,,,,not on a lasting show car though!
    It seems to be that with lacquer the surface drys with a gloss, meaning that (under a microscope), the surface is smooth, unlike B/C which has the paint sticking up,( hence the matt look), so there isnt any thing for the clearcoat to hold onto.
    Thus, the clear coat can come off. another problem seems to be that modern 2 pack clears do not allow the laquer to "breath", so the escapeing solvents of the laquer get trapped below the clear and help "pop" the clear off.

    I use Dupont 7600 clear as this clear seems to allow the laquer to breath and still adheres well to the lacquer. I dont know about other clears as I havent tested them.

    As Highlander said, lacquer and B/C do have similar bases in their make up, but there are a few things that you can do to improve adhesion, and have things more in your favour.

    A small amount of hardner in your lacquer so that the clear can chemically bond to that, and you could also add some clear B/C binder to your last coats of laquer so that it has the same matt finish that B/C has.

    Though what ever you do, You are asking products to do something that they werent really designed for, so are runnig the risk of a second rate paint job. On something important, I would buy the right product for the right job.
     
  19. On something important, I would buy the right product for the right job.



    The right product im seeking is a particular or maybe magical but it is a color.
    It happens to be a avsilable as a lacquer and if that's not bad enough in rattle cans only.
    Just local guys here but 12 hands on opinions of the spayout sample " that's a candy or tri stage" nope lacquer out of a spray can with clear. They don't really believe me but hey ...
    6 attempts to match it ($$$ each time ) in BC and no cigar. 2012 ford tri stage color is very close ( not it but changable from there) but the metallic is too small. However that is the largest metallic in those mixing rooms.
     
    Last edited: Mar 9, 2013
  20. Sounds like a paint store that has no idea how to mix custom colors. If their computer doesn't tell them what to put in they are lost.

    Sent from my DROID device using the TJJ mobile app
     
  21. Well it was more than one.

    The heavy hitter custom paint supply house said might be able to get close - at 200 a pint out of my pocket to see how close they come to matching a 12.00 rattle can.
     
  22. theHIGHLANDER
    Joined: Jun 3, 2005
    Posts: 8,162

    theHIGHLANDER
    Member

    I know guys who could simply look at it and know what to use. Sadly they're way over here in Plymouth, MI. The other thing is personal compromise. Sometimes something like flake size could be manipulated enough to get your effect so close only you and your paint rep know for sure. Dammit, does that sound like an old Clairol commercial!
     
  23. pimpin paint
    Joined: May 31, 2005
    Posts: 4,937

    pimpin paint
    Member
    from so cal

     
  24. stev8
    Joined: Jun 22, 2007
    Posts: 87

    stev8
    Member

    Pity you arent near here either....Cause little old NZ is a bit behind the rest of the world in technology, we havnt all lost the art of eye matching a colour.

    Hell, we hardly ever use our computers matching formulas....last time was 3 months ago...I think!!

    Give us a sample and we will be able to create a B/C formula for the colour too.
    You could air mail a spray out of the colour.
     
  25. Being that the Highlander has opened the door to base and lacquer being kissing cousins, the clear you should look at as a segue between harvested rattlecan lacquer and full-blown urethane, would be none other than DBC500 bonding clear :cool:. If you're not familiar with it, it's not much more than basecoat clear toner and basecoat balancing clear and hot thinner(according to what a PPG rep told me). It IS meant to be topcoated safely with urethane clear, and is safe over old and new finishes. I use it as a carrier for flake, as it flashes quick and sands well(when necessary). Give it a look. ;)
     
  26. Dbc 500 !!! I know it well and have some on hand.
    That stuff is almost magical - why you ask ?
    It's 50.00 a quart but when they add 24 parts of toner out of a 1000 it becomes 150.00 a pint.

    Thanks for the heads up on another use for it :)
     
    Last edited: Mar 10, 2013
  27. theHIGHLANDER
    Joined: Jun 3, 2005
    Posts: 8,162

    theHIGHLANDER
    Member

    Good call 'Shieb. Forgot all about that stuff.

    So 31vic, how'd it turn out? Anything yet, like test panels even?
     
  28. You've got me thinking here , thanks !

    You commented over on the mad man thread so I know you've seen it. I gotta say I love it. I can't stop looking at it lol.

    I have a DBC 500 question ,
    (This may be relevant as you scroll down- I had no apparent problems with the lacquer directly on the black primer for the test fender.)

    I want to know if I can put the harvested rattle can lacquer on top of the DBC500 ?

    Why you ask? Well here's my plan and I need something to possibly save a step or two and keep the lacquer from messing things up.

    The end final color is black, but its on a red lacquer base.
    In order to achieve a nearly perfect finish with surface prep being paramount , i feel i need to paint it black first, perfect the surface and then begin the red base. my plan is as follows:
    1-Black 2k primer blocked and wet sanded (this is almost completed and step 2 is on deck)
    2-black single stage, cut+rubbed . This needs to be perfect before proceeding. Anything that shows up gets fixed at this stage.
    3- 800 scratch on the perfected and buffed black SS + red tinted epoxy for a buffer between the SS and lacquer
    4- harvested lacquer red base / 800 sand if I need to
    5- few coats of black tinted DBC500/ 1000 sand any nubs or crap out,
    6 - Few coats of tinted UV rated clear top coat/ 1200 sand any nubs or crap out
    7 - few coats of non tinted uv rated clear for the final top coat to be cut and buffed.

    Sounds like alot of fucking work to me but that's what I feel I need to do to get the quality I want with my current situation and equipment.

    So I was thinking about substituting the DBC 500 in step 2 for the black SS paint. It will be on black primer and give me the black gloss I'm looking for. And if it will work , take the place of the epoxy buffer. It's cheaper than Quality SS and way better I believe.

    Will the DBC 500 do that for me ? [/I]

    If you guys want to , I'd appreciate a critique on my plan too
    Thanks .
     
    Last edited: Mar 15, 2013
  29. lippy
    Joined: Sep 27, 2006
    Posts: 5,392

    lippy
    Member
    from Ks

    Looks like a lot of material there. Lippy
     
  30. dtracy
    Joined: May 8, 2012
    Posts: 223

    dtracy
    Member

    Vic, I'd keep it out of Arizona when you're done because I think it will curl up like dried mud in the sun. Wow, that's a lot of material!

    Dave.
     

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