Rattle Can Finish - Scratches Visible - What did I miss?

Discussion in 'Finely Finished' started by GTG_Gopher, Jul 5, 2019.

  1. GTG_Gopher

    GTG_Gopher Tele-Meister

    Posts:
    108
    Joined:
    Dec 1, 2017
    Location:
    Minneapolis Burbs
    So I am doing a belly flop into the pool of refinishing guitar bodies.

    Last fall I bought a $50 Sawtooth ET guitar off Walmart.com. This spring I got the bright idea to repaint it a light blue color, and doing some general 'sharpening'.

    http://www.tdpri.com/threads/sawtooth-et-guitar-sharpening.953260/#post-9184913

    I've gotten to the point where I have made my first attempt at spraying the color, in this car Duple-Color perfect match lacquer.

    But after I sprayed, I see that I can still see scratch marks from removing the old finish. What did I miss?

    Here is what I've done so far:

    1) stripped the factory finish off with 60 grit sandpaper. My initial plan was to scuff the surface, but as I sanded I got through to bare wood in spots. So in for a penny, in for a point and I sanded the whole thing bare.
    [​IMG]

    2) sanded again with the 200 grit paper and 400 grit paper. I think perhaps I should have done a pass with 120 grit?

    3) I sprayed two coats of Duppli-color filler primer, then two days later I sprayed an additional coat of primer.

    4) after 35 minutes, I sanded the primed body, and wiped down with a cloth loaded with windex,

    5) I sprayed two coats of Dupli-Color Perfect Match lacquer, and after those, I noticed the very visible scratches still there.
    [​IMG]

    [​IMG]

    The temperatures for all of this was around 80 degrees with approximately 70% humidity.

    Did I need to do additional sanding on the body to get the scratches out, or did I not spray enough coats of the filler primer?

    From here, I think I need to sand this coat of paint back, can I then spray more primer, or do I have to go back to bare wood again and start anew?

    Thanks!
     
  2. bender66

    bender66 Poster Extraordinaire Silver Supporter

    Posts:
    6,481
    Joined:
    Jan 18, 2010
    Location:
    on my bike
    I'd have done more primer/sanding until I got a flat surface before shooting color.

    I wouldn't have done 200 grit either, but those scratches are all in the wood it looks like.

    Windex seems to be asking for problems too.

    Let's wait for the authorities.
     
  3. Dxhall

    Dxhall TDPRI Member

    Age:
    65
    Posts:
    11
    Joined:
    Feb 9, 2017
    Location:
    Denver CO
    As my old friends in the car restoration shop say, paint only colors what you have. Don’t expect paint to fill anything - that’s for other stuff.
     
  4. harold h

    harold h Friend of Leo's

    Posts:
    2,299
    Joined:
    Feb 15, 2004
    Those scratches are so small it is probably not worth re-doing the whole thing
    over again.

    Just hit it with a bunch of clear, which will help make the scratches less noticeable,
    polish it and be done with it.

    It will probably look really nice when you are done.
     
  5. EsquireOK

    EsquireOK Friend of Leo's

    Posts:
    2,812
    Joined:
    Aug 30, 2011
    Location:
    U.S.A.
    You initially sanded too deeply (a result of using a very coarse-grit paper), and then didn't use the right kind of filler to eliminate marks of that depth. Spray filler/primer does very little filling. You needed a paste filler before priming, and preferably a sanding sealer either before the filler, after the filler, or both.

    There's not much point in stripping now, but you do need to step backward if you want the best results. Sand that color coat as flatly as you can, then apply a lacquer based spray sanding sealer, and sand that as smoothly as you can. Then filler, dry, sand. Then for maximum smoothness, more sanding sealer and more sanding. THEN you can put on your primer, etc.
     
    Skydog1010 likes this.
  6. Freeman Keller

    Freeman Keller Tele-Afflicted

    Age:
    74
    Posts:
    1,781
    Joined:
    Aug 22, 2018
    Location:
    Washington
    Those are simply 60 grit sanding scratches that your subsequent finer grits didn't remove. 60 might have been too coarse for a starting grit - in any case you should have gone up each step - 120, 180, 220, 320, looking at the surface with a raking light to see if you can see any scratches. Basically each step takes out the previous coarse scratches (and puts in finer ones).

    Sand the primer to 320 - you are trying to completely level it and primer will fill some small flaws. I'm not sure about the windex - I blow or vacuum my guitars between coats (I've even heard not to use tack rags).

    At the point where you are I would sand until those scratches are completely gone, you may end up going back into the primer. Then start your color again, four or six coats, sand that to 320 and then the clear.
     
  7. trev333

    trev333 Telefied Ad Free Member

    Posts:
    21,899
    Joined:
    Dec 3, 2009
    Location:
    Coolum Beach,Australia
    those sharp new paper 60 scratches are hard to get out.... I'd be going to 80 after that, then 100, 120, etc.... with a lot of time on the 80....

    60 to 200 will never work out good on a thin finish....

    I've had to strip partly painted work back to wood to get those 60 scratches out....even when I thought I'd done a proper fill/seal job... PITA..:lol:
     
  8. Zepfan

    Zepfan Poster Extraordinaire

    Posts:
    8,628
    Joined:
    Nov 30, 2013
    Location:
    Horn Lake, MS
    I don't use sandpaper under 250 grit. I use a paint stripper and a plastic scrapper(metal digs/gouges) to get the old clear and paint coat off. If most of the paint came off with the stripper, then use a 320-350 grit to start.

    Use a sanding block and not your hand to hold the paper. Using your hand will result with uneven surface.
     
  9. Old Deaf Roadie

    Old Deaf Roadie Tele-Holic

    Posts:
    828
    Joined:
    Oct 11, 2017
    Location:
    Oregon
    Easy fix, just may take a few days.
    Apply 2-3 more color coats, then wet sand with minimum 800 grit until flat. Repeat the process until the scratches are no longer visible. Then, add 2 more coats & wet sand with 1500 grit. After that, you can go after it with Maguires buffing compound & then swirl remover on a foam pad on a drill motor. Complete the job with 5-7 coats of clear & wet sand until flat with 1200-1500 grit, and then repeat the Maguires process. That will leave a shine that actually has depth to it. The guitar in the pic was finished with Ace Hardware store brand (Krylon-made) and processed as I described. I used Bondo to seal the grain, then Ace brand brown primer under the color. Oh, and never use anything other than clear water or a tack cloth, not Windex, to clean during the finishing process. 20190122_094917.jpg
     
  10. dkmw

    dkmw Friend of Leo's Silver Supporter

    Age:
    64
    Posts:
    3,867
    Joined:
    Mar 30, 2016
    Location:
    Florida USA
    Duplicolor makes a high build primer that would have filled if you’d sprayed enough of it. But as has been said, it would have been easier to just do the prep a little differently.

    Live and learn, that’s how finishing works:)
     
    Skydog1010 and Lake Placid Blue like this.
  11. intensely calm

    intensely calm Tele-Meister

    Posts:
    110
    Joined:
    Apr 1, 2019
    Location:
    Florida
    Looks like it will be a nice color and good looking git!

    As many have mentioned, the initial sanding prep work has yielded the result you see.
    Too course to start, not enough follow-up sanding and pre-topcoat prep.

    This scratch revealing "shrink back" of primer, color and clear is more of a problem with lacquer than it is with other more modern finish options.
    Even when the surface and fillers, primers and color coats are prepped to perfection, lacquer shrinking can still be a problem.
    Back when automotive lacquer was a normal thing in shops, a newly repaired auto would go home with the owner, and weeks or months later "shrink back" may appear. It came down to the quality of prep work, and how the finish layers were applied and processed.

    Basically, the solvents in the lacquer layers soften other layers as they off-gas, this tends to allow the topcoats (color and clear) to soften the underlying coats.
    The undercoats can then sink into any sanding scratches or imperfections. That's a little over simplified, but basically what can happen.
    Another problem with some lacquers and application of, is that a "shell" can form, where the outermost coats off-gas rapidly and tend to seal the sublayers.
    This can result in a hard to the touch, but soft finish. This is typically only a problem when the finish is applied to heavily, climate issues, product incompatibility, or not allowed to gas between layering of product type.
    So, I would not add clear layers on top of what you have. A high build of clear will only seal in the scratches and possibly make them worse. You can see scratches through clear, they don't have to be "in" the clear.

    Yet other problems with lacquer is brand incompatibility. Just because it's lacquer, doesn't mean brands can be intermixed or over-layered.
    Some brand X stuff won't stick to brand Y, even if they are both lacquer.
    The newer polys are less likely to have this problem, as poly layers mechanically bond rather then chemically bond.

    A lot of newer "lacquer" topcoats are put over a more modern substrate now, such as a polyurethane, polyester or epoxies, as the polys chemically cure.
    These polys get chemically hard and don't shrink back into existing scratches and such once cured. Once the poly under-finish would harden, it can be sanded flat, and top-coated with lacquer if desired.

    If this were my guitar -
    I would let it dry for a couple weeks, get some fast-dry flat black and spray a very light misty "guide coat" over the entire body. Allow the guide coat dry per instructions on can.
    Then wet/block sand until all the "black guide coat" was gone. If any black remains in the scratches or low spots, I'd repeat the process until all guide-coat is gone. If the issues is really bad, additional primer-filler, high-build primer etc, would be applied and the guide coat process repeated.
    Oh, I would use 400 wet or finer. Maybe start with 400, then sand 600 or 800 before the new topcoat was applied.
    The grit of sanding would depend on what was being used as a topcoat.
    Lacquer can go fine (600 wet should be enough), poly doesn't need 600 or 800 - in fact that is too fine for a poly finish IMO.

    Pic_46319.jpg
    Not my car, not my project, just an example of guide coating

    After the new (lacquer) topcoat was applied to my liking, I'd let it dry for a couple weeks, then prep for polishing the final finish. Poly finishes don't need extended dry times.
    I'd start the wet color sanding with 1200, and keep getting finer 1500, 2000... A reflective dull shine can be achieved by sanding before polishing - if polishing is to be done.

    I'm not saying lacquer should be avoided, just has to be prepped and processed more delicately/differently than many newer finishes.
    Sorry this was a bit off topic and maybe not what you were looking for.

    Let us know what you do next and how it turns out.
    Should look great soon!
     
    Last edited: Jul 6, 2019
    Skydog1010 and dkmw like this.
  12. netgear69

    netgear69 Tele-Afflicted

    Posts:
    1,451
    Joined:
    Dec 21, 2012
    Location:
    england
    A jump from 60 grit to 200/400 will just polish up the surface and deceive the eye until that paint goes on making them deep 60 grit scratches visible
    Old Deaf Roadie has the right idea if you have paint left keep spraying and leveling between coats eventually they will go
     
    GTG_Gopher likes this.
  13. warrent

    warrent Friend of Leo's

    Posts:
    2,857
    Joined:
    Sep 15, 2009
    Location:
    toronto
    It depends on what you really want out of this project. If this is a one off and you don't want to do it again you could just leave it as is. From a distance no one will see it. If you are trying to learn to refinish properly then strip the finish with a chemical stripper and learn to sand the body correctly it will be cheaper in the long run. All you need to do is get the body sanded to 220 but you need to go through the grades starting with 80 to remove the scratches from the previous grade. wiping the body occasionally as you are sanding with naptha will help show any remaining scratches.
    Once you have the wood sanded correctly proceed to color. Your actual painting looks fine just not your body prep.
     
  14. dkmw

    dkmw Friend of Leo's Silver Supporter

    Age:
    64
    Posts:
    3,867
    Joined:
    Mar 30, 2016
    Location:
    Florida USA
    Looks like you may have experience similar to mine. I was involved in businesses where we took parts from prototyping to mold parts. When you get to making a mold part, it gets obsessive in the amount of fairing and repetive steps to get it “perfect”.

    One of my friends (sadly RIP) who did this stuff for a living also restored a 55 Ford pickup. He kept track of how much primer and black he put on and sanded off - it was $2400 worth. But he faired everything. Even the insides of the rain gutters. The back panel on the pickup bed is intended to be dead flat but of course never came that way from the factory. His was like a black mirror when done. Way over the top, but impressive nonetheless.
     
  15. GTG_Gopher

    GTG_Gopher Tele-Meister

    Posts:
    108
    Joined:
    Dec 1, 2017
    Location:
    Minneapolis Burbs
    Thanks for all the replies!

    I want to be able to get some colors for guitars that aren't available from the factory at my budget. Agreed that the scratches wouldn't be visible from a distance, but I tend to be a bit more up close and personal when I play the thing, so the 60 grit scratches have to go.

    I think that was my big mistake, not doing more steps between the 60 and 200 papers. I was going off what was on the shelf next to the Duple-Color at in the automotive aisle of Mills Fleet Farm...

    I made my run to Home Depot, and got the 80, 100, 120 and 150 papers. I spent some good quality time with the 80 grit here this morning., very therapeutic. It made quick work of the finish and the 60 grit scratches. I also made sure this time to make sure I only sanded with the grain, when I did the first pass with the 60, I ended up going across the grain as I moved across the body.

    The 100, 120, 150, 180, and my last sheet of 220 are on deck for the rest of the day. I have to do a little rearranging of the shop before I start spraying anything again. I realized another mistake I made was hanging the big shop light behind the place I was hanging the body from.

    Where does someone get the good sanding sealer? Is that something they carry at HD or the hardware store? Same with the filler, is that at HD?
     
  16. GTG_Gopher

    GTG_Gopher Tele-Meister

    Posts:
    108
    Joined:
    Dec 1, 2017
    Location:
    Minneapolis Burbs
    This sounds a lot like doing fret leveling! If I had started earlier in the season I'd consider giving this a try!

    Also a few folks mentioned sanding the color coat, is that something that is done with the metallic colors like the Dupli-color perfect match?
     
  17. Skydog1010

    Skydog1010 Tele-Holic Ad Free Member

    Age:
    66
    Posts:
    904
    Joined:
    Apr 20, 2019
    Location:
    North Carolina
    Or

    Leave it alone and call it road wear. ( Road Worn (tm) ) is a FMIC trademark.

    I would remove be what you have done if you want a perfect shine. But there's an underlying problem that might surface ( pun intended ) unless you prime your sanded / polished wood with epoxy primer. Once epoxy primer is smooth shoot your duplicolor, clear and polish. Good luck.

    Nice color choice from a rattle can.
     
  18. GTG_Gopher

    GTG_Gopher Tele-Meister

    Posts:
    108
    Joined:
    Dec 1, 2017
    Location:
    Minneapolis Burbs
    No need for any trademark fights! LOL

    Being the first time out on this type of project, I figured there would be some rework before I get it where I want it. Also trying to get it right is a bit of self growth work and trying to break some bad habits.

    Who knew a paint project would turn a bit philosophical?

    That blue color jumped off the shelf a bit, especially after seeing all the threads on TDPRI about the Lake Placid Blue special run Squier teles here this spring. I actually placed an order for one, but then I got the bright idea to do this project and figured I could get it done before the blues ones shipped. I may still make it, on Musicians Friend they are back ordered through 7/17/19.
     
  19. GTG_Gopher

    GTG_Gopher Tele-Meister

    Posts:
    108
    Joined:
    Dec 1, 2017
    Location:
    Minneapolis Burbs
    May have to do some sort of sealer after all. As I was going through the different grits, I must have punched through one more layer from the factor and think I really hit bare wood this time.
    [​IMG]

    More to come...
     
  20. Silverface

    Silverface Poster Extraordinaire Ad Free Member

    Age:
    67
    Posts:
    9,383
    Joined:
    Mar 2, 2003
    Location:
    Lawndale CA
    not usually. You need to find a contractor-type paint store. Try to find one that carries Mohawk products - they make a great sanding sealer AND primer.

    What kind of wood is that? Is it extremely light? If so, it may be Pawlonia - if so you need to be VERY careful with it - it scratches and dents VERY easily. Sealers and primers also soak into it like a sponge - hardness and porosity-wise it's just a few notches above balsa wood - and most $50 bodies are Pawlonia.

    It usually takes 2-3 coats of sanding sealer....each one sanded smooth, followed by a high build primer....to remove scratches from Pawlonia. The alternative is drop-filling the scratches with multiple passes oof thin superglue - which takes a lot fo practice.

    In fact, EVERYTHING you do should be done completely - from prep to final buffing - on scrap wood before working on the guitar. Learn how to control the spray distance, keep a consistent 90 degree angle to the surface (rig a stick so the body surface you are working on is always vertical and always work from top to bottom!) - refine all your techniques and learn how to fix mistakes on scrap - NOT on the real thing.

    Good luck!
     
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.


  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.