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Final polishing help on my applied finish

Discussion in 'Hardware, Setup & Repair [BG]' started by Groovecenter, Jun 28, 2003.


  1. I recently started a warmoth project, dying and finishing the body, and finishing the neck. The body recieved a analine dye in methanol (rubbed on) a sand and sealer coat which I most likely sanded through, than about 10-12 coats of nitro cellulose lacquer.

    I dry sanded only as necessary between coats to get rid of particales and runs or drips using 400 grit or 600 in certain areas. I never wet sanded between coats or sanded the entire body, just the flaws.

    I plan on letting the finish cure for two weeks, and than wet sanding it. This is my first finish job and I could use some help on the wet sanding.

    Do I wet the paper or the surface? How will I know when I've wet sanded with one particular grit enough to move up to the next?

    Here is a picture of the front after the gloss clear coats. The finish looks and feels pretty thin overall, and I don't want to end up sanding through anything.

    [​IMG]
     
  2. here is the back, its alder with a dark amber dye in it. Is this final polishing completely necessary? Would not doing it leave a harder finish on the soft Alder body?

    [​IMG]


    EDIT- I just wanted to add that since this was my first job, the first couple of coats I did just getting used to spraying (from spray cans courtesy of Stew Mac) were probably very thin. Overall, I would say I undersprayed, but still managed to go through 2 13 oz. cans of lacquer. The last maybe 4-5 coats were decently wet though.
     
  3. GC, that's a beautiful piece of work there! I love the color selection.

    Some points and answers to your questions:

    "I dry sanded only as necessary between coats to get rid of particales and runs or drips using 400 grit or 600 in certain areas. I never wet sanded between coats or sanded the entire body, just the flaws"

    You really should wet-sand between every coat but instead of using just water, I would use water with just a little soap mixed in. The soap helps lubricate the paper so that the particles don't build up and it keeps the paper from digging in too far.

    "Do I wet the paper or the surface? How will I know when I've wet sanded with one particular grit enough to move up to the next?"

    Keep a bucket of water/soap mixture to dip and wash your paper in. I like to wet-sand with my body sitting on a towel. It soaks up the excess moisture and I have a ready wiping rag to clear away the mud and assess the results. You can move to the next grit once you've completely sanded the entire surface. Additional sanding doesn't smooth the surface any more than that - it just takes more material off.

    Is this final polishing completely necessary? Would not doing it leave a harder finish on the soft Alder body?

    You can stop anywhere along the way you want. If you stop in the 600-800 range, the finish will have a satin gloss. This gloss will come up just a little bit more when the body is finish waxed. If you go further - 1200 and up - you can achieve a near high gloss finish before buffing. It all depends on the final effect you want to achieve. For a more in depth look at finishing, take a look over on the MIMF site. Join up and get into the archives for lots of informative discussions of methods and manner to get a good finish. BTW, once cured, a nitro finish with 10 coats is just as hard as one with 20 coats just thinner. Sanding is just a method of creating smaller and smaller microscopic peaks on the surface of the nitro. Once you've gotten them as small as possible with papers, a buffing will knock down the remainder until the surface is perfectly smooth. That's when you get those glassy, glossy finishes.
     
  4. Wow, that was an awsome response thanks very much, I sent you a PM about drilling Hambone.
     
  5. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
    Nice job. Like HB said, Really nice color selction. Classy. I have a project bass that I need to get to soon. Thanks for the inspiration.:bassist: