Nitro clear coat over OTM, how do I finish

Discussion in 'Finely Finished' started by trancedental, Jan 21, 2014.

  1. trancedental

    trancedental Tele-Meister

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    I've sprayed over 1 1/2 cans of nitrocellulose clear lacquer over my Ocean Turquoise Metallic JM but am a bit confused about what exactly to do next, the body has been drying for over a month.

    Do I finish by sanding with wet & dry paper adding a little washing up liquid, I've read to use 800 grit first & then use 1200 but not sure if this applies to metallic finishes. Or do I avoid sanding & just go straight to polishing? Or maybe start with finer grade wet & dry paper? :?:

    Any advice would be welcome because I really don't have a clue! :eek:
     
  2. Big tuna

    Big tuna Tele-Holic

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    I just sprayed a whole can of lacquer on one and orange peel is gonna have to be sanded down,did you have a smooth finish or will it need sanding to flatten? if the finish is good and smooth I would lightly wet sand with very fine paper like many youtube videos explain then buff
     
  3. StoogeSurfer

    StoogeSurfer Tele-Afflicted

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    First, let it dry 6 weeks.

    Don't use dry paper at any point when you begin sanding. Here's the drill from Reranch, it works very well:

    The sanding will be done with successively finer grades of paper. The paper found at automotive color supply stores works well. The grades required are #400, #600, #800, #1000, #1200, #1500 and #2000. One sheet of each is all that is required. Allow the paper to soak overnight in water before beginning.

    Use a small flat block when sanding to prevent your fingers from causing furrows in the finish. As noted a small computer battery is a personal favorite. Sanding first with the #400 grade, sand until all the shiny spots are gone. When done correctly, the finish should be uniform and matte. As you move up to the next grade check the finish in a good light. You should find that the finish is becoming more reflective and that the sanding scratches are becoming fainter. At the #1200 level the finish is now being polished and should reflect images. If you find you have missed a spot, sand backwards until the grade is reached that will blend the spot and then move back to the grade level where you were in successive grades.

    Use caution when sanding to avoid sand throughs. Be especially cautious when sanding at the edges of the body. The finish may be thinner there and the difficulty of keeping the block flat when sanding over an edge can make a sanding through more likely.

    After the final grade of sanding is completed, the final polishing can begin. Use a soft cotton rag either folded or shaped into a ball and held between the fingers. Either way try to prevent individual fingers from causing furrows. Polish in random circles. The polishing can be done in steps starting with a white polishing compound. If the surface was prepared as noted in the last section, red (more abrasive than white) compound should not be necessary. In fact white can probably be skipped and the finish can be polished with a swirl remover type polish. We use the 3M product, "Finesse It II" going directly from #2000 to final finish. Skipping the white and red steps may take longer to polish but on a relatively new surface the final polish seems more reflective.

    The instrument is now finished. Take more than normal care for the next month or so when playing and handling. The lacquer is still relatively soft and can scratch. The lacquer will continue to harden for literally years but should reach its practical hardness in 30 to 60 days. Enjoy your work with pride.


    The whole page is here: http://www.reranch.com/101a.htm
     
  4. CapnCrunch

    CapnCrunch Friend of Leo's

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    The Re-Ranch info will work, but there are numerous ways to reach your goal. Some people prefer to dry sand rather than wet sand. I'm not in that camp, but some are. There are a couple of things to keep in mind as you start.

    First, make sure your lacquer is hard enough to polish. Check your neck pocket or a pickup rout. If you can scratch it or dent it with a finger nail, it is too soft. Second, how much orange peel do you have? If your final coats layed down really smooth, you may be able to level sand with 800. The more orange peel you have, the coarser you will need to go, or leveling will take forever. 600 is a good compromise, but sometimes you have to start with 400. Third, keep water out of screw holes and bridge holes etc. If you let it in and let it sit, it will swell the wood fibers and you will have a sand through before you know it. Compressed air through a blower nozzle works great for clearing water out of holes. If you have the ability to buff with Menzerna or auto polishing compounds, you should not need to sand past 1200 (I often stop at 1000). Be careful around pick up routs and body edges both when sanding and buffing, sand throughs and burn throughs are easy to accomplish in these areas.

    You have sprayed a clear coat over the metallic paint correct? If so, you can sand and polish the clear coat. You do not want to sand the metallic coat at all. You will want to be very cautious of sand throughs, because there will be no way to repair the metallic base coat if you do go through your clear coat.
     
  5. musicalmartin

    musicalmartin Poster Extraordinaire

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    Dont forget if you coats are smooooooth enough you may not even need to sand it much ,its not obligatory .I use toothpaste and washing up liquid to polish cellulose paint or Chroma 1500.I only had to sand out one minor rough patch .
     
  6. PixMix

    PixMix Tele-Holic

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    This is Minwax nitro, cured about 2 months (you should be fine with over 1 month). Wet sanded using water and a couple of drops of dishwashing soap as a lubricant. Started with #800, 1000, 1500, 2000. Polished with Meguiars Scratch X 2.0. At this point it doesn't really matter if it is metallic, opaque or transparent as you're working only with the clear coat.

    [​IMG]
     
  7. trancedental

    trancedental Tele-Meister

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    I had already used 800 & 1200 wet & dry water with some washing liquid, so just went up to 1500 & then 2000, lightly with a rubber sander & without.

    I've put 2 applications of T Cut original, was a bit blurred after the 1st time, but the 2nd is now starting to shine, after using some elbow grease!!!! It's more of a deeper shine & will probably be more glossy when I try further applications.

    The front was last done with clear nitro about 6 weeks ago the back was 4 weeks because I knocked some of the finish off, unintentional relic! :rolleyes:

    I used Morrells Nitro lacquer cans http://www.wood-finishes-direct.com/product/nitrocellulose-lacquer-sprays They appear to dry quickly & you can put another coat on soon afterwards. No problem with the nozzles unlike others, easy to apply even for a newbie!!!

    Thanks for all the tips!! :D
     
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