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Sanding after grain filler?

Discussion in 'Finely Finished' started by TelZilla, Jun 9, 2019.

  1. TelZilla

    TelZilla Friend of Leo's

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    Working with a swamp ash tele body from warmoth and i have some questions about sanding after grain filler.

    • I see most using 220 grit. Is that as fine as i want to go?
    • I see some saying to sand back to wood, others saying that defeats the purpose, as you might expose more pores. So what do you think? How “deep” should i sand?
    • What should the surface look like before i move on (not sure if I'm going to sanding sealer or straight to the blond lacquer i have). Dull, with no scratches? I did some sanding with a small block and some 220, and i got to flat(no shine) but there are still visible scratches.
    Unrelated question: whats your solution for sanding the sides(not sanding sanding sealer specific, just general), particularly the inside curves? I don't have a spindle sander and I'm not really into buying one, so cheapo sloutions are appreciated

    Thanks for your thoughts.
     
  2. Silverface

    Silverface Poster Extraordinaire Platinum Supporter

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    Grain filler, when sanded, should look like smooth, void free wood - you should be sanding FLUSH to the wood surface. If the filler is doing its job there will be NO open pores - just filled ones. IF they are open you need to do another pass with the grain filler thinned more than in the previous pass. Depending on the woos I do a minimum of two and up to 4 filling operations, each progressively thinner.

    There may be SOME color (usually a cloudy gray) to it but that color becomes clear when you apply other coats on top (unless it is a tinted grain filler - or you have colored it with universal colorants.

    It should always be coated with another coat of sanding sealer which is also sanded smooth. 220 is fine - for both; with the lacquer sanding sealer you get no mechanical adhesion between it and subsequent coats - only chemical adhesion and lacquer melts into previous coats.

    Excessive roughness is a problem, so you want lacquer sanding sealer as smooth and even as you can get it - that is the LAST sanding you will do except for repairing small runs if you make a mistake. Some think they need the sanding sealer to have "tooth" to the other lacquer coats bite in - that's correct for "paint" but totally wrong for "lacquer". And NEVER sand between coats except to repair small runs.

    If all lacquer coats are applied correctly you'll be going straight to buffing when application is completed. Final "surface sanding". if needed, is a repair operation due to errors in spray technique - NOT a normal part of lacquer finishing.

    For sanding curves you can buy sets of small, shaped sanding blocks made of rubber. Rockler sells them; so does Amazon and dozens of finishing and hardware suppliers online. A spindle sander works at far too high a speed except for sanding bare wood - it would be a poor choice for sanding filler or sanding sealer.
     
  3. sleazy pot pie

    sleazy pot pie Tele-Afflicted Gold Supporter

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    You can also go buy one of those long foam pool noodles.
    Cut it into smaller pieces, cut some in half and quarter pieces and then wrap sand paper around that.
    Sanding and especially those inside horns can be a pain. Just take your time and be patient. It’s the journey not the destination.
     
  4. trev333

    trev333 Telefied Ad Free Member

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    sanding horns?.. find the right sized object at hand to use and sand away... my first build was hand sanded to shape it.. I used all kinds of tins and bottles, etc to get into those curves... hard work...

    then I bought a ROSS... :)

    DSCF0211.JPG
     
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  5. TelZilla

    TelZilla Friend of Leo's

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    Thanks for the replies. Very helpful.

    Got a set of these from Amazon for $14:
    BEB9C8B8-6EC6-49E9-9BE2-7F99EABB8003.jpeg
     
  6. TelZilla

    TelZilla Friend of Leo's

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  7. trev333

    trev333 Telefied Ad Free Member

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    one of these doo dads.. an oscillating spindle sander...

    not that expensive and pretty handy for guitar building..:)

    Tele on ROSS.JPG
     
  8. Silverface

    Silverface Poster Extraordinaire Platinum Supporter

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    Those are great, especially for outer radius body edges - exactly what I meant. There are also small velcro-hook hand sanders made for body work - I mainly use the curved handles rather than the flat paper attachment section for cutaways, horns and such.

    Foam "Caulking backer rod" from building supply houses is cheap and invaluable - you can carve it to any desired shape/radius and use adhesive-backed paper on it.
     
  9. Silverface

    Silverface Poster Extraordinaire Platinum Supporter

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    Don't use those for finish work! You can easily burn right through any coating system or filler. Great for shaping wood, but not for finish work.
     
  10. TelZilla

    TelZilla Friend of Leo's

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    You mean this guy?
    sander.png

    Is an orbital sander OK for front and back at this stage (grain filler/sanding sealer)? Also, is 220 OK for Sanding sealer, or do I need to use something finer?
     
  11. Mr. Neutron

    Mr. Neutron Tele-Meister

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    The foam pool noodles suggested by Sleazy Pot Pie above work really well, and are inexpensive. I use some black foam used for insulating the 3/4" copper water pipes under my house that works better for me, due to it's slightly smaller diameter than the pool noodles.......
     
  12. Silverface

    Silverface Poster Extraordinaire Platinum Supporter

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    Yeah, there are 5 or 6 different handle shapes. I only use the flat portion on small repair jobs, but th handles are great for all sorts of curves - like the inside curve on a Tele peghead!
     
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