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Thread: Bug spray Lacquer repair

  1. #1
    Registered User crooksj's Avatar
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    Default Bug spray Lacquer repair

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ID:	187446I’ve been asked to repair (reduce the appearance of) the damage from bug spray on a Gibson Sam Bush model. The areas affected are peg head and top scroll. I think the the peg head can be sanded and re-sprayed (if that does not affect resale value). The scroll area would be liquid polish rubbed out to match the surrounding finish.

    Customer's advice is make better but “do no harm”. What would you all recommend?
    Thanks!

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    Default Re: Bug spray Lacquer repair

    The damage to the resale value may very well already have been done.

    I do not know how the market functions on modern-era professional grade instruments, but in the vintage instrument world an instrument is significantly devalued when any new lacquer is applied, no matter how skillfully.

    You will have to research how the application of any new lacquer will affect the value of a modern Gibson, and your customer will need to be informed of what you find out before you start any work. I would suggest contacting someone friendly who routinely sells recent issue Gibson instruments.

    Before the market became so rigid about over-sprays, we would have level sanded the surfaces and over-sprayed the damaged areas.

    The finishes on modern Gibson guitars are quite thick. I don't know whether this applies to the mandolins.
    There might be enough existing lacquer on both surfaces to level them with fine sandpapers and rub them out without applying any new lacquer.

    But someone else will have to tell you whether doing even that would de-value a Sam Bush model.

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    Registered User sunburst's Avatar
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    Default Re: Bug spray Lacquer repair

    Quote Originally Posted by rcc56 View Post
    ...The finishes on modern Gibson guitars are quite thick. I don't know whether this applies to the mandolins.
    There might be enough existing lacquer on both surfaces to level them with fine sandpapers and rub them out without applying any new lacquer...
    I suspect this is the case. It would be the first thing to try regardless, IMO.
    The Bush model Gibsons that I have seen look to have plenty of finish for leveling and buffing. Can't be sure they are all like that though.

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  6. #4

    Default Re: Bug spray Lacquer repair

    Not as nutty as the antique furniture world, where original, uncleaned dirt over original, decayed finish is built into the value, or, somewhat more understandably, with collectibles like coins or knives which must be unused.
    Does this concern extend to also never playing an instrument?

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  8. #5

    Default Re: Bug spray Lacquer repair

    Sometimes you can get lucky. Sometimes not. I would try something milder before sanding like Meguiar's Cleaner Wax in an inconspicuous area and see what happens.

  9. #6

    Default Re: Bug spray Lacquer repair

    You can try this non- harmful method that I use for furniture.
    Combine the abrasive “rotten stone” powder with a liquid furniture polish. Mix enough to make a slurry, no too dry but not too loose either. (If I had to compare it to something familiar, I’d say the consistency of mustard.) Rub this slurry with a soft rag onto the affected area until semi dry. Once dry buff with a new clean cloth. You can then rub this area, or the whole mando, with straight furniture polish to a soft luster. Rotten stone can be purchased in a good paint store and sometimes even the big box stores. The rule of thumb with powdered abrasives is use rotten stone if the finish is dark and pumice if the finish is light.

  10. #7
    Registered User sunburst's Avatar
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    Default Re: Bug spray Lacquer repair

    Pumice, rotten-stone, various powders mixed with oils, polishes etc. are basically homemade buffing compound. Easier to just go buy some Novus 2 and use it right from the bottle.
    The trick is to start fine (grit-wise, abrasiveness-wise) and see if that does it, and then work backwards until something does work. I would first try using Novus 2. If that isn't enough to do it, I'd go backwards to Micro-mesh, then to 1500 grit sandpaper or whatever cleans up the damage, then work forward from there back to Novus 2.
    If I see that rubbing/sanding will not do the job, then either leave it be of prepare to do finish work.

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    Default Re: Bug spray Lacquer repair

    Agree with John completely. I'd add that I'd use a fairly stiff pad, almost like kraft paper, or you're not going to level those pits out. I think I'd just start with 1500 or 1000 grit and see how that works. Then work back up to Novus 2.

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    Default Re: Bug spray Lacquer repair

    I can't say for sure from the pictures, but it looks like the bug spray has left pin holes and small divots in the finish.
    If this is correct, I don't believe that I would start with compounds, whether they are modern or the old fashioned powders. They might only make the low spots in the finish deeper and wider.

    If there is plenty of finish to work with, I would start with 1000 sandpaper on a flexible pad such as an eraser, and use mineral spirits as a lubricant. If necessary, I would back up to 600 and work dry. I would work until the surface was nearly level or my instincts told me I was in danger of going through the finish to the wood. Then I would follow with 1500 and 2000 sandpaper with mineral spirits, and rub out with polishing compounds.

    In the old days, I would have scuff sanded and oversprayed, and rubbed it out using standard techniques.

    I've used rottenstone a for years, mostly on antique shellac and varnish finishes. I like the stuff-- I like the effect it gives. I do not use pumice often. I rarely use either on recent issue nitrocellulose finishes. I feel the modern compounds give more suitable results on nitro. I will sometimes use rottenstone on very old nitro finishes.

    Rottenstone barely cuts at all, unless you bear down hard. It mostly just polishes. Pumice cuts quite aggressively and must be used with caution. Another powder that has been traditionally used on varnish finishes is tripoli, which is in between pumice and rottenstone in abrasiveness.

    On some varnish finishes, a final polish with rottenstone and water can put a mirror like shine in the finish. If anybody wants to try it, the finish must be thoroughly hardened before you use it that way. Bear in mind that wet sanding temporarily softens finishes, and an instrument that has been wet sanded should be left alone for at least a couple of days before final rub-out with compounds or powders.

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    Registered User crooksj's Avatar
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    Default Re: Bug spray Lacquer repair

    Thanks for all the suggestions. Have not used Novus 2, but have Meguires 10 polish and 17 cleaner and Menzerna W58 solid compound, plus micro mesh pads.

    The owner did use a damp paper towel to wipe off the spray right away, causing some scratches. I’ve only looked at it briefly w/o magnification, so cant judge the depth of pits.

    Seems safer to start on peg head since it is flat with no color to sand through. I might just spray some Deet on one of my spray gun setup lacquered test boards and experiment on fixing that...

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    Default Re: Bug spray Lacquer repair

    I agree with John and Dale. For the scroll area you may wish to use the micromesh sticks that come in various grits and taper at the ends.

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    Registered User Charles E.'s Avatar
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    Default Re: Bug spray Lacquer repair

    I wonder how the spray affected those areas? When I worked for a guitar shop in Maine years ago, every summer we would get guitars with finish damage where the arm (coated in deet) contacted the top. Back then we used french polish to blend in the affected area with the nitro finish on the rest of the top. Would that still be acceptable today?
    Last edited by Charles E.; Jul-20-2020 at 6:10pm.
    Charley

    A bunch of stuff with four strings

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    Registered User j. condino's Avatar
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    Default Re: Bug spray Lacquer repair

    I saw the thread title and opened it up all excited to find some new secret method of using bug spray to fix nitro repairs!

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  18. #14

    Default Re: Bug spray Lacquer repair

    On an unrelated note, as I repairman I see a high number of "grandpa's guitars" that were poorly stored for decades -- attic, garage, shed, basement, etc., -- almost ALWAYS with tiny white paint flecks where they were being stored in the area of something being painted, but nobody had the decency to move the instrument during the painting!!! Real fun to remove those paint flecks! Needless to say, WHO stores an old Gibson without a case??????? Of course, if it had a case, then the CASE would have the white paint flecks..........jeesh.

  19. #15
    Registered User crooksj's Avatar
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    Default Re: Bug spray Lacquer repair

    Who knows, maybe DEET works as well as well as cellosolve...just can’t apply with a pump spray bottle!

  20. #16

    Default Re: Bug spray Lacquer repair

    Jeff, there was this theory that all paint splatters and drips fall less than three feet from the brush, so that two painters would be safe from each other’s droplets if they were six feet away. Then some pointyheads started talking about really tiny drops wafting around on air currents, but nobody took them seriously, since it meant laying tarps everywhere, and that sounded like too much work.

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  22. #17
    Registered User sunburst's Avatar
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    Default Re: Bug spray Lacquer repair

    Quote Originally Posted by Jeff Mando View Post
    ...WHO stores an old Gibson without a case??????? Of course, if it had a case, then the CASE would have the white paint flecks..........jeesh.
    The Loar-signed mandolin that was hanging on the wall over the mantle as a decoration and was apparently there while the wall was being painted, the one that two "old ladies" brought in to a music store to see if it was worth anything (it was discussed at length here), well that mandolin ended up belonging to a friend of mine. Last I talked to him about it he was slowly removing little white paint specks when he had time and felt like it.

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    Default Re: Bug spray Lacquer repair

    The curse of a decorative object. Of course you put grandpa’s mandolin on the mantel. Besides, who keeps moldy pasteboard cases around?
    I collect antique tools. Half the ‘country inn’ genre of restaurants, which are legion here, have un-vetted woodworking and ag tools NAILED to the walls. On Long Island, where I grew up, gold-sprayed violins and woodwinds adorned restaurants and catering halls.
    I’m sure Mr. Condino can relate some of the particularly gross things double basses have been turned into.

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    Rush Burkhardt Rush Burkhardt's Avatar
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    Default Re: Bug spray Lacquer repair

    "safe from each other’s droplets if they were six feet away. Then some pointy-heads started talking about really tiny drops wafting around on air currents, but nobody took them seriously"

    Yep! All conversations these days lead to Covid-19!
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  26. #20
    Registered User crooksj's Avatar
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    Default Re: Bug spray Lacquer repair

    Just an update on the results of my repair attempt. After using 400grit through 12000 micro mesh + buffing & polishing on my Deet sprayed test board, I repeated that method on the peg head. I would say 80% improvement. Still some pits, but felt I was running out of finish to remove more.

    The damage on the rest of the mandolin (it showed up everywhere the owner touched it!) was Meguire’s 17 and 10. That worked best on the surfaces that were dulled, eliminating the haze. The pitted areas were very much improved by polish, but not eliminated. I decided not to sand the top partly because the lacquer had shrunk enough to highlight distinct grain lines. Was afraid of creating a areas of grain lines/no grain lines. The polish alone made a significant improvement.

    Here are my AFTER photos. Thanks again to all for the suggestions.

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  27. #21

    Default Re: Bug spray Lacquer repair

    Looks good, John!

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  29. #22
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    Default Re: Bug spray Lacquer repair

    Good work.
    Knowing when to quit is essential on a job like this.

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    Registered User Roger Adams's Avatar
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    Default Re: Bug spray Lacquer repair

    Great job! Gotta wonder who does not know that insect repellent is harmful to an instrument.....just saying.
    If you can read this, thank a teacher. If you can read this in English, thank a vet.

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  33. #24
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    Default Re: Bug spray Lacquer repair

    Looks mighty fine, to quote Lester Moran... Looks great. As said above, good to know when to stop. Now it's a little story in the instrument's history.

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  35. #25
    Registered User Tom C's Avatar
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    Default Re: Bug spray Lacquer repair

    Quote Originally Posted by Roger Adams View Post
    Great job! Gotta wonder who does not know that insect repellent is harmful to an instrument.....just saying.
    Rule number one of the Mandolin Club... Do not get bug repellent on your mando.

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