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  #1  
Old 05-21-2020, 01:06 PM
DesertTwang DesertTwang is offline
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Default "Rescuing" an unsatisfactory job at buffing out by spraying with gloss finish?

This is a question for those of you who have experience building or repairing guitars. A few years ago, I decided to buff out the satin finish on my 2013 Martin 000-15sm, because it had acquired some scratches and shiny spots that bothered me. In hindsight, I would never do that again. I had done months of research before doing this, and I had read every single thread that had been published on this and other forums on the topic.

I thought I knew enough to tackle this job, but I didn't. Long story short, I sanded way too much, and in one spot, on the back, through the finish. The buffing out worked out OK, but it never resulted in the shine I had hoped for (and seen in guitars of this model buffed out by others). On the back, where I had sanded through the finish in some places, I re-sprayed with 12 or so thin layers of semi-gloss, and the result was acceptable. If the whole guitar looked like that, I may not even be complaining.

The sides look decent, too. But I was never happy with how the top came out. When I polish it with a lot of effort, it looks really nice, for a few days, but then it slowly turns to a matte look again that just doesn't look great. It kind of has that "greasy" look that you would get on an old fashioned plaster cast after a few weeks of wearing it.

My question is: would it be worth considering to spray the top (and possibly, the whole guitar except for the neck, of course) with high gloss lacquer? It wouldn't have to be perfect by any means. The plan would be to lightly sand the top and apply several thin layers of high-gloss lacquer from a spray can, since I don't have the means and equipment to use more fancy methods. I have to make do with masking tape, rattle cans and hanging the guitar from the ceiling in my garage.

What say you wise men out there?

Below are a few photos that show the guitar in its present state.









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  #2  
Old 05-21-2020, 01:30 PM
charles Tauber charles Tauber is offline
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From your extensive reading, you are aware that the pores of the wood were not filled prior to applying the top coats. No matter how shiny you polish/buff the surface, it is still going to be a shiny pitted surface. As you know from experience, you cannot sand the finish sufficiently to level the pores: you'll sand through the finish first.

The back appears to show the texture of the spray application, an orange-peel texture. That was not sanded flat. Again, the best you'll get unless it is sanded flat is a shiny pebbled surface.

It isn't clear from what you wrote what is your desired finished appearance. Do you want a mirror high-gloss with a spectral reflection? Do you want it dead flat, with no texture but not a high-gloss? Or are you just wanting a uniform sheen? Without known specifically what you want to end up with, it isn't possible to provide meaningful input.

You also didn't state what you used for "buffing". You state you "sanded", but didn't state with what.

High quality finishing is difficult. It requires skill and experience. The question that every novice do-it-yourselfer should ask themselves is, "Is the work I'm going to perform have a good chance of making it better, worse, or no better?" With finish work, most novices make it worse and are best advised to leave it alone - rather than make it cosmetically worse - or take it to a professional. The chances of a novice improving the appearance by over-spraying the body are near zero. It is possible to do a good job with rattle cans, masking tape and hanging from the ceiling, but it takes skill and experience to obtain that result.

Last edited by charles Tauber; 05-21-2020 at 01:36 PM.
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  #3  
Old 05-21-2020, 03:19 PM
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JayBee1404 JayBee1404 is offline
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Not my guitar, so probably none of my business, but it looks pretty nice to me - if it was mine I’d be very happy with it. The only further treatment I’d make to it would be to apply some Dr Ducks or similar oil, to the Bridge and FB to darken them some and make them look less ‘dried-out’.

Otherwise, it looks a nice instrument.

The usual disclaimers apply......IMHO, YMMV etc.
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Old 05-21-2020, 05:35 PM
SkipII SkipII is offline
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I've not done an acoustic guitar but several elertrics and a houseful of furniture -- all using lacquer.

1. You need to fill the pores, unless you like that look.

2. Proper lacquering is many coats but precision around sanding each between coats almost completely down. Constant fill and level You have lots of orange peel, so you did not sand down each coat (perhaps wary after burning through the finish on the back).

3. Ideally your finish should be determined by your sanding, not the lacquer. Best is to use gloss lacquer and learn how to sand that down with progressively finer sandpaper and rubbing compounds and polish to get the sheen you want.

4. How long did you let the finish cure? The fact that the sheen is shifting is evidence that you sanded too soon. I let my lacquer finishes cure for weeks before I think about final sanding and polishing.

If all that sounds intimidating or complex, it is simply that lacquering (and French polishing) are the most demanding processes in wood finishing. Take your time and learn, or shop it out to someone who does it in their sleep.
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Old 05-23-2020, 03:28 PM
Howard Klepper Howard Klepper is offline
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Suggest you look up the First Law of Holes.
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Old 05-23-2020, 11:45 PM
runamuck runamuck is offline
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The grain isn't filled on that model so when you spray gloss on it it's going to look terrible.

Also, you have the neck, a pickguard and the bridge that's in the way of doing a good looking refinishing job - which is possible to be done by someone with experience but done by someone like yourself - chances are you're going to regret it.

Leave it alone.
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