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nitrocellulose damage - how do I fix it? Help!

mfretton

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May 29, 2007
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UGH! I used isopropyl alchohol to clean a mark on my LP Standard and any of you with the silghtest bit of sense will know the result...a smeared mess of ripples in the nitro finish.

Can anyone help with advice on how I can get the finish back to something that doesn't make me want to cry or shoot myself for being such a fool? It's an area of a couple of square inches on the upper bout near the switch.

I don't mind knocks and dings but self administered vandalism doesn't look so cool!
Matt
 

J.D.

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Just use a good auto finish swirl mark remover or hand glaze and work it very gently by hand (or preferrably with a small RO buffer) and most of it will come out pretty easily.
 

Browneyes

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hand rub hard with cleaning solution.. it should buff out... pics needed though.
 

mfretton

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I've tried hard, but can't get the damage to show-up properly on in a photo. Just to make me feel more stupid, I can't work out how to get the photo into the message from my desktop!

In the meantime I've tried just vigorously buffing/rubbing and it's smoothed the marks a bit, but there's still an orange peel effect and some marks that look like scratches, along with a slightly rippled surface.
 

J.D.

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You may need to "color sand" a bit before buffing. Color sanding is wet sanding with very fine 1000+ grit paper prior to buffing. You need to be *extremely* careful not to sand through the thin laquer top coat, just enough to haze the blem and blend it into the surounding "good" finish prior to buffing.
 

Buzz

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Do a search under "micromesh". Also any advise from Tonefiend on this topic would overide any well wishers.
Of course if you have a buddy that is a luthier ask him to buff out the area, and than you could finish up at home with restorer and polish. I had some stand rash on an otherwise perfect finish, I was at Lay's and Dan kindly buffed out the areas saving me many hours of labor hand rubbing with micromesh.

First off though, rubbing alcohol would not harm Nitro, only whatever wax was on top of it. I've heard there are polishes which leave a film, some actually contain lacquer. Good guitar polishes (and there are so many), remove scratches so the Lacqer shines naturally.

What I think you got going on is that there was some kind of film build up, the alcohol dissolved it, sorta like how acetone dissolves lacquer on contact.

Like previous poster said, using cleaning "restorer" or swirll remover polishes will do the job. Unless your familiar, be carefull rather than fast. Micromesh sold at many luthier shops such as Stew-Mac is a set of cloth backed abrasive sheets. Not "sand" but labratory space age technology went into them making every particle uniform in size so that scratching is impossible. This is the "Woodworkers kit" by Micromesh, about $45.00. The sheets last forever! They are not like ordiary sandpaper, I've been using the same kit for over 5 years. They go from 1500 all the way up to 12,000 which is allmost like a slightly dulled polishing. This kit comes with instructions and a rubber pad. The rubber pad is used so that your fingertips don't leave gauges.

In your case, I think starting out with 2400 would be as coarse as you need. Used dry they are more much more aggressive. They perscribe the sheets to be used in warm slightly soapy water. After going thru each grit progressing thru, and not skipping any, finish up and use liquid polish for a mirror-like finish. Stopping at about 3600 - 6000 grit and not polishing will make it look sorta "under-the-bed" relic.

For best results, as a minimum remove the strings but if you want perfection all over the guitar, remove all the parts. The strings can have microscopic abbrasive debris magnetically sticking to them which can get on your polishing rags.
 

Toecutter

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Yes rubbing alcohol will destroy nitro finish, I've seen it first hand. Never and I mean never ever use rubbing alcohol anywhere near a guitar painted with nitro.
 

J.D.

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Yes rubbing alcohol will destroy nitro finish, I've seen it first hand. Never and I mean never ever use rubbing alcohol anywhere near a guitar painted with nitro.

+1

Rubbing alcohol will *absolutely* attack nitro. Learned that one the hard way.
 

mfretton

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Yes rubbing alcohol will destroy nitro finish, I've seen it first hand. Never and I mean never ever use rubbing alcohol anywhere near a guitar painted with nitro.

I thought so - the finish blistered a little on contact with the alchohol.

I can't find Micro-Mesh anywhere in London (or the UK) and have not so far been able to find wet & dry paper finer than 1200.
 

Adwex

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Hmmm, I wouldn't have guessed that rubbing (isopropyl) alcohol would've done anything. I wonder about booze (ethyl) alcohol? Do I have to worry if I spill my beer?
 

mfretton

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Do I have to worry if I spill my beer?
LOL - it depends how old you are! If you're part of the first generation of senior rockers and have the uniform of very tight jeans, t-shirt and trainers, with thinning hair that's stuck in a style somewhere between the 1970s & 80s, then spilling your beer is nothing to worry about.
 

Tonefiend

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If the guitar can be fixed you will need to sand and then polish it out. Not a job for anyone but a pro. This could get messy very quick!
 

Buzz

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I thought so - the finish blistered a little on contact with the alchohol.

I can't find Micro-Mesh anywhere in London (or the UK) and have not so far been able to find wet & dry paper finer than 1200.

Why can't you mail order from Stew-mac or others abroad? There's probabbly some on Ebay.

As for my remarks about alcohol, I was WRONG! I looked it up in my Stew-Mac book: Guitar finishing Step by Step 1st edition page 11. Says "it will soften lacquer, but not as well as Lacquer thinner". It dicusses the various types of alcohol, what it's main uses are: dissolving stain and or Shellac flakes, and it's good at de-greasing bare wood.

I'd have replied earlier and investegated the alcohol blooper, but I wasn't aware of replies.
 

mfretton

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thanks Buzz. I just ordered some Micro-Mesh Soft Touch Finishing Pads from Stew Mac, but am a little anxious about doing anything after Tonefiend's message.
 

Adwex

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LOL - it depends how old you are! If you're part of the first generation of senior rockers and have the uniform of very tight jeans, t-shirt and trainers, with thinning hair that's stuck in a style somewhere between the 1970s & 80s, then spilling your beer is nothing to worry about.

:wow Is there a camera in here??!!
 

Adwex

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LOL - it depends how old you are! If you're part of the first generation of senior rockers and have the uniform of very tight jeans, t-shirt and trainers, with thinning hair that's stuck in a style somewhere between the 1970s & 80s, then spilling your beer is nothing to worry about.

What I meant was....will the alcohol in beer damage nitro?
 

mfretton

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Thanks everyone for your help. The Micro-Mesh Soft Touch Finishing Pads arrived from Stew Mac & I've managed to remove all the visible damage to the nitro with them and a soft buffing pad for my electric drill.

I was tempted to stop at about 3600 - 6000 grit and not polishingfor the "under-the-bed" relic Buzz suggested, but couldn't resist that last buff!
 

Buzz

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Thanks everyone for your help. The Micro-Mesh Soft Touch Finishing Pads arrived from Stew Mac & I've managed to remove all the visible damage to the nitro with them and a soft buffing pad for my electric drill.

I was tempted to stop at about 3600 - 6000 grit and not polishingfor the "under-the-bed" relic Buzz suggested, but couldn't resist that last buff!

I've been using a Micromesh woodworkers kit ever since hearing about it when this forum started, I was never aware that anything could do what it does. It's also about becoming familar with the properties of a lacquer finish and learning to figure what can and should be done. Sometimes you do have to start out with more abrasive grits, but you can't put back what is gone so don't take chances. There is a big differance between 600 - 2000 grit paper and the Micromesh's 1,500 - 15,000. I'm glad to know you didn't have to get it refinished after all, how about some revealing before and after pics???:salude
 
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