How To Clean Vintage Guitar with Nitro Finish???

[Gordon Bellerose]

I need some tips on cleaning a vintage nitro finish.

The guitar is a 1964/5 Gibson ES 355.
The finish is checked and has fine cracks in it, so I want to be careful that anything I use to clean it will not remain in the cracks.
It has been sitting in someone's closet for the last 30 years, and the grime was never wiped off, so there is some pretty crusty stuff under and around the knobs too.

I have some pretty good chrome cleaner for the pickup covers, but that grime on the guitar top is pretty tough, and I don't want to start scraping.

Does anyone have some good ideas about cleaning this thing?

[Mark Fogleman]

Naptha will get most of the crud off the finish and not leave any residue. Use an old toothbrush and Qtips to get into tight spaces.

[David King]

Often the crud and old finger grease will eat into the nitrocellulose surface so you may not like what you see when you start removing it. At that point you have to decide what your next step is but letting the owner know what to expect so that they don't blame you for making a mess is helpful. In my view you want to avoid a guitar finish that looks like it has been "messed with" if at all possible.

[Freeman Keller]

I had one guy specifically tell me that he DID NOT want his guitar cleaned. All that muck on the fretboard was part of "his sound"

[Mark Fogleman]

Mojo workin'

[Clay Schaeffer]

Deionized water is often suggested as a cleaner to - remove - dirt from cracks, so maybe it would also clean without pushing dirt into cracks. That is what I would try first.

[Barry Daniels]

It often takes some solvent to dissolve crud. I use a lot of odorless mineral spirits for general cleaning including old finishes.

[Gordon Bellerose]

Thanks for the replies guys!
I ended up using naptha. The tougher crusty stuff mostly came off without damaging the finish.
I didn't rub too hard.

[Mario Kessels]

Good to hear the Naptha worked. My experience with the older NC finishes where the NC has gone 'soft' is that the naptha does not do a good job and leaves a white-ish residue.
I have used other products with good results but these will stay in cracks so will not work for you here.
For mineral spirits I get the translations 'terpentine' , or 'spiritus' here. That would mean that its pretty much a mix of alcohols (methanol , ethanol) and water when it's spiritus and when it would be terpentine it would mainly be naptha.
Would be interesting to know which one it really is. Do you know Barry?

[Mark Wybierala]

Here, Mineral Spirits and Turpentine are two very different things. I don't know if there is actually any standard for "Mineral Spirits". I think that technically "mineral spirits" could be a wide range of products but on the shelf here in the USA the product is fairly consistent at the hardware store.
I have encountered a number of old lacquer finished instruments and found myself in an "OH-SHIT moment" when attempting to clean and polish. At the end of a repair, just wanting to remove a hazy mess of fingerprints turns into 45 minutes of fairly intensive labor. As mentioned above, the lacquer can become contaminated. Its an issue that you need to be careful with. I've never had a complication where Naptha has caused an irrecoverable problem. I'd certainly stay away from anything related to alcohol.

[Brian Evans]

I've been known to clean with naptha (I use camp stove fuel), then wet-sand (I lube naptha cut lightly with mineral oil, not water) with with 800 - 1200 grit paper and re-polish old nitro finishes. I did this following a fairly extensive drop fill session, a number of chip/scratches/gouges through to wood. Finish looked excellent, for 72 years old, after this work. The normal surface checking is still there but not as prominent, the edges of the check lines got subtly blended.

[Steve Sawyer]

I have visited the furniture preservation and repair shop at The Henry Ford (previously The Henry Ford Museum and Greenfield Village). Their furniture preservation expert says the very first thing they try on a piece of dirty furniture is spit.

Seriously.

Saliva contains enzymes that will dissolve many of the organic components in the grime and dirt that collects on things like musical instruments and furniture onto which we place our filthy hands. It will also not damage the "patina" of a priceless heirloom. The next thing they try is distilled water. If neither of them work, they proceed very, very cautiously using the mildest solvents possible, starting with distilled water and a drop or two of detergent, similar to what we'd use for wet-sanding. I don't recall them using naphtha as both visits pre-dated my own discovery of naphtha so I didn't know to ask.

[Steve Sawyer]

The other thread re using mineral spirits for French polish got me wondering, and found this info on Wikipedia:

Turpentine (also called spirit of turpentine, oil of turpentine, wood turpentine and colloquially turps) is a fluid obtained by the distillation of resin from live trees, mainly pines. It is mainly used as a solvent and as a source of materials for organic synthesis.

White spirit (UK) or mineral spirits (US, Canada), also known as mineral turpentine (AU/NZ), turpentine substitute, petroleum spirits, solvent naphtha (petroleum), Varsol, Stoddard solvent, or, generically, "paint thinner", is a petroleum-derived clear liquid used as a common organic solvent in painting.

The word "mineral" in "mineral spirits" or "mineral turpentine" is meant to distinguish it from distilled spirits (distilled directly from fermented grains and fruit) or from true turpentine (distilled tree resin).