Proper method of cleaning/removing decades of surface dirt, grime & etc. from old lacquer finishes.

[Redacted]

Where to start with an instrument from 1928-30 that has wonderful checking. I know I cannot get aggressive but I have a finally guitar on the bench that needs a good cleaning to start with before I begin with repairs.

Suggestions please.

Methods and materials.

This Stromberg Voisinet is the guitar.

[Palle Clausen]

I have tried A LOT of different product for really gummed up guitar finishes.

After a lot of trial and error, I have settled for these two products:

 - Music Nomad guitar polish

 - Legend quality guitar polish

Apart from going at it with a heavy cut compound, those are the only two products I have found that can actually take off the gunk instead of just smearing it around and make a mess...

[Greg Mirken]

Guitar polishes may work to some extent, but that's not really their intended use. You might google furniture conservation for ideas, but the products that pros in that field use are real expensive. What I have used for decades to remove thick grunge from old sensitive finishes is a pink gel called Sterling's Magic. It's not cheap either; I have found it from art and book conservation suppliers, but I bought a case of tubs of the stuff long ago. It is completely harmless [you can eat it] and it has never failed to do well on sketchy 100 year old finishes, with no ill effects at all.

[Palle Clausen]

Don't be fooled by the 'polish' in the name... They do a lot more than just polishing. Have you actually tried them?

[Greg Mirken]

Palle, I'm not fooled by names. I know, for example, that Grape Nuts cereal contains neither grapes nor nuts. The Music Nomad polish claims to remove oxidation and restore faded finishes. It does this by removing the outer surface with a (mild) abrasive. If that's what you want to do I'm sure it's a fine product. If your goal is just to remove dirt and oil buildup it's not the ideal product; you only need a good, safe, cleaner. That's what I suggested.

I have worked on vintage instruments for 45 years. One of my goals is always to disturb the originality of a vintage piece as little as possible. Removing the patina of age that a piece has acquired over 90 or so years has become a serious no-no, and has a negative effect on its value.

[jbbancroft]

From the picture it doesn’t look that bad. If you just want to remove the dirt I just use a small bowl of warm water with a drop or two of dawn dish soap. Wipe the instrument down with this solution, then rinse with clear water.

Anything that solution didn’t remove I’ll then wipe down with Naphtha.

Jim

[onewent]

Agree re patina.  I own and work on lots of these type guitars, and that patina should remain.  Otherwise, the guitar just looks 'messed with'.

Tom

[Redacted]

So do you classify bodily fluids, sticky substances, other filth and foreign matter to be included as patina?

[Greg Mirken]

No, patina is what's left after you carefully remove that stuff.

[onewent]

yup