Grimy surface damage to varnish

[soulrockcity]

Hello all! This is my first post after lurking for a while. I’m finally looking to deal with a finish issue on my bass, and I’m having trouble describing it (which makes searching for solutions difficult), as I’m not knowledgeable about these matters. I hope this post makes sense and doesn’t break any rules!

I have a wonderful custom bass that I commissioned from one of my best friends about 15–20 years ago. Unfortunately, I’ve recently noticed (or maybe ignored for too long) that the finish has started to look and feel bad right where the bass rests on a multi-guitar stand. At the two contact points with the stand, the varnish has become dirty and uneven. I’m using “varnish” or "finish" for lack of a more certain term, as it seems like a surface-level problem, not something affecting the wood underneath as it might appear.

It looks like the material from the guitar stand has reacted with the finish at those touchpoints, resulting in a “scratch-off lottery ticket” rubbery grime in the finish, and some misshapen areas. It feels like something I could rub off, scrape off, or sand off, but I don’t want to risk damaging the instrument further. I’ve attached two photos of the two affected areas at the bottom of the bass. It's possible, since this was a custom build, that my friend did something (too much varnish? not dry enough?) that caused this issue which would not happen with a store bought instrument. But this storing of the bass on this stand for so long is my fault, and the bass is amazing in every other way.

I’d greatly appreciate any advice, keeping in mind that I’m a novice when it comes to finish repair. I’m also happy to finally join the forum and discuss this wonderful instrument—my bass guitar. Thank you!

 

[JRA]

welcome to TB!

i can't help you directly, but there are a bunch of "finish experts" here, and they'll have good advice/counsel --- if not more questions --- so hang in and hang on for a dialog in your favor!

good luck with you ax!

 

[Hoochie Coochie Man]

Step one is to determine what type of finish was applied. Most likely nitro-cellulose lacquer.

If it is nitro, it is most likely reacting to a chemical, (probably a "plasticizer") in the soft material on the stand.

The good news, (if it is nitro), is that it should be a fairly easy repair for someone who is knowledgeable about such things.

I would never leave any of my nitro finished instruments in contact with any synthetic soft materials.

Once you get this sorted out, you could drape a cotton cloth over the soft parts of the stand to prevent contact with the parts that are causing the adverse reaction.

If the finish is nitro, try a solvent called naphtha on a soft cotton cloth to see if you can buff out the blemishes.

I buy naphtha from my local hardware store.

Here is a link to an Amazon seller, (of a lifetime supply) of such stuff:

Amazon.com

I could be completely wrong about this, (as I often am), so please don't blame me if taking my advice causes your bass to melt.

 

[Brian Patterson]

That is a weird 'smudgy' looking abrasion - not likely to be polyurethane or a varnish of any kind.

Probably nitro as Hoochie Coochie is thinking - but how do you determine that? Get some Naptha nd see if it helps?

 

[bherman]

Get in touch with your friend and ask him what the finish is. If its poly or varnish, it might come off with a soft cloth and 70% Rubbing Alcohol. If its nitro (doesn't look like it to me if its 15-20 yrs old, nitro "ages" and it would have some checking and such) then the suggestion for naptha is good advice. You can buy pint/qt containers of it at Home Depot or any good paint store. Use a very soft cloth (think old, soft t-shirt) and work slowly and carefully. It may or may not need to be refinished, depending on how much comes off and whether the finish itself is damaged.

 

[H K]

It's the chemical compounds of the varnish reacting with the chems in the stand.
You get specialty stands for nitro finishes, with cork, fabric or some other non-reactive padding.
This is the most common type of damage from a stand. 2nd most common is probably around the headstock, from a hanger, then theres the rare "left my coil cable ontop of my guitar in the case for 10 years".

IMO theres not enough info about this to the customers on for example nitro painted fenders and gibsons. It's more of like an unspoken thing. But it's super prevalent on vintage guitars. Some like it, and tbh, I think the right kind of wear like this is beautiful

If it makes you sad, sand it down and re-finish it. It's not that difficult, and you can get the nitro clear finish in a rattlecan, by company called Dartfords.
If not, then leave it.

But 100% go get a new stand. Preferrably one made from wood, or cork. Ask at a music store or just check to make sure it says it doesnt react with finish.
Then atleast it wont get worse.

 

[MCF]

Look here. They used to sell a clear Nitro pen that was good for spot repairs.

Guitar ReRanch ~ Guitar Refinishing Products