I get this question often; "How do I remove rosin dust that has flaked off the bow and gotten stuck to the body/bridge/fingerboard of my bass?"
Well, this is definitely a case of "prevention being the best cure" - in the future, carry a clean cloth and wipe off the dust at the end of each bowing session to prevent it from building up. But this isn't about "I told you so," it's about handling a current problem of buildup.
So there are several options, some which work better than others.
Before using any of them, my lawyers advise me to tell you that you try any of these suggestions AT YOUR OWN RISK -- and that it's very wise to test each method in an inconspicuous location first, to ensure that it won't damage the finish. Please don't call or email me to tell me that you tried one of these suggestions and rubbed the finish right off the face of your bass.
If the buildup is on the bridge
, a plastic (not metal) scraper will often do the trick. Ones like the photo to the right are often used by sign shops to remove vinyl from windows, and are small and safe enough that you can't bear down enough on them to have an "oops" moment - but they are effective because they still have a keen edge, with no metal burrs that could gouge into the wood. You can buy a package at sign shop supply houses online. Go slowly and gently, and you can often peel away layers of rosin with a little elbow grease. Some folks often try a little steel wool (#000 or finer) for the bridge. I'd be careful of using that on the body, though, you're likely to remove some finish without realizing it.
Removing rosin from the body:
A flat scraper is likely not as effective removing rosin from the compound curves of bass bodies, though you could try a credit card, which can be bent into a curved shape, for big lumpy chunks. If scraping doesn't work, and you're not ready to take the bass to a luthier just yet, a more chemical solution (no pun intended) may be the next step. Kolstein makes a cleaning/polishing kit, and the cleaner is specially formulated to remove rosin. It's also certified by Kolstein to be safe on fine instrument finishes. We sell that kit here on the site, so that's an option. It also includes a nice big bottle of polish and a couple of micro-fiber cloths.
We also carry the rosin remover and polish made by Petz, which is another similar type of solvent that can be used to break down and remove the rosin, with the follow-up polish to restore the luster beneath. It's reported to be pretty effective and safe for most finishes.
For the do-it-yourselfer, a common chemical used for rosin removal is toluol (aka Toluene)
-- which may possibly be an active ingredient in the cleaner(s) mentioned above -- and you can purchase it at some better-stocked hardware stores. It is a potent chemical, and you should use it sparingly, with proper ventilation and skin/eye protection. And again, test in a place where it wouldn't be seen before trying it on the face of a finished instrument. Gently applied, it should quickly dissolve most rosin, and the remaining residue will leave a flat finish that can be buffed out with a clean cloth.
Toluene may damage a nitrocellulose lacquer finish, but it shouldn't hurt a varnish finish. For a nitro finished bass, you might instead use an orange oil (not just a cleaner with orange scent, real orange oil). Similar results might be had with lighter fuel or 3-in-1 oil, but again, all disclaimers are repeated, as anything good at softening the rosin may also soften the finish
. Some luthiers advise against the use of any oils or polishes on the body of the instrument, as they can seep into very small cracks and permanently alter the bare wood under the finish.
It might be a job for a luthier
. On the body, a luthier might use very fine sandpaper or very fine steel wool to remove buildup; either of those options will almost definitely leave a spot where the finish is flat -- and therefore he or she will need to do a french polish
to restore the original finish. So yeah, if it's really persistent, you might want to leave it to the professionals.
Which takes me back to the initial point: once you've solved this issue, remember that a stitch in time saves nine - meaning that a little preventive maintenance (a wipedown of the strings and bass with a clean cloth after each session) will ensure that you don't have another buildup problem to face down the road.