Double Bass Removing rosin from the body

[YosemiteSam]

(This looked like the best subforum for this. If you disagree please feel free to move or delete. Thanks.)

I recently bought a used Shen hybrid that has bow rosin all over the top. The luthier from whom I got it suggested using denatured alcohol thinned 1:1 with water. I just tried this and it didn't help at all.

Does anyone know how to safely remove excess rosin without damaging the finish?

Thanks in advance!

-- Sam

 

[KUNGfuSHERIFF]

There are rosin cleaners (solvents) out there. I need to do the same for my bass and will be interested to hear your results.

You may be able to get some of it off using the edge of a credit card as a scraper. It depends on how heavy the buildup is, and how long it was left there.

 

[Ben B]

I don't know what type of finish Shen uses, but denatured alcohol can damage a shellac finish which is often used on violin family instruments. You may want to check with Shen regarding the finish before attempting to remove the rosin. On a shellac finished instrument, I would try using naphtha first.

 

[BassinCT]

+1 to what everyone else has suggested. For light rosin removal on bows, 1:1 water/alcohol is commonly used but a little shellac goes with it. Naphta would be my first choice- I clean rosin off of fingerboards with it, but as with anything else, consult the manufacturer.

A long time ago, I tried a cleaning product sold by Shar and goofed up the varnish on a cheap school violin due to user error. Which ever product or solvent you use, be sure to frequently fold the cloth and use a fresh surface after a few passes.

 

[james condino]

Like KungFu said, at the Oberlin workshops a couple of sessions ago, bass Jedi Robbie McIntosh showed me how to take an old credit card and put a tiny little burr on it like you would a scraper and use that to get the old rosin off. A burr on the plastic is stiff enough to remove stubborn old rosin, but not so much that it will trash the finish. Any kind of solvent on old finishes makes me nervous; you could easily turn a 20 minute rosin removal into a 6 week finish nightmare. Good luck.

j.
www.condino.com
www.kaybassrepair.com

 

[csrund]

If memory serves, Steve Kosica recommends this: Amazon.com: Citrus Cleaner/Degreaser - 8 oz - Liquid: Health & Personal Care

At least I think he did, because that's what I bought and used. My first Shen had a lot of rosin build-up when I bought it. I gave it a rubdown with Citrisolv and a cotton cloth (no scraper; I'd have been too nervous to try that). It did okay. I left the bridge alone; it's too heavily covered. Probably have to be sanded off, and I'd rather not tinker with it; just keep it from getting any worse.

However, I've since read that many luthiers discourage using any sort of liquids on the instrument finish, due to the possibility of it penetrating into the wood by way of micro-cracks in the varnish. Anyone have an opinion on this?

 

[KUNGfuSHERIFF]

Depends. Solvents like naphtha will wick away without contaminating the bare wood inside a crack.

Skin oils, dirt, oxidization, rosin, chicken grease...probably not a good thing.

 

[old spice]

From Rufus Reid's "The Evolving Bassist:"
"Use some fine oil, like '3 in 1' oil, and the finest steel wool. Work in an area about 2 inches in diameter. Put a little oil on the bass and work lightly in a circular motion. Be careful not to work in a larger area as the oil will sit too long and begin to soak beneath the finish. After you finish that area, wipe it completely clean with a clean, soft cloth....Remember not to rub hard or use much oil or you may harm the finish of your bass."
I've not done it, but remembered reading it.

 

[Michael Eisenman]

Why not send a message to John Sprague?

 

[Jon Stefaniak]

I've used something called citra-solv in the past, but it wasn't as good as the red stuff Kolstein sells. Maybe start by lightly scraping with a credit card, then it's just a lot of rubbing with with a cloth and the Kolstein stuff.

 

[Ortsom]

Yes, check w/ Shen 1st as Michael suggests. The wrong solvent on the top can send you deep into the abyss. I wouldn't use steelwool either, regardless of the number of 0's, as it will take off some of the finish.

The bridge can be scraped lightly w/ a sharp knife, without burrs. It may become lighter in colour.

 

[groooooove]

i once brought a potential bass purchase to my luthier for a once over,

one of the issues was the bass was excessive rosin buildup. the owner of the instrument inquired about using off-the shelf rosin cleaners, and according to the expert the store bought stuff used to be fine, but since it was found to be carcinogenic they've changed ingredienets and its not nearly as effective.

the luthier said he can still get and use the hardcore stuff, but has to do it outside on a windy day and all that.

moral of the story; a good luthier can remove it. i wouldn't take a scraper to the top of my bass..

 

[YosemiteSam]

Thanks for the tips. I contacted Shen and they said they use "Solvitol", which apparently is from the UK and not readily available here. They also suggested scraping with a credit card for really heavy buildup, but specifically just the bumps, not scratching the surface of the top with it. I too would be leery of that, steel or bronze wool, etc. I'd rather live with a little rosin buildup than mess up the finish.

I'll figure out who John Sprague is, dwell on it a bit, decide how much it's worth pursuing.

-- Sam

 

[John Sprague]

Hi Sam,
I am the person at CSC who responded to your earlier email. For others, I'll paste what I wrote this morning:

Thanks for getting in touch. We use Link Removed for most clean-ups. It’s slow acting, so you need to rub some on there, let it soak in a bit, take some off, repeat. Alcohol can remove oil varnish, so if you use it you may end up a few shades lighter. A professional can work with it, but I wouldn’t recommend it. If it’s caked on pretty thick, you can gently remove some with a credit card first, avoiding making contact with the top.

The word of the day here is "careful". Oil varnish can be pretty forgiving if you have some experience with it, but not so much if you don't. When we get a nasty rosin mess in, our guys will even use straight Xylene, but you have to be very careful and know that the varnish will definitely start moving. It's for pros only, please don't try this at home. If you use anything strong, assume the varnish is softening up, so once you're done let it sit for a day to dry before you touch it again.

Or visit your shop, that's the safest route.

Solvitol can be ordered on Amazon (so I've heard) or from Link Removed. Twelve bucks gets you a lifetime supply.

All the best, and be careful!

 

[YosemiteSam]

Hi Sam,
I am the person at CSC who responded to your earlier email. For others, I'll paste what I wrote this morning:

Thanks for getting in touch. We use Link Removed for most clean-ups. It’s slow acting, so you need to rub some on there, let it soak in a bit, take some off, repeat. Alcohol can remove oil varnish, so if you use it you may end up a few shades lighter. A professional can work with it, but I wouldn’t recommend it. If it’s caked on pretty thick, you can gently remove some with a credit card first, avoiding making contact with the top.

The word of the day here is "careful". Oil varnish can be pretty forgiving if you have some experience with it, but not so much if you don't. When we get a nasty rosin mess in, our guys will even use straight Xylene, but you have to be very careful and know that the varnish will definitely start moving. It's for pros only, please don't try this at home. If you use anything strong, assume the varnish is softening up, so once you're done let it sit for a day to dry before you touch it again.

Or visit your shop, that's the safest route.

Solvitol can be ordered on Amazon (so I've heard) or from Link Removed. Twelve bucks gets you a lifetime supply.

All the best, and be careful!

Thanks, John! I somehow didn't make the connection between the email and your name mentioned here. I've got some woodworking and refinishing experience, but will still avoid the strong stuff for now. The buildup isn't really all that bad, more texture than visible, so I may just opt to leave it alone. BTW, my luthier/dealer is Doug Heydon in Springfield, OR.

Thanks again!

-- Sam

 

[tyb507]

I've seen naptha used, after a credit card with a sharpened edge to scrape some of the rosin off. This was on an 18th c. Italian bass, on the bench of a well respected bass luthier. I can't speak to whether this is safe for all finishes, and obviously there are health concerns with exposure to naptha.

 

[Dr Rod]

Xylene or any goo remover with xylene. Test it first in a small area. It will not damage shellac or oil varnish, but you need to test it anyway just to make sure. And just watch the rosin come off with no pressure whatsoever.

It is a carcinogen, which is not uncommon for these solvents. It's summertime so perform this job outside and let the fumes dissipate outside.