Tips for disinfecting and cleaning bows, violins, violas, celli or bass.
Thoughts on risk assessment, medical research on SARS-CoV-2, effectiveness and usefulness of sanitising options for musical instruments and a few practical tips for teachers in the classroom or via e-learning.
On all presented methods, always try a little bit on an inconspicuous place on the instrument first before bravely scrubbing down the full instrument or bow and finding that the method you are trying takes off your varnish.
This article turned out to be a bit longer than anticipated, because it just touches on so many subjects and disciplines, but there are some possible solutions at the end.
But let’s start at the very beginning…
In these uneasy times of the SARS-CoV-2 pandemic and the governmental climate of recommendations and decisions changing as often as the weather, you might look for some clarity regarding safe use of stringed musical instruments by yourself and others. Here are a few researched methods of incapacitating a coronavirus and later we will discuss how well each method can do on your instrument.
As far as is known by medical scientific research on the efficacy of various disinfectants against SARS coronavirus, the tested wipes and cleaning hand rubs help significantly in inactivating virus particles to below detection rate, where hand rubs were used for 30 seconds and specific surface cleaners were tested for live viruses after 30 mins and 60 mins. In summary, SARS-CoV can be inactivated quite easily with many commonly used disinfectants.
When on a potential surface outside the body, we see that the virus gets less and less effective over time and the stronger the disinfectant, the shorter the virus ‘lives’ on a surface.
Weak disinfectants will need more time to do their work, but are expected to leave the original surface well alone, whereas strong disinfectants can be used for a short amount of time and the instrument can be used more quickly, but this treatment might affect the original surface more aggressively. Of course we need to find something that does NOT affect the precious (in most instances) varnishes of our instruments, but still makes the instrument safe to pass to another person to be played rather quickly.
All surfaces are not equal in contact transmission of SARS-CoV-2
As clear as this may appear, this medical research article is more aimed towards polymers, because polymers are most commonly found in personal protective equipment (PPE) like gloves, scrubs and face masks for healthcare staff. But polymers make up so much more surfaces, for instance the organic compounds we humans are made of, or specific varnishes on our instruments (like oil varnishes on higher end instruments or nitro lacquer on student instruments most commonly used for class tuition). Spirit varnish does not count as a polymer as the chemical chain of alcohol is rather short and not very complicated.
Find more on the final varnish coating of your violin, viola, cello or bass here in this article.
Normal “pre-Covid” professional cleaning routine of your instrument
Always try on an inconspicuous area first to see how your instrument’s varnish reacts to the treatment!
For most cases I just use a specific liquid polish with a tried and tested recipe which I blend myself to clean down instruments. It contains a bit of alcohol to dissolve the rosin deposits on the front, but not too much, that it also touches the varnish. It has water and natural turpentine to take away dirt and finally a non-drying oil as a bit of a varnish protection. This mixture works perfectly on bows as well, but avoid the hairs.
For some cases where the dirt is a bit more stubborn, I might first use a specific Japanese metal polish paste as a very fine ‘cutting lubricant’. This works extremely well with persistent rosin combined with other things that have adhered to the varnish under the strings of your instrument, or on your bow. As the metal polish is fatty/oily the paste does not interfere with the varnish.
In other cases where there is more of a stain on the varnish I might decide to use a chemical solution, which takes away the dirt, but not the varnish. To clean off the chemical rests I can use my original cleaning mixture again.
Finishing off it is often sensible on higher end instruments to add a protective layer of wax. The wax I use has been developed and designed in the British Museum to be used on artworks and artifacts of various materials and surfaces, like paintings, sculptures, porcelain, furniture and other varnished surfaces.
Thoughts on transmission prevention through instruments
There are a few surfaces that we touch when playing and handling a violin, viola, cello or bass. For instance: chinrests, bottom bout of the back plate area, neck underside, pegs/tailpiece adjusters, strings and fingerboard. And of course let’s not forget the bows around the frog area. Especially on shoulder held instruments we also breathe onto the instruments and if someone touches that area and then their face for instance that could be a risk as well.
After so much care to use servicing products that leave the precious varnish alone, the best option for the instrument would be to leave it alone and quarantine it for 4 days as SARS-CoV-2 has been found to be inactive after 4 days on a wooden surface in this study and this study too.
The best advice is washing your hands for 30 seconds with soap before and after you play or handle your - or any other - instrument. If you do not have soap handy, a disinfectant containing at least 70% alcohol should be a good alternative. A case could be made to use an alcohol wipe any neck area that comes in contact with any surface on the instrument as well. Wait a minute or two before you let your hands and neck touch the instrument for the alcohol to be effective and evaporated.
Switching instruments often or passing instruments between students
If instruments have to switch handler more regularly (particularly on violins and violas) covering the chinrest with aluminium (kitchen foil) could reduce the viral activity time from 4 days to 2-8 hours and if you can find a way to get paper to cover the chinrest (and change it often) that could come down to 5 minutes even as we see published in this study and this study. To understand these inactivating time durations it is important to know that in medical research they add a lot of virus copies on a surface to check the half-life and even the detection (i.e. impossible to detect = all or almost all virus copies are inactive or “dead”) of the virus.
Viral load is typically reported as copies of a virus in a milliliter (mL) of a specific medium (like water). Changes in viral load are usually reported as a logarithmic change (in powers of 10). For example, a three log increase in viral load (3 log10) is an increase of (10 * 10 * 10) or 1,000 times the previously reported level, while a drop from 500,000 to 500 copies would be a three-log-drop (also 3 log10 => /1000). The studies mentioned above even list numbers of 4 log10, 5 log10 and 6 log10. That means 10,000 - 1,000,000 specific virus copies on a surface, which might not represent every day life, therefore viral inactivation could be less than the times mentioned in the studies above.
Iodine and Alcohol
Methylated spirits (alcohol) is used here to break the bonds of the animal glue in a controlled way.
The watery solution PVP-I (Povidone-Iodine) incapacitates coronavirus (according to this article), but could stain skin (and other surfaces) brown/yellow, so it is not advised to use it on your hands or instrument after varnishing. Some violin makers use diluted iodine to lightly stain the wood before starting the actual varnishing process, but once the varnishing process is completed, the iodine won’t hold as after the varnish has completely cured, it should resist water dripping on it. (It very much depends on the instrument’s final coat what the actual water resistance is. Spirit varnish should resist accidental spillage, but it will not resist a damp cloth and rubbed cleaning, whereas properly cured oil varnish you need to take off with heavy duty paint stripper, so it should be fine to wipe with a damp cloth.
The same article states that 70% strength ethanol (2-carbon chain alcohol) has been found to have the same effect on coronavirus as PVP-I. But be aware that if you use alcohol, the bonding of the glue could weaken.
UV and Ozone
UV light radiation is often mentioned or advertised as a disinfecting method to kill SARS-CoV-2. Someone even advertised it to clean and sanitise cars at a servicing station local to us. UV light as we understand it comes in 3 wavelengths, named UV-a, UV-b and UV-c. While UV-a and UV-b rays are transmitted through the atmosphere, all UV-c and some UV-b rays are absorbed by the Earth's ozone layer. So, most of the UV rays you naturally come in contact with are UV-a with a small amount of UV-b.
Scientists have developed the technology to create UV-c radiation on earth, and it is for instance used for sterilising medical equipment and hospital operation rooms. UV-c is also used for bio purification of water. This is done at night and through short and intensive bursts. No human is close to the rays or even in the room. That is because UV-c is HIGHLY carcinogenic creating melanoma cells in under a minute, it can create permanent eye damage within seconds of looking into the light source, and it kills fertility and the immune system. UV-a and UV-b are not found to be sufficiently potent for germicidal use.
After UV-c radiation, ozone emitting devices are implemented to neutralise the remaining radiation to make the area safe again after the ozone dissipates. This study suggests that ozone in and of itself could be used to inactivate the novel coronavirus as it is found to work well with the original SARS-CoV. However, the use of ozone has its own health risks and it is not recommended to use either the UV radiation or the ozone emitting devices in an uncontrolled setting (i.e. at home or at a school) and without proper training.
Household surface cleaning methods
There was one study, that tested common household cleaners (like bleach, dettol, lysol (i.e. ammonia and alcohol), antibacterial soap and pine oil on their virus fighting powers. The researchers found, that they all are effective, in reducing virus count by between 1,000x (3 log10) and 50,000x (4.5 log10) depending on which product was used and in which strength/concentration. The surprising one I have not heard much about is pine oil. It is a turpentine-like oil with disinfectant properties and even mildly antiseptic effects. Out of all the disinfectants listed in the study, pine oil sounds like something a violin maker would/could use on the surface of violins - albeit sparingly of course, after all: everything in moderation… and do wipe off excess liquids.
The reservation with this study is that it was not performed with SARS-CoV-2, but with another ‘envelope-style’ virus called MHV (Murine Hepatitis Virus).
If you do try out any of the cleaning agents mentioned above (or similar untested products) on your instrument, remember to try it on a small patch first to see how it treats the specific varnish on your violin and take proper precautions so you are safe.
The spirit varnish traditionally used on bows is very susceptible to damage and removal by alcohol!
Effect of high-% alcohol on a violin bow’s varnish
Tips for instrument teachers in class and on e-learning
Keep your own instruments and bow fighting fit, so you do not need to borrow student instruments to demonstrate anything.
Keep instrument switching to a minimum.
Wash hands before and after handling or switching instruments.
Keep - where possible - a safe distance between student and yourself.
Encourage students to wash or sanitize hands before and after they handle their instrument.
If you can, it might be beneficial to cover the chinrest (on violins and violas) with wrapped around aluminium foil (or aluminum for our American friends) and/or fixed paper or a piece of cloth each student privately owns.
Encourage students to buy/bring their own shoulderrest when using the same instrument for multiple students.
Use gloves if you have to handle other instruments or if you wish to protect your skin from oversanisising, but disinfect the gloves as often as you would your own hands. (tip: you can cut off the tips that cover your fingers: only protection on the hand palm is better than nothing at all.
Educate yourself on how to recognise the specific varnishes on your students’ string instruments, so you can recommend which cleaning solution might be best for them. Check out my other blog post to get you started on an introduction on varnish.
Find a cleaning agent that works with your varnish (i.e. cleans off the dirt and not the varnish) and use it sparingly.
Best of luck and I am always interested to hear what works for you, so if you have found your solution missing from the list, please do get in touch!!