Double Bass How to revive old rosin using rubbing alcohol...

[Don Kasper]

My 8 year old Pops and 9 year old Carlsson rosin did get soft with the alcohol treatment but did not get grabby like new Pops.

Playing Hayden’s Concerto for Violin and Tschaikowsky’s Serenade with a chamber orchestra. Was getting frustrated and wondering if bow rehairs were needed, but no it’s the old Pops. (Scottish ancestry wants to keep using the ancient Pops and save money, my Swedish Viking ancestry wants to kick butt and buy a new cake)

My bass has a low B Thomastik and high A. It takes good rosin and hair for them to sing on fast passages. I tried the treatment then tried a new cake of Pops, on a Schicker bow and Hudson bow.

New Pops is the way to go for best results.


View attachment 7461097

Before you toss the old Pops and old Carlsson, put both in the freezer for an hour...then crush each cake into a powder in a plastic baggie (or close to a powder....).
Then melt equal amounts of each together in the microwave - STIR when molten with a toothpick.
Then pour into a small silicone container. (Amazon).
Cool overnite.
It may yield a useable cake, sharing the desired qualities of each.
IMFE.
thx.
Thanks.

 

[Jay Mendoza]

Heating and re-melting the rosin will soften it, temporarily, but once it fully sets, it will be harder than before because when you heat it to it's melting point, it drives off some of the essential oils and volatile solvents in it, mainly the turpentine, and that makes the rosin harder. You can smell these essentials evaporating and going bye bye when you heat it, which is a red flag. Adding turpentine when re-heating can work, but its very tricky because you have to experiment to find out how much is the right amount to add.

A few drops of turpentine on an old cake of rosin, in sealed container, like Pops comes in, left to sit for 3-4 days works pretty well. You can tell when you have the right amount because the cake will deform easily when squeezed, just like a fresh cake of POPs. I add a little turp to the cake, set it aside in the sealed Pops can, and add a little more if it's not soft enough after 3-4 days. If you add too much, just open the lid for a day.

Alcohol will also soften the rosin, but once applied to the bow, the alcohol quickly evaporates leaving the rosin harder than before, and it quickly turns to powder and causes squeaks when bowing. Then you have to re-apply the rosin more frequently and eventually wind up with too much rosin on the bow and squeaky noises. Then you have to carefully clean the bow hair, or have you bow re-haired.
BTW, alcohol dries out, and eventually will ruin, your bow hair.

 

[bassically_eli]

Heating and re-melting the rosin will soften it, temporarily, but once it fully sets, it will be harder than before because when you heat it to it's melting point, it drives off some of the essential oils and volatile solvents in it, mainly the turpentine, and that makes the rosin harder. You can smell these essentials evaporating and going bye bye when you heat it, which is a red flag. Adding turpentine when re-heating can work, but its very tricky because you have to experiment to find out how much is the right amount to add.

A few drops of turpentine on an old cake of rosin, in sealed container, like Pops comes in, left to sit for 3-4 days works pretty well. You can tell when you have the right amount because the cake will deform easily when squeezed, just like a fresh cake of POPs. I add a little turp to the cake, set it aside in the sealed Pops can, and add a little more if it's not soft enough after 3-4 days. If you add too much, just open the lid for a day.

Alcohol will also soften the rosin, but once applied to the bow, the alcohol quickly evaporates leaving the rosin harder than before, and it quickly turns to powder and causes squeaks when bowing. Then you have to re-apply the rosin more frequently and eventually wind up with too much rosin on the bow and squeaky noises. Then you have to carefully clean the bow hair, or have you bow re-haired.
BTW, alcohol dries out, and eventually will ruin, your bow hair.

I’m a little confused. Are you talking about adding alcohol directly to the rosin? That’s not how I’ve been doing it. I place an open cup of rosin in Tupperware with a little bit of ethanol in the bottom and put the lid on. The rosin is only exposed to the fumes.