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

[gerry grable]

Which nail polish remover? Acetone is the traditional solvent, but most are now synthetics. It seems that lots of organic solvents will work for this. I'm very happy, as I have a bunch of dried up old cakes of Nyman and Carlsson which I luckily never threw away.

Great tip. I just used the acetone/ water 50/50 on my hard as a rock Petz #4. I tried water alone for months to no avail. I'm sold on this method.
Now the question is, how do I keep it that way. Back in the jar with pure water? Or maybe, since it's so easy just keep it in it's green plastic cup?
Thanks

 

[Andy Mopley]

I think now that I know how easy it is, I'll just store rosin in its container and when it looks like hardening up, give it the "old magic" ...

 

[gerry grable]

I think now that I know how easy it is, I'll just store rosin in its container and when it looks like hardening up, give it the "old magic" ...

Funny. I heard that somewhere

 

[mrbaloo]

I just tried this rosin treatment procedure for nearly three hours. I think my piece of Pops rosin transformed from very hard to just perfect soft. Amazingly! Thank you for the tip!

 

[Matt Weiner]

It works

 

[Don Hergert]

Yup. Many thanks to the OP and early adopters for writing this up!

 

[iamthebassplayr]

Tried it last night on two cakes of Pop's. One a year and a few months old, the other little under a year, and (with the rosin saver) just starting to get more firm than I like... Cakes looked beautiful this morning after about 7 hours.

Feel like between this and Rosin Saver I'll have 'fresh' rosin for ever.

Going to get a buddy's scary, old, crusty Pop's and give it a shot with something REALLY far gone...

 

[MrSidecar]

I don't know... I hate to be that guy, and who am I to argue with all you wizard chemists here. But for me, it didn't work.

I had this not-old-but-too-old cake of Pops. That age where it seems alright judging by the looks and feel, but somehow on the the bow it's not really working anymore. Playing-wise a night-and-day difference to the fresh stuff.

So I gave the 50/50 method a try: 50% rubbing alcohol and 50% water, just a tiny drop of the mixture, sealed container, few hours.

The surface of my cake initially got really soft (like leave-fingerprints-on-it soft), so I let it dry up a little. Now it's still super-soft, but essentially, it's old soft rosin, as opposed to old dry rosin before. It does make zerzo difference playing-wise to before the experiment, even though it's easily applied, and I'm tempted to say, you absolutely can't beat fresh rosin, and you can't revive it. Once it's lost, it's lost.

Now, I might very well have done it all wrong. Certainly, since it seems to work for all of you guys.

But I figure, the Rosin Saver (you know- that plastic container with the silicone and the dampener cushion) works, and it does so by exposing the rosin to a constant humidity (as in, WATER in the air around), to keep the rosin from drying out. I'm not a chemist, but to me it seems logical that if you saturate the air around the rosin with water, you keep the WATER from leaving the rosin, not necessarily or NOT ONLY the other fluids in it.
The alcoholic fumes, however, replace only that part of what's gone, and don't take the water with them, I could imagine. Result: perfectly soft, (or if overdone, running) old and mojo-less rosin. Please, someone with reputable chemistry knowledge, chime in.

Me, I'll buy a fresh cake as soon as possible, and keep it in my rather new Rosin Saver.

Best
Sidecar

 

[wathaet]

I tried with several cakes and like you it got soft, but it is now a different rosin than Pops.
It does not have the grab of fresh regular pops and it seems to require reapplication after very little time.
A no-go for me

 

[Matt Weiner]

Further experimentation confirms what the last 2 posters have said. Yes it gets soft again, but its not like the new pops. Its not as grabby, needs frequent reapplication, still powdery, and your friends make fun of you for your silly little science experiment.

 

[Don Hergert]

You know, the first thing I do when I buy a Pops rosin is carefully peel off the paper "tray" that it comes in and put the rosin cake into a plastic wrapper (a cut-up piece of a thicker zip-lock bag) that I can fold all the way around it inside the Pops plastic container, so the cake of rosin is basically sealed within the plastic wrapper, within the Pops plastic container. And after the alcohol treatment and after I let the rosin cake solidify I sealed it up this same way again.

My alcohol treated Pops hasn't gone dry and/or powdery and is till tacky and functional in daily use about 6 weeks after doing the alcohol treatment.

I'm in southern California where it's dry and hot now so I'll continue to watch this, but as of now I'm not seeing any problem.

 

[Bigbassguy]

I'm trying it tonight. Let's see.

 

[Bigbassguy]

I had two old pops cakes and did this treatment for about 4 hours and it seems to work.
Thanks for the chemistry lesson!

 

[T_Bone_TL]

I use Sherman's (hard as heck) quite happily. But it does have a nasty tendency to shatter when dropped. Having shattered mine again, I gave the "in a sealed container with alcohol" method a try and while it quite quickly wetted/gooed the surface, the bulk material was remaining hard after many hours without much increase in the gooey depth. Had it merely been cracked the method might have filled in the cracks, but I lost a few chunks this time (stepped on one before I realized I was shedding chunks) and I need bulk flow to fix it - so it's in the oven now. Temperature is as low as this oven goes, unless that proves not to be sufficient. 170F.

Plenty hot, seems basically done in just a few minutes of heating.

To me, this implies that you could probably do a fine job with a large cup or bowl of boiled water (no need for an active double-boiler set up) and your rosin in a waterproof container (such as a silicone rosin cup) set in it, if you didn't have an oven handy. It tends to be "ready to use" as soon as it cools, rather than needing to off-gas vapors for days, and the general practice of remelting/repouring rosin (perhaps slightly overcomplicated in some cases) appears to be well-established for rosin rejuvenation.

The last time I did this I had to use a wood-fired stove-top, and melted in one foil container before pouring back into the wooden trough that Sherman's comes in - this time I had already just wrapped the block with foil, with a rubber band to keep it tight across the ends, for the alcohol experiment, and I just popped that in the electric oven to melt-in-place. The temperature is too low to bother the wooden block or rubber band (or a silicone rosin cup, if you had one of those) and risk of ignition is very low in a properly controlled electric oven at low temperature, while not having to deal with keeping water out of the process is convenient.

Edited to Add: Might be the alcohol sped up the melting (hard to be sure until I try without doing that first) - but definitely the alcohol is still hanging around, days later the cake is still much softer than normal (or ever.) Too soft, for my taste.

 

[tbplayer59]

Did this last night and it certainly works wonders. Thanks to the collective wisdom found here on TB

 

[Don Hergert]

Interesting side-line to this... If you have the adhesive versions of Velcro and want to remove the adhesive layer, use this same alcohol fuming technique overnight. The adhesive will shed off in a single gooey sheet. No soaking in alcohol necessary, in fact soaking won't do it. Just fumes and time do it.

(I use adhesive velcro under the fingerboard to prevent fingerboard piezo wire from rattling. I adhere the furry layer directly to the under side of the board, then sandwich the wire between it and the hook layer, on top. I can very effectively de-adhesive the hook layer using the alcohol fuming technique.)

 

[Simon Toth]

Hey! I tried it on my old cake of pops and oh boy it was messy! I was scared AF because the whole cake was sticky! So I put it on a shelf and overnight it became as soft as the new cake I just bought! (it's still a little bit sticky but I'm gonna give it more time to dry or whatever) It worked!

 

[Don Hergert]

Just fyi, in this TB/DB thread there is discussion of using a microwave to melt/blend/reconstitute rosins... I'll be trying this next time.

 

[Matt Weiner]

I went back to fresh pops. There’s nothing better and the small extra cost is worth it.

It’s funny how we will spend everything they have on a bass and a bow, and then try to save a few dollars any way we can on the rosin.

 

[krfoss]

Jist did this last night with an old kolstein rosin cake. I just thought the "before" is how the rosin was supposed to feel, but the cake is now tacky. Hopefully I'll get a chance to practice tonight and see how it really goes. Cool trick.