reshaping rosin

September 27, 2017, 5:08 AM · hi all
i recently bought a we hill violin rosin(dark). its top was soo indented so i decided to make it more flat looking. i first work with sandpaper. than i use the spilled dust(no dust came from sandpaper) to fill the deep gaps by melting them by a lither. my conserne was "does melting rosin by lighter harms it?". while melting, i didnt burn it or i didnt see any smoke outcoming.

Replies (30)

September 27, 2017, 5:13 AM · You can burn it to be different, but not too fast usually.
Usually you just put it in the oven and let gravitation do the rest to get a perfect new shape.
September 27, 2017, 5:31 AM · I would have asked the dealer for an exchange of the defective rosin for good stock. Now that you've applied sandpaper, it's probably too late for that. At this point, you'd save yourself a lot of time and trouble by just scrapping the current rosin and buying a replacement.
September 27, 2017, 5:37 AM · I tried to melt a light amber cake of rosin with a lighter once. It left black streaks of, I'm guessing soot across the top. I ordered the same rosin you have, it came in the same way as yours did. I decided to scrape it smooth with a metal scraper and tossed the scrapings- not much anyway.
Edited: September 30, 2017, 3:27 PM · I've used a toaster oven set at a temperature below 200°F to reintegrate broken rosin cakes. I have shaped some aluminum foil with a bottle cap, dumped in the rosin pieces and heat the mess in the toaster oven until it looks like a rosin cake again.

When I have bought rosin with "wrinkled" tops I just wear them down over time rosining my bows - it worked fine.

I would not use a flame.

September 27, 2017, 5:53 AM · thanks for your answers. i shouldnt melt rosin by fire. at that moment i tought it was the easiest way :) . anyway, i will try to cut the upper part of the cake by 5mm or less to reach a better face.
September 27, 2017, 6:33 AM · Sandpaper will leave imbedded grit that will harm the bow hair.
September 27, 2017, 6:51 AM · Rosin does not need to be scraped to start it, this is a myth that needs to be debunked. Neither does it need to be flat to start with. Just use it and keep turning it as you go.
You can always tell an amateur if they have deep grooves in their rosin. This bunches the hair as they rosin, results in uneven application, and can be a cause of a whistling E.

Cheers Carlo

September 27, 2017, 8:18 AM · Thanks to everyone for answers.
September 27, 2017, 8:35 AM · @Carlo is that true, so many opinions out there. And a lot from experienced players and player/teachers. Perhaps there should be a list, with categories like; "Really Bad Advise", "Not So Bad Advise"; "Almost Good Advise"; "Good Advise"; and, "Doesn't Really Matter Advise"-- it will make it so much easier on beginners such as myself.
September 27, 2017, 8:48 AM · Reminds me of the time in the very beginning when I ordered rosin. I made sure it was some of the best. Did a lot of research on it, then when it came, it had this cloth attached to it.

I had to get rid of that cloth right away by tearing it off of the rosin. Another beginner "duh" moment.

From what I can tell rosin seems as if it could last a player 50 years. I'll probably die before I get through all I have right now. I rosin my bow quite a bit and I still haven't managed to put any marks on the rosin cake. More likely I'll get tired of looking at it and throw it away before I use it all.

September 27, 2017, 9:12 AM · and I just read rosin should be replaced no later than four years... yeah, that was from the makers, could be sales security for them... back to my categories
September 27, 2017, 9:31 AM · @jim, that's great to know. A great excuse to try something else.Probably is sales security.

In you have lived where there's lots of pines, you might remember the pine sap oozing out of the trees on a hot summers day. If it drips on your car or gets in your hair that's bad news. Probably could get your own there though and harden it up.
I'm not bold enough to try that. Maybe more accurately I'm too lazy to try it.
I'm wondering if I could use my old colored rosin as an ingredient in a Christmas fruit cake. No one eats those anyhow. Just blocks with colored hard things on them.

Edited: September 27, 2017, 9:42 AM · Actually, if we approach scientificly, rosin doesn contain any cemical that can solve in air by time. But metals like silver, copper and lead that is in the cake can be oxsidated by time. I dont know the efects of those metals in cace but if they get oxsidated, they wont do their role. To ged rid of those oxides, simply we can cut of the surface by 2 or 5mm. Also by melting the rosin we MAY change the percentage of mixture of the rosin intigers in the layer (i assume rosin is not soo homogeneous) which will also cause problem. In the other hand amber that contains fossils is also rosin of a tree. If they can survive millions of year, why not our rosins cant :)
September 27, 2017, 10:30 AM · I was amazed to see that Anne-Sophie Mutter has a deep deep groove in her rosin.
Time: 3:16
Not really an amateur :-)
Edited: September 27, 2017, 10:56 AM · Ata, of course it does. You can smell rosin cakes, ergo something dissolves into the air.

I have a 50 year plus old cake somewhere, it cannot gert used anymore. It is incredibly hard now, like a rock. I got a rosin from my student days (Hymann or sth like that) that is still usable after more than 15 years (price tag is in DM which means it is older than 2002, I would guess late 90s).
Melos seems to last longer than my Andrea Solo, which I replace every two years while my 4 year old Melos is still ok.
Rosin does change over time, how much depends on the type though.
Although playing a lot my rosin lasts quite long in terms of quantity. I think a lot of people overrosin their bow making the response worse because they build up rosin on the strings within minutes.
My bow hair lasts maybe a year or one and a half, but the rosin is still at 90+% quantitiy at this time usually.

September 27, 2017, 11:30 AM · I have melted and remolded many rosins as a part of my program called "Rosins of Love." The name was inspired partly by "Violins of Hope" and partly by the fact that the mold is a heart-shaped silicone mini-cupcake baker, so you get a very cute heart-shaped rosin out of it. I have not tried putting it into the microwave oven. I melt the rosin in a small foil-lined steel measuring cup over the stove and pour it into the mold. I offer this service for free for locals. Anyone who wants to see my PowerPoint on "Rosins of Love" which has pictures of the process can send a message to me by my regular email address, which is very easy to find since I'm a public employee. (I also have a PowerPoint called "Bow Holds of the Masters".)
September 27, 2017, 11:47 AM · I personally think that rosin changing over time is one of those things where there may be some truth to it, but the truth is diluted in horse crap at a ratio of about 1:10.

Rosin is mostly abietic acid and other carboxylic resin acids, which are chemical compounds having structures (particularly as a mixture) that are not amenable to crystallization. When molten rosin cools, you end up with an amorphous glass. There are other components notably terpenes, which are volatile, and that's probably what you smell when rosin is warmed. It seems likely that the minor components of rosin (possibly including mosture) may play a significant plasticizing role in the physical properties of the bulk substance. Abietic acid contains C=C double bonds which are subject to free-radical-induced coupling and oligomerization over time, eventually leading to the substance we know generally as amber. I rather whether metal or metal-oxide particles have much to do with the behavior of rosin, but if it turned out to be true, I'd be first in line to learn more about that.

September 27, 2017, 11:50 AM · Very intersting Mark. I wasnt know that, maybe because im new. Finally, i have corelli crystal strings. Im using we hill dark rosin. Is it a good idea? I noticed that both strings and bow are a little bit sticky and i am hearing a very quiet rustling sound while playing on g, d and below the 3th finger in a string. Weather where i am is 50-80% humid and temp is between 20 38 celcius.
September 27, 2017, 12:04 PM · Rosin drys out over time. There are volatile substances the evaporate from the block and it becomes harder. I store all my rosins in tins, whether they came with them or not. I change rosins no less every two years. It is cheap enough and you can give the "old" rosins to deserving students.

Cheers Carlo

Edited: September 27, 2017, 12:22 PM · I agree with you Paul. I remembered the organic cemistry after your last post. As you said, rosin is made up mostly from organic compounts (*organic* acids and other things that contain C, O, N, H, S) that are containing carbon atoms and sulphur,O, H, N ... . In a result, we should expect lots of carbon and polymer type bondings. Those kinds of bondings in atomic scale are very weak. They can be broken by long times or any simple solvent or even high heat(burning, smoking).

September 27, 2017, 1:21 PM · If your rosin feels to sticky try a harder one. Its hard to tell from distance, but it sounds like it might help. Make also sure to clean your strings. This may cause brittle sound too.
Edited: September 27, 2017, 8:08 PM · Ata, thanks for the support, but I can't really endorse your description of the organic chemistry of rosin. I would expect very little nitrogen or sulfur content, and I don't agree that "polymer type bondings" are "very weak."

I agree with Carlo on one key point: Rosin is cheap enough that if you think it "goes bad" over time, by all means, buy a new cake and give your old one to someone else. Or send it to me and I'll turn it into a Rosin of Love.

Edited: September 28, 2017, 10:13 AM · I've got two rosin cakes I'll send you Paul. Better than tossing them in file 13. Maybe I'll just combine them and see what happens. I don't know any violin, viola or cello players around here.
September 29, 2017, 9:36 PM · A new rosin cake is never perfectly flat. Over 50 years of playing, I’ve found that it doesn’t matter. I just rotate the cake when I use it, and after a while I end up with a flat surface. I certainly wouldn’t call it a defect.
September 30, 2017, 3:24 AM · So it's just another goal to shoot for, Scott. I think I rosined my violin bow last week, maybe the week before.
September 30, 2017, 11:41 AM · Jim, bring it on.

Bob, that's the great irony of rosin. The people who swear by rosin that's $75 per cake also claim never to use any.

Edited: September 30, 2017, 3:53 PM · If you can smell something, molecules are escaping/evaporating. you can smell rosin, therefore…. I was amused some years ago when the Tartini rosin brand advertised that it had found a centuries old cake of rosin, analyzed it, reproduced the formula(s) and was selling it as TARTINI ROSIN (later sold as ANDREA ROSIN). I wondered how they could know the amount of volatile compounds had been in the original rosin. But I tried and it was a fine rosin that I used for a number of years. (I had previously used the well-reputed Liebenzeller rosins, but I felt they either fatigued or wore off before I was ready to stop a playing session and did not want to re-rosin yet (middle of a movement). I did not have that problem with the Tartini or Andrea brands. I also found that the rosins under the MAGIC brand were very good with a wide range of characteristics. Nor do I have any problem with the $67 Leatherwood that I now use, which by the way I got from the maker at half price.)

A used rosin cake came with the cello I received in 1948; I found it again when I stared a granddaughter on violin lessons in 53 years later, it seemed to work fine. I have documentary reasons to believe that rosin was 19 years old when I first received it.

I now use a rosin that costs $67/cake (not $75). It's good, very good. There are also other brands of rosin that can do the job. It takes a while to find the right rosin for oneself. There are a lot of factors involved, which one learns with experience. The good thing about the search is that it is cheaper than searching for the right strings.

October 15, 2017, 9:00 PM · I made the mistake of making a cross trench in my rosin cake. To save the remaining rosin, I heated the rosin for 20 secs intervals with a hair blow dryer until it became soft enough to press and flatten back into shape. Of course it doesn't look as good as a new cake, but it seems to work just fine. I'm not sure if it would work with a completely cracked cake but just putting this out here just in case someone else has this problem.
October 16, 2017, 6:01 PM · Since I have a stockpile of defective rosins, I just chip them off into a metal mould, cover it in aluminium foil, melt the rosin, pour into a rubber mold if i wanted to.
October 16, 2017, 10:42 PM · Has anyone tried layered rosin? Like dark on one side and light on the other. If you can do it with jello. There must be a way to do it with rosin. I am asking because I have a bunch of both.

This discussion has been archived and is no longer accepting responses.

Facebook Twitter YouTube Instagram Email is made possible by...

Shar Music
Shar Music

Pirastro Strings
Pirastro Strings

Corilon Violins
Corilon Violins

Yamaha YEV Series Violin
Yamaha YEV Series Violin

Dimitri Musafia
Dimitri Musafia, Master Maker of Violin and Viola Cases

Metzler Violin Shop

Bay Fine Strings Violin Shop

Bobelock Cases


Nazareth Gevorkian Violins

Los Angeles Violin Shop

Pluhar Violins

Potter Violins

Pro-Am Strings Ltd

Violin Lab

Violin Pros

Wangbow Violin Bow Workshop