Rosin repair

November 21, 2019, 5:08 AM · This is a Deja problem, but could apply to others.

In an effort to deal with the awkward packaging of the Deja rosin, I removed it from its cloth and glued it to the lid of the can. So far, so good. Fabulous rosin, BTW.

Now, I find that it has broken off the lid, leaving some of itself behind. So it is more or less unusable, if I want to keep clean hands. And re-gluing it is not the best option, as it didn't come off 100%.

Has anyone dealt with this, and found an elegant solution? I have access to an oven and tin foil, but am trying to figure out what is most possible given the constraints of this particular piece of equipment.

Replies (13)

November 21, 2019, 6:09 AM · Yeah, scrape it off, melt the cake down, remold it, and then attach it to a small square of microfiber cloth (like the kind that you clean your glasses with) or chamois. The latter can be accomplished with a touch of the iron from underneath. The ideal mold is a simple round silicone mini-cupcake mold. The rosin will melt easily on your lowest stove (smoothtop) setting or in a 250 F oven (watch it and take it out as soon as it's melted).
Edited: November 21, 2019, 7:19 AM · I was thinking of putting it into a tinfoil cylinder, shaping that by putting it into the rosin can. Finding a mini-cupcake tray is not going to be absurdly easy.

I still have ambitions of glueing the new cake back to the lid. Baker's does that, iirc, and it is much better than having to coax a cloth wrapping out of the can without having it all tumble to the floor.

Edited: November 21, 2019, 7:35 AM · I usually use aluminum foil shaped on another rosin cake or a bottle cap of appropriate size, fill it with the rosin pieces and heat it for as short a time as necessary in a toaster oven at 200°F or less. The foil peals right off when it has cooled.

I also keep a few old wine corks around so I can cut a thin slice as a shock absorber between the lid and the rosin.

November 21, 2019, 10:35 AM · Be careful heating rosin, don't do it inside. Stay away from the fumes as well.
November 21, 2019, 10:42 AM · Don't glue it to the lid - just heat it lightly on the surface. The stickyness of the rosin should be enough to hold it.
November 21, 2019, 11:17 AM · Should be, but I've had that fail more than superglue.
Edited: November 21, 2019, 12:16 PM · I dropped a light rosin cake* some years ago and it split fairly cleanly into two similar pieces. I "glued" them together with superglue and it's still going strong. Admittedly, this may not be an appropriate solution to Stephen's specific problem, but I think it's worth bearing in mind generally.

* with one exception, my current rosin cakes date from the 20th century.

November 21, 2019, 6:27 PM · I once re-moulded a cake of rosin that broke in a toaster oven on the re-heat setting in an aluminum foil mold, removing it as soon as it fused as I wanted. It darkened it a little, but seemed otherwise the same.
November 21, 2019, 8:02 PM · I had rosin to melt and mold and found a piece of clean PVC pipe. Cut it in half. Sanded the bottom inside surface a bit to make the rosin hold better. Sealed up both ends with aluminum foil to form a small boat. It's longer than a rosin cake is, so in a sense it's easier and faster to rosin, and I don't have to worry about touching the rosin. Ever. And it's well protected on that one U-shaped side.
Edited: November 21, 2019, 11:36 PM · Tim, that sounds like a nice idea. And for those looking for something "nicer", this can easily be done with a pice of wood as well. Now I know with the broken rosin cakes I regularly collect from my son's case!
November 21, 2019, 11:41 PM · Stephen, the silicone mini cupcake molds I found in the Ama-zone are mostly "shaped" (like cupcakes, bunnies and whatnot). You might as well use a silicone mold for ice cubes. That way you get two or three small cakes out of one broken large one. And usually they will come without any sharp edges.
Edited: November 22, 2019, 4:17 AM · Yes, ice trays could work, and are pretty well available. Of course, skimming through Amazon these days will produce any sort of gadget.

Thanks to all for tips. Hadn't thought of the cork on the lid. That makes a lot of sense.

One thing that occurs to me is that 200 is below the boiling point of water. Suggests the possibility of another source of heat.

Edited: November 22, 2019, 7:21 AM ·


I have one that has heart-shaped wells. It's very cute. I call my rescued rosins "Rosins of Love," a vague reference to "Violins of Hope."

200 F probably not hot enough although some rosins may melt in this range. Rosin is mostly abietic acid but the melting point will depend greatly on the identity and concentration of other substances. The reason the toaster oven works is probably because it overshoots a little.

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