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I have quite a number of Edison "Gold Moulded" black 2 minute cylinders that are severely mold-damaged. (Heavy pitting all over the playing surface, and some evidence of previous attempts to clean)

Is there any possible future use for these (shave and re-record?), or should they just be broken and thrown away ?

Some of the original carboard tubes are in decent shape; is there any reasonable way to sterilize them and re-use w/o "infecting" clean cylinders ?

And lastly, I have some cylinders with light, localized mold pitting - will playing these risk damage to the stylus on my Edison C reproducer(original) ?

Thanks for your help !

DS Frank

I have had pretty good luck just playing some of my moldy ones
and in the process it helps clean the mold off.My black wax were
only slightly moldy though. If yours are really rough there
may be a better way that one of the pros can elaborate on.

Sorry to bring the bad news, but any mold damage is irreversible as the fungus eats the wax. That is why proper storage with good ventilation (e.g. open boxes) is essential, because mold spores are practically everywhere and you won't be able to keep them away. The important thing is to keep the conditions so uncomfortable that no spore will grow on your record. And I am pretty sure that there won't be any miracle solutions available in the future.

This is the kind of mold on black wax that you won't be able to really do anything about. The spots will also not go away after cleaning as it is now the part of the wax structure:


Cleaning cylinders is in general a good idea, but always with super extra care. I have described my method very recently here: Cleaning cylinders

Shaving black wax is not good idea unless you have spare shaving knives. These cylinders were never intended to be shaved down and the harder wax will likely ruin the knife of your shaver, plus there are lots of tiny bubbles captured in the wax underneath the grooves. I am very sure that is the actually the reason for the 'needle' holes that we can sometimes see on these records. The harder wax can also damage the stylus of your recorder or at least will wear it much quicker.

The already blunt stylus of an Edison Model C never seem to have problems with pitting, according to my experience. However, the record will receive more wear to the pitting areas when the stylus hits the edges of the pits.

WDC wrote: These cylinders were never intended to be shaved down and the harder wax will likely ruin the knife of your shaver,

I read somewhere recently that 4 minutes blanks were made with recycled 2 minute GM cylinders.
The 4M blanks I have certainly seem to be just as hard (now) as a 2M GM, & some have suffered from the same mold problems too, but whether they originally had something else added to the mix to make them a little softer and they've hardened over the years, I dont know.
Dictaphone & Ediphone cylinders are a little softer though, but then they could be 40 yrs younger than GM's & not has as much time to dry out.
I've had success recording on shaved gold moulded cylinders, but only using a 4 minute recorder. They dont record very well at all with a 2M recorder, even when heated with a lamp.
I have found I've had to be careful shaving 2M cylinders on my dictaphone shaver, and only take the least amount of wax possible off with each pass, otherwise the cutter can appear to have bounced along the surface, leaving the surface with a feathered look, which adds a lot of noise to the hecording.

I have touched on this subject before on moldy records, some can be improved, just read my earlier posts, I don't want to sound like a broken record. I have recycled them in molding experiments, and slightly softened them to make four min recording blanks by adding more chemicals. The holes when you shave them are not air bubbles, it is the shaver tearing the surface, the cutter head is advancing too fast, a four min box shaver, or thowing the belt off slowly feeding the shaving head accross the blank will obviate this. I have used lamp oil, and a cotton cloth to blank them out, this softens the surface for recording too. Disclaimer- recording on moulded wax,and on purpose made four minute orange box blanks can damage cutters and shavers.

edisonphonoworks wrote:I don't want to sound like a broken record.

Or a moldy one

edisonphonoworks wrote:The holes when you shave them are not air bubbles, it is the shaver tearing the surface, the cutter head is advancing too fast, a four min box shaver, or thowing the belt off slowly feeding the shaving head accross the blank will obviate this.

Thanks for the info, I will check this with a shot 2M black wax in the future. But when speaking of 4M wax I have verified lots of tiny bubbles resting under the surface while examining a piece of a broken wax Amberol where I used a sharp knife to slowly shave off a part of the surface. The open bubbles would not have been shiny if it was torn by the knife.

Hi All

I was once told by a collector with many years experience in cylinders, that it is not mold, it is rust. What are the thoughts on this?

Regards Marcel

saxymojo wrote:Hi All

I was once told by a collector with many years experience in cylinders, that it is not mold, it is rust. What are the thoughts on this?

Regards Marcel

I wonder if the collector who told you this was a gardner ?

Brownish patches on plant leaves are commonly referred to as "rust", and are usually the result of a fungal infection...

The usual use of the term around inorganic things refers to the oxidation of ferrous (iron-bearing) metals into ferrous oxide (red / brown rust).

Advanced cases usually result in pitting of the surface, so I can understand the analogy drawn by your mentor....

But given EdisonPhonoWorks explanation above, about microbes eating the animal-based stearate out of the black wax, this is a mold-related issue, and technically not an oxidation ("rust") problem.

In both cases, moisture/ excess humidity is a contributing factor.

Hi Frank

I thought rust sounded odd but anything is possible, do you happen to know the ingredients used to make a black cylinder?

Regards Marcel