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Interesting! That´s a comparatively small machine. Thanks about this pic!

The smaller metal part is a stamper probably from the 40s I have, it is nickel faced and copper backed and .046" thick 1502-A is the matrix number, it is a language I am not sure of, sound Russian maybe. The other is a modern metal master (not stamper) for a 12" 45 dance club record, and it is .034" thick in contrast, but is silver faces, nickel backed.

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It looks like, while pressure certainly is important the steam temperature, and pressure are paramount. The 78 biscuit or puck is usually square,as they were rolled out of the mixing mill and into other rollers.

Odeon wrote:

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The press seems to be made by a Francis Shaw & Co., I can't quite make-out the location, but think it might be "Manchester" ?

At any rate, the press seems as though it might be English.


Thanks for sharing this photo.

Good eyes

edisonphonoworks wrote:It looks like, while pressure certainly is important the steam temperature, and pressure are paramount. The 78 biscuit or puck is usually square,as they were rolled out of the mixing mill and into other rollers.

Back in the days before WW II, most maunfacturing plants used steam for a variety of applications because it was readily available: mechanized operations were run by line-shafts and belts, driven by a stationary steam engine(s), the plant was heated by steam radiators (if at all), so there were already boilers and piping available.

Steam would have been convenient and comparatively cheap as a motive power / heating / "hydraulic" source.


If we were trying to set-up a press today, particularly a small operation, the heating would probably be achieved through electric heating elements ( at least for things like the biscuit tables ), and the pressing pressure via hyrdaulic pumps run by electric motor. If the record press is of a nature where it needs to be heated quickly, then perhaps a burst or "flash" of steam would still work best, although if any part of the steam system were allowed to cool below 212* F. the steam would condense in the system, and form pools or "slugs" of water, which could interfere with heat-transfer on the next heating cycle.

My bet would be that when they were doing a run of pressings, they would get the presses hot, blowing-out any condensation, then keep them hot until the run was finished.

While steam can nominally be thought of as having a temperature of 212* F, depending on the pressure on the system, the temperature can actually be above or below the boiling point of water in an open vessel.

For each pound of pressure increase above atmosphere at sea level (14 psi), the boiling point is raised approx 2* F.... so, for instance, our household pressure cooker at 15 psi, will reach an internal temperature of approximately 242* F.

In a high-pressure system, such as a steam locomotive, operating at boiler pressures in excess of 100 psi, the temperature rises accordingly.


I would think there was a sweet temperature for the shellac compound where it was plastic enough to take the impression from the stomper, yet still hold its shape when the press was opened.

Does anyone know if the stompers were treated with any sort of "releasing agent" ? ( I've certainly destroyed enough waffles trying to pry them out of the plates of the iron when they stick... )

Does anyone know if the stompers were treated with any sort of "releasing agent" ?

According to some old German articles, the (hot) stamper had been wiped of with a cloth soaked in oil.

I would think that the steam in the record press would be at a lower pressure than the boiler and, therefore, would be throttled to that lower pressure to form dry super heated steam. It would be easy to, there by, adjust the process temperature to a relatively constant value, that constant temperature could be adjustable based on the extent of throttling, and by bleeding super-heated steam through the press condensate (water) could be eliminated. The other reason for doing this is that wet steam at high speeds can erode the components it is in contact with. The greater the degree of throttling (lower process pressure) the higher the temperature of the super heated steam. Throttling is the expansion of steam with out doing work i.e. a constant enthalpy process.
I think we need some one like Jay Leno with not only the steam generating equipment but the deep pockets to pull off a project like this.
Best regards,
Allen