Edison Recorder Question

[wpiet]

Hello all. My name is Bill Piet and I am new to the board. I have inherited an Edison Standard B in working condition and am getting ready to do some needed restoration (mostly to the case).

My question concerning the Recorder - it is in the original box and in great condition, but the recording stylus has become detached from the mica diaphragm. Could someone inform me what the best adhesive would be to use to reattach the stylus (shellac being used originally). I would one day like to try to use it - the sapphire cutter is in perfect shape.

I have enjoyed reading the board and have already learned a lot!

Thanks in advance for your time.

Respectfully,

Bill Piet

[crankyamberol]

I have found that using regular super glue attaches the cutter to the diaphragm pretty well.

[matty]

I've used superglue with success too, but it can also be a problem unless you see exactly where the stylus mount was originally attached to the diaphragm.
If the stylus isn't aligned dead centre, you'll find the stylus will cut on a slight angle, which causes the recording to play back with an echo. This means if you have to re-align the stylus mount, you'll have to apply acetone/fingernail polish remover to soften & remove the superglue before re-alignment.
I mix my own shellac using orange flake shellac, and I've found it a lot less troublesome to put a single shellac flake between the mount & diaphragm, and heat it with the tip of a soldering iron for a few seconds. This melts the shellac & acts as an adhesive, which hardens after about 30 seconds. If you find the stylus is slightly out of alignment, then it's simply a matter of heating the mount again, and adjusting the stylus mount, without the need to remove the shellac & starting from scratch.
If your recorder has a glass diaphragm, it's best to use as little heat as neseccary to melt the shellac so the chance of the glass fracturing is greatly reduced, but it's not so important with a mica diaphragm as they can take a lot of heat for a long period.
If you do use superglue on a mica diaphragm & have to move the mount, make sure you give the solvent plenty of time to soften the glue, because if you try moving the mount while it's still attached in the slightest, it will delaminate the layers of mica or at worst, tear a hole in the diaphragm.

[wpiet]

Thank you both for your replies. It will be easy to align the mount as there is a perfect outline on the diaphragm. I like the idea of the flake shellac - but now I am not sure if the diaphragm is truly mica or is glass. The diaphragm is perfectly clear - does this indicate it to be made of glass or is the mica clear also?

Thanks again for your help - it is very much appreciated

[chuckrr]

Every one of those Edison home recorders I have ever seen or
worked on all have a mica diaphragm that is .002" (two thousandths
of an inch) thick.

On my two earliest rebuilds of those done in the late 1970s and early
1980s, I used superglue to fasten the copper stylus holder to the
mica, and also to hold the sapphire cutter to the copper.

Then, to re-seal the diaphragm to the edge of the weight, I used
contact cement. The combination of contact cement and superglue
works, and both of those recorders are still working great.

However, in recent times (2009-2010), I got a few more of those
recorders and rebuilt them. Now I use beeswax to seal/mount
the diaphragm to the rim of the weight.

I use melted shellac (heated in alcohol flame) to fasten the
cutter to the copper holder. I use stratena (made by Peter Wall
and sold on ebay) to fasten the holder to the diaphragm.

On one recorder I used beeswax to fasten the holder to the
diapgragm.

By using the stratena, beeswax, and shellac, the result is not
nearly as "one-way permanent" as it is when using the contact
cement and superglue.

It will be awefully tough to ever disassemble and rework those
first two I rebuilt using those adhesives!!

Where as when using the older adhesives, they are all easily
removable. Stratena dissolves in water. Beeswax melts or
peels easily away. Shellac melts with some heat or dissolves
away in alcohol.

I would therefore highly recommend those adhesives instead
of the "quick fix" of superglue. Not that superglue doesn't
work, but just that 40 years in the future, it might not come
apart so easily... ;D

[edisonphonoworks]

I agree Stratina is what they used in the old days, and works.