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Mix & Genest Weltruf

Started by countryman, April 11, 2021, 11:03:57 AM

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countryman

I found this phone on eBay classified ads lately. Nothing looking too spectacular, it could easily be mistaken for a German W28 or a TN Maingau of the same period. But it is a Mix & Genest Weltruf.
The name is a pun, it can mean both "worldwide reputation" and "worldwide call", seems appropriate for a phone :-)
It's from 1934 with matching dates on the capacitor, the transmitter and a sticker inside. It was painted red when I found it, not badly done but I elected to strip the paint off. After replacing the cords the phone worked right away, even the transmitter is not "dead".
Mix & Genest (of Berlin) was one of the oldest German phone manufacturers. They went up in ITT from the late 1920ies on, so I assume the Weltruf is already influenced by ITT, although I could not find the exact date and circumstances of it's appearance.
While the design with a pressed metal base and Bakelite upper part is not too spectacular, it has a number of unique features. The dial is special for this early model with it's mechanism and the layout of the fingerwheel. The handset can't be found on other models as well. It uses the old larger sized transmitter capsules from earlier metal handsets and not a receiver capsule like the W28 and many others, but the classic setup.
The Weltruf is not exactly rare in the meaning of sought after, but you don't see them often either. So I could not resist when this one was offered. I'm quite happy with the find.
The lower pics were made during restoration with the red paint partly still on it.

Doug Rose

First thing I noticed was the layout of the dial.....quite cool. Beautiful phone....Doug
Kidphone

dsk

As Doug, I noticed the dial as pretty special, and when I look at the details on the dial it is a design having a construction that became more common 15 years later.
If they had  made it with a longer travel from last pulse to stop it could have been the same as the Germans used on the last W48. 

The circuit with disconnecting the ringer when off hook is good, and  the ringer (with higher resistance than standard) with 2 bells  in each other is also used many years later. The induction coil with only 4 terminals and an ohm-ratio more suitable for an ATA than most other German phones is remarkable.



countryman

#3
The dial is special indeed. It has some similarities with the Merk dial though, which in return is influenced by the AE Mercedes dial.
It has some advantages over the contemporary Siemens types. These use a heavy governor running a slow speed. This one, like the AE, has a fast running, small and lightweight governor. It is remarkably easy to adjust. There is a small sliding element on the governor shaft limiting the effective length of the springs (red circle in picture). On the picture in my original post you can see the tiny set screw. Unlike many other governors this one has a definite calibration device at all.

Edit to add, the number ring puzzles me. Other Weltruf phones I saw have black numbers on a white background. The pattern is reversed here, and looking closely, the numbers look hand painted. But to paint them like that it would take a real artist.

dsk

How easy it could have been if that became a standard.  :)

tubaman

Nice find! I picked one up a couple of years ago (http://www.classicrotaryphones.com/forum/index.php?topic=21968) and it's one of my favourite phones.  The number ring on yours does indeed look hand painted and is rather curious.
Very nice restoration - I assume you needed to repaint the metal parts once the red paint was removed?
:)

countryman

I see it was even Phone of the Month in February 2019 :-)
Yours has a Nickel fingerwheel, I'm envious ;-)
The red paint came off relatively easy with paint stripper and the original black coat underneath wasn't completely ruined, but seemingly wasn't the best already before it was painted over.
I sanded the outer surface and gave it a quick coat with glossy black paint spray. It looks as original as possible now and the inner side still has its patina. To my pleasure the decal on the back side of the Bakelite part survived the stripping process without further damages.

Budavox

Hello countryman, I was looking for 'painted bakelite' and I landed on this post.
I had the same problem as you, my Heemaf 1938 was badly painted using oil paint  :-[
It looks OK from afar but we look closely, it is ugly.

For the metal parts I'm sure I would do the same, i.e. sanded over and black spray paint.
For the bakelite part you used a paint stripper. What kind of paint stripper did you use? Was that the one for plastic? I checked here there are some kinds, like for wood, or metal..
Have you tried using other liquids? Here I have wasbensin (white gas) and paint thinner... are they safe for bakelite?

countryman

#8
Hi Budavox, the name wasbensin must be a remainder from the Dutch colonization as well as the Heemaf phone? Wasbensin is easily understandable in German  :)
Both solvents are safe on Bakelite, even acetone can be tried. The paint stripper available here in Europe is no longer as strong as it used to be, after certain ingredients have been banned for safety and environmental reasons. I used a "Grüneck" brand from a hardware store. It has a citrus smell, so I assume it pretty much the same stuff that has been mentioned as Citristrip by our American friends. It also is safe on Bakelite. But never try all these products on other plastics! And better make a trial on the inside before doing the entire shell.
Mouthpieces and other small parts can be made from "modern" plastic, not Bakelite, even on older phones!
The different types of paint all react in different ways. Simple wall paint may come off even with hot water or paint thinner. Oil paint or lacquer most times takes paint stripper. If you are lucky it peels right off. The most nasty paint I had turned into a gooey sticky mess. But it also came off eventually.
Good luck with your operations! Keep us reported...

HarrySmith

I can't say for sure but it appears bakelite is pretty much bulletproof. I have used all kinds of solvents on it and it is never been harmed at all. Any paint stripper or as mentioned acetone works well. I mostly use Citristrip only because it is mild and can be used indoors. It woks well on most paints or finishes but I have yet to use it on some.
Harry Smith
ATCA 4434
TCI

"There is no try,
there is only
do or do not"

LarryInMichigan

Anything that dissolves phenolic resins will be unkind to bakelite.  One of my favorite cleaning solutions, LA's Totally Awesome Cleaner will damage bakelite if used in a strong concentration.

Larry

FABphones

Quote from: LarryInMichigan on April 29, 2023, 10:42:12 PMAnything that dissolves phenolic resins will be unkind to bakelite...

Could you give detail on what effect it has on Bakelite (and give us some example products)?
A collector of  'Monochrome Phones with Sepia Tones'   ...and a Duck!
***********
Vintage Phones - 10% man made, 90% Tribble
*************

LarryInMichigan

It seems to remove the shiny layer from the bakelite, leaving it dull.  I once unintentionally destroyed a phenolic resin clock gear by trying to clean it with LA's Totally Awesome Cleaner.  It dissolved the teeth off of the gear.  I believe that Bakelite has a similar resin.

Larry

countryman

#13
That reminds me of my first restoration attempts when I used a similar product, a strong household degreaser from a pump spray bottle. It released dark brown material from the Bakelite. I thought it was massive cigarette smoke. But I found the surface very dull after cleaning.
To this day I'm not sure what happened. Maybe it was dirt indeed, maybe the shiny surface had deteriorated already before my cleaning attempt, maybe the cleaner in fact is too aggressive. I resorted to dish soap for normal cleaning, however.
I never noticed similar ill effects from solvents or even paint stripper.
One collector even advised me against using water on Bakelite at all, and to use white gasoline or lacquer thinner instead. But that was the only time I heard it, an individual opinion apparently.

TelePlay

#14
One of the tests used by antique dealers to see if an item is bakelite is to wet a Q-tip or small piece of cotton cloth with original 409 cleaner and rub it on an inconspicuous small area of the item. If bakelite, the cotton will turn a "cigarette smoke residue" yellow.

I suppose using a liberal amount of anything having a similar composition of the chemicals in 409 would remove a thin layer off of the bakelite and soaking the bakelite in the cleaner/solvent may do significant surface damage.

"Bakelite is a cross-linked polymer, which means it has a three-dimensional network structure with covalent bonds between the monomers. This makes it insoluble in most solvents, including toluene, acetone, and methanol."

Bakelite is insoluble in solvents but the combination of chemicals in household or industrial cleaners, created well after the discovery of bakelite, may be causing a chemical reaction breaking down the bakelite into a new soluble material.

While bakelite is insoluble, components that make up bakelite could react with chemicals in a cleaner to change the bakelite into new chemicals or compounds which are soluble.