Craig's List Find: Old Rose 302 3/39

[unbeldi]

Receiver capsule:  2-1-39
Transmitter Capsule:  3/39

There are no date markings on the inside of the brown bakelite handset.

Starting in early '39, instead of a date stamped in ink near the cord entrance, WE started adding a date molded code on the handle. Please look again with the receiver cap removed. It should be a code such as 19 (for 1/39), 29 (for 2/39), 39, etc.

The only numbers I could find on the handset with the receiver cap removed are so small I almost missed it.  It looks like "46" is molded or stamped on the rim.  I also have an ivory painted 302 set with a seamless brown bakelite handset from 1940.  It appears to have "129" stamped or molded on, in larger numbers, although it looks like it may have another number under it, in a smaller size, possibly ending in a 4.  I can't make out the other number.

Yes, this ivory handset was made in Dec. 39.

Indeed, your rose one doesn't have the mark.  So all this confirms is that your handset was made before they started this regiment.
That is worth knowing too.

We don't know yet, what the small numbers mean, "46" in your case.  IIRC, they are always facing inward, while the date stamps are facing outward.

[unbeldi]

I would say that you have one of the finest early, colored 302s that I have seen.

Complete with stainless-steel finger wheel and card frame.

Well worth the price.

[dencins]

The molded in number like the "59" and "46" usually is the cavity number.  Companies use multiple cavities to make the same part and the number is used to identify what cavity produced a specific part.  This is helpful when quality problems are detected.  It can also be used to track how many parts a cavity produced to track "wear" on the tool.

Dennis Hallworth   

[poplar1]

The molded in number like the "59" and "46" usually is the cavity number.  Companies use multiple cavities to make the same part and the number is used to identify what cavity produced a specific part.  This is helpful when quality problems are detected.  It can also be used to track how many parts a cavity produced to track "wear" on the tool.

Dennis Hallworth   

That may be true for the small number. However, the large number always corresponds with the month and year: 59=5/39 for solid core handsets or 5/49 for hollow core handsets.

[unbeldi]

The molded in number like the "59" and "46" usually is the cavity number.  Companies use multiple cavities to make the same part and the number is used to identify what cavity produced a specific part.  This is helpful when quality problems are detected.  It can also be used to track how many parts a cavity produced to track "wear" on the tool.

Dennis Hallworth

That may very well be the case for the small numbers, but not likely the large ones. The large ones that always face outward have been fairly unambiguously linked to the production date, by correlation with telephone sets that had all matching dates for all components. Usually the imprint is the month before the rest of the dates on the phones.  We have speculated that this may indicate that handsets had to be stored for some "setting" time for the polymerization reaction to cure.

Furthermore, the large numbers are not a mold imprint, but were stamped with a tool, as the impression into the plastic is not always uniform, sometimes a portion of the number shape is visibly more or less defined.   In the case of the ivory handset here, that is dated 129, the mark was applied directly on top of the mold mark, as Jim noted in his description, and this is visible in his picture.

[unbeldi]

The small numbers are not always in the same spot either.  One would think that it would be so, if they came from the molding press.  I have not made up my mind whether they are molded in or stamped on, but having them in various places the latter explanation would seem more satisfying.

[JimH]

The small numbers are not always in the same spot either.  One would think that it would be so, if they came from the molding press.  I have not made up my mind whether they are molded in or stamped on, but having them in various places the latter explanation would seem more satisfying.

On very close inspection on the "rose" picture, it appears that the "46" is a "raised" number, that is, higher than the material around it.  This leads me to believe that the "cavity" number is not stamped, but molded in.  Thanks for all the great information guys!  I've learned a lot!

[unbeldi]

The small numbers are not always in the same spot either.  One would think that it would be so, if they came from the molding press.  I have not made up my mind whether they are molded in or stamped on, but having them in various places the latter explanation would seem more satisfying.

On very close inspection on the "rose" picture, it appears that the "46" is a "raised" number, that is, higher than the material around it.  This leads me to believe that the "cavity" number is not stamped, but molded in.  Thanks for all the great information guys!  I've learned a lot!

I had the same impression from your picture, indeed.  However, I have looked at many of these and it usually looks more like pressed in. I think we need higher magnification to make that decision.

[dencins]

Phenolic material is a thermoset plastic and has an extremely brittle surface.  Stamping letters or numbers into it would leave broken edges along the stamped area.  A thermoplastic material can use a heated stamp to leave clean impression since it would melt the surface of the material but you can not melt the surface of a thermoset material.  It is possible to cut numbers into phenolic but you would see the rough edges.  If you want characters in thermoset they need to put done by the mold. 

On page 44 of the 1939 "From the Far Corners of the Earth" shows the molding press making handset handles.  It is a rotary compression press with five open molds showing.  Once material is put in the molds, the press closes and rotates so other molds come around to the operator.  The operator takes out the parts and puts in preheated material.  The molds closes and this process goes on and on.  To make the number of handset handles produced by WECo, it would take hundreds of molds.

A copy of the 1939 "From the Far Corners of the Earth" is here:

http://www.telephonearchive.com/pdf_page/index.html

Dennis Hallworth

[unbeldi]

Phenolic material is a thermoset plastic and has an extremely brittle surface.  Stamping letters or numbers into it would leave broken edges along the stamped area.  A thermoplastic material can use a heated stamp to leave clean impression since it would melt the surface of the material but you can not melt the surface of a thermoset material.  It is possible to cut numbers into phenolic but you would see the rough edges.  If you want characters in thermoset they need to put done by the mold. 

On page 44 of the 1939 "From the Far Corners of the Earth" shows the molding press making handset handles.  It is a rotary compression press with five open molds showing.  Once material is put in the molds, the press closes and rotates so other molds come around to the operator.  The operator takes out the parts and puts in preheated material.  The molds closes and this process goes on and on.  To make the number of handset handles produced by WECo, it would take hundreds of molds.

A copy of the 1939 "From the Far Corners of the Earth" is here:

http://www.telephonearchive.com/pdf_page/index.html

Dennis Hallworth

That's all fine and good, but you can still scratch Bakelite and leave imprints with sharp tools, especially when the material is fresh. It's not like steel, but it is indeed harder than a thermoplast.
It can even be machined. They did that in the fifties to produce F4 handsets.