What year did Radio companies start to switch from Bakelite?

fifties · **Posted:** Jul Wed 04, 2012 10:02 pm

mcpherjc wrote:

I asked the inital question because I see many radio's listed for sale that I am fairly sure are plastic (modern day plastic like that used in childrens toys) say bakelite and also some that I am fairly sure are Bakelite say that they are plastic. Often these same radios will list a year that they were made so I was curious if the date could be a better guide to determining which one they are.

As was pointed out, the transition didn't just occur overnight, but over a period of years.

Most of the Bakelite cabinets I've seen are either painted over -usually in off-white- or naturally Chocolate in color, other than Catalan sets, so that's one assist in determining.

Another is touching the inside of the cabinet with a soldering iron, to see if it causes a distortion; in Bakelite it won't, plastic it will (hence my previous suggestion about newer miniature tubes not requiring a Bakelite cabinet, but able to reside in a plastic one with no effects to it.

The white craze seen on the left top of many Bakelite radios was caused by the intense heat emitted by the GT audio output tube...No such problem existed with it's junior replacement). Nor have I seen metal or Asbestos heat shields in miniature tube circuits, as were used in some of the GT chassis.

dberman51 · **Posted:** Jul Wed 04, 2012 10:14 pm

fifties wrote:

The white craze seen on the left top of many Bakelite radios was caused by the intense heat emitted by the GT audio output tube...No such problem existed with it's junior replacement). Nor have I seen metal or Asbestos heat shields in miniature tube circuits, as were used in some of the GT chassis.

Please stop repeating this misinformation. Two people have already informed you that it is incorrect. Tube heat dissipation in AA5 sets is exactly the same whether the set uses the octal 12SA7, 12SK7, 12SQ7, 50L6, 35Z5 line-up or the miniature 12BE6, 12BA6, 12AV6, 50C5, 35W4 line-up. If you don't believe us, please just check the RCA tube manual for heater ratings and cathode current in typical operation. You will note that they are equal.

-David

fifties · **Posted:** Jul Wed 04, 2012 10:47 pm

dberman51 wrote:

fifties wrote:

The white craze seen on the left top of many Bakelite radios was caused by the intense heat emitted by the GT audio output tube...No such problem existed with it's junior replacement). Nor have I seen metal or Asbestos heat shields in miniature tube circuits, as were used in some of the GT chassis.

Please stop repeating this misinformation. Two people have already informed you that it is incorrect. Tube heat dissipation in AA5 sets is exactly the same whether the set uses the octal 12SA7, 12SK7, 12SQ7, 50L6, 35Z5 line-up or the miniature 12BE6, 12BA6, 12AV6, 50C5, 35W4 line-up. If you don't believe us, please just check the RCA tube manual for heater ratings and cathode current in typical operation. You will note that they are equal.

-David

You seem to have ignored,

Quote:

Nor have I seen metal or Asbestos heat shields in miniature tube circuits, as were used in some of the GT chassis

and I would be interested in your explanation on the cause of white haze on the top left side of some GT tube sets.

Your information will be appreciated.

oldradioparts · **Posted:** Jul Thu 05, 2012 1:23 am

Dave, you have indeed educated us all here... Celluloid seems to be the real "first plastic" and I will never say Bakelite was again !
Whats amazing is how the explosion of plastics seemed to happen during WW2.

Mark Oppat
www.oldradioparts.net

ggregg · **Posted:** Jul Thu 05, 2012 2:19 am

One tip not discussed yet is cleaning.

Bakelite can handle just about anything but plastics can be very sensitive to strong cleaners, or products that can be used as cleaners. Don't ask me how I know....... :oops:

mcpherjc · **Posted:** Jul Thu 05, 2012 4:58 am

Personally I think the Bakelite is superior to modern plastic because other than being a little on the brittle side it seems much more durable.

oldradioparts · **Posted:** Jul Thu 05, 2012 6:02 am

Bakelite is VERY durable. You can use paint strippers on it. It doesnt shrink or warp. Some of it seems to oxidize on the surface and loose its "finish" which I am not sure you can ever really get back.

However, it was a bit toxic to make... so the workers suffered. By the mid 50's the other plastics had taken over.

Mark Oppat
www.oldradioparts.net

mcpherjc · **Posted:** Jul Thu 05, 2012 6:09 am

Since it was mentioned. When you get the Bakelites with that white haze on it, you see this a lot with the dark brown ones, is there anything that can get that off without damaging the bakelite?

Robert Lozier · **Posted:** Jul Thu 05, 2012 12:31 pm

The white haze you see on dark Bakelite is most likely the exposed filler. The Bakelite is not 100% resin, a filler and pigments make up a significant percentage. A popular filler was finely ground walnut shells.

What has happened is that the resin at the surface has been dissolved or worn away... The most common mistake made by folks wanting to clean up Bakelite cabinets is using caustic cleaners like Fantastic, Super Clean, Purple Stuff, etc. You know that you are using such cleaners when a white cloth turns yellow/brown.... That is the resin going into solution.

The cure then is stain and lacquer or just lacquer paint... Only clean Bakelite with regular Goop or Go-Jo.

Robert

mcpherjc · **Posted:** Jul Thu 05, 2012 2:40 pm

When you say stain do you a same type of stain that you would use on wood? Thanks.

Robert Lozier · **Posted:** Jul Thu 05, 2012 4:46 pm

I have used black or walnut analine dye stain and and a thin overcoat of clear lacquer. If I don't like the results, I move to black lacquer OR just live with the haze..

Robert

codefox · **Joined:** Nov Sat 27, 2010 6:15 pm **Posts:** 3601

When supplies dried up and cheaper alternatives became available. Late 40's early 50's.

What year did Radio companies start to switch from Bakelite?

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