Sanders plug suffering the effects of damp.
 

Hi,
I have a box of old UK plugs which have been kept in a plastic storage box in the cellar. Among them is a 'Sanders' 15 amp plug with sleeved pins. Said sleeves have swollen badly due to damp, which makes me wonder what they were made from? Something organic, no doubt, but what?
I also have a Sanders 5 amp plug with red sleeves. These have also swollen, but not as badly as the white ones on the other plug.
All the other plugs are OK, but these have definitely suffered.
Cheers, Pete.

Re: Sanders plug suffering the effects of damp.
 

That's a mess!

Ebonite/Vulcanite maybe?

Or the stuff they made the "forks" for 200-series telephones from which deliquesces?

Re: Sanders plug suffering the effects of damp.
 

Lord knows!. It does look as if a cell has set up between the steel screws and the brass pins, but what made these particular plugs vulnerable..?

Re: Sanders plug suffering the effects of damp.
 

Celluloid?

Re: Sanders plug suffering the effects of damp.
 

That's what I was thinking of!

See this snippet from Andy Emerson's book: https://books.google.co.uk/books?id=...luloid&f=false

Re: Sanders plug suffering the effects of damp.
 

Interesting thanks.
Cheers
John

Re: Sanders plug suffering the effects of damp.
 

Oh i see- if it were celluloid the screws might be under acid attack.
The interaction between PVC and ABS mentioned on the previous page is rather worrying- makes me glad i have a battery isolator on my vehicle.

Re: Sanders plug suffering the effects of damp.
 

I'm surprised to see sleeved pins on plugs of that vintage. I assume the corresponding socket would not have had a shutter back in those days?

In my ignorance I thought sleeves were a relatively recent safety feature.

Re: Sanders plug suffering the effects of damp.
 

The sleeved pins were a rarity, offered as an extra feature by a few manufacturers including Sanders and GEC. They were also used on the Wandsworth proprietary gauge, where the switch was operated by inserting the plug. Shuttered sockets existed and I believe the sockets offered by Sanders concurrent with these plugs were indeed shuttered. Various other safety features were introduced ad-hoc, such as proprietary interlocking systems that usually captured the earth pin while the switch was on, fuses - both cartridge and bare wire in SP and DP configurations, and handshields that kept fingers well away from the pins.

Re: Sanders plug suffering the effects of damp.
 

Celluloid, or perhaps Casein - which was a strange pseudoplastic whose main ingredient was milk!

"Erinoid" - the result of mixing Casein and Formaldehyde - was used in all sorts of stuff in the first half of the 20th century.

Re: Sanders plug suffering the effects of damp.
 

I also don’t remember seeing sleeves on pins way back, but you live and learn.
Cheers
John

Re: Sanders plug suffering the effects of damp.
 

Indeed .....but I don't always remember it:-/

Re: Sanders plug suffering the effects of damp.
 

Hi,
The Sanders plugs had no finger shields, so sleeved pins were a necessity.
I think Crabtree were an early exponent of sleeved pins, among others.
Cheers, Pete.

Re: Sanders plug suffering the effects of damp.
 

I would never put Celluloid near power.
Have you seen how it used to burn?
My mum told me a story about a mate of hers who chucked a broken toy into the coal fire.
It flared up and set the chimney on fire so that big flames came out of the chimney pot.

Re: Sanders plug suffering the effects of damp.
 

I've heard it can burn very easily.

Re: Sanders plug suffering the effects of damp.
 

It does. An early bombing raid (mentioned by Guy Gibson if i remember right) mentioned it's use in incendiaries designed to initiate a forest fire at high summer in axis territory.

Re: Sanders plug suffering the effects of damp.
 

I have a 5A Sanders plug. The insulation had already disappeared from one of the pins by the 1950's, leaving black insulation on the other, still intact today.

I can vouch for the inflammability of celluloid. In the mid-1950's an uncle gave me a roll of 35mm nitrate cine film , odd clips and a couple of wartime ministry of food shorts as I recall. It got packed away with my train set, and having read of how such films can deteriorate and spontaneously ignite, I dug it out. It had reached an advanced state of decomposition, so I put it in the garden incinerator, unreeled a few feet to use as a fuse, and lit it. Once the flame reached the main spool, it sent up in a spectacular sheet of flame. Not the sort of stuff suitable for electrical insulation.

Re: Sanders plug suffering the effects of damp.
 

I was told, though how true it is I'm not sure, that this is why 'modern' film had words like 'Kodak Safety Film' on it, because it wasn't cellulose. I also seem to remember a projectionist at our local cinema, giving us a tour of the facilities (whole other story) and mentioning the risks with the old film.

Re: Sanders plug suffering the effects of damp.
 

'Nitrate' film, used until the early 1950s, 'celluloid', and nitrocellulose a.k.a guncotton are all basically the same material, partially or fully nitrated cellulose with or without plasticisers. The flammability of nitrate film mandated elaborate safety precautions in projection boxes and on projector mechanisms, both to extinguish the fire and to prevent it spreading from the source of ignition (the heat of the lamp on the film in the gate) to the film in the spool boxes. I am not aware of small celluloid components in equipment combusting though.

Re: Sanders plug suffering the effects of damp.
 

It may be an urban myth, but I've heard that an early application of nitrocellulose was in the manufacture of billiard balls, which swiftly ceased following a number of explosions on impact.