Blackened pins on NOS valves, any tips?

[Bomber county]

Anyone have any tricks for cleaning up the blackened pins on NOS valves? had a few and they take a worrying amount of effort to push into the rather tight sockets on far Eastern valve stuff. Coca cola or vinegar any good or is it too harsh?

[paulsherwin]

T-Cut, Brasso or something similar will clean off any surface dirt.

[Viscount]

I've used brasso on a cotton bud, seems to work.

[Nymrod121]

Goddards Silver Dip (= non-abrasive):

https://www.amazon.co.uk/GODDARDS-Si.../dp/B005UXU4FS

No connection with the supplier/online distributor, just a very satisfied user (1986: spent a happy couple of days cleaning up klystron cavities at Belmont with this stuff! )

[Andrew2]

I've come to rely on my fibre pen for this kind of thing. It's far better than I imagined, but it may be a bit of a faff for valve pins.

[Bomber county]

Originally Posted by Nymrod121

Goddards Silver Dip (= non-abrasive)

Ahh, wife has some of that somewhere, I shall go and "borrow" it then.

[HamishBoxer]

Fibre glass brush works, the type used on pc boards.

[Maarten]

Fibre glass brushing increases the surface area and therefore the amount and speed of new oxidisation.

[G6Tanuki]

I've used the PCB-cleaning fibreglass brushes, followed up by a suitable high-voltage-rated contact grease to prevent further oxidisation.. Electrolube CG80 seems to work just fine on the STC 5B/25x series of 807-alikes with 500V or so on the anode-pin.

[Bazz4CQJ]

Re Goddards Silver Dip, from their website, "Goddards Silver Dip is easy to use. Just dip, rinse and dry for a brilliant shine. Tarnish will dissolve away to bring out the natural beauty of your silver. Goddards Silver dip should never come in contact with stainless steel (my underlining). That stuff is only intended to be used on silver.

If the pins appear black, then that must be some kind of oxide, so it will only come off with either abrasion or chemical dissolution, but that may leave the pins very vulnerable to further and more rapid oxidation.

What are the valves? I've ever only seen black pins on Acorn valves, which I think used an unusual copper/iron (?) alloy.

B

[Diabolical Artificer]

I cleaned up some valve base pins yesterday with a fibre pen then tinned them with solder, could you do likewise?

Andy.

[John M0GLN]

Originally Posted by Bazz4CQJ

What are the valves? I've ever only seen black pins on Acorn valves, which I think used an unusual copper/iron (?) alloy.
B

I've got an English Electric C178A/5894 ( Mullard equivalent QQV06-40A) with all it's pins blackened, I always assumed it was perhaps some silver oxide, a quick look on the web and unless it's the way they've been photographed quite a few of them also appear black, the one attached is from 'The National Valve Museum', website.

[snowman_al]

Not sure I would go that far Andy?
Tinning them will make them even harder to insert into a 'tight' socket. And not sure there is any benefit?

I assume that Bomber is talking glass button base (B9A / B7G) types as you seldom see octals blackened.

Like others I use the fibre or brass jewellers pen first. I might resort to fine wire wool and Brasso for stubborn cases, but do it out side or well away from the equipment so as not to leave any wire strands near the sockets ...

Alan

[ColinTheAmpMan1]

What about a small chunk of abrasive ink-rubber, suitably sized and with a hole that the pins will go in reasonably tightly? I think I may even have used fine emery-paper in the past, but I cringe a little at the thought now!
Colin.

[vidjoman]

Those of us that are old enough will remember that valve pins back in the day, when new, were an almost black colour. Apart from the gold plated ‘special quality’ they were not shiny silver coloured metal like some of the newer specimens. Nothing with that, it was just the way it was.

[stitch1]

I use fine emery paper, too abrasive?

John

[Goldieoldie]

You could try putting the pins in lemon juice .Keep checking after say 10 mins so not to overdo
I haven't tried this on valves but works really well on battery terminals
Cheers
Pete

[Silicon]

Is there a danger that corrosive liquids could dissolve the metal pins where they pass through the glass envelope an let the vacuum out?

[Sideband]

I use a suede brush....always have done. Suede brush to clean the pins and some contact cleaner sprayed on the pins afterwards (never in the valveholder). Never had any problems.

[joebog1]

On novals and miniature valves I use a square of "Scotchbrite" pot scrubber, with the normal WD40/RP7 sprayed onto it. I push the pins into the scotchbrite and tilt/rotate the valve in the scrubber. I clean up with a clean rag or tissues. Works fine for me.
One does have to be careful with the white or yellow paint used for some valves identification, as the WD spray can dissolve some markings.

Joe