[Boatanchors] Ceramic Sockets

[Arthur Shulman]

All the ceramic product used to make tube sockets that I can think of, are also
wonderful abrasive in their own right. You have just observed the principle in
reverse! You can't clean ceramics safely with a softer material like brass,
unless you take care not to abrade the softer material. Acid can remove the
metallic residue in many cases, but you need and acid that will attack brass
alloy components (tin & copper). I forget whether sulphuric or hydrochloric
acids are really suitable. I would think that dilute nitric acid might be
better.

All these will leave a conductive residue when they have done their work, which
must be removed with multiple changes of distilled water as a soak.

All these must be handled with great care, or not at all if one is inexperienced
with their properties. They are all different in their properties, some of which
are really nasty. Suggest you seek the advice of an experienced friend if you
proceed this way.


There are two more problems:

Some ceramics, once the surface layer is damaged, might be porous, and readily
absorb moisture. Therefore, mechanically exposed new surfaces are at risk, and
must be oven-dried to drive out any traces of moisture from the acid and
distilled water rinses. This caveat does not apply to glazed ceramic where the
glaze has not been penetrated.

Then, if that's not daunting, how do you propose to protect the metallic parts
of the sockets from the acid during the treatment? You might have to carefully
apply it with a brush or plastic applicator.

In the long run, it might be a lot easier to just replace the sockets with new
stock!

Arthur Shulman VE3ZV



Mark Bell wrote:

> Hey Gang --
>
> I had some nasty arcing on the 5R4GY ceramics sockets on the DX-100B I'm
> working on.   Got most of it off with isopropyl alchohol.    One of the
> sockets had it almost ground into the socket, so I used a brass brush on a
> moto tool.
>
> It came off OK, but I found that the surface is now a shiny metal color!
> Don't know much about the chemical makeup of ceramic,  but I expected to see
> buffed white!  I didn't think it could be conductive, but did a continuity
> test on the shiny metal part anyway, and there was no conductance.
>
> Why shiny metal instead of buffed white?   Should I just leave it, or dab
> some white model airplane paint over it?
>
> 73 Mark K3ZX
>
> _______________________________________________
> Boatanchors mailing list
> Boatanchors@mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/boatanchors