[David G4EBT]

I was given a tip on cleaning valve pins many years ago by a TV engineer who doubled as a night-school lecturer on a course I attneded, when valve TV's were still much in evidence. I use it to this day.

Take a block of hardwood, say 50mm cube, and drill a hole in it with a slickbit ("flatbit") say 25mm diam to a depth of about 25mm.

Then take a piece of Plasticine, and nead into it iron filings so that the Plasticine is thoroughly impregnated with the filings. Then fill the hole in the bock with the mixture.

All you have to do to clean the pins is to plunge them in and out of the plasticine a few times, and the pins come up shiny, and as good as new.

It really does work, and the plasticine seems to last for ages.

I just use a piece of scrap cast iron (rather than mild steel), grind it away on an electirc grindstone till I have enough filings, then collect them up with a magnet.

If there is some carborundum mixed in from the grindstone, so much the better.

Hope that helps!
David Taylor.