I never used crocus cloth
because it have iron particle that come off
and stick themselves in the contact surface and then can rust.
Never
ever file a contact surface.
Use paper and if needing to
dissolve something on the surface, dip
the paper into alcohol. If the contact needs to be polished,
use the
Jonard burnishing tool. It does not remove any contact surface
like
files, it just moves the surface metal. We used to attach them
to insulated
spudger tools and carried them in our pocket protectors.
I have been in the service
business for 50 years, field and in-shop.
When I worked on a Plan 55 automatic TTY switching center, we
had over 1 million open relay contacts just one of our
centers.
If cleaning & polishing did not work, we replaced the
contact and
its leaf.
73, Joe, K8JP/K5
I've used those before, but when I lose them which happens more often than I would like to admit especially when I was doing field service, I upgraded to using fine emery cloth 220 to 320 grit cloth will give a good polish on your contacts and remove oxides.
What I do is buy a sheet of fine crocus cloth (crocus cloth is made from iron oxide metal particles with a cloth backing).
I fold it in half to mark it, then I take some rubber cement and apply it to the non-abrasive back sides, then I fold them so the backs stick together, and I place a few heavy books on them, and let it dry overnight.
Then I cut them into approximately 3/16 inch strips by three inches long. I have filled a 3 inch by 2 inch plastic storage box full of them - a lifetime supply.
But the fiberglass pen works much better but you have to be able to have an unobstructed access to the contact - so I just take apart the key.
I find the fine crocus cloth works better than the burnishing tool.
73DR
-- Regards, Joe, K8JP/V31JP, Ronnie, Martin & Sidney Pontek 175 Diamond Loch Rd., Apt. 5 Gilmer, TX 75644-9374 U.S.A. 903-204-2318 (My TX cellular) Member FOC-1743 Feb 2001, QCWA-LM21894, OOTC-4607, A1OP, CFO 1055, SKCC-3171T, NAQCC-5798, Flying Pig-2819, FISTS-7625CC951, A1C-2299, SOC 1075, 10-10 22977, PG1915841, CW Rag chewers #21, Facebook: Joe Pontek