12 years ago
Got a Hobart 250 amp Beta Mig from Craigs list for 100 bucks. Owner
had two, and didn't know why this one stopped working. Got it home and
it turns out it was just a broken wire on one of the control relays.
Now it seems to work fine, but the tap selector switch is very stiff
to turn, so I opened it up. The switch contacts look fine, but the
inside is coated with some type of grease which has gotten very
stiff. I guess the grease helped lube the switch to prevent corrosion
and keep it free moving. I've cleaned out the old grease and am
thinking of using Silicone spark plug contact grease or some thick Dow
Silicone "O" ring lube that I have. I'm hoping the wiping action of
the contacts will clear the contacts enough to allow good contact.
The old grease dissolved in solvent very quickly, so it don't think
the original grease was silicone based. The contacts are 1/8" thick by
3/4" wide bare copper strips in a housing about 6" diameter. Anyone
try this on switch contacts for low voltage? The Silicone is a bitch
to remove if this does not work..