Corroded faucet stem assembly

[Marilyn & Bob]

I asked this a few weeks ago, but I am trying again for more replies. We have a standard Gerber widespread faucet in a cast iron pedestal sink. The cold water faucet washer has never been changed in the 22 years since it was installed. A lot of corrosion formed in those years. I removed the handle hold down screw with a left-hand twist drill and removed the handle with a handle puller. Now I am trying to unscrew the stem assembly.

I've tried various penetrating oils including Kroil and Aero-Kroil as well as white vinegar. Nothing has budged. I can't apply too much torque as eventually the who fixture will begin to turn. Are there any other suggestions such as muriatic acid or heat (I have one of those cigarette lighter size butane torches) that I could try before I give up call in the plumber to replace the fixture?

[Rick-Meister]

Hold/cold cycles with either a heat gun or small torch with intermittent soakings of HOT vinegar. Also, soak a washcloth in vinegar and wrap it around the stem overnight.

I've never had luck with ordinary penetrating oils. I think they're designed pentrate iron oxide (rust) and not the kind of corrosion that sets up between brass and zinc (or whatever the cast materials are made of).

[Oren]

So try tightening the fastener a 1/8 or 1/4 turn tight, soak it again. Doing that will help in the reverse. I've had to tighten a bolt to break it loose. Soaked and removed.

Break the corrosion and the oil will get there.

DO not use" muriatic acid" on metal.

[Marilyn & Bob]

Thank you, thank you about the muriatic acid. I have tried the tightening trick with no success. I will try dpb's suggestions tomorrow.

[Marilyn & Bob]

OOPS, that's Rick-Meister's suggestions, not dpb.