Matt wrote:
....
So I just put the old plug back in---that wasn't too hard to do. But I
am afraid of cross-threading the plug and ruining it sometime.

Next time I have the plumber over to do some work I thought I might ask
him to do something about those threads.

Would he have some kind of tool to clean out the threads without much
risk of messing things up?

Sure, but might mention it specifically when you call so he's sure to
have the threading tap w/ him on the truck -- it's likely it's in his
standard kit, but for a routine call threading a fitting would be pretty
unusual so might not carry them all the time.

What you need to do while it's fairly recently been out is take it back
out and use white lead or a non-drying plumber's thread dope on it
liberally.

That will help keep the threads from "growing together" w/ time/ corrosion.

I have several which have the plastic plugs in cast as well and they do
tend to gall. The nice thing is they can always be destructively
removed w/o hurting the cast if it ever does come to that, but by using
a dope or grease liberally you can prevent a goodly amount of the problem.

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