freeze plugs

I usually use Indian Head gasket sealer, though it is not necessary. I only use the minutest amount, enough to help the plug slip in a bit easier. It is supposed to be for low temp applications but is good up to 350 degrees. Comes in a little brown bottle with brush on applicator. Made by Permatex: Indian Head Gasket Sealant
Again, you do not need it but an old timer I know swears by using a little dab and I have never encountered problems using it.

Make sure that the mating surfaces are clean.

Russ