Best sealant for installing freeze plugs

[Scott Marzahl]

What would the recommended sealant be when installing freeze plugs in a SBC?

Thanks,
Scott

[Joe L.]

Re: Best sealant for installing freeze plugs

Scott-----

Just "peeking in" again while travelling. I recommend either silicone RTV or a non-hardening sealer like Permatex Aviation.

[Wayne W.]

Re: Best sealant for installing freeze plugs

I never use anything.

[Bernard M.]

Re: Best sealant for installing freeze plugs

Scott, Contrary to the other posts, I use a hardening sealer like Permatex 1A. This is for semi-permanent assembly (their term, not mine). I would particularly recommend it for plugs used in the oil gallery where higher pressures are seen.

[Clem Z.]

i have used permatex part # 80019

aviation form a gasket for all sealing on every engine i ever built, oil gallery plugs,head bolt threads,gaskets and block expansion plugs and never had a problem. JMHO

[Joe C.]

Indian Head Sealer or Permatex *NM*

[John D.]

Re: i have used permatex part # 80019

I use the Permatex Aviation #3 Clem and have been doing so for a long time. I apply it with a q-tip as the brush is too messy.
I really like Loctite #545 hydraulic sealant though for many applications. I use the 545 on the fuel injection fittings and it does a nice job. Great for inlet fittings on carbs and the FI's providing you keep back about 1-1/2 threads so it doesn't wash off and get inside. Love it for vacuum line fittings. Barry Homes, our old friend, told me about the 545 20 years ago. Buy it from Travers tool since it is typically not available in auto stores. Don't know if it's good on freeze plugs because I don't work on the blocks. Have enough problems with FI's. John D.