Garage Storage Organization and Garage Cabinets

**Mr Overkill** · **to coat or not to coat the freeze plugs**

i have always put a TINY amount on the plugs to help out but some people say yay some say nay

so let me hear it

86Tona · 10-03-2006, 11:14 PM

Coat with what? I've always used some Permatex. Not RTV though.

**Mr Overkill** · 10-03-2006, 11:49 PM

something like permatex i know rtv and silcone is a nono cause they can slide out over time correct?

oldgregg · 10-04-2006, 01:00 AM

I never seal them because they wouldn't do their job & pop when the time, if needed, came.

allmotor · 10-04-2006, 08:04 AM

permatex #2 is what I've used in the past, then when dry.. in either case I never had a problem. NEVER use RTV

anonymous_user · 10-04-2006, 11:57 AM

Permatex and I have had them pop (thank gawd) when needed.

Note to self: Always replace water with antifreeze before storing race car for winter

86Tona · 10-04-2006, 02:15 PM

The amount of Permatex used is only a thin film to close any potential gaps that may exist between the outer diameter of the plug and the inner diameter of the hole it goes into. Since I'm in Florida and the likelihood they would ever need to pop out is extreemly rare I use and always have. Because the distance between the inner and outer diameters is so very very small and the Permatex only fills the gaps and because any 'extra' would be squeezed out toward the outside of the block and wiped off there really isn't anything to hold it in place should it need to pop out. Just remember to coat with a thin film on the plug not the hole and any extra is wiped off once it's in place. There would be none inside the coolant jackets.

**Mr Overkill** · 10-04-2006, 04:51 PM

yup tona just wanted to make sure people out there also used this method

thanks

Dodgeboy77 · 10-06-2006, 07:57 PM

I've used a thin coat of silicone gasket sealer many times - never a problem. Bill

Rosco · 10-08-2006, 10:25 PM

I've always used the permatex #2 and I'm old!

Tim_K · 10-17-2006, 07:37 PM

I've done this on about 10 engines, all Chrysler 4, 6, and 8 cylinders, 1970-1989 model years.

Sandpaper the freeze plug hole to make sure it is clean.

Coat back side of freeze plug with a thin layer of RTV.

Pound freeze plug into hole, making sure edge of freeze plug is BELOW the edge of the machined hole surface in the block. I've seen lots of experts install plugs flush with the block surface, and it's no wonder that the plugs pop out! The edge of the plug flange has to be able to bite into the flat metal. If you install it flush with the block surface, that crucial edge isn't grabbing anything, and the taper of the edge surface is already trying to pop the plug out!

Then once the freeze plug is properly installed, I give the front side and especially the edges a good heavy layer of RTV to "glue" (kind of) it in place and seal the metal plug from rust.

Never had a plug come loose or leak on me yet.

Wizard · 10-23-2006, 03:09 PM

Do the smallest freeze plugs exist?

Like 3/8", 1/2" so on.

Cheers, Wizard

1st gearhead · 10-23-2006, 06:08 PM

They're core plugs, not freeze plugs. Their sole purpose is to seal the holes that provide an exit for the casting sand. They are not designed, or intended to provide ANY protection from freezing.

Wizard · 10-25-2006, 07:02 AM

Back to the question do these core plugs in smaller sizes exist?

like 1/2", 3/8" so on? Like plugging oil holes for the DOHC 16 valve conversion.

Cheers, Wizard

1st gearhead · 10-25-2006, 08:17 AM

Quote:

Originally Posted by Wizard

Back to the question do these core plugs in smaller sizes exist?

like 1/2", 3/8" so on?

Cheers, Wizard

Yes.