Freeze plug-silicone or no silicone?

[GBowman]

So after my rad cap issue ie,..too much pressure in system, I developed a slight weeping from the pass side freeze plug. It still leaks a tiny bit, I am planning to replace it. Do I use silicone or just put it in dry?

thx all

[frdfver]

I like to use permatex form a gasket #2. Thin bead around the circumfrence and pound it in, wipe excess off....

[Dwight]

my engine builder uses silicone and applies a thin coat on the back of the steel freeze plugs. He claims it buys time on the rust.



Dwight

[Karl Bebout]

"my engine builder uses silicone and applies a thin coat on the back of the steel freeze plugs. He claims it buys time on the rust"

Why would someone use steel freeze plugs when brass plugs are not that much more expensive?

To the original question: #2 Ptex was the recommended sealer, for decades, but I'm partial to RTV. Much easier clean up, if nothing else.

[jwd]

Originally Posted by frdfver

I like to use permatex form a gasket #2. Thin bead around the circumfrence and pound it in, wipe excess off....

Yup. RTV and anti-freeze don't mix.

[redmt]

Aviation Permatex and brass freeze plugs. Punch them in with an installer or a socket if you don't have an installer set.

[Gaz64]

Originally Posted by redmt

Aviation Permatex and brass freeze plugs. Punch them in with an installer or a socket if you don't have an installer set.

Yes and yes.

The best way.

[Bill Bess]

Here is what I do, if a freeze plug leaks a little bit and the plug is good just dump a tube of Alumiseal into the old radiator and don't over pressure the system with a high pressure cap.
When my motor was brand new I put a very high pressure cap on it to help with the cooling, result one of the freeze plugs started leaking. Went to a 10# cap and alumiseal...stopped it, that was five years ago..no leaks now.
I carry n extra in my tool bag..just in case.

[blykins]

I use both brass and steel freeze plugs. A little bit of black RTV around the outside edge, then knock them in. I have never had a freeze plug leak.

[redmt]

The problem with ATV is that the residual from inside the plug can come loose and end up who knows where in the cooling system. I've never found a practical use for ATV anywhere in an engine. Too many down sides.

[blykins]

What's ATV?

[redmt]

Originally Posted by blykins

What's ATV?

All Terrain Vehicle. I meant RTV 'cause I always misspell silcone

[blykins]

Oh, I thought you were referring to aviation silicone or something.

I can honestly say that with the engines that I've torn down and freshened up, I've never found any RTV anywhere in them, or in the filter after a dyno run. I use it pretty sparingly though, not in big globs, but in thin coats. I use it on freeze plugs, oil pan end gaskets, around water jackets on heads/intakes, etc.

I also like using "The Right Stuff" to make up intake manifold end gaskets. That's about the only place I use it though as if you use it on oil pans, you about destroy the pan trying to get it back off....

[redmt]

When I first started building engines in the late 60's and 70's I don't remember having silicone to use (fuzzy memory). When it became popular, you'd find it in radiators, pick up screens and filters. There would be blue strings of snot everywhere.

Cat has two products I swear by. There is a non hardening and a hardening that I use exclusively along with aviation Permatex sparingly. I think if you tried them , you'd throw away any tubes of RTV/silicone you have left. If you don't have a Cat dealer nearby, I'd be happy to send you a tube of each.

[blykins]

I appreciate it John, but it's one of those things that after you've used something for so long with no issues, it's hard to change to something else.

I think the reason you found so much of it in radiators, pickups, etc., is because guys tend to just squirt out big blobs. My application of RTV is almost like a layer of paint....very thin.

The Right Stuff is probably a form of the stuff that Cat uses. I have heard that before. I use it on intake manifolds and you can pull all the bolts out, hook an engine hoist to the intake and pick the engine up off the ground. It also hardens very quickly so you can light an engine off pretty soon after you button it up.

[redmt]

Right Stuff may be similar to the hardening Cat sealer. I use it on the ham covers of bulldozer final drives. It's near impossible to remove even with jacking screws and heat, but they don't leak!

[blykins]

An't that the truth....it's like you welded the whole engine together....hahaha

[redmt]

I think we 'jacked his thread,,,,,,,,,,,,,,,

[blykins]

Ah yes.....sorry Gary.

[Cashburn]

Ford Racing Boss 351 Blocks have screw in freeze plugs...