MTFCA Forum

I love Permatex number 2!
However.
It does slowly dissolve in/with alcohol!
And since many antifreeze products contain alcohol?

Both cooling and fuel systems these days contain some alcohol. So some care must be used when using in both those areas. For cooling systems, if used between steel/iron necks or tubes and the connecting hoses? Or blocks and covers? There should be such little exposure to the alcohol that the Permatex 2 should do the job just fine. The Permatex sandwiched between the metal and rubber hose or gasket will minimize the exposure.
The same is true in fuel fittings. As long as the Permatex is placed secondarily, largely protected by the primary fittings, threads, and other connections? It should work fine. I find I am much more careful placing Permatex in fuel lines ever since alcohol was added.
The problem with Welch/freeze type plugs is that the primary mechanical connection is tenuous at best. We begin to rely on the Permatex to guarantee sealing, when that is exactly what it cannot do under those conditions.

I agree that some spare freeze plugs along is a good idea. If you don't have one when you need it, you can take a socket wrench, a ball peen hammer, and a nickle and curve the coin to fit. Then use it for a plug. I personally use the brass ones. They seem to last longer than the steel ones. Not sure what kind I have in the car. They were painted when the engine was painted.
Anyway, what I think happened is that they had been seeping for a long time, but before every tour, I check the coolant and look for leaks. The usual places for leaks are the radiator, the hoses and if you have a water pump, the pump. Since the seeping has been slow, it is not noticed because they are behind the manifolds or need to bend down to look toward them. And when parked there are oil drips and maybe a few drops gas from carburetor, in that area, the water drops are not noticed. So on this tour which was about 150 miles up and down mountains, and stop for lunch. I should have checked the coolant at least after stopping for lunch, but I didn't and when it started getting hot, I was almost home so I thought I could make it home. The pressure of steam got so high it blew the weakest point in the head gasket. Naturally, that was the only place I noticed, because it is very close to the rear freeze plug, but after placing the new gasket, I checked that area and saw the leak. The front one had been seeping earlier, and I smeared some ultra black on the outside of it. Anyway, today I have the day off, need to take Dolores to the doctor. Just a checkup, not any problem unless they find one today.
Norm

While the brass should be soft enough to conform to the hole, years of corrosion doesn't leave a good surface to work with. What I have found is, most of the recesses are gunked up with rust etc. so can't get a good seal. They need to be scrapped out good, down to bare metal. Even after cleaning, I have yet to have a welch plug just go in the hole without rework.

So don't forget a file.

Maybe modern antifreeze has alcohol in it, don't know, I use stuff made for older cars so Permatex No 2 works for me.

I don't know if it was due to years of antifreeze or hot water, but old #2 definitely failed in that application for me.

Choosing among plugs is pretty easy. Steel will rust out, of course, while brass will not. But I think the nickel Norm suggested will last even better than brass. It's also cheaper, if that matters. It's what I use.

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