Leaking at radiator connection (single pipe): what type of dope?

will_4

I just bought a house with single-pipe steam heat, to do
all the floors (hardwood) I disconnected all the radiators and when I hooked them back up, I used regular blue pipe dope on the pipe connection. After several cycles of heating (we hit about 45 degrees in MA yesterday) I noticed minor leaking (the most was probably 1/4 cup) in three of the 11 connections and was wondering if I should
1) not worry about it guessing that the rust/silt would eventually block the leak, 2) re-seal or 3) do something else (not sure if there is another solution (i.e. gasket)).

Also wondering, aside from having the furnace tuned-up, if there was something else I should do to the system (i.e. clean it out?).

Any help would be greatly appreciated.

thanks
Will
willr@edocs.com

Mike T., Swampeast MO

Are you talking about the UNION connections? If so, these are supposed to seal solely by metal-to-metal contact with no dope/tape required.

But after many decades, I suppose anything can happen...

Again, if the union connections, I'd suggest disassembly and careful cleaning of the mating surfaces. A soft copper brush and coarse, dry, CLEAN rag would be good. Try to avoid any cleaning solutions in a steam system unless you really want to skim the boiler...

Tighten the union firmly but not too tight--they can be destroyed if you tighten too greatly. If it still leaks, tighten a bit and see if the leak stops. If not, I'd try some Teflon tape on the union threads--quite a few turns.

If all of this fails, the union is likely damaged and will have to be replaced. It's been my experience that very slightly leaking unions tend to leak worse over time, while very slightly leaking pipe threads tend to seal themselves.

Matt Undy

It is most likely some sort of misalignment of the connection. Make sure it fits together square before you slide the nut over the connection. You could try gasket maker type silicone or teflon tape on the ground mating surfaces (not the threads) if careful alignment doesn't work. Make sure the pressuretrol/vaporstat on the boiler is set very low (under a pound or less). Given the very low pressure I would guess either the parts weren't aligned right or the mating surfaces of the union have rusted.

Matt

bob young

permatex --the final solution

when all else fails---try permatex. if that don't work ,then it is replacement time.

Weezbo

I personally agree with Bob:)