Leaking radiators with painted connection threads

bwroga

Almost all of the radiators in my house leak a little bit where they are attached to the open/close valves. And these connections, including the threads have been painted many times. I tried tightening the connections but was unable to, I assume because of the paint. Are there any ways to stop them from leaking without stripping the paint from the threads? Would replacing the spuds/valves be an option, or would the paint need to be stripped for that too? I have a young son and am concerned about lead. For now, I have put little yogurt cups under the connections to catch the drips.

mattmia2

Can you show us a picture of exactly what part is leaking? The amount of force needed to tighten fittings that size will easily move the paint out of the way.

EBEBRATT-Ed

If you can't tighten them, take them apart and clean them up and re assemble with "never seize".

what steam pressure are you running?

bwroga

@mattmia2 Here's a photo. Water is dripping off where the arrow is pointing.

bwroga

@EBEBRATT-Ed It runs at 1/2 psi.

If I took them apart, would I need to move the radiator? I'm not sure if I would be able to.

ChrisJ

Curious,
Can you show us a picture of the wrench you tried using on it?

Jamie Hall

That's a union. Tightening a leaking union without taking it apart almost never works -- and risks cracking the clamp nut.

Therefore. Take it apart. Use a correctly fitting open end wrench or a crescent wrench to do it -- not a pipe wrench. You may have to rock the clamp nut both ways a little to break the paint seal, but that's it. Once you get it apart, you may have to move the radiator slightly to the left to get at and clean both mating faces. Then slide it back together. The two pieces must be in line with each other, and neither angled nor offset. A very very thin layer of never seize or something like that on the mating surfaces may help. Then tighten the clamp nut finger tight, and then no more than half a turn with a wrench, if that.

bwroga

This is what I was using
I won't use it anymore!

pecmsg

They make Smooth Jaw wrenches.

That is too small to move against all that paint.

PC7060

What @Jamie Hall said. You’ll have to drain down the system first. 

bwroga

Thanks everyone. I'm going to ask our heating guy to do this for me. I think it's a little beyond my capabilities.

WMno57

For the OP or anyone else that wants to DIY this. You can buy a 24 inch Crescent style adjustable wrench at Harbor Freight for under $40. Not as good as my vintage Diamalloy adjustable, but close enough.

PC7060

Ask this old house has a couple YouTube posts which walk you through the process as well.

This one has be edited down and skips the part that show to use the wrench to turn the old valve slightly so you can slide the radiator end forward to get room to replace the valve. Otherwise it’s pretty complete. 

 https://youtu.be/_44vzZvmFLM

ChrisJ

I wouldn't use the wrench like he did to remove the old one.   


And pipe dope on the face of the union!  Come on.... Really?

BenDplumber

I appreciate the OP knowing his limitations and calling a pro in before it gets to that Oh **** moment. Knowing when and where to proceed with a task that one is not comfortable with is saving themselves time, money and frustration. Just like any professional, having the proper tooling and access to trade specific parts turns a 3 hour homeowner job into something manageable for field personnel

pedmec

Yes, we use pipe dope on the face of every mating surface. All the old timers did it where I work and that's how i was taught. Works every time and there is absolutely nothing wrong with it. Whats wrong with using pipe dope? The threads are not the seal on a union type valve. Its the mating surfaces that create the seal.

bwroga

One of the This Old House videos is where I got the idea to use the pipe wrench

WMno57

Pipe wrenches are for round soft steel pipe and fittings.
Crescent pattern wrenches are for hex and square nuts.
Using a pipe wrench on a large hardened steel nut (trailer ball) will break the teeth on the wrench.
Using a pipe wrench on brass will chew up the brass.

Jamie Hall

bwroga said:

One of the This Old House videos is where I got the idea to use the pipe wrench

Some of those videos are actually pretty good. Some aren't helpful. Some are just wrong. That one was one of the latter.

ChrisJ

@Jamie Hall

I've been trying to post why not to use pipe dope on a union sealing surfaces and gave up

Jamie Hall

ChrisJ said:

@Jamie Hall

I've been trying to post why not to use pipe dope on a union sealing surfaces and gave up

Aren't computers fun? Main reason I can think of is that you shouldn't need it at all. What's your take? On the other hand, if it's a very light coat and not lumpy, it won't do any harm.

JUGHNE

FWIW, what has worked for me for years has been "LaCo" "Slicktite". (pipe dope)

Very thin teflon paste. Seems almost too thin for regular pipe threads.

Especially good for PVC tubular slip joint threads and washers.
Good lubricant for those.

Also on any union threads, and a little touch on the faces, also some behind the nose for the rotating union nut.

ChrisJ

Jamie Hall said:

@Jamie Hall

I've been trying to post why not to use pipe dope on a union sealing surfaces and gave up

Aren't computers fun? Main reason I can think of is that you shouldn't need it at all. What's your take? On the other hand, if it's a very light coat and not lumpy, it won't do any harm.

My opinion is if it seals and then some dope that shouldn't be there in the first place works it's way out it's going to leak.


It's a metal to metal seal and thread sealer doesn't belong on it 

I recently got to try and fix flares someone felt they should use some goop on that was fun too.

realliveplumber

We coat the threads of the union as well. Thin coat of of a thin dope. #5 special gray or teflon. They come apart effortlessly forever.