Stop Leak

AlfredRose

Have two Burnham thin tube hot water style radiators I picked up from a contractor's garage. Have sandblasted and spray painted both with Krylon High Heat Max paint. One is a three tube, 18 section, and 25" high. Will not hold 10 lbs of air for any long length of time. The other is a four tube, smaller height and length, it holds air fine.
Can not hear air coming out anywhere. Flushed both out with garden hose before blasting. Used teflon tape with Gasoila thread compound with Schrader valve and 60 lb gauge, had air leaks from tape only. Have not tried soapy water yet as I don't want to mess the paint up.
Am looking for stop leak suggestions that I could apply before service use if possible.

WMno57

Fill with water, then pressurize to find the holes. Drill and tap the holes, then small pipe plugs with Loctite. Install on top floor of building, so static pressure on leak will be lower. I have a radiator on my top floor with nails brazed into some holes. Has been holding for years. Brazing yours would mess up the paint, but you could do a paint touch-up.

Mad Dog_2

Yes, you can do the same on Cast Iron Boilers too, but above a Certain BTU, you'll need an ASME approved boiler inspection, me thinks... I had a customer drive a large nail through a Recessed C.I. Sunrad on a HW system.  Hercules Propoxy is still holding 35 years later...amazing.  Mad Dog 🐕 

AlfredRose

Thanx for the tips folks. Paint job looks so nice but now I'll try the soap water first as it's lighter than filling with water. See now that I'm going to have to do the paint over anyway. Still have enough black beauty to blast if I need to. Worked at a plumbing supply house in the seventies and eighties, sold Propoxy there. Was looking for Boiler Liquid and see the Propoxy is still around. Have torch's to braze with if necessary but drill and tap will be method of choice depending where the leak is. Didn't look the gift horse in the mouth, radiators were given to me. Another steam challenge - love it ! !

AdmiralYoda

Soapy water won't hurt the paint at all. Windex works... dish soap and water works even better.

I've been there. I had a leak between sections and cleaned it up and used JB Weld. Worked for half of a season but the leak came back. The only way I could fix mine was to split the sections where the leak was. I had a rotten push nipple.

No replacement push nipple of that size existed so I removed that section and I was good to go.

AlfredRose

Will most likely use Dawn dish and water. If I have to remove a section, what, if any, torque values are there when re-assembling ? Have two what look like 1/4 x 20 studs on the bottom and top. Can chase threads down for a shorter length and cut off the excess. Would not want to stretch those old shafts too much. Could always use threaded rod to replace them with but would rather keep the originals.

WMno57

Torque value would be similar to torque used for a 1/4 inch grade two bolt, so not much. Use a 1/4 drive ratchet, short wrench, or even a nut driver. If using a long handle ratchet or wrench, choke up on the handle.

Pumpguy

Also consider Loctite wicking grade 290 thread locker. In addition to securing already assembled threaded fasteners, Loctite recommends this product for sealing porous castings and weldments.

AlfredRose

Thank you again for your comments and suggestions. Sure helps navigation through the process.

mattmia2

AlfredRose said:

Will most likely use Dawn dish and water. If I have to remove a section, what, if any, torque values are there when re-assembling ? Have two what look like 1/4 x 20 studs on the bottom and top. Can chase threads down for a shorter length and cut off the excess. Would not want to stretch those old shafts too much. Could always use threaded rod to replace them with but would rather keep the originals.

The rods are just to hold it together, they should be just a bit more than hand tight. You should use clamps to pull the sections together. No reason to not use new threaded rod if the old rods aren't full threaded.