Feasibility of brazing/welding radiators

Timothy H. McGinn

We have an Old School House (1910) in our town that is now owned by a preservation non-profit. It has a steam boiler system. The boiler was recently replaced. There are a few radiators that were disconnected from their risers years ago, apparently because of leaks. Recently some other radiators have sprung leaks. The disconnected radiator leaks are where sections join up and from holes in the section, the new leaks are at section joints too. We know this is not a typical brazing job. Does anyone have success stories in repairing such leaks? One more detail the radiators are 10 to 14 feet long with two rows of sections this length hung on the wall below the windows.

Mike T., Swampeast MO

Leaks between the sections usually come from what I've heard called "nipple rot". IF you see rods going across the radiators with bolt caps at the ends you might be able to disassemble and replace the push nipples. As the iron AROUND the nipples will likely be quite corroded as well, the probability of success is probably very low.

Again, IF they can be disassembled (not to many wall-hanging radiators can be) you should remove the nipples and wire brush the radiator sections VERY well. You can try a continuous bead of pure silicon around the new nipples and inside the radiator sections. Since new leaks are appearing between the sections you will really have to replace ALL of the nipples. This won't be particularly easy and it still might not work. Try one small one first!

If they cannot be disassembled the radiators are most likely a loss. I have heard of successful brazing of cracks in water radiators that have frozen, but such is not easy and certainly not always successful.

Since you say there are leaks in the sections themselves the rads are likely VERY corroded and even if you can fix the holes new ones will likely appear.

Sorry to give such a pessimistic answer but they are likely beyond any reasonably long-lasting repair.

kevin_5

Amen to the silicone Mike

Make sure it is the RTV (room temperature vulcanizing) stuff that you find for automotive uses in any auto parts or hardware store. It will do amazing things in gasketing applications. Kevin

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SteveT

leaks


I have used a two part automotive epoxy on small leaks. You have to grind out the rust with a dremmel tool, and apply the epoxy into the groove. It's been 5 years and counting
good luck
Steve

flange

the "mechanics" around here who work in the school district have over three hundred buildings, many of those very old steam systems. leaks are common between the sections. after years of trying, here are the solutions they use. if its a small leak they wrap it with a salt treated rag to get it to rust upto get through the school years, then repair in summer. if its big they must install new nipples, which is a pain. the method of breaking sections apart is to use the little childrens letter blocks as a wedge, as these are made of some really hard wood and dont hurt the rads. once apart clean thouroughly. then install new nipples.

greg_7

Steam Rad Leaks

I used JB Weld, a two part epoxy, to seal a crack in a one pipe steam rad.

I wire brushed the area with a small hand grinder. Then I drilled small holes on either end of the crack to stop any further splitting.

I applied the stuff and voila! No leak.