Pinhole in restored cast iron American Radiator Co. Rococco

HenryB

Hi all,

Henry here, a homeowner on Long Island restoring a 140yo Victorian. Our house had mismatched, improperly sized, and leaking radiators, so we decided to go ahead and seek out some to restore. After sandblasting, powder coating, installing and pressurizing, one pinhole developed in the intricate portion of one of the fins. It’s literally a pinhole. I’ve since gone back to the place I bought it to get its twin to restore, but curious if anyone has any luck in repairing a pinhole? I’ve read a lot about jb weld, and spoke with a few welders who gave me high quotes with low probability of success. 

Any help is appreciated! I also read all of Dan’s books. Fascinating stuff, this is.

Thanks in advance,
Henry

Mad Dog_2

Hiya.  Cool project.  Where on the Island 🏝..?  JB Weld might work or Propoxy. 
I would hit it with a grinder, drill, tap, plug.
Mad Dog 🐕 

Jamie Hall

Steam or hot water? If it's steam, I'd give @Mad Dog_2 ;s procedure a very good chance of working. Hot water, less of a chance, but still worth the try.

HenryB

Thanks! Sorry I didn’t include the type in my original post. It’s hot water. We’re in Sea Cliff.

HVACNUT

Very nice rads, but even if that pinhole gets repaired, who knows where the next one might poke through? 
Any way to know the water condition on the system it came from? Probably not.
You should get a spud wrench, a compressor, and make up some fittings to pressure test before purchase. 

hot_rod

you could try to drill and tap it with a small bolt like an 8-32. Screw the bolt in with Loctite then file or grind the head off

If the metal is thin or corroded it may  require a larger bolt, maybe a 1/4”
 

For a small casting hole this will work

if too much of the metal is corroded it may not be repairable and will pin hole in other places

mattmia2

You could also braze it. Brazing is likely to fix that spot, the question is if there are others as others have said.

Mad Dog_2

Sea Cliff is Long Island Gold Coast Paradise. I've restored many ancient heating systems up there. Sea Cliif is where I installed THE BOILER THAT NO ONE WOULD TOUCH.  It was a Large, two pipe  gas Vapor system in an Old WW I Officers Barracks that had been moved through the Long Island Sound on a barge..  The boiler was in a ten foot deep vault in the middle if the Gorgeous home.  I serviced it 2 yrs ago..humming along. Mark Starr was the owner at the time. He also happens to be one of my testimonials.  Very proud of that difficult job.. Drilling and tapping will stop a hot water leak under 20 p.s.i. pressure easily. Low Pressure steam, you'll get away with Propoxy or JB Weld.  You can't worry about the integrity of the rest if the radiator. It is what it is.. .I have repaired many like this and didn't have any other holes popping up.  A sand hole can happen in Casting.  It doesn't mean there's multiple ones.  Mad Dog.  

EBEBRATT-Ed

I would drill and tap it for 1/8" pipe and put a plug in it. You could use a flush 1/8" plug like used in an oil pump. Chances are with CI it is not corrosion but just a pinhole that was exposed during sand blasting. You can always try moving up to a 1/4" plug if need be.

If it is corrosion any type of welding or brazing will just make it worse

hot_rod

mattmia2 said:

You could also braze it. Brazing is likely to fix that spot, the question is if there are others as others have said.

If they are already refinished I would not braze or weld.

Mad Dog_2

A Black plug will blend in better too.  Mad Dog 🐕 

retiredguy

many years ago, I carried concentrated iodine and lead wool in my service truck that I could use to seal pin holes in cast iron boiler sections and radiators. I do not know if you can still buy the very concentrated iodine any more but if you could I would try that first. You would need to take the rad out of service, pour the iodine into the pin hole and fill the hole with the lead wool by tapping with a ballpeen hammer The iodine caused the cast iron the rust quickly and the lead wool helped to fill the hole. If this does not work you can always do the other fixes.

hot_rod

The metal may be thin in that spot. So a fine thread would be more apt to thread. That why Id start with a fine thread bolt instead if not plug. Plus a much smaller hole😗. You can always go bigger if needed