Went to the coast today bought two cast iron rads.

[wardk]

I will take pics , strange fittings rusted solid , I think I will start with sand blasting and go from there, any suggestions would be greatly appreciated. K

 

[BoilerMan]

Try a little heat if you need to remove some fittings. If there is any way to get a plug in it and do some pressure testing with air and some soap and water. If all is good then procede to blasting/painting.

TS

 

[wardk]

A few fittings to to 1/4 for air , how many psi would you suggest?

 

[Eric Johnson]

A few fittings to to 1/4 for air , how many psi would you suggest?

Don't overdo it. Compressed air can be dangerous. I'd keep it below 50 psi. Actually, I'd hook it up to a hose and fill it with domestic water. Then you're getting a higher pressure and a safer situation. Let it sit overnight and see if anything leaks out. Those "odd" fittings are probably screw-on pressure connectors that most old cast iron rads are fitted with. If you want to use them again, you'll probably need to replace the "ball" part (I forget what it's called). You can buy them online or at a plumbing supply house. What I do is just take them out and put in black iron reducers and connect the rad to the system with black iron or copper. Just make sure you put isolation valves on either side.

Cast iron rads are fantastic with wood-fired hydronic heating systems. What's the difference from gas or oil? Gas and oil cycle on and off. Wood, generally speaking, just keeps on providing a steady heat.

 

[maple1]

Yes - water under pressure will show leaks much better than air under pressure. I found that even with air pressure and a squirt bottle of soapy water, a tiny leak can be missed that will be pretty obvious with pressured water, especially if in a place you weren't expecting to find a leak (like an unseen crack). That said, if there are specific spots you want to check for leaks at, air and squirt bottle might be the better choice just because filling then draining water can be a messy pain.

 

[Donl]

I just bought 9 cast iron rads from a 1945 house being renovated in Toronto for $250.00. I pressure tested to 45 lbs air and repainted them all. So far I have 6 of them installed and operational. Both wife and I are extremely pleased with their operation.

You mentioned that you are having difficulty removing the fittings. On mine I discovered that the threads entering the rads are all reversed threads. Check yours to see if they are also.

 

[BoilerMan]

9 for 250 smackers? Wow, you got a great deal!.

I love CI rads, I've installed a few in newer homes, they are extremly forgiving with flow, you need almost nothing for flow for them to really crank out the heat. I'd say in the 1-2gpm range. Remember supply in the top and return out the bottom of the other end. I usually don't mess with the old air bleed plug if it can't be budged, I install a bleeder T on the top elbow where the copper threads in (supply). That is if you don't mind looking at copper pipe above the floor.

TS

 

[Donl]

Remember supply in the top and return out the bottom of the other end.

The rads I bought have both supply and return on the bottom on the same end. This really concerned me because I could not figure out how that was going to work. I was really happy to see them cranking out the heat once they were put into operation. Magic I guess!

 

[BoilerMan]

Yes some of the dead men who installed bottom used both bottom ports for supply and return. If this is the case, then be certain not to overpump them as the water will just flow through the bottom (end to end) and not migrate to the top making the best use of all the iron. If you have a multi-speed circulator try it on low first, as with all hydronic pumping, low first and see how it goes. Slower is better with CI rads, alot of them were setup for gravity flow back in the day....... 1gpm at best.

TS

 

[wardk]

If they leak other than fittings are they done or can they be sealed between the wafers?

 

[goosegunner]

If they leak other than fittings are they done or can they be sealed between the wafers?

Some have posted that they can be brazed or even fill the joints between sections with JB weld. I haven't personally done either but I may in the near future. I have collected 13 radiators so far.

gg

 

[wardk]

One of the rads for the house the other for the shop , I think I'll test the house rad in the shop first under realworld conditions leak cleanup is a nonissue there.

 

[Eric Johnson]

If they leak other than fittings are they done or can they be sealed between the wafers?

You can even remove/replace the columns, if one is cracked. Not especially easy, but it can be done.