Advice on steam radiator repair

[Georgie]

Hi all,

I got a few of these steam radiators to repair. They are from the early 60's, made in Austria, used in a continuous oven. I cant find any info on them and the tanks i believe are steel but not sure what the tubes are made of but they are NOT magnetic.

Im pressure testing the rads with compressed air and soapy water to pinpoint the leaks.

What would be the best way to weld up cracks on the tubes and also where the tubes meet the steel tanks?

I can tig weld pretty good and also have the option of oxy acetylene (but not very experienced at it)

Thanks!

[aametalmaster]

Tubes are probably copper. I would soft wire brush where the tube meets the tank and see if they were brazed. Whatever and however it’s done it will be a learning experience you won’t forget

[Electric4Life]

I'd be reluctant to offer any specific advice for a repair.
Radiators are often furnace brazed.
Appears to have been repaired using Silicon Bronze at some point.
The biggest issue is any heat can cause the existing joints to separate and exacerbate the issues.Meaning repairing will likely be a never ending endeavor.
Seek a professionals opinion from a reputable radiator repair shop before getting in too deep.
DO NOT WELD this.

[Georgie]

Yeah i did that last repair you see a few years ago. Used silicone bronze tig rods but it started to leak in other places.

I was thinking oxy acetylene would put in less heat thus reducing the possibilities of causing more harm than repair. However, im seeking advice one which method will cause less headaches, even if it means learning a new skill.

Thanks for your reply!

[Georgie]

Hey guys would any of these rods below be suitable?

Sil Fos 5 self fluxing 5%silver 89% copper 6%phosphor.

Soudotec T536 aluminum-bronz alloy containing maganese and nickel tig in 2.5mm.

And Harris LFB-FC and they are coated yellow. (Oxy acetylene i assume)

Would any of these be good for joining the copper tube to the steel tank? Also if i find any pierced tubes, would the Sil Fos 5 be good for that and can i tig it or should all these be done with oxy acetylene?

Attached are a few pics of a close up of tube after wire brushing (pointing finger)

Thanks for all advice.

[Georgie]

Got a smith little torch and im using LFB-FC. Braze one leak and another pops up.

This is time consuming and also nerve-wracking as these radiators are proprietary to its machine .

Heres some pics

[aametalmaster]

I would say they lived their useful life. They either need replaced or you will have headaches forever. I have been there

[Electric4Life]

Its been said that repairs on soldered joints will cause failures to the surrounding ones.
It's only a matter of melting temperatures.
Keep practicing

[Georgie]

Thanks for advice. Its getting a little easier to get the metal flow once i used a longer flame and stop putting black past flux and rather use the rod as is. It has a yellow flux on it and seems to work. Cleaning is also a game changer. The cleaner the easier but its hard to get into the center row.

Ill keep you posted on progress. I have 8 spare rards but they are much larger and would have to be modified heavily to fit and i believe they are galvanized so not sure about that rout...

[Georgie]

Its been said that repairs on soldered joints will cause failures to the surrounding ones.
It's only a matter of melting temperatures.
Keep practicing

Its not the tubes that start leaking. Its the tank(steel part ) thats seems to be cracking

[Georgie]

So after a bunch of money spent on a little torche and various rods, along with a bunch of time, i temporarily gave up on this specific rad and shifted my concentration on retrofitting some massive rads i have in stock. I have 5 of these heavy duty rads and they can be cut and welded to make a total of 10 replacement rads(2 per).

I believe these are galvanized steel. The finns are also magnetic. They weight around 600 lbs each. After cutting them i made some stainless plates to cover the tanks. Ground off all the galvanization as best as i could and welded them shut. Next is to make the intake and return bungs. Will use 1" NPT female bungs welded to the tanks and then do a pressure test.

Alot easier to weld on this stuff than the previous ones.

Will keep yall posted.

Thanks

[ryanjones2150]

What did you use to weld the stainless plate to the carbon steel?

[Georgie]

What did you use to weld the stainless plate to the carbon steel?

Its just what i had laying around that was close to the right size... is it a problem to use dissimilar metals? I used 316L filler.

Thanks

[ryanjones2150]

It can be some trouble with dissimilar metals, but I think you’ll be ok with 316. 309 was made for joining SS to carbon steel.

[MAC702]

As mentioned, E309 is the best choice, but any carbon or stainless steel alloy will blend into a weld to some degree, and is likely to be plenty good enough for what you're doing.