an interesting Aquatherm modification

A customer of mine purchased an older 275 that had some cracks and leaks, from an overheat I suspect. He is a power plant welder for Babcock Wilcocks. He sandblasted the entire stove and pad welded all the weak spots.

Then he used high temperature boiler cement to line the fire box with old ceramic tiles, to keep the flame from impinging on the mild steel drum used in the early Aquatherms.

hr

A wood boiler owned by a friend of mine sprung a leak and no welder we called would even consider working on it. "Nothing to weld to on a boiler" is all they would say on the phone.

Turns out they were right. I think it was a victim of low-temp return water corrosion. The back wall right above the return tapping was paper thin and eventually it just cracked. That's also the place where the chunks slam into the back of the firebox when you're not careful loading them in. We poured about a gallon of boiler stop leak into it, which bought him about a day. The boiler was 12 years old. It's probably halfway to China by now.

I tried to find out some information about low temp return corrosion and everything I read was it is a process on the fire box side due to condensation on the wall and subsequent attack. I was trying to find if there was anything to do with the increased oxygen carrying ability of water at low temps or anything like that but no dice.

I think that's right--it just corrodes in the firebox and flakes off over time until there's nothing left. Banging chunks of wood into that spot doesn't help matters much. Putting thicker steel back there wouldn't solve the problem, but it would probably add life to boilers installed without adequate protection, which is to say a percentage of all those sold.

Nice work on the old boiler

I welded new mud legs into my old Kewaunee 3r7 - in the process welded in two 2 inch threaded flanges in each corner - made it easier to wash it out. If there once was enough to weld to, there should be still - someplace - once the effected area is hacked out -

But then there is always the law of diminishing returns to play upon your decision to repair of scrap!

I've stitched together some cars that didn't have much to attach too, you plan on a little patch then you have new rockers, floor and subframe!

Eric you always talk about people "ringing the bell" and mistreating your boilers. I think you should talk with a professional about these scars.