To the basement, or to the scrapyard? My attempt to resurrect a Tarm Excel 2200 Wood Gasification boiler

[aczlan]

I picked up a Tarm Excel 2200 Gasification Wood Boiler this week, from the tag it appears to have been made in 2001:

It is a Wood/Oil (or Wood Propane) boiler, on the wood side it heats the wood till it smoulders, then burns the gas/smoke at around 2000F below the firebox:

Picture from: Tarm Furnace | Excel 2000/2200 | Wood and Coal Furnace Parts

A demonstration video of the next size down (the Excel 2000):

The previous owner was using it and it sprung a pinhole leak in the back of the firebox, they ran it (with the pinhole) for about a month on oil until they could get someone in to replace it (they put in a wall mount condensing gas boiler to replace it).
Not sure how often it got cleaned out as it had a lot of ash buildup/creosote buildup inside, here is a picture shortly after I started:

And where I stopped for the night. Can someone confirm that the corners (circled in red) should be square? It looks like they should be, but I don't want to break something if they are supposed to be angled. It appears that there is a bunch of creosote or ash built up there which is a solid lump:

IIRC, the leak is somewhere around where the yellow circle is, if not its a few inches below that:

I pulled out about 10 gallons of ashes out and that was just the easy to get stuff:

The flame tunnel from somewhere in the clean out process:

And how I left it for the night, 200w fan heater in there to warm things up and hopefully dry things out (sitting on a metal plate to keep it dry), not sure if the refractory absorbed any water (or if it can), but I figure that if everything is dry, it will be easier to work with than if its wet:

The plan is to get it cleaned out, then tape my needle scaler to a stick and pound the back wall until its clean.
Once its clean, I will look for pitting, pressurize the "tank" and spray soapy water on the back wall to see if there are any other leaks.
If there are not, it will get welded up and installed in the basement this spring/summer.
If there are, it will get sent to the scrapyard.

Aaron Z

 

[aczlan]

Made a little progress the next night, adapted my needle scaler to get the back wall (while keeping my face out of the firebox and thus breathing clean air):

After doing a test patch:

Where I ran out of time and stopped:

The nastyness on the scaler from what was still damp:

Liking what I see so far of the top 2/3 of the back wall, the creosote just about fell off when I took the scaler to it.
Lower 1/3 (where the hot wet ash has sat against the steel for the past month) is more like what I was expecting to find.

Aaron Z

 

[aczlan]

A few pictures from Friday night:

Air hammer with a chisel blade made short work of the clumps of creosote at the bottom of the walls, they looked like lumps of coal:

Some chunks in a pan, 1/2" diameter pin for scale:

Cleaned out firebox (for now, will probably clean more once it's all dry):

Dug a lot of sludge out from under the vertical tubes in the back, no pictures, but there was ash almost to the bottoms of the tubes.
One more night with the heater in the firebox and then it gets moved below to try to dry out the lower section.

Next up is to shorten the wooden "handle" on the needle scaler so it fits completly inside the firebox and I can get at the lower section straight on instead of at an angle.



Aaron Z

 

[aczlan]

Someone on Hearth asked about using a angle grinder vs a needle scaler.
I thought about using an angle grinder with a wire wheel, but controlling it that far out when it "grabs" would be difficult and it would throw a lot of dust around.
The scaler and air hammer throw little or no dust that makes it out of the firebox and are easier to control.


Aaron Z

 

[groundcover]

Hope you can save her. They are good boilers. Going to be able to reach it with the welder ?

 

[aczlan]

Nothing much happening today, replaced some seals in my pallet jack so I can move this beast around the shop easier than with my forklift (its at the edge of what I should be picking up from the end with my little walk behind forklift due to how long it is).
The pallet jack seals were bad enough that I could not pump the handle fast enough to lift the boiler up when I was trying to bring it home.


Aaron Z

 

[aczlan]

Hope you can save her. They are good boilers. Going to be able to reach it with the welder ?

I have a stick welder and its straight in, so I should be able to.

Aaron Z

 

[groundcover]

Keeping my fingers crossed!

 

[5030]

I've always wanted an HS Tarm and never bought one, they are the Cadillac of gasification units. If I were you, one, I'd go to HF and buy one of their needle scalers, I have one, works very well and two, I'd MIG weld it, not stick weld it. Much easier, will give a much cleaner weld too. I'm on the Firewood Hoarders Club. Everyone on there burns wood including me. If you decide to scrap it shoot me a PM and I'll come and get it and pay you for it.

 

[5030]

I might add, the bottom corners of the firebox are small radius. That is built up had creosote from pizz poor care.