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

[aczlan]

As some of you saw in my other thread I picked up a Tarm Excel 2200 yesterday, from the tag by the lifting ring it appears to have been made in 2001:

Previous owner was using it with no storage 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.
If there are, it will get sent to the scrapyard.

Aaron Z

 

[peakbagger]

Give the folks at Tarm USA a call https://woodboilers.com/ They usually are quite helpful on old Tarm boilers since they were the importers. A friend of mine needed help with one of the old wood/oil Tarms and they let home know all the places to check. Back then storage was not required, that meant a lot more cycling of the boiler and I expect more erosion of the firebox. I do not think they used a Thermovar back them either so even more extended fire side corrosion especially when operated without storage.

My Burnham is from that era, I think the Burnham approach was just build them with thicker steel.

 

[aczlan]

I spoke to Scott last week about the boiler, we will see how it looks when I get the back cleaned off.

Aaron Z

 

[peakbagger]

Great, you started with the right person.

 

[aczlan]

Great, you started with the right person.

He seemed to be the go-to guy.
He said that my plan sounded solid, unlike the last boiler I was picking his brain on (a Solo Plus 40) where he was of the opinion that it was overpriced and strongly suggested checking the back wall very thoroughly.

Aaron Z

 

[aczlan]

Made a little progress last night, adapted my needle scaler to get the back wall:

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

 

[pettibone]

I have a Tarm Solo plus and before I bought mine was going to look at a newer one than mine which I believe were made in Turkey that had the same issue. I was wondering about being able to reach the back wall and at the same time see what you're doing especially when welding. I like your idea with the needle scaler but I had thought getting a grinder in there to really clean it off would be tough. It will be interesting to see how you make out.

 

[aczlan]

A few pictures from tonight:

Air hammer with a chisel blade made short work of the clumps of creosote on 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 inside the firebox and I can get at the lower section straight on instead of at an angle.

Aaron Z

 

[aczlan]

I have a Tarm Solo plus and before I bought mine was going to look at a newer one than mine which I believe were made in Turkey that had the same issue. I was wondering about being able to reach the back wall and at the same time see what you're doing especially when welding. I like your idea with the needle scaler but I had thought getting a grinder in there to really clean it off would be tough. It will be interesting to see how you make out.

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

 

[TimfromPittsburgh]

Really interesting. Thanks for posting your work. Being the proud owner of a Tarm 502 this gives me some idea about might be possible come the day when my boiler springs a leak.

 

[aczlan]

Really interesting. Thanks for posting your work. Being the proud owner of a Tarm 502 this gives me some idea about might be possible come the day when my boiler springs a leak.

You are welcome, that is why I posted it on here, vs one of the other forums I frequent, a thread on this forum is more likely to help another Tarm owner vs one of the other forums I am on.
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

 

[peakbagger]

You made me look, the "spare" Tarm in my garage is a 2008 Tarm Solo Plus Mark 2. I think they switched over to Scantek in 2008 so it must have been on the tail end of the production. It had a 20 year warranty when new (presumably to the original owner) and has been out of service for at least a couple of years so it should have some life left on it.

 

[pettibone]

The Tarm that was for sale here had a big sheet metal door on the front, had to open that to get to the other doors. Maybe that would tell the difference. And that was a Solo Plus Mark 2

 

[peakbagger]

That sounds like the Scandtec version that replaced the Solo Plus Mark 2. Reportedly its the same guts just different front panel. https://woodboilers.com/hs-tarm-boilers/

 

[aczlan]

Took the top cover off of the exhaust area, 1-2" of fine silty ash went right into the vacuum cleaner:

Oil side was a little better:

All nice and clean (still need to clean inside the tubes):

Will need to figure out why this damper sits open a little and replace the lid gasket as it's shot:

All in all, still happy with it, need to get the lower section rinsed out and finish vacuuming out the firebox, but I haven't found any showstoppers yet.

Aaron Z

 

[aczlan]

Took it outside and rinsed it out with a hose, got enough out for now to work on it without getting covered in ash, will pressure wash things later.
Inside the firebox:

More to the front of the firebox:

Down below:

Where I washed out out:

I now have a box fan sitting on the cleanout opening pushing air through to push the "loose water" out.
Before I go to bed, I will put the heater in the bottom and hopefully finally start to dry everything out.

Aaron Z

 

[pettibone]

Don't know how anybody could use that like that, what a mess. But I guess it says a lot about the quality of steel used by Tarm that the whole thing isn't rotted out. I'll still be interested in how you go about welding the back where it leaks. Good job

 

[peakbagger]

Back when I worked around large industrial boilers I was always amazed at what a good welder could do. Some guys had the eye hand coordination to use a mirror and a bent rod to weld on the back side of boiler tube and still come up with a perfect weld. They also on occasion would do a window weld where a window would be cut on the front side of tube or panel to weld up an issue on the back side. When done they would weld the window back in.

 

[aczlan]

Had a conversation with my neighbor (who has run/maintained steam boilers for years at work) and he suggested when I'm ready to fully dry it out and/or to finish curing refractory cement to stick a salamander heater in the opening where you would load wood and let that run for an hour or so, let it cool off and repeat.

That should get it up to a couple hundred degrees, let me get the first couple of stages of curing the refractory cement taken care of in a controllable fashion (without having to fill it with water and try and run it slowly without having it hooked up to the house).

That should also let me finish drying out whatever water has been absorbed into the fire bricks in a controlled fashion.


Aaron Z

 

[peakbagger]

That will work as there is good airflow but realize when you burn anything it gives off some moisture. Electric heaters work pretty well as there is no water. That is what is used on dearators for post weld heat treating. Just heat it slow so the moisture in the refractory does not boil.

 

[aczlan]

Got the back cleaned off tonight:

Surface rust, but not bad. No significant pitting or erosion that I could find.

Started cleaning off the door (so it doesn't put creosote on my arm all the time) and it is the rusty mess that I was expecting the back wall to be:

Going to have to replace the insulation and the round vent adjuster as it is rusted through.

Snapped off my first bolt (lower left on the door), will weld a nut to it and see if it comes out.
If not, I will center punch, drill and try not to snap off an extractor in it.

Aaron Z

 

[pettibone]

Are you going to remove the refractory to weld , almost looks like the rustiest part is where that meets the back?

 

[aczlan]

Are you going to remove the refractory to weld , almost looks like the rustiest part is where that meets the back?

I wasn't planning on it (as with my luck the chances are excellent that I will manage to break at least one of the pieces of refractory), but now that you mention it, I really should to see how bad the wall looks behind them and hit behind them with high temp paint...

Aaron Z

 

[aczlan]

Pressure tested it today, found 4 leaks in the back wall.
Top right is the one that was leaking when I saw it, the others are pinholes:

I am going to bet that the gasification part did NOT work properly after they replaced the firebricks, the nozzle brick was installed backwards so they had no flow through the nozzles.
This end was towards the door:

Instead of this one (they're supposed to be one unit, but it broke in the middle and now there's two halves):

The backside of one of the nozzle bricks:

The outer bricks look ok:

Some closer pictures of the back wall after taking a wire wheel to the leak points:

Aaron Z

 

[pettibone]

Is that cracked where the soapy water is running down on the left side? I would get the biggest piece of steel you can fit through the door and try to cover as much as possible with one piece, maybe lay it on it's back somehow so don't have to hold the steel in place. Looks like a fun project. I have a Tarm that was made in 1979 and it didn't have any leaks at all when I took it out the beginning of last winter, never had any storage and definitely was a creosote maker, has me wondering how much water quality has to do with it.