Cracks in sides of Harmon Mark III

Cracks in sides of Harmon Mark III

PostBy: titleist1 On: Wed Nov 14, 2007 5:15 pm

We have a Harmon Mark III which is 14 years old. We have been very happy with it. Fired it up for the first time this year and noticed a smell of smoke. Checked it out and noticed severe cracks on each side lining up with the weld line of the internal baffle. Didn't notice them last year. Looks like the top of the baffle is warped just enough to pressure the sides into cracking.

Anyone else have the same thing happen to them? Is this just the normal fatigue of the steel after years of use? I am shopping for a replacement and probably will go with the Mark III again just because I am used to the "personality" of the stove and all piping is set to go.
titleist1
 
Hot Air Coal Stoker Stove: Harman Mag Stoker (old style) one in basement, one in workshop
Hand Fed Coal Stove: Harman Mark III on standby for long power outages
Coal Size/Type: Rice/Anthracite; Nut/Anthracite

Re: Cracks in sides of Harmon Mark III

PostBy: bksaun On: Wed Nov 14, 2007 5:21 pm

Are you using a barometric damper to prevent over firing? Sounds like she got real hot last year.

BK
bksaun
 
Stoker Coal Boiler: Hybrid, Gentleman Janitor GJ-6RSU/ EFM 700
Hand Fed Coal Stove: Hitzer 503
Coal Size/Type: Pea Stoker/Bit, Pea or Nut Anthracite
Stove/Furnace Make: Hitzer/ EFM-Gentleman Janitor
Stove/Furnace Model: 503 Insert/ 700/GJ-62

Re: Cracks in sides of Harmon Mark III

PostBy: titleist1 On: Wed Nov 14, 2007 7:55 pm

Yes, we have a barometric damper. I didn't run it any differently last year than the previous 13 and I didn't notice any particular time it was running away.
titleist1
 
Hot Air Coal Stoker Stove: Harman Mag Stoker (old style) one in basement, one in workshop
Hand Fed Coal Stove: Harman Mark III on standby for long power outages
Coal Size/Type: Rice/Anthracite; Nut/Anthracite

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Re: Cracks in sides of Harmon Mark III

PostBy: Wood'nCoal On: Thu Nov 15, 2007 8:24 pm

I suppose it could be welded if there is not a gap where the cracks are. The length of the crack isn't as important as the space or gap created by the crack.

I'm intrigued by this, the Mark is a pretty solid stove. Have you contacted Harman at all?
Wood'nCoal
 
Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert

Re: Cracks in sides of Harmon Mark III

PostBy: coaledsweat On: Thu Nov 15, 2007 11:06 pm

Before you weld it, drill a hole at each end of the cracks to prevent their return.
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Re: Cracks in sides of Harmon Mark III

PostBy: titleist1 On: Thu Nov 15, 2007 11:23 pm

I am interested in contacting Harmon, however there is no phone number or email address on their website. It seems they want any customer issues to go through their dealers. For what its worth, one of their dealers told me they were bought out by Quadrafire and the sale was finalized this week. They had been told that no shipments from Harmon would be made until after the sale so that their inventory would be static for accounting purposes.

I thought about welding the crack, however I don't trust the interior baffle to be stable at this point. I am thinking that if it was welded and the baffle flexed again it would crack further along the baffle weld line. Its not something I want to wonder about while trying to sleep at night.
titleist1
 
Hot Air Coal Stoker Stove: Harman Mag Stoker (old style) one in basement, one in workshop
Hand Fed Coal Stove: Harman Mark III on standby for long power outages
Coal Size/Type: Rice/Anthracite; Nut/Anthracite

Re: Cracks in sides of Harmon Mark III

PostBy: Yanche On: Thu Nov 15, 2007 11:27 pm

coaledsweat wrote:Before you weld it, drill a hole at each end of the cracks to prevent their return.
Ideally find a welder that works in the aerospace or aviation industry and owns a TIG welder. Take whatever advise he recommends.
Yanche
 
Stoker Coal Boiler: Alternate Heating Systems S-130
Coal Size/Type: Anthracite Pea

Re: Cracks in sides of Harmon Mark III

PostBy: Wood'nCoal On: Sat Nov 17, 2007 11:28 am

I suppose a really experienced welder can repair the cracks and reinforce /repair the baffle to stabilize it. A new stove is expensive, the repair would be a great cost savings if done correctly. a professional welder knows the characteristics of metals and how to address these issues.
Wood'nCoal
 
Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert

Re: Cracks in sides of Harmon Mark III

PostBy: Wood'nCoal On: Sat Nov 17, 2007 11:48 am

titleist1 wrote:I am interested in contacting Harmon, however there is no phone number or email address on their website. It seems they want any customer issues to go through their dealers. For what its worth, one of their dealers told me they were bought out by Quadrafire and the sale was finalized this week. They had been told that no shipments from Harmon would be made until after the sale so that their inventory would be static for accounting purposes.


I'm not too happy about not being able to contact Harman directly, I'm more satisfied getting answers from the manufacturer, I find that some of the dealers are really not that well informed.

I'm a little dismayed about the sale of Harman to another company that you mentioned. There are lots of reasons why a company owner decides to sell, some good, some bad, but I worry that sometimes after the sale the product quality begins to decline when the new owner changes how the units are manufactured.
Wood'nCoal
 
Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert

Re: Cracks in sides of Harmon Mark III

PostBy: Wood'nCoal On: Sat Nov 17, 2007 11:55 am

I checked Quadrafire's website, there is a brief mention of Harman on the following page, but no mention of coal burning stoves.

http://www.quadrafire.com/About_Us/Company_Profile.asp

More digging shows Quadrafire as a company owned by Hearth & Home Technologies, which is a subsidiary of HNI industries. So it looks like the big fish swallowing the little fish several times over.
Wood'nCoal
 
Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert

Re: Cracks in sides of Harmon Mark III

PostBy: traderfjp On: Sat Nov 17, 2007 1:08 pm

Write a letter. Letters seem to be more effective anyway. It seems to be that a stove would be designed to handle the maximum output of the stove without cracking. Maybe the metal they used already had a stress crack in it.
traderfjp
 
Stove/Furnace Make: Alaska
Stove/Furnace Model: Channing 3

Re: Cracks in sides of Harmon Mark III

PostBy: coaledsweat On: Sat Nov 17, 2007 2:15 pm

Is it steel? If so, weld it. It is a simple repair that any competent welder can make. It can be ARC, TIG, MIG or even brazed. Its cold out.
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Re: Cracks in sides of Harmon Mark III

PostBy: jpen1 On: Sat Nov 17, 2007 5:07 pm

Did the weld crack or did the plate steel itself crack? If it is the weld You should grind out the weld on several inches either way of the crack. What has happened if that is the case the weld has what welders call porositiy in it. It comes from running the stick or mig gun to cold for the type rod or wire. If it is a stress crack in the middle of a sheet I would get some dye check from grainger or the like and check the rest of the side sheet for micro fractures before trying to repair it. It could have been a bad batch of steel with what they call lamination(s) in which case the stove should be retired. This is also caused by incorrect temps. in forming/rolling process.
jpen1
 
Stove/Furnace Make: Leisure Line
Stove/Furnace Model: 110 Boiler

Re: Cracks in sides of Harmon Mark III

PostBy: Wood'nCoal On: Sat Nov 17, 2007 7:29 pm

When I first bought my Harman I inspected all the welds, and I was impressed with the quality of the workmanship, esp. the welds. Having done some welding myself, I can appreciate quality welding. Everything jpen1 said sounds right on target, a good weld should be stronger then the metal around it.
Wood'nCoal
 
Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert

Re: Cracks in sides of Harmon Mark III

PostBy: xackley On: Sat Nov 17, 2007 8:59 pm

Heat effected zone is the weakest point :)

Worst case scenario is a 3/32 sheet of mild steel to cover the whole side.
xackley
 
Stove/Furnace Make: Leisure Line
Stove/Furnace Model: Pocono

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