Harman Mk I latch adjustment???

Harman Mk I latch adjustment???

PostBy: rberq On: Fri Jan 23, 2009 10:19 pm

I want to adjust the loading-door latch on my Harman Mk I, so it will pull the door a little tighter. The hinge side is snug, but the latch side is loose; there is no tension at all on the latch mechanism.

The only way I can see to adjust it, is to bend the curved piece that is bolted to the stove body. It is very thick steel and does not look like it would be easy to bend. If I put a wrench or vise-grips to it, will I damage or break the bolt? Is there some other simple way to do this that I am entirely overlooking?
rberq
 
Hand Fed Coal Stove: DS Machine 1300
Coal Size/Type: Nut -- Kimmel/Blaschak/Reading
Other Heating: Oil hot water radiators, propane

Re: Harman Mk I latch adjustment???

PostBy: Uglysquirrel On: Fri Jan 23, 2009 10:42 pm

The compression of the door and the latch friction works in parallel with the compression of the rope that goes around the inside of the door, if your rope is more that 2-3 years, think about replacing the rope with a similar size. Other than that you could bend the steel strip, it's likely 1030 carbon and will bend pretty easily in a vice. I would however remove the strip by bolt removal since rapping the strip with a hammer or some sort of impact while the strip was attached to the stove could (unlikely) cause the bolt to partially crack in a place you may not see since the bolt nut & threads are exposed to coal corrosion. With thermal expansion/contraction the bolt could fracture later when you least expect it. I also would replace the bolt. That's just conservative me with some limited design metalurgy experience and failure experience on airplane enjuns.

Of course removing the strip would cause you to use two matches this season !!!
Uglysquirrel
 
Stove/Furnace Model: Pocono

Re: Harman Mk I latch adjustment???

PostBy: rberq On: Sat Jan 24, 2009 9:58 am

Thanks, squirrel. I think conservative is good when it comes to airplane engines.
I already used my second match this year when I shut down to replace the door gasket.
You were right, the strip bent fairly easily. I was able to do it in place, by slipping a crescent wrench over the end and levering it toward the stove body. I only had to move it a tiny bit and now there is no red glow visible between gasket and stove body.
rberq
 
Hand Fed Coal Stove: DS Machine 1300
Coal Size/Type: Nut -- Kimmel/Blaschak/Reading
Other Heating: Oil hot water radiators, propane

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Re: Harman Mk I latch adjustment???

PostBy: Joe in NH On: Sat Jan 24, 2009 10:18 am

I do not know if the latch mechanism on your MK I is the same as on my Harman SF 260 but it sure sounds the same. I have a similar problem and first thought of whacking the metal catch with a hammer but had visions of the bolt head flying across the floor. I then thought of removing the catch and grinding a little metal off the back where it attaches to the stove. Bending with a crescent wrench is the way to go. Thanks.
Joe in NH
 
Stove/Furnace Make: Harman
Stove/Furnace Model: Trident SF 260 Boiler

Re: Harman Mk I latch adjustment???

PostBy: coaledsweat On: Sat Jan 24, 2009 11:23 am

Break the bolt? I don't think so unless it is smaller than 1/4-20, one smack with a hammer ought to tighten it up. Make sure your door gasket is up to snuff before making any adjustments.
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Re: Harman Mk I latch adjustment???

PostBy: coalkirk On: Sat Jan 24, 2009 12:11 pm

coaledsweat wrote:one smack with a hammer ought to tighten it up. Make sure your door gasket is up to snuff before making any adjustments.


BINGO! Never underestimate the usefullness of a good 'ol hammer.
coalkirk
 
Stoker Coal Boiler: Harman VF3000
Coal Size/Type: antrhcite/rice coal

Re: Harman Mk I latch adjustment???

PostBy: Cap On: Sat Jan 24, 2009 12:47 pm

Just use a 10" or 12" adjustable wrench, close the jaws and use as a pry. More prcision than a BFH.
A pry is one of your 7 basic tools!
Cap
 
Hand Fed Coal Boiler: Harman SF 250, domestic hot water loop, heat accumulator

Re: Harman Mk I latch adjustment???

PostBy: rberq On: Sat Jan 24, 2009 3:34 pm

Yeah, I was considering the hammer, too, but the wrench turned out to be easier to control. If I hit it too hard with a hammer, then I would have to un-hit it to adjust it back outwards a bit, and I don't know how to un-hit something.
rberq
 
Hand Fed Coal Stove: DS Machine 1300
Coal Size/Type: Nut -- Kimmel/Blaschak/Reading
Other Heating: Oil hot water radiators, propane

Re: Harman Mk I latch adjustment???

PostBy: Uglysquirrel On: Sat Jan 24, 2009 5:30 pm

My mind is in rocket science, I gotta pull it away sometimes, cresent wrench it is.
Uglysquirrel
 
Stove/Furnace Model: Pocono

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