Wood stove pipe damper problems... again...

[flagmanruss]

OK, all you wood burners out there, WTF is going on here.  Wood store is an antique 1890-1910 King circulator an oval upright barrel of red Russian iron (so called) with cast iron top, bottom, door.  Our pipe goes up one (3') section of 6" pipe  & elbows to the left for 4 sections (all riveted together) where it goes into a masonry chimney through a round liner thimble. 

Last year, the dampers stripped out so the handle would spin but the damper plate was jammed closed.  This year, my wife complained about my closing down the dampers but since she's lugging wood & tending the fire (I have trouble with my legs on the stairs so if she wants to be in charge so be it!).  I haven't even gone down stairs or if I did, I put the dampers back as I found them.  What I've found is the bump in the damper handle is now in the groove, instead of up against it, locking it.  Sooo  the handle is in too deep, the springs have no tension against the pipe & the damper moves when it feels like it.  WTF!! 

At least this year the handle is moving with the damper...  We're now parking old horse shoes as weights to bind the handle so it doesn't self adjust. 

This is just crazy.  My only thought is the cheap China steel (recycled WW2 bombs?) is bending under the heat of the fire allowing the parts to slip out of position.  How do we stop this from happening?   

[RJC2]

It sounds like you need to replace your damper.  It sounds like that is going to be a pain where a pill won't reach, with your set up. 

AND...  You are right about the cheap Chinese steel.  I can't believe that we have fallen this far.  Can't even buy an American made damper!!!

 

Respectfully, I have to disagree with you about the bombs.  If they were recycled U.S. bombs they would last a long time because they would be made of Pittsburgh steel, some of the best on the planet.

 

Good luck.  (I can smell the smoke from your stuck damper)

[Mopar1973Man]

  Don't even have a damper...

[flagmanruss]

I already bought replacement dampers.  Guys, my concern is that the dampers are failing during a single heating season & we only use the wood as a booster!  I'm only burning 3 cord a year.  I still have last year's in my scrap metal bin!   I don't want to have an emergency caused by a faulty damper...  (did last year when the damper closed itself & did not respond to moving the handle...  backed smoke up into the basement!  Had to ventilate in freezing weather.) 

 

Like I said...  the shaft has a smooth bent bump which engages the cast damper plate.  The shaft is under spring pressure constantly...  when the shaft gets hot, is it bending?  Allowing it to slide under spring pressure.  I want to run this by my blacksmith & resident metallurgist.  

[dorkweed]

Do you have the damper in the vertical or horizontal section of pipe???  Take a picture also.

[JAG1]

My stove pipe kept rotting out in less than a year so I ripped it out and put in stainless pipe. 14 yrs later, it's still good.

 

 About your damper, I'd probably have one fabricated out of ss.  If you can or have a fabrication outfit cut out the parts w/ ss. Seems to be the only way these days. Lots of folks around here that want very good quality are keeping our local fabrication shop very busey.

Edited March 18, 2014 by JAG1

[flagmanruss]

Damper is in the vertical pipe...  only (1) 3' vertical section right above the stove, elbow, (4) nearly horizontal sections to the thimble.  Masonry chimney outside above the peak of the roof.   

[flagmanruss]

About all casting is done overseas now, in this case China.  The dampers are dirt cheap but don't last.  I did a bunch of searching & found a few others who have the same problem...  their conclusion is that the shaft is barely big enough & poor material which wears quickly, allowing it to fail.  

The question is what tools I have to work with to self construct a shaft.  One option is to have my blacksmith make a copy out of good carbon steel or even SS.   An option is to go to a larger shaft & drill & tap a bolt to do the turning.  Some of the posters have reached in & welded a new steel damper solving the problem...  if the pipe fails, it will have to be done again.   

[Mopar1973Man]

Just using my stove for example I've got a pyrometer installed about two or so feet above the top of the stove. On my first start I can see at least 1,400 to 1,600*F worth of stove stack temps. I've even gone as far as pulling the gauge out of the stack and the probe is absolutely red hot. So if it just cheap steel with cast damper I bet the heat is enough to soften the steel rod and give you this problem.

[flagmanruss]

Think about this design for an instant.  The cast in guides in the damper are a loose fit...  the steel shaft has only a small bump, barely enough to hold by jamming against the cast iron.  But there's a spring load holding the bump jammed.  Then, we fire it up red hot like a blacksmith's forge...  enough to soften the steel shaft, the spring load draws the shaft towards it, compressing the bump (exactly what mine did).  Then the spring no longer holds the shaft from turning, because the shaft moved enough to unload the spring.   

A skilled metal worker would make that "bump" bigger and the engaging surfaces would not be a ramp/wedge shape.  WHAT?  The bump would be bigger & the engaging surfaces would be vertical at that point, not a ramp...  so there would not be a bending force.   _I L ---   It should last "forever".   I want to run this by my blacksmith / welder.