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Tricking your RMH to start for the season

 
rocket scientist
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Location: latitude 47 N.W. montana zone 6A
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cat pig rocket stoves
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Hi All;
I just completed converting my 8" J tube with piped mass, over to a 6" batchbox using the same piped mass.
Any large mass that has set over the summer will need encouragement to start drawing well.
A completely new build can take weeks to dry out and heat up before starting to draw strong.
In my case I had a new batchbox with a large amount of freshly mortared bricks. Forming a circular bell to guide the gasses down into the horizontal transition area.
In other words a new cold wet area to heat up first before my seasonally cold mass could even start to warm up!

If this was a complete new build, I would have installed a bypass to get a part of the system warm before allowing it to travel thru the mass.
Alas I don't have a bypass so I needed to trick the system into thinking it had a draw!
If I had been in the auto shop I would have used an oxygen/acetylene torch to heat the exhaust  stack cherry red.
Not in the shop and very few people happen to have a torch setup anyway.
Plan B) Called for a handheld propane torch.  Most folks have one of them.  It takes a bit, but setting it down pointing at the pipe where it leaves the mass will heat up a small glowing circle.
I just moved it to a new spot a few inches away and continued heating.   My Dragon breath monitor (also know as a candy thermometer) in the exhaust stack started rising.  
The new batch was burning well... I removed the propane torch. Things looked good.
I walked off to do a few things outside.  I checked every few minutes to see if all was going well.
The exhaust stack temps had cooled without the propane help.  But the fire seemed to be going well.
Next time I checked the room is filling with smoke!!!  I quickly lit the propane torch again.  As soon as it started turning red on the pipe the draft switched and thru the viewing window I could see flames again!  A few minutes later the smoke is cleared and the stove is drawing well again.

Our J tube exhibited the same cold start issues. Seemingly burning well until you walk away and come back to a smoke filled room!  
Once I get the mass to heat up, it will stay that way all winter long!  No issues ever with a warm mass.

The new batch rocket is a success!
As much as we liked the J tube rocket .
I Know we are going to like the Batch box more!










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Our beloved 8" J tube
Our beloved 8" J tube
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The new 6" batch
The new 6" batch
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Shes burning now!
Shes burning now!
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A little help from a friend
A little help from a friend
 
gardener
Posts: 1712
Location: Kingman, Arizona
491
building solar woodworking rocket stoves wood heat greening the desert
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Sounds like a father sharing his woes of having to teach his immature baby dragon to not puff in the wrong direction.

Very good advice for a waking dragon as well. Thanks for sharing this good tip at the beginning of burn season Thomas.
 
gardener
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Location: Southern alps, on the French side of the french /italian border 5000ft elevation
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A liter or two of alcohol, like 90°, that has the advantage of not smoking back! In France we call it burning alcohol. In UK, it was called methylated spirit. But it had coloring, and not smelling the same.
 
pollinator
Posts: 1773
Location: Victoria BC
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Neat, thanks for sharing!


Given how cool the exhaust on a RMH should be... could one simply stick a fan on the chimney to provide the needed draft for the warmup period?

What about a fan blowing into the firebox?
 
Gerry Parent
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Yeah Satamax, I can see it now, a little for me, a little for the stove.

D.  I have heard of people using fans to get a draft going (sometimes to overcome an exceptionally long pipe run) with good success.
Some people may consider it cheating or just want to keep their stove as off grid and simple as possible, so I think it really boils down to what you feel comfortable with in the end.
 
thomas rubino
rocket scientist
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Location: latitude 47 N.W. montana zone 6A
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Hi D;
Never mind those two scientist's nipping alcohol over there... as long as any fires they start are in the firebox... its all good!

Yes a fan work's well when all you are dealing with is a cold mass. I this case I have 60-70 clay bricks each soaked in water for 10-15 minutes or so.
Everyone of them must shed that water.  Until that happens I end up with cold moist smoke desperately searching for an easy way out.
In my photo's today you can see the white spots of varying sizes. That is all moisture leaving.

I am continuing to trick it into flowing.  No heating of the pipe needed this morning.
Today I built one full fire and since then I have been putting small kindling size pieces to keep spiking the temperature.
My exhaust gas temperature is still extremely low but it has risen a bit all by itself this morning. That's a good sign!
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Rocket Scientists
Rocket Scientists
 
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The smoke back is real! My first start up this year was allot of fun. It filled my house as if cheech and chong were in my house! Never force a start up. It's like trying to force feed a child something they don't like. Just pukes it out! Slow encouragement and love is what they need. Running fine now!
 
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