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!