thomas rubino

Hot tubs do not get nearly hot enough; most run below 104F.
Fill it, heat it, use it, and drain it, all over one weekend.
There used to be a "snorkel stove" wood burner sold specifically for hot tubs.
Will a rocket stove work?
Yes, probably, but your stratification chamber would need to be small, or it will stall on you.
How long would it take??? I'm guessing quite a while (many hours)
Perhaps simply putting your tank on a stand and building a fire underneath might be quicker.

Hi Jjuk;
I was just looking at your numbers on the six-inch J-Tube
I see an issue, you have the covered portion of the burn tunnel at 450mm (18") (This should be 10-12" (250mm-300mm)
The total length of the burn tunnel is 750mm (29.5"). (This one should be no more than 24" ( 600mm)

I tried this myself many years ago.
Here is what happened.
My J-Tube roared; I was very happy.
For about 3 months... and then in the middle of a Montana winter, she started acting sick.
Just not burning as it had been. I was beside myself, it is the middle of winter in northern Montana...
I had no choice but to pick a day that was marginally warmer and open her up in the middle of winter!
What I found required a partial rebuild (OH SHIT) !!!

This is when I discovered just how wonderful working with clay mortar is!
Bricks just pop apart with a rubber mallet; the mortar goes in a bucket to be rehydrated and reused.

What had happened was (unknown to me) an incomplete burn, but you sure could not tell that for the first 2 months of operation!
Ash buildup had plugged my transition area and almost all of my piped mass!
That all needed to be vacuumed or blown out; and the burn tunnel roof had to be shortened to 10" (250mm).
Once I did that (and it only took four hours!), my J-Tube Dragon was back roaring around our mountain valley, and she stayed that way for the next six years, until I replaced her with my first Batchbox!

Try contacting Matt at Walker Stoves.
https://walkerstoves.com

He may know if someone is currently offering these.

Hi Matthias;
No, the angle-cut bricks on the floor are not required.
I do not use them in my stoves.

I use a short handle scoop and pull ashes to the front.
I use my gloved hand to pull any ash from the port.
Inside the riser, I use a vacuum.

Shorty does use a bypass high in the bell until it is warmed up for the season.

Hey Scott;
Next, try using slimy mud between each brick and then coat the whole outside with mud; it will work even better.
Clay bricks will work fine.
If you try concrete, beware that it will crack or even burst if the wrong materials get superheated.

This is an L-Tube design; you must keep pushing your fuel into the fire.
Play some more with bricks and try out a J-Tube.
After you try that, then get firebricks and try out a Batchbox...
And before you know what hit you, you will have caught the RMH bug...
After that, you may find you are an apprentice Rocket scientist.

Check it out, a few blows with an 8# sledge, and the smoke shack is back in place!
The door works, but I still need to repair the Walker chimney before I can fire up the oven.
I will do a real repair on the building later this summer.
Back in business, I cooked lunch for the kids out there today

Oh My Gosh, all sorts of damage or injuries could have happened.
The smoke shack, just sitting back in place, was amazing!
The seriously strong roof with light-gauge tin that was hardly damaged.
Had I built this with rebar, it would have been much worse.

Oh yes, the boys were all bombarded with many thanks.

John, I just do not believe that for a minute:)

The boys showed up this morning, and two hours later, the tree was on the ground!
No problems, and most importantly, no one was hurt, and nothing new was damaged.
Once the tree was off the smoke shack, it moved right back close to where it belongs, with no holes in the tin and only a couple of wrinkles in the metal itself!
Once the weather warms up, I will jack each corner up and add new cement. Perhaps I will add a steel strap at each column for extra strength.

One bag was not enough.
With two bags, we had enough extra for a 12 x 12 slab.