Mini Mouse for a Camper?

Hi all,

I had been living in a 30' bumper pull camper for the past four winters, and decided to start work on a heat system for this small space. When I saw the Mouse heater post for the love shack it looked to a reasonable answer to my needs. Space is very limited, so I pulled out the bench seating for the dinette that is centered along the entry wall to make room for the Rocket Mass Heater. Because this camper is on wheels total weight is a concern, and I've salvaged 1/2" plywood to reinforce the floor and cover over 2" rigid foam insulation under the heater and up the wall.
I have a 30 gallon steel barrel to place over the J-Tube exhaust and tapered fire brick to line the bottom of the J-tube.
As a student in a welding class I have the means to build the J-tube, but could use some advice for dimensions, thickness, and actual layout for the barrels to be joined. The photos in the article were helpful, but there is a lot of guess work at this point that I would like to eliminate.

Thanks for your insight!

John

Hi John ;  Welcome to Permies!
I believe this is the post your referring too. https://permies.com/t/71576/tiny-house-rocket-mass-heater
Its not a J tube design but a batchbox design.
Built by RMH master Kirk(Donkey) Mobert.
It is a technical build. Much more so than a J tube.
No barrel used. Very little if any , welding involved.  
This is a super little batch box heater and a similar built one would go a long way towards heating your trailer.
Here is a link to another RMH site http://donkey32.proboards.com/  This is Kirk Mobert's site
And here is  Peter Bergs batch box site http://www.batchrocket.eu/  This is the best information site about batch box's .

This is the one I was looking at, the Minnie Mouse Heater.
https://permies.com/t/62190/Peter-van-den-Berg-inch
I did look at this batch box cook top version, but it didn't seem quite suited to a small structure with weight restrictions.

Thank you for forwarding links to the batch box versions.

Hi John;
After looking at your link, I see that Peter did built a mini mouse for the love shack.
Its a very nice stove, and as a welding student I can see the attraction. Its possible that writing Peter a purple moosage thru Permies might get you better build info directly from the master builder himself.

In my opinion an all brick stove with no barrel would work well for you. Slower to heat,but would not run you outdoors when that barrel gets cranking. Top of my barrel 8" can run over 1000F.

I've been interested in building a more "portable" version of a rocket mass heater. Hard to conceive of, but I only need to heat a small dwell dome.
I figure there must be a way. Interested in incorporating solar heating tubes with a combined heat exchanger on rocket heater to keep a good reservoir of hot water, day and night.
Anyone attempted anything like this?
Ideally could be transported every year or two.

As someone with experience in Towing and RVs you're going to want to Center the weight over your axles and put something heavy on the other side of the trailer opposite of your heater in order to even your load otherwise you'll get sway in your Towing also adding sway bar tension kit to your ball hitch will help with this as well