Coydon Wallham

In the most recent podcasts from Paul, he and Alan Booker essentially sent out a call for help from the public to advance the "experiment" with the Willow Feeder (WF) model. A primary concern expressed by Alan was to see if WFs in various climates would produce similar Returns On Investment as have been seen from deposits made at the Willow Candy Warehouse at Wheaton Labs.

I'm not aware of a fully comprehensive resource describing a complete build of a WF, or laying out the various design considerations that present options a builder would want to consider. This ain't exactly Rocket Science, but it would still be good to have a document that approaches the comprehensiveness of ones for RMHs as done by Ianto Evans or the Wisners.

I'd like to maintain this thread as a clearinghouse for questions and answers about the pesky little details that would prevent or stall various efforts to complete and maintain a Willow Feeder operation by inspired Permies. I started planning out a system for my land last year and have a few such issues that are making the process seem like a much more difficult undertaking than it seems it should be.

1) Pressurizing the Candy Chamber
2)

The greatest hurdle I've had trouble moving past in design thoughts has been how to engineer the negative air pressure in the 'candy chamber'. Obviously it is based around an exhaust pipe extending from the chamber to the exterior of the building. Options used at Wheaton Labs to generate the negative pressure have been battery fans and trombe walls.

The trouble I am having at the conceptual stage is how to create the air tightness in that chamber to allow pressure to build and draw up the exhaust. Can dimensional lumber alone be utilized with tight enough tolerances, or does it require some sort of liner? It seems a rear access door that would be used to cycle the bins in and out would be particularly difficult to construct to form and maintain a seal, such a large, unfixed plane being prone to warping over time.

The other part of this equation is the air intake. Does this need to be strategically placed? Is the gap around the access door the default intake? I would guess that the system would perform best if the exhaust were at one end of the chamber and the intake at the other to ensure flow over and around the bin(s). Would it work to have an air intake from the interior of the feeder to help cycle fresh air into the occupied area?

A related issue is air around the seat access. I recall the WL Feeders have regular seats that have been altered to sit flush with the surface of the candy chamber top such that they form an air seal while in the closed position.

In the most recent podcasts from Paul, he and Alan Booker essentially sent out a call for help from the public to advance the "experiment" with the Willow Feeder (WF) model. A primary concern expressed by Alan was to see if WFs in various climates would produce similar Returns On Investment as have been seen from deposits made at the Willow Candy Warehouse at Wheaton Labs.

I'm not aware of a fully comprehensive resource describing a complete build of a WF, or laying out the various design considerations that present options a builder would want to consider. This ain't exactly Rocket Science, but it would still be good to have a document that approaches the comprehensiveness of ones for RMHs as done by Ianto Evans or the Wisners.

I'd like to maintain this thread as a clearinghouse for questions and answers about the pesky little details that would prevent or stall various efforts to complete and maintain a Willow Feeder operation by inspired Permies. I started planning out a system for my land last year and have a few such issues that are making the process seem like a much more difficult undertaking than it seems it should be.

1) Pressurizing the Candy Chamber
2)

thomas rubino wrote:Hey Eloise;
A first-generation batchbox would be the most familiar to a box stove operator.
Nothing special about lighting one, all mass heaters start super easy once the mass is warmed for the season.
One catch would be that to hold your heat overnight, the air intakes need to be closed.
Your friendly neighbor would want to come by to shut it down in the evening.
If your stove has a bypass gate, it must be easily identified and have a clear open and closed operating position that your neighbor is aware of.

They must understand there is no damping a mass heater down, these stoves run wide open all the time until it coals and then the air intakes are closed to keep your heat from drafting out the chimney overnight.

If using a J-tube, they would need to understand that the whole wood feed is the air intake that needs capping after the fire has run it's course, and that while burning the wood should be contained in the vertical opening and not placed in the horizontal burn tunnel.

Also, my experience with an 8" J-tube is that it will burn for about 15-25 minutes with a load of softwood (pine), and about 30-45 minutes with hardwood (mixed).

Douglas Alpenstock wrote:Interesting problem. If you're mounting to a hardwood stump, the lag bolts might be cracking the wood slightly so they won't hold. Drilling pilot holes before screwing in the lags might be helpful.

I did have it in a maple stump last year, but it was barely big enough and eventually blew holes out the side of the stump. I think the larger stump I have now was from a Doug Fir haul...

In one of Paul's recent podcasts, I think it was Alexandra mentioning that one of her 'bootlings' found the use of the kindling crackers was 'more fun than a birthday' or something similar. Sounds like a great marketing line if there's ever a need to push the kindling crackers, but seems like they sell themselves at this point?

What I need is advice on mounting mine. I used the biggest (lag) bolts I had in my garage with washers that fit the cracker feet, but they are working themselves free pretty quickly in the cold when smashing the big knotty hardwood into the blade. I'm guessing I need to buy a special type of screw to work in the endwood of a stump in frigid conditions? Is this where the "timberlok" (RSS?) screws I've heard of are needed?

Trace Oswald wrote:
I'd be great with that, but by the time you figured gas and time from Wisconsin, I could buy the chimney blocks here for less money.

Right now I'm planning to drive through LaCrosse next weekend, depending on Friday/Saturday night accommodations. I can bring whatever fits in my 5 foot bed (and hopefully won't break the transmission) with me no problem. More weight for icy road traction...

Trace Oswald wrote:
Thanks for the tips.  I'm near LaCrosse.

Ah, your mention of Duluth threw me.

The County Materials I noticed around there was a bit East of Trempealeau.

thomas rubino wrote:Well, that is simple.
They are cheap and just down the road from Trace's house.
Normally solid clay bricks are used.
If using the 3 holers without filling the holes they would be insulating the bell.
Filling them with clay is easy and cheap, Trace has clay pockets on his land.

Well I use the three holers for the outer wall on my Bamm-Bamm style RMH. It worked pretty well, seems to be a good match for yurt/tipi environments as it can be broken down without as much effort as mortar or cob. I still have a surplus of old fashioned pure clay chimney bricks, maybe Trace is interested in a swap?

thomas rubino wrote:
Your three-hole bricks will become solid clay bricks after you fill the holes with clay.

I feel like I've missed the key head on this Hydra like discussion. Why three-holers for the RMH and why fill the holes with clay?