Ray Dudley - Lessons from Our Rocket Mass Heater

Lessons from Our

Rocket Mass Heater

R AY & R ANDI D UDLEY

Copyright 2015 Ray &Randi Dudley

All rights reserved. No part of this bookmay be reproduced or transmitted in any form or by any means,electronic or mechanical, including photocopying, recording or byany information storage and retrieval system, without permission inwriting from the author.

Produced by 12 Chickens Publishing

ISBN 13: 9781499125818

ISBN 10: 149912581X

To my wife and kids.

L ESSONS FROM O UR R OCKET M ASS H EATER

Preface

If youre purchasing this booklet wereassuming you have some rudimentary knowledge of rocket massheaters. After all you didnt find the booklet by searching forcute bunnies around the globe. Our assumption carries with it thepresupposition that you have a basic idea of what they are, howthey work and perhaps have seen pictures or watched videos of them.And since there really is a ton of information out there about howto build them we felt it wasnt necessary to write another how-tomanual. This little booklet is more along the lines of the a Gee,wed wished wed have know that BEFORE we finished or a Wheredid they find that manual.

We bought the books and videos and visitedthe forums (multiple times) and finally took the plunge and builtour heater. But, along the path of building it we found that westill had a lot of questions that we had no easy answers for. Forinstance, we knew wed be building a cob bench, but, we didnt havea clue what cob really was and no one really talked about how tomake it. No one spoke about how to get those nice tiles into thecob. We were stumped about coloring the cob as well as how toactually build the bench. We didnt know that wet cob has atendency to flare out at the bottom when stacked too high too soon.Wouldve been nice to know.

And so we decided not to write a step bystep heres how to do it book. We decided to compile a list of theblank areas which we struggled with and try to cut down on theresearch time others would have to put in looking for answers wealready found.

We hope you find this book enlightening andentertaining. Its not written with the hope of making anyones topten list and it certainly isnt written like some scholarly tome.Its laid back and filled with tips, pictures and resources as bestas two non-writers could do it.

We absolutely love our rocket mass heaterand have given many tours to folks that hear about it and need towrap their heads around the dirt pile with a 55 gallon drum stuckin our living room. Its warm both in looks and in the heat itprovides and were ecstatic to take frequent naps on it.

Lastly, were proud of it. My wife and I did97% of the work required to build it with curious friends sometimesjumping in help us out. It took us months to accomplish and attimes the pace was frustrating. But, its not everyday (at least inNew England) that you get to stomp clay and create something sounique. And each one thats built IS unique. Youll be proud ofyours as well.

There are several resources mentionedthroughout the book, but, we made a quick reference list after thelast chapter.

A little bit of upfront candor here from us:Some of our links have affiliate codes attached to them. This meansthat should you purchase something using one of our links we couldreceive a referral fee. Use them or not, we just wanted to keepthings out in the open.

Good luck and many warm wishes from us.

About This 2ndEdition

The truth be told, when we wrote the firstedition of our booklet we didnt expect anyone to buy it. Honestly.It was our first attempt at writing anything, but, we knew wewanted to put all of the lessons we learned as well as all of theresources we had to hunt down into a central location andpublishing it just in case anyone else could use the informationseemed like a good idea. We even did the art work and editingourselves (not such a good idea). Were not sure how many folksweve driven into therapy with our grammatical errors, but, trustus were sorry!

Almost a year later weve sold over athousand booklets and would like to take the opportunity to sayThank You to anyone that bought the original booklet.

Were updating it because as weve re-readit we realized several things:

1) Our editing skills stink. Weve foundwords that were missing or words that werent missing, but, were inthe wrong context. Like meaning to use knew, but, instead usednew. DUH. So weve set out to correct that (we hope).

2) Looking back, theres some info we feltwas missing. Things such as addressing the portion of the exhaustpipe which was outside. Or editing some of the photos to enhanceclarification and hopefully explain some things better.

3) We wanted to add some extras to givethe booklet a little more value and so were including a shortchapter that talks about a rocket mass heater workshop we heldafter writing our booklet. It doesnt go into a lot of detail, but,we thought it might bolster your enthusiasm and courage to see andknow that theres a whole lot of other folks out there that shareyour curiosity for these creations we call rocket mass heaters.

4) Lastly, theres been some new resourcesthat have come along which we thought might be helpful and so weveadded them in as well.

If this is the first time that youre buyingour booklet wed like to say Thank You and that its our deepdesire that it really helps you to feel a bit more confident as youconsider building your heater.

We say it in the booklet, but, it bearsrepeating: Have fun, take lots of pictures and love the wholelearning process. We did.

Ray & Randi

Chapter 1

The burn chamber is prettybasic. Your biggest decision is trying to decide between a burnchamber thats made from bricks or one that is poured. IantoEvans & Leslie Jackson who wrote Rocket Mass Heaters - Superefficient Woodstoves You CanBuild and Ernie & Erica Wisnerauthors of Bonny Convection Bench: 8 Ductdiameter (the main resource of ourbuild) both currently lean toward the brick type of burn chamberswhile Matt Walker, owner of Permsteading.com , has used bothand even has a video, complete with instructions and dimensions,about how to create the mold that would hold your poured material(found HERE ). Both systems have pros andcons so why dont we take a look at each.

Lets start with using bricks. On the proside for bricks are the facts that they usually free (and we reallylike free), theyre pretty easy to carry, theyre easy to stack andwork with, and they can be torn down or dismantled withoutdestroying the whole thing, and can easily moved and rebuiltsomewhere else. That last point is important if you make a mockupburn chamber outside to play with (highly recommended by the way)and then want to move it to its final resting place. The cons arethat they may have to be cut (not a super problem), they HAVE to besealed well between them to prevent gases from escaping, and theytend to move easily if you bump them. The dimensions of theinterior of the burn chamber are pretty precise and the interiorwalls need to be as smooth as possible so as not to put drag on thefire. If the bricks move a bit on you the walls may be irregular insize and smoothness and that can have some minor changes inbehavior. But, theyre the go to material on most builds.

Next up are the pros and cons of pouring theburn chamber. On the plus side are the facts that its one solidpiece (no gaps to seal), its precise in its dimensions and itmoves as one unit. The downsides are that it can be a lot moreexpensive depending on the materials used, it moves as one unit(meaning that theres no tweaking anything once its poured), itwill usually be poured somewhere other than its final resting spotand since its damn heavy (over 100#) it takes at least two peopleto move it and place it, and if you damage it you just wasted bigbucks and may have to re-pour the whole thing. And yet, we like thepoured version.