MWH

An Unexpected Roadside Discovery

By July 18, 2011 No Comments

How commercial boiler parts found in a snow bank transformed our traditional view of chimney lining products and their applications.

Albie started thinking about using large clay flue tiles as the outer skin of a lower cost masonry heater about l0-l5 years ago. It all began when he saw a line of twenty or so 500 pound round two foot tall, thirty six inch inside diameter and 3″ thick tile, laying in a deep snow bank beside the road in Madison, Maine where a new Junior High School was being built.

The tiles were to become the chimney flue liner for the big boiler that would heat the large new building. He did not know at the time that such large and heavy clay tile liners were being made, but he liked them. He liked the color, the shape, the thickness and the height. You can roll a two foot by three foot tile up a ramp and through a door. With some simple lifting equipment you can even set one tile on top of another and have a stack four feet or six feet tall.

He began designing a masonry cooker/heater with Hans Nicholaisen. Master welder and designer in his own right, of Waldoboro, Maine with whom he had done several previous projects. When they were done they had a round clay tile masonry cooker/heater with a common brick on edge liner mortared in clay and a 22.5″ by 22.5″ square (o.d.) firebrick firebox centered in the tile liner.

Covering the top omasonry heater flue tile plansf the tile, Nick fabricated a lipped heavy steel top with a round cast iron loading plate in the center. Little covers near the edges adjusted draft controls that fed into steel channels under the top and turned ninety degrees down into the two front corners of the firebox. Left to right across the firebox and down the sides into the heat exchange channels, Nick designed and fabricated a baffle assembly that rested on top of the two sides and rear of the firebrick firebox.

In the rear of the baffle, a pivoting plate with a handle protruding through the cook top allowed a quick start kindle position for the gases to go directly up from the firebox, through the kindle damper opening into the round collar and stove pipe on the top rear of the cook top. With the kindle damper closed, the flame and smoke came up to hit the cook plate/loading lid then went down the front three channels, under the baffle and then up the back channels and out the chimney flue. Air coming through the rather long horizontal draft tubes was pre-heated before entering the firebox.

We took this original masonry heater design to the Common Ground Fair for a couple of years. It developed a vertical hairline crack in the tile which did not affect its performance. Although it was possible, we did not add to this unit a domestic hot water jacket. We eventually sold and installed the unit in a modest owner built passive solar home in Gouldsboro, Maine where it worked very well as a primary masonry cooking and heating source in the home. It was the beginning of our work with clay tile lining and led to new interesting projects down the road.

Inspiration for innovative masonry design can happen just about anywhere… in the heart of a home, or even a portable yurt.

During the summer and fall of 08, we were joined by a fine young mason from Pennsylvania and Colorado named Matt Helike. After a month or two of Matt tenting in our woods, we reacquired a twenty-foot portable yurt about thirty years old. We picked it up with our empty flat bed trailer after Matt, Arthur and Albie completed a huge six sided stone masonry heater with soapstone heated bench and caps in the Adirondacks last summer.

masonry heater yurt design

The yurt had started its career here when Peter and Trish Glasson were part of a metal stove building team that had their workshop in our garage building the Sunshine Stove, many of which are still in use today. Peter and Trish took the yurt with them when they moved away but it came back for a second stay when John Fisher, now a well known masonry heater and oven builder living in Sweden, apprenticed with us for a bit for more than a year and set the yurt up on stilts in a little hollow wet run in the woods.

Matt chose a new spot further into the woods in a little flat spot surrounded by hardwood trees not yet ready to blow down on something. He dug deep holes and gave it a beautiful foundation of pressure treated posts and joists to support the deck panels. He also added a nice hatch cover insulated root cellar accessible from inside the yurt, but his even more ambitious accomplishment was a large masonry footing and foundation dead center below the yurt on which Matt designed and built a second generation three foot by two foot clay tile masonry cooker/heater. He used the last clay tile of the three I bought many years ago and also used recycled brick and firebrick we had on hand. He wanted to avoid buying a fancy metal top and baffles so he spent hour after hour scratching his head and designing a highly efficient and attractive wood heating system from materials we had on hand.

yurt clay tile masonry heater project

Matt did all of the work on his own with only very fleeting visits from Albie to check on his progress. The design and construction challenge of the masonry heater/cooker within the yurt was a big one and the more Matt did on his own, the more he learned. He decided that he wanted to build his cooker/heater three feet tall so he laid up several courses of brick in a matching circle as a base to set the tile on. He then decided to bring in combustion air through the base brick course and inside the liner brick wall before introducing it to the upper firebox corners from within the unit. He made all of these air channels out of carefully cut masonry. He walked many cuts over to our powered red shed and the big wet diamond saw and also worked some of his project from the site with our Honda generator.

Matt decided to cast the top in a couple of large slabs from castable refractory rather than using metal and he installed a modest cast iron rectangular plate with a round 7-8 inch lid in it as his cook plate and loading port. With Chris helping in our masonry shop, they designed and fabricated a kindle damper with the handle protruding through the plate. And in a final community push, Scott, Chris and Matt all installed a stove pipe which traveled through one panel of the faceted ceiling skylight, (plexiglass replaced with metal) and transitioned through a roof mount factory chimney section with a smaller factory chimney above the roof.

Matt got engaged just before he joined us and left his fiance working for the Forestry Service in Colorado while he traveled to Maine. With the modern blessing of cell phones and unlimited calling plans Matt kept in constant touch but his heart kept calling him back to his love far away. He stayed as long as he could with us and worked on a few good projects and stayed one extra night, working well into the wee hours to finish his cooker/heater and then decided to give it its maiden voyage burn and sleep in the yurt for the first time with real cozy masonry wood stove heat. He left with pride in his heart and a gleam in his eyes.

The yurt is up with the round cooker/heater gracing the center ready for the next guests to arrive.