Yelm Contraflow Repair

I recently repair a contraflow heater in Yelm, WA.  This heater was built around 1992.  It was built with a tappered throat as you would see in a traditional fireplace but would no longer see in contemporary heater designs.  Over the last 20 years of heating the bricks in the throat had deteriorated and begun to debond and fall foward as shown below

20141124_131649  20141124_131644

The heater had in the past had a metal oven insert.  This insert had been removed previously and the area around it had deteriored quite a bit.  Bricks were missing, debonded and cracked.  The upper porations of the inside side channel walls were also debonded.

20141124_131557 20141124_173700

The rebuild began with demoing and removing the throat.  The throat was built on top of a skewed brick made of precast refractory that allowed the throat to built easily with a taper as the bricks were layed on the skew rather then level.  I was hoping to be able to demo the throat, all the masonry in between it and the back wall, then remove the skew to lay the bricks level while corballing foward. This would further allow me to tie the bricks into the masonry more and lead to a stronger throat.  Unfortunatley, the masonry behind the throat bricks was to solid to remove.   I thus had to rebuild the taper with the brick tilted forward as origonally designed.

Rather then rebuild with regular firebrick, I elected to cut a 24″ tile in strips that would span the entire throat and thus be tied into by the side channel walls as shown below

20141126_102928

I added a removable liner to the back wall of the firebox as it was taking the most abuse.  The custom made skewed piece on the back wall tied all the way into the back rear wall of the heater.  It had a crack in it so I wanted to protect it in particuclar rather then leaving it exposed to the highest temperatures in the heater.

20141126_164312

The firebox was reset. I few new pieces put in and the bricks around the air intake redone.

20141126_164318

Some of the facing brick around the door was experiencing cracking.  The rear part of these bricks were exposed to the inside of the firebox so I installed some shielding.

20141126_164323

Lastly the oven which had previously been a metal insert was bricked in to create a white oven.  (meaning it is heated from the outside in as gases flow around it)

Unfortunately I did not take a finished picture.  However here is one during the process.  It was tricky working with such a small access.  The oven was built on top of the tappering throat.  I relayed the upper portion of the side channel walls.  The began building the oven walls.  There was not enough space to build the oven walls and then insert the ceiling tile in.  So I built up the rear bricks, built half of the oven walls then inserted the ceiling and proped it up on the rear bricks, finishing building the oven walls, unproped the ceiling tile and lowered it onto the oven walls.

20141128_140013 pictured here are the first two courses of the rear oven wall.  The long vertical pieces in front is propping up the ceiling tile so that I can continue building the oven wall to 3 courses.

It was a fun but challenging job.  Rebuilding such a significant portion of the heaters insides proved to be quite a challenge clearence wise.  Hopefully, this gives the heater another 20 years of life.  I believe contemporary heaters without tappered throats will be holding up longer, further contemporary replacable firebox liners allow for easy repair of the firebox.

 

Advertisements

Custom Carved and Inscribed Flower Press

At a previous years Stone fest, I had the wonderful experience of being introduced to the craft of stone inscription by two amazing carvers.  Karen Sprague and Tracey Mahaffey.  These two artists and carvers do inspiring work, working with families to create and carve by hand custom tombstones and memorials amongst other things.  They got me started in v cut lettering, a method of inscribing letterd into stone with a hammer and chisel.  I found the work very meditative and enjoyable.  I have been seeking the time to carve more and hope to incorporate stone carving and inscription into more projects.  Recently I carved a custom letter press.  The carving was done with a single lettering chisel on slate.  The inside was lined with a cork to provide a firm, yet soft surface to press the flowers and clamps were added to give and additional tightness.

Getting started,

20140615_151739  20140616_160436

To me V cut lettering charm is in the shadows

20140618_205142   20140618_205046

Finished

20140630_081548

North Carolina Custom Bell Heater facing

I just recieved finished photos of a heater I had the pleasure of helping face with fellow Masonry Heater Association Members following our annual meeting.  The build was led by Edward Small of Sheridan Brick and Stonework based in Maine.  Edward is a great guy and a restoration specialist.  The custom design of this heater was done by bell expert Alex Chernov of Stovemaster.  The design incorporates a traditional fireplace (with a more efficient modern design; notice the sway forward and back in the rear wall of the fireplace) as the center piece of the project, wrapping the heater around the fireplace.  This design places the actual heater firebox on the side of the heater with bells wrapping around the fireplace.  The heater core was built by Edward before the annual MHA meeting.  Following a week of heater/oven building, experimenting, testing, workshops, and meetings along with some hanging out and a big pizza party, I had the pleasure of working on the facing with Edward Small and Steve Cohen of Hot Rock Masonry.  The stone proved to be much harder then expected and as a result much harder to shape with a hammer and chisel.  This led to a lot of dust and noise as we had to do much more grinding then desired.  I am personally not a fan of grinders and prefer a hammer and chisel.  We had to rough out the stone with grinders and saws and come back and dress the stone with a chisel.  Working long days, breaks were spent admiring the view and a proper tea break or two.  On the road we spent evenings in a beautiful log cabin on a ridge in the blue mountains.  Steve and Ed are great guys to spend time with.  I, of course, tried to soak up as much knowledge as I could from these older master masons.  A few evenings were spent with Steve schooling us on the game of pool, as he is know to do.  I believe he lost one game that week.  I was able to stay on the job for 8 or so days and had to continue my east coast trip before it was finished.  The end result is gorgeous.  Steve Cohen deserves the credit for the beautiful arch work.  The hearth and bench stone is a Tennessee sandstone called crab orchard sandstone.  It is just gorgeous in person.  Thanks again to Edward Small and Steve Cohen for inviting me on the project.

 

Getting started facing the core

20140424_191006

A good view of the crab orchard sandstone, and arch work of Steve Cohen

burnsville6

Coming up in the back and setting the selves

20140428_174151

The finished heater

SAMSUNG CAMERA PICTURES SAMSUNG CAMERA PICTURES

SAMSUNG CAMERA PICTURES  SAMSUNG CAMERA PICTURES

And the views of the beautiful Blue Mountains of North Carolina

From the jobsite

20140424_191313

From the cabin

20140426_092309

Oak Harbor Soapstone Masonry Heater part 2

20140522_121540

Once the firebox is complete the lintel is set.  Ceramic wool allows for the core to expand while functioning as a gas tight gasket.  After the firebox, the throat is built corbelling back and bringing the gases from the fire-box behind the oven.

20140526_133738

Once behind the oven the hot gasses travel up spilling over top of the oven into the two (side) down channels.

20140526_133733

20140526_170029

A top view of where the heat travels from the center channels into the side channels and then down the side of the heater.  The circle in the back is the up channel which connects to the chimney.

This heater contains what is called a white oven as no fire or gasses actually go inside of it.  A white oven is heated by the hot gasses that surround it.  In this heater, the oven is heated below by the fire-box, then the gas travel behind it heating the back, they spill over the top and then travel downwards along side of the oven thus heating the oven on four sides.

Next the capstones are placed, the chimney connections are made and the heater is complete.

Soapstone contraflow masonry heater

Soapstone contraflow masonry heater

Oak Harbor Soapstone Masonry Heater part 1

Soapstone contraflow masonry heater

Soapstone contraflow masonry heater

This past week I had the pleasure of traveling to Oak Harbor, WA (on beautiful Whidbey Island) to build a masonry heater with master mason Steve Cohen of Hot Rock Masonry.   We built a soapstone Contraflow with added passive bells on both sides of the chimney up channel.  Soapstone is the most efficient material for masonry heater building as its density allows for maximum heat storage capacity.  This heater contained (I believe) around 9,000 lbs of soapstone so it should store quite a bit of heat.  Due to the massive amount of weight (ie thermal mass)  every heater needs its own foundation.  We built up a foundation out of CMU and then poured a concrete slap up to the height of the subfloor.  We did this a few weeks before the actual heater build so no pictures.

The base slabs of the heater were put in first, followed by the bottom course of the down channels which connected to the two heated benches the wrap around the heater.  An ash dump doubling as an air input into the fire box was built in the center.

20140520_163355

Next the core (interior) bench channels were capped

20140521_103216

From there we put the exterior bench in place and began building the firebox and down channels.  The holes on the back of the firebox provide an additional air input into the back of the fire to further aid a complete combustion

20140522_104024