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My new side blast


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I decided to build a Side Blast forge,  Mark A. forge design with a Super Sucker Hood into a 10" dia. chimney. The criteria for the forge is it must be portable with no part weighing more than 50#. 

The forge is in the -734 picture. The 10 gal. water tank is to the rear left and is connected to the Tuyere via. an upper hot water hose and the bottom cold water hose. The Hearth is 24" sq. x 9" deep. The Champion Blower is below the Hearth and is powered with a 1/3HP motor. Picture -729 shows the air hose, the Guillotine Gate Valve and the top Hot water outlet and the bottom cold water inlet. Picture730 shows the Tuyere in position prior to loading the hearth with Fill Lime.

Lessons learned: Welding the tapered 5" and 2-1/2" air pipe inside and outside is very difficult. A flux core wire welder was used to make the welds. The flux core weld is rough and hard to make water tight. The inside welds were done with a Inverter stick welder which turned out to be better quality. First pie slices were removed with a Plasma Cutter from both pipes. The pipes were heated with a torch and the four sides pounded together. The Air Pipe was welded to the front Donut. The water tightness was tested by placing the donut on a piece of putty and the pipe filled with water. The outer 5" pipe was welded inside and out and placed on a  putty  seal to test for leaks. The outside pipe was centered on the Donut  and welded together. The assy was then water tight tested. Using the Plasma Cutter,  upper and lower holes were cut for 3/4" female pipe connectors. Then the connectors were welded in place. the final step was welding the rear plate on the Tuyere. The bottom hose connector was plugged and the top connector was used to fill the Tuyere with water to test for leaks. To meet the 50# criteria, the Tuyere was separate from the Water Tank, connected using 3/4" ID hoses. 

The 10 gal. Water Tank was also welded inside and outside. Initially, it leaked almost everywhere. The tank was filled with water and the leaks marked and welded shut.  This process was conducted several times to fix all leaks. 

The Guillotine Air Gate Valve is shown in -729. A slot was cut in the 2-1/2" Schedule 40 pipe and the lever operated Guillotine  was welded in place. There is enough air leakage to keep an Anthracite coal fire lit when the forge is in the idle mode.

The first and second test firing was a partial success. The water cycled nicely from the Tuyere back to the Water Tank. The Tuyere plunged up and was cleared by disconnecting the air tube and running a rod thru the air tube to remove the blockage. 

Corrective actions required: The Tuyere will be raised to be 5-6" above the Hearth bottom when covered with fire brick. The air inlet will be changed to a "T" with the air coming in the bottom. The outboard tube well be plugged. When the Tuyere gets plugged, the plug will be removed and a rod inserted to remove the obstruction. The forge Hearth will have fire brick placed on the bottom and the extra space so a small amount of coal can be used. The Fill Lime will be replaced with Wood Ashes. The ashes will be wet and packed to make the Duck's Nest.

I have used Bottom Blast stationary and Rivet forges for over 20 years. The clinker problem triggered me to build the Side Blast forge.

Question: With the old bottom blast forge, the fire was extinguished by raking the red coals out on the forge pan to cool. How do I extinguish the Side Blast Forge fire as there isn't any place to rake the red ashes out to cool. Also, I don't want to mess up the Duck's Nest and mix coal with wood ashes. If the air is turned off, and I am using soft coal, I will come back to find all the coal smoldering the next day.

The next part of the project is constructing the chimney. The chimney will be a 10" tube salvaged from a wrecked Grain Auger. The Super Sucker Hood is finished and will be mounted over the Tuyere as close as possible. A frame will be needed to support the hood. The grain elevator tube has a flange end which will be mounted to the top of the Hood. For any servicing of the forge or moving of the forge, chimney must have a removable section.  The flange section of pipe will be cut 4' long. A 2' section of 10" chimney pipe will be attached between the 4' peace and the remainder of the chimney.

To keep rain water out of the chimney, a flap will be used to cover the open pipe. The design is similar to the balanced exhaust caps used on farm tractors. A cable will be attached to the cap to pull the cap open when the forge is being used.




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yes you will come back to find a pile of ash.   this depends a lot on the coal.. 

You can just pull the heart of the fire out and disperse it. Or pull it out and put it into an airtight can.  Looks like the hearth will be tight between fire and fuel and is one of the reasons I like a little more hearth. Not only to hold tooling and extra coal but at the end of the day I will pull clinker and throw in bucket and then dump the remainder of the pot on the hearth. 

i'd put either a piece of sheet metal or some insulation between the hearth body and the tuyere. I can see a gap there and dust and crude will fall out. 

I love your inventiveness but the moving cap for the chimney isn't really needed. Unless you are heating the place and are afraid that during non use the heat will go up the chimney. then a better option is a plate for the front of the hood vs a cable going up the stack or separately through the roof. 

A chimney cap is all that is needed for rain or snow .  the cap on the stack on the trailer works very well as it has enough volume to not choke back the stack draught. 

You did a great job on the build.  When is your first firing? 


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I am in the process of making a height adjustable bracket to be able to move the Tuyere up and down to be able to tune in the best height of the air tube to the bottom of the Duck's Nest.

I like your idea to use a Chimney Cap instead of the sealing plate. ??? Your cap has a bottom plate on all four sides. Is this plate used to allow the smoke to break free and not follow the chimney back down? I believe that smokestacks have a protruding ridge at the top so the smoke can break free of the stack.

From everything I have read, the Hearth is filled with sand or wood ashes. The Duck's Nest is then made in this media. Has anyone used bricks to fill up the extra space and then used Fire Brick to build the Duck's Nest? I am concerned with sand or wood ashes mixing with the coal when the fire is pulled.

My test firing of the forge, without a chimney, shed doors full open, revealed the Tuyere was too low, the fire brick under the Tuyere was glowing red, and the Tuyere air outlet kept plugging up. Raising the Tuyere so the air outlet is about 5" above the bottom of the Duck's Nest may solve the plugging problem. I am redesigning the air input. The 2-1/2" air pipe will have a new "T" section welded to the Tuyere. The rear of the "T" will be plugged but the plug can be removed so a rod can be run straight thru the air tube to clear any obstruction. The "T" probably will restrict air flow because of the 90 degree turn in the air supply tube. This problem can be resolved by altering the motor/blower pulley diameters.

I have no idea how much air a side blast forge requires to reach welding heat. Is the air supply  equal to the bottom blast forge??. 

Once the Tuyere is mounted in the new mounting plate, the forge will be test fired up to find the proper location for the air blast. Second will be finding what angle the Tuyere should be mounted: horizontal, or facing down ???degrees. The water tubes are located to the rear of the Tuyere. A few degrees downward tilt won't expose any free space where water can't reach. 

If I find the water boiling in the tank, (the water was steaming in the test) A screen type water cooling system will be added like was used in some 1900's gas engines/tractors. Rising hot water should be able to rise several feet into the cooling screen.  I also plan on raising the water tank so the bottom of the tank is equal to the top of the tuyere's hot water outlet tube. That will increase the water pressure in the tuyere.

If you or anyone else has suggestions or comments please correspond with me. I am all alone with this project, no other smithy has a side blast forge. You'll be my sounding backboard for helping resolve problems.

PS: I got my power hammer running today. It is a 25# Shatto & Son hammer. The rabbit bearings appeared to be relatively newly poured. I made new spacers for the bearing caps. I haven't been able to find out anything about the hammer. It doesn't appear in any book. Does anyone out there know anything about this hammer?P1040749.thumb.JPG.480a4dd2312f4957156c9912741294af.JPGP1040750.thumb.JPG.7d45b1bd30d02c7b1a7eb51a65c47dbb.JPG

To get adequate belt traction, an idler pulley was added so the belt would make a 180 degree contact with the motor pulley. I made the motor bracket as the hammer is designed for overhead shaft drive. The driving block travel in a "V" groove, each side, see the two dark vertical steel bars. When the hammer is engaged, the large pulley is pressed against a flat disk, (visible to the right of the belt) which applies rotational power to the hammer .his is a very simple designed hammer as compared to known hammers;L Little Giant ---.

I also have a 500# anvil (in like  new condition) that was part of a Blacker Hammer. It is possible that Fisher may have made the anvil. I also have 3 Trenton, 1 Peter Wright, 1Fisher, a no name 112#, 2 Vulcan anvils and 4 swage blocks. Three stationary forges and 3 farm or Rivet forges. Two Cones, a  hollow 4' tall and a solid cone 30" tall. I have been collecting blacksmith items since 1980. Are we having fun yet?




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You bet we are having fun.:) Your power hammer is a new one on me but looks really good. Where did you find it? You might start a new thread for it in the Power hammer section, someone there may have run across one. I just looked through the Blacksmith's and Hammerman's Emporium but there is nothing about it. BTW that should be Babbit bearings, I had to pour all of them on my 30 Pound Star, quite an experience.

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On 9/28/2019 at 12:16 AM, hdvoyager319 said:

I am concerned with sand or wood ashes mixing with the coal when the fire is pulled.

Not a problem. When the forge is cold, pull the coal and coke out with a rake. If you have something with teeth like a comb or mesh like a strainer to capture the larger lumps of fuel and let the sand and ash pass through, you'll be fine. Then dampen the ashes and reform the firebowl.

On 9/28/2019 at 12:16 AM, hdvoyager319 said:

Has anyone used bricks to fill up the extra space and then used Fire Brick to build the Duck's Nest?

I have some big pieces of chimney tile lying flat on the sand around the fire, to help keep the fuel from getting sand and ash mixed into it. However,  the point of the sand/ash fill of a side-blast is to allow you to shape the firebowl to suit the job, so I don't use any bricks there.

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