Steel & Brick

Steel side draft coal forge inmy old shop.

Built of brick and steel plate as anexperiment to see if a hoodlessdesign would make the task ofheating the iron more comfortableand convenient. This forgeoutperformed any other type offorge I have ever used in suchdramatic fashion, that I will continueto build this style of forge in thefuture in preference over any other.This was my third forge and wasdesigned for making wroughtironwork (gates and railings), tools, machine parts, and horseshoes. The chimney drew smokein all types of weather including heavy snow, heavy rain, and very windy days. And thechimney drew smoke so strongly that the smell of coal smoke had been completely andpermanently banished from the shop. And by this I mean that ALL smoke went up thechimney - not just some of it.

Page updated October 06, 2010. Under construction, re-write in progress.

The forge shown here at right, was inspired by the large shop forges that were featured in thebook The Blacksmith ~ Ironworker and Farrier by Aldren A. Watson. The large hearth sizeoffered plenty of space for placing tools and coal and hot iron, near the fire. The chimney flueis 12" square. A large chimney cap kept rain and snow out. The hearth plate measuring 72"long by 40" wide, was made of 5/16ths steel plate reinforced with 1/4 x 2 inch angle iron. Thehearth plate was supported by the corbelled sides of the lower chimney at one end, and by twobrick pedestals built over the front of the forge foundation at the other end. A tool rack wascast into the brick structure to hold hardies and hardie tools. Detachable tongs racks weremade to hang from the edges of the hearth plate. The internal chimney dimensions were takenfrom an article in an old issue of the Anvils Ring. I had discovered entirely by accident, afterwitnessing the action of a smoke shelf that I had inadvertently created while stacking brick upbetween the fire and the rear wall of another forge - that smoke shelves have a tremendousinfluence on reestablishing smoke draft in a chimney that has experienced a downdraft due towind turbulence. That forge was my old fabricated steel forge that is featured further downthis page. Anyone that claims that smoke shelves don't work, obviously hasn't ever worked

5.24.2011 Steel & Brick

http://www.beautifuliron.com/steel.htm 1/8

with a properly designed smoke shelf. My steel and brick forge (shown here) was a greatsuccess and I plan to build another like it again in the future. And now let's look at where thechimney design came from.

Chimney design based on article by DimitriGerakaris in the Anvil's Ring. Internaldimensions of the chimney were based roughlyon those found in the Anvil's Ring Vol. 7 #1 fromMarch 1979 (also known as the Hoodless Forgeissue). These designs were chosen because theydid not smoke like other chimneys of the previous era. Anyonethat has seen an old brick chimney built during the 1900s is aware that the chimneys duringthat era were all smoky. The internal designs of these chimneys solved the smoky chimneyproblem and featured a smoke shelf to help chimney draft during weather turbulence.

Constructing the forgeForge construction took about 2 weeks. The weight of masonry requires the builder to add nomore than about 2 to 3 feet per day. The temperature dropped during the second week as I wasbuilding the chimney and work slowed to 2 feet per day.

Materials used in this forge & chimney construction. Materials were good quality brick andmortar. 1/2 inch rebar was also used throughout the lower part of the foundation and upthrough the level of the upper smoke chamber (near the top of the wooden knock-down formsseen in the picture at right. No flue tiles were used in this forge due to problems trying toobtain them. The hearth was made from 5/16 inch steel plate.

Knock-down forms used during construction. In the photo nearright is the chimney under construction, this time showing theforms used to support the uncured masonry while constructingthe smoke shelf and the upper smoke chamber. The forms weredesigned to be broken apart and removed after construction. Thelintel bar was also supported by wood blocks to prevent itsweight from damaging the mortar while the mortar was curing.The sloped wall of the smoke shelf was created by rammingmortar against the knock-down forms and packing the inner part of the shelf with mortarbroken bricks and rubble as fill material. This method of creating the smoke shelf resulted inall exposed inner surfaces inside the chimney being smooth and clean. Rebar was cast throughthe walls of the chimney and horizontally through the smoke shelf - strengthening the mortarand rubble construction of the shelf.

At far right is a photo of the chimney a little later in construction after the brick has been builtup over the wooden forms. The corbelled shelves built low on the sides (level with the bottomof the smoke entrance) will support the chimney end of the steel hearth. The hearth is made of5/16 inch steel plate and is very heavy and will remain stationary, so the only place where it



will be bolted down is to the masonry legs at the front of the forge. The hearth simply restsunder its own weight along the corbeled sides of the chimney since it isn't likely to move if it isbumped or struck. A hardie rack was cast in place in the mortar near the base of the chimney.The space between the rails of the hardie rack fits my anvil tools, or about 1-1/8" between rails.

Positioning of the firepot in front of the chimney. Because room inside theshop was at a premium I was forced to locate the chimney as near to the wall aspossible and so the smoke hole in the chimney was offset to compensate forfirepot placement. The photo (right) shows the position of the firepot near thechimney. The rear edge of the firepot is about 3 inches from entrance to thesmoke hole of the chimney. This was one of my experiments to find out if it wasbeneficial to place the firepot on a rotating separate plate to allow the firepot tochange position for different jobs. I recommend that others don't do this becausethe firepot is never rotated. I now build coal forges with the firepot inset into the hearth, so theedges of the firepot are placed level with the surrounding hearth plate surface.

Refractory material protects brick nearest firepot. Fireplace cement was molded onto the frontsurface of the chimney nearest the fire to help protect the masonry. The intense heat of the firewould quickly deteriorate the masonry otherwise.

Lintel bar. A lintel bar of angle iron supports the brick structure above the smoke entrance inthe bottom of the chimney. The lintel bar is offset outward, so that a small sheet metal hood canbe hung from the protruding edge of the lintel bar.

Hearth. The raised sides of the hearth are made of 1/4 x 2 inch flat steel, and are weldedaround the perimeter of the hearth to help keep fuel from falling off.

The photo (far right) is a view of the side of the hearth nearest thesmith. At center of this photo the cutout area of the rim aroundthe forge hearth, is clearly visible. The small hearth extension isvisible (an extension of the hearth projecting out towards thesmith) at the cutout area. And of great importance in this view is the reinforcement of the edgeof the hearth in this area. It can be clearly seen that edge of the hearth is reinforced around itsperimeter by the rim welded to it, but to remove a portion of the sides or rim anywhere alongthe hearth would leave it weak and prone to bending or collapse in that area. To strengthenthis area the rim or side of the hearth is continued from underneath with a piece of 1/4 x 2 flatmaterial welded to the underside of the hearth edge. The reinforcement overlaps the ends ofthe sides from underneath and gives maximum reinforcement to support this area as thoughno cutout existed. Also visible in the photo (near right) is the plumbing of the air blast pipefrom the blower.

The blast air delivery piping is placed around the front of the forge and thendown and backward into the hollow of the chimney where it then bends up andforward again to enter the tuyere pipe of the firepot. This was a mistake. Eachbend of the air pipe restricts the flow of blast air. Had a hole been built into thelower-rear of the brick chimney structure, a single bend, or possibly a bend and a half would



have directed air into back of the tuyere. There are a total of 5 bends between the blower andthe tuyere pipe in this picture. Each bend makes it more difficult to get air into the fire.

Simple hanging tongs racks were fashioned from 1/4 x 1" flat stock which weremade to hang from the sides of the hearth rim. The racks hung down well belowthe top edges of the hearth rim so that the ends of the jaws of the tongs weremade lower than the hearth rim so that they didn't foul tooling or iron whileworking in the fire. At lower left is the smaller tongs rack near the anvil which kept the groupof tongs most used or needed immediately.

Firing the forge for the first time. In the photo at left (Click on the thumbnail) afire has been lit for the first time in this forge and a small bar is being heated.This was in the middle of December and the cold weather slowed the curing ofthe mortar so I didn't want to chance a large full size fire. Even with a small fire

like this one, notice that the draught of the chimney is so strong that it actually bends the flamebackwards towards the smoke hole. The edge of the rim which runs around the hearth, cutoutto allow for level placement of the iron through the fire. In the picture at left the iron and tongscan be seen hanging over the edge of the forge nearest the smith. A small extension plate waswelded to the edge of the hearth plate here at an angle slightly above horizontal, to give addedwork area to help support long pieces in the fire and to help keep fuel from falling off theedge. Also notice the group of fire bricks laid along the fire both in front of the fire and behindit inside the chimney. These bricks create a trough to help build up the height of the fuel in thefire and to help maintain the fire. Some of the older all-brick and mortar forges were built witha trough cast into the surface of the hearth to create this same effect permanently. To see whatthis effect is based on, look at the pictures on the Dows Blacksmith forge.

...and one year later.These pictures show the forge as it looked after more than a yearof use. At right is a photo showing the forge and most of theshop area. Coal was simply dumped in a pile on the hearth withas much as 100 lbs. of coal on the hearth when a new bag of coal

was added. The hearth was large enough to support all of the coal with plenty of room leftover for placing tooling in easy reach, and for small bars or objects to cool safely beforequenching. Fire bricks are placed around the perimeter of the firepot to help raise the height ofthe fire. Free hanging tongs racks were hung on the side of the forge hearth for tongs used mostoften, and another hung at the front of the hearth for tongs that were used less frequently.Tongs racks were hung low enough to allow the jaws of the tongs to remain below the hearthand out of the way to avoid snagging tooling and work being moved back and forth aroundthe fire. The building was very small but with convenient and efficient placement, the shopwas uncluttered and everything was in comfortable reach - anvil, blower, hearth, water barrel,vise, and drill.



A piece of pipe or other object placed across the opening of thehearth rim near the fire kept fuels from falling off the hearthduring use. Seen here in the working photos at left are somelarge scrolls being heated. The weight of the scrolls rests on the

pipe placed across the opening in the hearth edge, but if it caused any obstruction toplacement of objects in the fire, the pipe could be removed quickly. The small shelf near thisopening in the hearth edge, was slightly inclined to help fuels stay on the hearth when theopening here was not blocked up with pipe. As can be seen in these photos, smoke enteringthe side draft chimney literally lays over sideways to enter the bottom half of the entrance inthe chimney. This demonstrates the strength of the draw acting on the smoke and forcing it intothe chimney.

After months of continuous work, cinders accumulate in a sloped pile in the bottom opening ofthe chimney. This poses no problem and is actually desirable. The cinders or fines protect thebottom surface of the chimney from direct flames of the fire. Periodically some of the excesscinder pile will need to be removed (about once a year) and discarded.

There are about 6 firebricks in front of the fire to raise the height of the fire - making the firedeeper and easier to maintain. More firebricks are hidden beneath the cinders between thefirepot and the chimney entrance.

At left are two photos of the view the blacksmith seeswhile standing at the anvil.

At right is the view of the shop and forge when looking into the building.Because of the tiny size of this shop ( 11' x 16) space was at a premium. Behindthe photographer and to his left and right were a drill press and a Little Giant25-pound power hammer.

Hardie racks were cast into the brick work on the side of the lower section of thechimney during construction. Hammer racks were cast into the rear of the brickstructure to hold lesser used hammer tools. Again the pipe laying across thecutout area of the rim of the forge hearth is visible here in place to help hold fuels on thehearth. The pipe is not necessary, but is a simple and quick convenience.

Not visible here also, was a wood-burning stove for heat. The stove was located to the left ofthe forge in this photo and about 6 feet away from the smith.

My old steel fabricated forge.



At left and below left, arephotos of my first successfulforge built of angle iron andsheet metal. A CentaurVulcan firepot and a BritishAlcosa F-70 hand-crankedblower, both bought new,from Centaur Forge areinstalled on this forge.Firebrick lines the rear wallof the hood right up to thebottom of the chimney flue.This steel forge (photo atleft) worked well enoughthat I used it for 6 years. Itwas a of a conventional

style of fabricated forge with a half hood. Similar in design to modern fabricated forges whichcan still be purchased from Centaur Forge today. A tong rack was welded to the front tosupport some of the tongs I used for blacksmith work. Firebrick lined the rear wall of the hoodup to just below the chimney pipe. Smoke actually is attracted to brick structures and will hugthis wall until entering the chimney. The top of the fire brick acted as a smoke shelf - helping tocontrol the back drafts that would otherwise push smoke back down the chimney during windgusts on windy days. It should be noted here that, the original hood configuration allowedsmoke to blow back down the chimney during wind gusts on windy days. After adding thebrick wall under the hood (as shown in the photo at right), these back drafts stopped, and therolling action that the smoke shelf caused on the smoke was quite visible during wind gusts bysimply looking under the hood. There was one more row of brick stacked up under the hood -but due to the dark photo, this is not visible. The top of the brick was 4 inches above thebottom edge of the hood. Only after building up the back wall on this forge to its final height,did I finally discover the effects of a smoke shelf. It was this forge shown at right, that causedme to seriously consider the contributions that the smoke shelf offers in chimney construction.The open construction of this style of hood allows the smith to look up under the hood to seehow well smoke flows over a smoke shelf under every condition. And just for the record, Inever intended to build a smoke shelf on this forge. The smoke shelf is an incidental part ofstacking up a brick wall behind the fire to help guide the smoke. My discovery of the action ofsmoke shelves was entirely accidental.

The chimney is a custom made sheet metal pipe, made at a local fabrication shop. A newAlcosa F-70 hand cranked blower was fastened to an arm extending from the back of the forge.The firepot was a Centaur Vulcan which at that time cost about $85. (They are about doublethat in price now I think.) Firebrick was then built up around the fire pot to help create adeeper fire and make use of gravity when tending the fire. The forge hearth measured about 40inches side to side, and about 60 inches from front of tongs rack to rear of chimney. Hearthheight (from floor to hearth level) was approximately 32 inches. I used this forge to makeeverything from wrought iron gates to draft horse shoes. All of the tongs seen in these photosare made by me as well.



yThe firebrick in the back of the hood wasn't in myoriginal plan. But over time as I learned to use theforge for more complex forgings and repairs, thebrick wall in the rear of the chimney and the

bricks around the fire were added. It basically evolved over a year until the forge looked as itdoes in the first photo shown above right.

Note the convenient position of the blower which is mounted so that the crank does not comein line with the path that long bars take when placed in the fire. Long bars could thus be heatedwith this forge without fouling them with the hand crank of the blower.

One problem encountered with this forge is height of the tongs racks. I found throughexperience that tongs should always be hung so that the jaws are below the level of the forgehearth so that they don't interfere with or foul the bars or objects that are placed in the fire. Thisis especially a problem when working on large scrolls and parts for gates and when makingrepairs to large awkward machine parts.

My newest semi-portable steel forge

Here is my latest all steel semi-portable side draft shop forge. The side drafthood is fabricated of sheet metal and angle iron welded together. Thedimensions for the inside of the hood follow the internal dimensions of thesidedraft forge designed by Dimitri Gerakaris in the Anvil's Ring issue March1979 and are similar to the dimensions used in the brick chimney seen above.

To see more on this forge go to the Steel Sidedraft Forge page here:http://www.beautifuliron.com/mysteel.htm .

The hearth plate was cut out of the remains of the hearth plate of the brick and steel forge(photos at top of this page) when I moved to my new shop. While I plan to build a large forgeagain in the future for my ornamental ironwork, a good sidedraft forge was needed in theinterim which could be transported to use in the field as well as setup permanently in a shopsetting. The hearth measures 32" wide by 36 inches long, and stands 31-1/2" tall or about 1"below the knuckles of the hand when standing beside it. The firepot is a Centaur Vulcan savedout of the brick forge above and the blower is the same Alcosa seen in the photos of the brickforge above on this page. The firepot measures roughly 13-1/2" wide by 12-1/2" long (thelonger dimension being across the width of the forge or in line with the steel bar seen placedacross the forge in the photo at left). The distance between side edges of hearth and edges offirepot is 9". The rear edge of the firepot is 7-3/4" from the rear of the hearth and the front edgeis 15-3/4" from the front of the hearth.

Latest update 06 October 2010.



The author can be emailed at address in picture below:

Page created around November 1999.



Documents

Steel & Brick