Solid fuel forge build question

[Jordhandson]

Hi all I am in the process of building my  first forge I have the hearth 6 inches deep with 2 inch thick night storage heater brick in the base now i am adding a furthur 4 inches of side panels making a total of 10 inches deep this is reduced to 8 inches deep because of the heater brick,

The question should I go 10 inches from the bricks or leave it at 10 inches including the bricks sorry if its a daft question its just bogged my head.

 

Cheers  Jord

[JHCC]

You're going to need some more depth in the middle, to allow the clinker from your fire to collect at the bottom without impeding the blast from the tuyere. I'd recommend losing the four bricks from the middle and filling that space with sand.

[Charles R. Stevens]

Ok. Your questions are fuel and tuyere size specific. With a 3/4-1” ID tuyere 8” total is sufficient for coal. That is 2” for the brick, 1” for the slag, 1” for the tuyere and then 4” for the fire ball. 

 

[Charles R. Stevens]

The above chart is for coal. I would suggest subtracting 1” for charcoal and not exceeding 1”. If you need bigger than a 8” fire ball use multibe tuyeres. 

Tilt the tuyere down word just a hair (think plumbing fall of 1in 10) push the fire ball forward away from the tuyere if you want a round fire instead of a trench. 

I like using brick but it is wholly unnesisary in the bottom of your forge exept for two bricks emediatly below the fire ball to keep you from digging all the way to the floor of your fire pan and surrounding the tuyere, again for durability. From here depending on your tuyere size and fuel a box made of brick 4-12 inches is sufficient. Fill the rest with sand or bentonite clay cat litter or dri-sweep and top with brick for a hard work surface. Note for charcoal bring the brick hearth to the mid point of your fire ball, wile with coal 1” shy gives you space to store fuel on the table. You can bank your fire with coal as fire spread is limited, but with charcoal stored fuel on the table will all be alight so use extra bricks to bank your fuel against to keep the fire size and sharp effecent for the work at hand.

a further note. Coal slag sticks to brick like glue. A thin layer of ash will prevent this so leave a bit of space for ash to collect and don’t clean all of it out. Classic English sideblast forges acualy fill the hearth with flyash and clinker, with a bit of brick imefiatly under and around the tuyere. Each time the fire is rebuilt you form a new fire bowl (often with a largish soup can a bit of water). Note a new fire filled with sand is a PITA as silica sand trapped in the peat that became coal is what slag is made of. Enugh ash collects and the fire improves. Cat litter works beter, as tho the slag sticks to it, it doesn’t itself melt. 

 

This illustration is poached from another member’s post.

Where in the darker squiggles represent inert fill, the lighter squiggles represent extra coal, the red is ignighted coal wile the yellow is your hottest and generaly working area, the purple is slag collected below our fire and not blocking the air stream. This is the advantage of side blast forges, as slag collects over the tuyere in bottom blast forges. Bottom blast is generaly more portable tho.

 

As to those of us working with 1/4-2” stock I recommend a 30” hearth size as being big enugh to keep fuel and tools on the table with out having to stretch to reach the fire. A further 30” fire resistant (brick) table imidiatly to the right or left is useful. The vice can be connected to this at the far end and if desired your quench tank at the fare end. Having your quench tank high and fare from your fire and anvil reduces the chances of dropping tool steel in it either buy habit or accident.

[Jordhandson]

Cheers that some good info realy like the idea of Having your quench tank high and fare from your fire,I was going to fit it on the front but now you changed my mind thanks makes a lot of sense.

Added a few more pics of my build

Cheers Jord

[Charles R. Stevens]

It’s been a decade ago that I bent the ear of some of our British smiths and started looking at archilodical evidence of forges. Then I build a box full of dirt and began to experiment. Thus the mark I JABOD forge was born. It is my intention to build a permanent side blast forge as you are based on the information and experiments I have performed. 

 

[Jordhandson]

Cheers Charles, I thnk, ha ha didnt quite get the last bit but hey I aint no smithy just love messing with metal.

As sonn as I have finished this project I havejust picked up a nice piece of steal hopeing its going to be the backbone to a tire hammer Ive seen lots of photos on the internet so thought I would have a go at building one.

 

Cheers

 

Jord

[anvil]

1 hour ago, Jordhandson said:

I aint no smithy just love messing with metal.

 Good to know, it sets the stage.  A smithy is the shop. 

You need 4" of coke under your work. A y more and you are burning too much coal, any less and you are working too hard to maintain your fire.

This is for a "1" shop, meaning your average material is 1" or less. You can work larger stock, but it takes a bit more time to heat your iron.

[Jordhandson]

Cheers you learn somthing every day which is great

 

Thanks 

 

Jord