Azur Jahić

how much air to forge

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Good point - and more coal is generally better than less because the excess fuel can be wet down to act as insulation for the fire. When I first began forging, I was chary with my coal and would only make a small dry pile in the firepot, which tended to burn down quickly. A few years into it, I was fortunate to get an opportunity to watch Francis Whitaker demo and saw how he managed the fire. He piled fresh coal in the hearth, used a little coke in the pot, and put wet coal on each side so a channel was formed over the fire's heart. As it burned hollow, he simply kept moving freshly coked fuel in from the sides. I watched him closely and began to pay more attention to how I managed a fire.

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Alrighty. I'm up from the shop and in the comfort of my armchair and I've got a little time to relax. I like a project. :P
Did you decide to make charcoal like Bigcity suggested? I use small pieces of charcoal. The size of your thumb or less, see if that helps.
You want lots and lots of charcoal inside a deep firepot (metal, brick, mud, clay or wood if you must it'll work once.). Deeper than the length of your hand.
Tell us what number color the fire is to you. And what number color your steel is.
post-19492-0-99756100-1348112816_thumb.j

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As everyone eyes see colors differently (due to health, life experiences, etc) you may wish to review the following article on seeing colors.

http://www.iforgeiron.com/page/index.html/_/lessons-in-blacksmithing/lessons-in-blacksmithing-seeing-colors-r104

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Fire needs three things: oxygen fuel and heat, if youi remove one of them the fire goes out. And that holds true of a Quote..." A balanced fire with the steel in a zero o2 zone is where you have to start."

No O2 no fire...
:

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This just seems like the place to share a link I found a while back. I dug it out.
The science of fire.
I was very surprised not to find any real blacksmithing specific info on the site after seeing the forged steel flint striker, but there are some good reads. Hope it helps, it does discuses the charcoal conversion.

Any trouble your having is due to a lack of fuel or a lack of air. I do not believe your using too much air. I'd imagine its too little charcoal if that round forge you've got there is mounded high then look for another air source.

I'm reminded of a story I read in one of the blacksmith books.. toward the beginning of my journey. I wish I could remember the book but.. A fellow used a large pipe suspended from a tree. It was basically one huge chimney that burned wood into charcoal during forging operations.. although I could be remembering it wrong. Initiating a draft somehow may help you if an electrical option doesn't present itself.

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HW: As I recall the 13th edition of Machinerys Handbook is the cut off for a lot of the smithing info...Jock over at anvilfire knows the details...

According to your source the Machinerys Handbook information on tongs stopped at ed 20/1977, forging at ed 25/1996, anvils at ed 18/1968, forge welding at ed 18/1968, and blacksmithing at ed 20/1977.

The older books covered different things than the more modern editions. The more modern editions include the more modern alloys for instance.

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There surely are many world-class smiths that participate on this website and I know who they are, they know who they are, and I respect every one of them. You should ask why we see less and less of their postings. I think they knew what I meant by zero O2 zone.

And those of them that teach basic blacksmith courses know that they have to teach their students how the fire works from the get go. It’s not just a pile of burning coal or coke.

As for my “armchair” comment, should have said “a lot” instead of “most”.

I’m not the only member that feels that way!

And by the way, there are also lots of very talented individuals who are not world-class that contribute here.

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There surely are many world-class smiths that participate on this website and I know who they are, they know who they are, and I respect every one of them.

I think they knew what I meant by zero O2 zone.



I am sorry but whatever type of 'smith you consider me to be, when I contribute, I am not trying to to inform those that know, but those that want to know, me included, so could you please clarify and explain exactly what the zero O2 zone is and where it is located, and how it occurs.

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I am sorry but whatever type of 'smith you consider me to be, when I contribute, I am not trying to to inform those that know, but those that want to know, me included, so could you please clarify and explain exactly what the zero O2 zone is and where it is located, and how it occurs.



John,

A coal fire is no different than a gas flame in the sense that it can be oxidizing, neutral, or reducing. With a gas flame it is controlled by adjusting gas and/or the amount of air that is mixing with the gas. With a coal fire there are regions of the fire that are also oxidizing, neutral, or reducing. So depending on how your fire is constructed and how much air you are blowing into your fire you will find those regions.

Closest to the air blast you will have an oxidizing region where you have more oxygen then is being consumed by the combustion of the coke. Next you will have a neutral region where most of the oxygen is being consumed. And above that you have a reducing region where there is not enough oxygen to support full combustion so it is a reducing region. Now all that being said, it you are blasting the forge with too much air the entire fire can be oxidizing.

The place in the fire where you will produce the least amount of scale and the most efficient or sufficient amount heat will be in the neutral region of the fire.

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size...........dia of outlet...........fires
0000..........2 3/4 inch.............2
00..............4 1/8 "................4
0................4 3/4 "................7
1................5 3/4 ".................10
2.................7 1/2 "................15
3..................9 "...............20
4.................10 5/8 "................27
5.................12 1/4 "................35
6.................14 5/8 "................60

from mc phersons machinery and tool merchants catolog 1912

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i need forging temperature that will be orange to yellow color And in my place blacksmiths make thay own charcoal of plum tree


Whether it is charcoal or coal or coke all fires burn the same way from the blast to the top. One of the mistakes that a novice makes is to think that just because they are forging small things that the fire doesn't have to be large. By large I mean tall. The rate of burn is controlled by the air blast. If you don't have enough fuel then your fire is going to be oxidizing no matter what unless you are blowing air through a soda straw.

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i have my bellows but i dont know how to post video and if i post a video of my bellows working you can tell me do i have enaugh air to forge

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how fire much be tall. I make my best result with my hair dryer but it get overheated and break i get red colour .But it brake down that is my best result .

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John,

A coal fire is no different than a gas flame in the sense that it can be oxidizing, neutral, or reducing. With a gas flame it is controlled by adjusting gas and/or the amount of air that is mixing with the gas. With a coal fire there are regions of the fire that are also oxidizing, neutral, or reducing. So depending on how your fire is constructed and how much air you are blowing into your fire you will find those regions.

Closest to the air blast you will have an oxidizing region where you have more oxygen then is being consumed by the combustion of the coke. Next you will have a neutral region where most of the oxygen is being consumed. And above that you have a reducing region where there is not enough oxygen to support full combustion so it is a reducing region. Now all that being said, it you are blasting the forge with too much air the entire fire can be oxidizing.

The place in the fire where you will produce the least amount of scale and the most efficient or sufficient amount heat will be in the neutral region of the fire.


Thank you for that enlightening explanation, many will benefit. Can you explain what a reducing fire does?

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like i am acetylene plumber i know that you have 3 kind of flame one is use to welding it made with acetylene and oxigen if you put small acetylene and a big size of oxigen you will get oxidizing flame which is good for welding pipe But if you put small size of oxygen
and large size of acetylene you will get neutral flame which is good for cuting steel

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Hi Azur,
We have established that you are using charcoal, and that other 'smiths in the area use the same fuel succesfully,
also when you used the hair dryer you had some success, so the forge design is working to some degree,

You don't specify the tue design or sizes you are using in the fire pot, or if you have an adequate ash dump arrangement,

You also say your bellows work to supply air to the hearth, (and it appears to be a bottom blast hearth you have there)

My suggestion would be to light the fire, and when lit pile on your charcoal and try various pump action speeds/strokes and see how the fire performs, a slow regular pump keeping the top chamber partially inflated should produce an even fire,

If you just pump and let the top chamber collapse after each action, you should get a small pulsing fire, as the air enters the fire it should get bigger, and then as the air is expended it should quiet down.

Its time to get down and try again, getting someone with experience near to you to help and see what is occuring would be of great benefit. once you get the hang of it, you should be away and working.

Hope you get it sorted soon.

Listening to the air flow also gives an indication of the throughput,

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Just to clear up confusion, that ace/oxy description doesn't sound right to me. I've not done any acetylene welding, but I believe your supposed to weld in a neutral flame. Same with Cutting.. big/small may just be confusing me.
Good luck.
(welding principles and applications 6th addition- just wanted to make sure)

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Just to clear up confusion, that ace/oxy description doesn't sound right to me. I've not done it be I believe your supposed to weld in a neutral flame. Same with Cutting.. big/small may just be confusing me.
Good luck.
(welding principles and applications 6th addition- just wanted to make sure)

This may be a translation problem, my understanding is;

Neutral flame for welding, (equal amounts oxy and acet)

Neutral flame as for welding, plus oxygen injection at higher pressure for cutting,

Reducing or carburising flame for brazing or hard soldering, excess acetylene to oxygen

Loads of info on google regarding flame shapes for each application etc.

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i will try to film my bellows working on fire and post to forum I think i was doing this wrong you say i should light the wood fire and wait to get a lit pile and than to push air in it i was pushing air in fire flame

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Thank you for that enlightening explanation, many will benefit. Can you explain what a reducing fire does?


The reducing region of the fire will heat your metal more slowly and will produce the least amount of scale but bear in mind that as the metal heats the top side will be exposed to more atmospheric oxygen so one side of your metal will have more scale than the other.

The ideal situation is to find that neutral spot where you are getting the most heat and the least oxygen.

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Azur, please photograph and post your fire pot, the air holes, and your tuyere. No video needed for this request.

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...
I'm reminded of a story I read in one of the blacksmith books.. toward the beginning of my journey. I wish I could remember the book but.. A fellow used a large pipe suspended from a tree. It was basically one huge chimney that burned wood into charcoal during forging operations.. although I could be remembering it wrong. Initiating a draft somehow may help you if an electrical option doesn't present itself.


I recall downloading a book with this in it.

Phil

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The reducing region of the fire will heat your metal more slowly and will produce the least amount of scale but bear in mind that as the metal heats the top side will be exposed to more atmospheric oxygen so one side of your metal will have more scale than the other.

The ideal situation is to find that neutral spot where you are getting the most heat and the least oxygen.


Thank you, in retrospect it all points to good fire management and control of airflow, ( patience helps too)

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