When I was starting in blacksmithing, I didn’t know a lot of things, including what fuel should I use for the forge. Since choosing the proper fuel for blacksmithing is a crucial part, I decided to write this complete guide so every blacksmith knows which should they choose.
In terms of solid fuels, bituminous coal is typically the best fuel choice for blacksmithing purposes. On the other hand, propane is spelled as the best gas fuel. Other popular fuels for blacksmithing forge are anthracite coal, lump charcoal, and natural gas. Keep in mind that each fuel has its pros and cons so each fuel should be chosen according to individual needs and experience.
In this guide, we will cover:
- How to choose proper coal for blacksmithing?
- How much coal should you buy?
- Is charcoal a good fuel choice?
- Should wood be avoided completely?
- What is better, coal or gas forge?
- Benefits of using the gas forge
- What is the gas best forge for knife making?
Well, let’s begin.
Coal as a Blacksmithing Fuel
Coal is considered the king of all solid fuels for blacksmithing purposes. You could also say that coal is historical blacksmithing fuel as many historical masterpieces are forged in it. Unfortunately, good coal for blacksmithing work is getting harder and harder to acquire.
When you compare coal with other options in terms of availability, it is probably the lowest in rank. However, if you got into blacksmithing purely out of its traditional values, then coal is your ideal fuel choice. There is nothing like the mystique of burning coal and managing the fire.
One of the great advantages of using coal is its versatility. Namely, you can forge almost any project of all shapes and sizes in the coal forge while you can’t do that in the gas forge. Also, you can achieve a solid localized heat without any limitations. Due to its extremely high burning temperature, it is possible to do forge welding which is great for many projects that require it.
Unfortunately, lighting a coal fire can sometimes be trouble, especially if you don’t have a lot of experience in fire management. Forging with coal requires constant attention to the fire. You can’t expect to simply leave the forge and completely focus on the work at the anvil. You should always be close and add air when needed.
This is why I always recommend learning proper fire management before jumping straight into blacksmithing stuff. If you don’t know how to light, maintain, and finally put out the fire, do not start working with the coal, otherwise, bad things will happen. I mean, the last thing you want is to burn yourself and your whole workshop.
Bituminous Coal vs Anthracite For Blacksmithing
There are many different coal types, but only two of them are commonly used for blacksmithing purposes. These two are bituminous and anthracite coal. Both of them are good options but bituminous coal is considered a superior choice.
Namely, with bituminous coal, you are less likely to get an oxidized fire because oxygen has a great surface area to react with. It also doesn’t require a strong air blast as anthracite would do.
Also, when burning bituminous coal has a lesser tendency to pop out from the forge. While this is great news for your safety don’t think wearing safety goggles not necessary. I should note here that you should always wear safety goggles in the shop, especially near the forge. If properly managed, bituminous coal will transform into coke, which is burned coal with removed volatiles.
You can think of coke as what charcoal is to wood. Also, coke is much lighter and breaks up easily when compared to coal. Coke is almost all carbon content, however, it does produce clinkers. Clinkers are mass that stays on the bottom of the forge. Another great benefit of using bituminous coal is that produces a very small amount of smoke.
In terms of its availability, if you live in West Virginia, Pennsylvania, Indiana, Kentucky, and Illinois, bituminous coal should be accessible.
On the other hand, you have anthracite coal. It is the highest rank of coal in nature and it is divided into three groups: semi-anthracite, anthracite, and meta-anthracite. The combustion of anthracite is very slow, primarily due to the low volatile content which contains somewhere between 2-12%. It is also known for its low sulfur content.
Anthracite coal is widely used in blacksmithing, primarily due to its clean burning. On the other side, anthracite coal has a small surface area relative to its weight, which makes it much harder to burn. This is the main reason why you may get an oxidized fire with anthracite. It also requires a stronger airblast, so don’t walk away from the fire. Anthracite fire extinguishes more quickly than bituminous coal, so keep that in mind.
If you are a beginner blacksmith who is just starting forging with coal, you may only need about 50 lbs before making any bulk order. However, if you can make a bulk order, somewhere around 400-500 lbs would be a solid amount to get good price breaks.
Charcoal as a Blacksmithing Fuel
When coal is not a convenient or even a possible option, you need something else to fuel your forge. For practical and economic reasons, there is only one solid fuel that comes to my mind and it is charcoal.
Although may not be as good as coal, charcoal is a very popular fuel option for many blacksmiths, especially beginners. If properly managed, charcoal in fact can achieve high enough temperatures for forging purposes. Charcoal burns out very quickly, so it doesn’t require nearly as much air blow as coal does.
Charcoal is actually burned wood. The slow process called pyrolysis removes volatiles and water and all that is left is pure carbon content. Unlike wood, charcoal can achieve much higher temperatures and also produces less smoke.
In terms of availability, charcoal can be found in many stores. You can also create your own if you want. To achieve the same level of heat as coal does, a huge volume of charcoal is required.
We can also say that charcoal is a historic forge fuel. Namely, in the past, charcoal was the common fuel option for the majority of blacksmiths. Coal usage as a blacksmithing fuel began only recently.
How to Properly Manage Charcoal Fire?
First things first, the forge must be cleaned from the previous forging session. That means it should be cleaned from all clinkers and fuel leftovers. Your piping system which is typically underneath the forge should be cleaned up for proper airflow.
Keep in mind that charcoal can be lit in several ways. For instance, you can light it with the paper by placing it below and lighting it first. On top of that, you can also place some wood, depending on how big a fire you want. Another very common way is to light it with some combustible liquids.
After you set out the fire, add some air, but not too much. As you see the fire going, add charcoal gradually. Keep in mind that proper air control is a must. Since charcoal burns very quickly in comparison to coal, it does not require a lot of airflows.
Again, keep in mind that charcoal sparks a lot, so make sure your forge is not positioned near flammable materials. Sparks can fly anywhere so always wear safety goggles and appropriate blacksmithing clothing.
Lump Charcoal or Briquettes?
While these two may be visually similar, they are not in terms of burning ability. Charcoal briquettes, also known as bbq briquettes are mixed with many additives which help them burn consistently. You can think of them as the fast food of charcoal. They are cheap and easily available and you don’t know what is actually inside them.
During burning, these additives produce a chemical smell that may be harmful. Briquettes also produce dust and fumes that irritate the lungs and also can cause respiratory problems. They also emit carbon monoxide, a dangerous invisible, and toxic vapor that can cause poisoning, unconsciousness, or sometimes even death.
This is also why having a good carbon monoxide detector (affiliate link) is crucial to have in the shop. Do not spare money on buying a good one. It can save your life.
Advantages of Briquettes
- Easy control of consistent temperature
- Burns longer
- Cheap
- Do not emit smoke
- Easily available
Disadvantages of Briquettes
- Takes longer to light
- Produces a huge amount of ash
- Chemical smell
- Can produce carbon monoxide
On the other hand, lump charcoal is the most natural and purest form of charcoal. This is why it is a superior choice for many blacksmiths. One of the advantages is that it produces less smoke than briquettes. You will also notice that the lump charcoal is easier to control in the forge due to a greater response to oxygen.
Advantages of Lump Charcoal
- Burns hotter
- Lights quickly
- Easy fire control
- All-natural
- Easily available
- Produces less ash
Disadvantages of Lump Charcoal
- Burns faster
- Less consistent
- More expensive
Wood as a Blacksmithing Fuel
You may now wonder why did I include wood on this list. While it is true that plain old wood is not ideal, you can still use other wood choices for blacksmithing purposes. I would recommend using hardwood instead of softwood as it will burn hotter. If you are a beginner blacksmith I would recommend using whatever fuel you have on hand rather than spending a lot of money on something like coal and waiting for it to arrive.
Without using a bellow, you can achieve temperatures around 1200 °F (649 °C) which will make steel a dull cherry red. However, with a bellow, you can increase temperatures by several hundred degrees. Unfortunately, you won’t be able to achieve forge-welding temperatures with wood.
Expect to burn a lot of wood during forging as it burns very quickly, especially when using a bellow. The higher the temperatures, the more wood forge will require. What this actually means is that the metal will be hot enough to be worked and shaped. However, your time working on the steel will be significantly shorter. Your shaping and bending work will take longer.
One of the important factors which will dictate how hot your wood forge can get is the setup. Namely, building your forge with soft refractory brick will increase the amount of heat, so keep that in mind. In the preparation phase, you should consider the amount of surface area of the wood. For example, a large piece of wood is not as oxygen friendly as the same piece that is split.
Note that the more surface area you have, the faster you produce charcoal and create a nice fire. Controlling the airflow to the fire is crucial.
Blacksmith’s wood forge: Mini Whitlox Wood-Fired Forge (affiliate link)
Gas as a Blacksmithing Fuel
Gas forges are becoming more and more popular in both blacksmithing and bladesmithing. This is all due to one great reason. As you know, everyone who is getting involved in this craft knows that there is so much to learn. Heat-treating, tempering, forging, steel choice, tools are just a few. If you add to the fact that you should learn proper fire management, it will be overwhelming for most people.
As you may already know, gas forges are extremely easy to light and use. All you must do is to turn on the burner and gas tank. This is a big advantage over coal forge as with coal forge you have to wait a couple of minutes to achieve desired temperatures.
A gas forge is better than a coal forge in production work due to fast lighting and less time spent checking the fire. For example, if it takes 10 minutes to prepare and light the coal, this is 1 hour per week, 5 hours per month, and an incredible 60 hours per year. Gas forge doesn’t require any special skills or a lot of experience. All you need to have is somebody to teach you how to use it safely and correctly.
With more and more blacksmiths started using it, their availability has drastically increased. You can order them online or find them in the store. Depending on the size and number of burners, the price may vary. Just don’t expect to pay the same price for a gas forge with one burner as for one with more burners.
Propane or Natural Gas?
There has always been a difficulty in choosing natural gas or propane for forging purposes but I will try my best to properly compare them and draw a conclusion.
Propane is able to achieve higher temperatures than natural gas, primarily due to its energy content. Namely, propane contains almost twice as much energy as natural gas does. More precisely, one cubic foot of propane contains 2,516 BTUs while natural gas contains only 1,030 BTUs. As you can see, this makes a great difference when it comes to forging.
Propane is also known to burn less volume per hour than natural gas. In 1 hour 100,000 BTU propane burns somewhere around 40 cubic feet. On the other side, natural gas burns 100 cubic feet in one hour. Yes, it is a big difference.
In terms of safety, natural gas dissipates more quickly in the air due to its lighter weight. Keep in mind that you should still wear a respirator during the use. Both gases require proper ventilation as they can produce carbon monoxide.
If you have to choose between natural gas and propane for blacksmithing purposes, we would recommend using propane. It burns less volume per hour and achieves higher temperatures than are required for blacksmithing.
Another good thing about using gas forge is that is neighbor-friendly. Namely, unlike coal forges, gas forge doesn’t produce any smoke, which is great news for your neighbors. Imagine a nice and warm Saturday morning. You and your family are sitting and chilling in the backyard. All of sudden you see toxic coal smoke drifting in through your open windows into your house.
It is your blacksmith neighbor doing his usual stuff. Gas forge solves that problem. You can work in peace without any problems and focus more on your projects. In fact, nobody would even know if you are a blacksmith or not.
As more and more new blacksmiths are replacing the coal forge with gas forge, I strongly believe that in the meantime, gas will become the standard fuel in both blacksmithing and bladesmithing due to economical and practical reasons.
Advantages of the Gas Forge
- Quick and easy to light
- Burns clean
- Easy to operate
- Excellent for production work
- Easily available and simple to make
- More suitable for beginners
- Portable
- Neighbor-friendly
CONS of the Gas Forge
- Quite noisy
- Versatility
- Hard to get localized heat
- Radiates a lot of heat in the room
