I run both a coal forge and a propane forge, and people always want me to declare a winner. I will not, because they are good at different things. What I can do is tell you which one makes a better first forge for most people, and why my answer is usually propane even though I love my coal fire.
What each fuel is actually like to run
A propane forge is a burner blowing into an insulated box. You open the tank, light it, and in a couple of minutes you have a steady, even heat that just sits there while you work. There is no fire to tend, no ash, no sourcing runs. You turn it off and it is done. For learning to forge, that simplicity is worth a lot, because every bit of attention you are not spending on the fire goes into your hammer control.
A coal forge is a live fire you manage the whole time. You build it, you feed it, you rake it, you keep the sweet spot where you want it. When it is dialed in, a coal fire is a joy and it can drive an intense local heat right where you place the steel. But it is a second craft layered on top of the first. You are learning to forge and learning to run a fire at the same time, and the fire will humble you for a while.
Heat, and where each one wins
Both fuels get plenty hot for general forging. A tuned gas forge holds a broad, even heat across the whole chamber, which is great for consistent work and for heating a long section evenly. A coal fire concentrates a very hot spot in a small area, which is why coal has the reputation for forge welding and for heating heavy stock: you can bury a bar in the heart of the fire and get one zone screaming hot without cooking the rest.
So if your plan is mostly knives, hooks, small tools, and general work, the even heat of propane is not a compromise, it is a feature. If you already know you want to forge weld a lot or work big stock, coal earns its keep sooner.
The costs people forget
The forge is only part of the spend. Weigh the rest:
- Fuel and sourcing. Propane is available anywhere and easy to store. Good smithing coal is not sold on every corner, and you may end up ordering it by the bag or driving to get it. That inconvenience is real and it is ongoing.
- Consumables. A gas forge burns through refractory and burner parts over time. A coal forge burns firepot and grate parts and needs ash cleanout. Neither is free forever.
- Setup. Coal needs a chimney or a serious hood to pull smoke, or you and your neighbors will not be happy. A gas forge needs a clear, ventilated spot but no chimney.
Ventilation is not optional for either
This is the part I will not soften. Both forges demand real air. A propane forge produces carbon monoxide, which you cannot see or smell, and enough of it in a closed space will put you down before you understand what is happening. Run a gas forge with cross ventilation, ideally outdoors or in an open bay, and put a carbon monoxide alarm in the room. A coal forge adds smoke and combustion products to that same problem, so it needs a proper chimney or hood pulling the smoke up and out, and it still needs fresh air coming in.
I have known too many people who treated "I cracked the door" as ventilation. It is not. Treat the air in your shop as seriously as you treat the hot steel.
What I would tell a friend
If you are buying your first forge and you are not sure, get a propane forge. You will be making things the same afternoon instead of fighting a fire, you will not be chasing coal, and the even heat will not hold back anything a beginner wants to make. Learn to forge first. The fire is a great skill to add later, and when you are ready for it, coal will be waiting.
If you already know your heart is in forge welding and big work, or you just love the idea of the fire, then start with coal and go in with your eyes open: budget for a chimney, plan your air, and give yourself patience while you learn to read the fire. Either way, the forge that makes you want to come back to the shop is the right one.