Propane Forge vs Coal Forge: Which Should a Beginner Buy?

The short answer for beginners

If you are buying your first forge and you mostly want to make knives, hooks, bottle openers, and small tools, buy a propane gas forge. A gas forge is the least fussy way to reach forging heat: open the valve, light the burner, and within a few minutes you are working steel at a temperature you can hold steady all afternoon. There is no fire to build, no ash to rake, and almost no smoke.

A coal or coke forge is not a beginner mistake - plenty of smiths swear by it - but it asks more of you on day one. You have to build and tend a fire, source solid fuel, and manage smoke that your neighbors will notice. For someone spending their first few hundred dollars and still learning hammer control, that is a lot of extra variables. Propane removes most of them so you can focus on moving metal.

How each forge actually makes heat

The two forges heat steel in fundamentally different ways, and that difference drives everything else.

A propane gas forge burns gas inside an insulated chamber, usually lined with ceramic fiber and a hard refractory. The burner - atmospheric on most beginner units, sometimes blown - fills the whole chamber with hot gas, so your steel soaks in even heat. A single-burner forge runs roughly 80,000-110,000 BTU and is perfect for knife-length stock. A double-burner unit runs about 170,000-200,000 BTU, gives you a longer chamber, and can reach forge-welding heat, though it burns close to twice the gas.

A coal or coke forge does the opposite: it builds one concentrated, very hot fire in a firepot, and you push steel into the sweet spot. That localized heat is intense - forge welding is arguably easier in coal - and you can heat one small section of a large bar without heating the rest. The trade-off is that you are constantly managing the fire: feeding fuel, controlling air from the blower, and clearing clinker and ash.

What propane actually costs to run

The one place coal can genuinely win is fuel cost, so it is worth understanding what gas really burns. Propane holds about 21,548 BTU per pound, so a full 20 lb tank stores roughly 430,000 BTU. A single-burner forge sipping around 90,000 BTU/hr will run several hours on a tank; a double-burner at roughly 180,000 BTU/hr can drain one in a little over two hours of continuous use.

Refill cost varies by region, so rather than trust a number someone quoted online, plug your burner size, run time, and local propane price into the propane forge cost calculator. For most hobbyists forging a few hours a week, propane is a very manageable running cost, and the convenience usually outweighs the fuel savings coal offers - unless you are forging many hours every day.

When a coal or coke forge is the right call

Coal is not just for traditionalists. A coal forge for beginners makes real sense if:

• You want to forge long or oddly shaped stock that will never fit inside a gas chamber.
• You have a cheap, reliable fuel source nearby (smithing coal, coke, or lump charcoal in a pinch).
• You are working in an open shop or on rural property where smoke will not upset anyone.
• You specifically want to learn fire management and forge welding in solid fuel.

The heat a good firepot delivers is hard to beat for heavy work, and the fuel can cost less per hour than propane if you source it well. Just budget for a blower, a firepot or brake-drum build, and somewhere to store dirty fuel. And know that a smoky fire in a suburban backyard is the fastest way to a neighbor complaint.

Pitfalls before you buy either

A few things trip up first-time buyers on both sides.

• Chamber size on a gas forge. Measure your intended projects. A compact single-burner is great for knives but frustrating if you want to bend a fireplace poker. Check the opening height, not just the length.
• Propane supply and tank freeze. A hungry double-burner can outrun a 20 lb tank in cold weather - the tank frosts over and pressure drops. Sizing up the tank or drawing from two tanks fixes it. See propane tank sizes for forges.
• Coal quality. Cheap hardware-store coal is often high-sulfur and smoky. Real smithing coal or coke burns cleaner and hotter, but you have to find a supplier.
• Ventilation for both. Every forge, gas or solid fuel, produces carbon monoxide. Neither is safe in a closed garage.

If you are still torn between the two propane options, the single vs double burner comparison breaks down the gas trade-off in detail.

The bottom line

For the vast majority of beginners in the US, start with propane. A gas forge blacksmith setup gets you forging on day one, holds temperature while you practice hammer control, runs clean enough for a garage with the door open to the driveway, and packs away when you are done. You can always add a coal forge later, once you know what kind of work you love and whether you have the space and fuel for it.

If you already know you want to move big stock, weld heavily in solid fuel, or you have cheap coal and an open shop, a coal forge is a legitimate first forge - just go in expecting a steeper learning curve. Either way, run the gas numbers first with the propane forge cost calculator.