Best Double Burner Knife Making Forges: Heat, Insulation and Safety Basics

The best double burner knife making forge has a well-insulated chamber, reliable burners, a sturdy frame and a chamber size that fits the blades you make. Two burners give more heat and room for longer stock, but they also use more fuel and demand more ventilation. Forging involves serious fire and burn risks, so follow the maker’s instructions and safe practice at all times.

Why Choose Two Burners

A single burner forge heats compact work such as small knives and tools. A double burner spreads heat along a longer chamber, which helps with longer blades, billets for pattern welding and heating large sections evenly. It also recovers temperature faster after you open the door. The tradeoff is higher fuel use, more weight and a bigger footprint. If you mostly make small knives, a one-burner design may be enough, but a double burner leaves room to grow.

Forge Design Types

Insulation and Lining

Insulation controls how fast the forge heats and how much fuel it uses. Ceramic fiber blanket is common, and a refractory coating protects it from flux and scale and reduces loose fibers. Fiber insulation can release fine particles, so use a respirator when handling it, and follow manufacturer safety data. Check for a wall thickness that balances heat retention and usable interior space. A good lining resists thermal shock and heats up quickly, but it is a wear part that eventually needs relining.

• Seal exposed fiber with a refractory coating.
• Use a kiln shelf or floor protector to catch flux.
• Keep the interior free of debris and scale.
• Check for cracks after heavy use.

Burners, Regulators and Fuel

Most forges use propane with atmospheric or blown burners. A regulator and hose must match the burner’s pressure requirements. Check that fittings and hoses are rated for propane and that there are no leaks, which you can test with soapy water. Two burners increase gas consumption, so plan on a larger tank. Keep the cylinder upright and away from the forge heat. Do not store propane indoors or in enclosed spaces. Look for burners that run stable at low pressure and let you control the flame to avoid excessive scale.

A propane regulator with hose for forge use should be chosen to match the burner’s stated requirements, so read the specifications carefully.

Workspace, Ventilation and Personal Protection

Forging produces carbon monoxide, intense heat, sparks and bright light. Work outdoors or in a well-ventilated shop with a CO detector, never in an enclosed space. Keep a fire extinguisher rated for the likely hazards within reach and clear flammable materials. Wear safety glasses with appropriate shading, cotton or leather clothing instead of synthetics, leather gloves and closed leather boots. Hearing protection is wise with blown burners. Keep children and pets away, and never leave a hot forge unattended.

Basic tools such as blacksmith tongs for knife making and a solid anvil or substitute help you handle hot steel safely. If you are new, consider a class or an experienced mentor before buying equipment.

Buying Advice and Common Mistakes

Compare chamber dimensions, burner type, door design and weight. Look for clear instructions and replaceable parts. Beginners sometimes buy a forge that is too big and waste fuel, or too small and cannot heat a full blade. Check shipping details, because forges are heavy and fragile when lined with fiber. When browsing, compare double burner propane forges for build quality, included regulators and clear safety documentation.

Another mistake is skipping a heat treatment plan. A forge heats steel, but you also need a way to quench and temper blades, and to know which steel you use. Learn the steel’s heat treatment instructions from its supplier, because wrong temperatures ruin a blade. Keep notes on every blade, tools and settings, so your results improve over time. Store the forge in a dry place and keep the lining free of moisture to avoid cracking on the first heat. Always check local regulations for propane storage and open-flame use at your home.

Burner tuning is a skill. A forge that runs rich, with too much fuel and not enough air, produces a reducing atmosphere with less scale but can emit more carbon monoxide. A lean flame produces more scale and wears the lining faster. Many bladesmiths aim for a neutral atmosphere, adjusting the choke or air supply until the flame is stable and quiet. Start with the maker’s recommended settings and adjust gradually while watching for soot or a roaring flame at the doors.

Think about the layout of the workshop. Place the forge on a non-flammable surface such as concrete or a steel stand, with working room on all sides and a clear path to the exit. Keep the gas cylinder away from the heat and from the direction of flying scale. Store flammable liquids, solvents and quench oils away from the forge area. Having a bucket of water for hand safety is not enough around oil quench tanks, so know the appropriate extinguishing method for each hazard.

Frequently Asked Questions

Is a double burner forge too much for a beginner?

It can be more than needed, but it offers flexibility. Beginners should focus on safe setup and gradual practice.

How do I know the forge is hot enough?

Steel color and the maker’s heat treatment guidance help, and some smiths use magnets or pyrometers. Follow the steel supplier’s data.

Can I use a forge in a garage?

Only with proper ventilation, CO detection and fire safety. An outdoor or open-sided workspace is safer.