Forges for knife making: gas, coal, induction and DIY
For most beginners the best knife making forge is a small propane forge with one or two burners, its ceramic fibre lining sealed with a refractory coat, run outdoors or in a well-ventilated shop with CO alarms. It lights in seconds, heats evenly and is easy to turn down for heat treating.
Coal is cheaper to run but smokier and harder to learn. Induction is clean but costs thousands. A two-brick torch forge is enough for heat treating small blades.
This guide compares them, recommends specific gas forges, and covers the parts most buying guides skip: burners, sealing the lining, UK propane fittings and carbon monoxide.
Gas, coal, induction or DIY: at a glance
| Forge type | Typical cost | Pros | Cons | Best for |
|---|---|---|---|---|
| Two-brick torch forge | ~£30–60 | Very cheap, quick to build | Small; uneven heat on longer blades | Heat treating small blades |
| Budget propane (1–2 burner) | $85–190 / ~£150–300 | Easy to learn, clean, even heat | Lining needs sealing; regulator issues in the UK | Most beginners |
| Premium propane | $339+ | Hotter, tougher lining, better burners | Price; some sold out or US-only | Regular forging and heat treating |
| Coal / coke | Forge from ~£0 (DIY) | Hot, focused fire; cheap fuel per hour | Smoke; fire management; fuel rules in England | Traditional smiths with space |
| Charcoal / solid-fuel DIY | ~£0–50 | Cheap; good learning tool | Fuel cost adds up; sparks | Scrounger budgets |
| Induction | £1,800–4,920 | No flame, no CO from fuel, fast | Cost; needs a big supply and cooling | Pro and high-volume shops |
Prices are dated Oct 2026 where a source gave one. The GBP range for budget propane forges is our estimate.
What's the best type of knife making forge for a beginner?
Propane, for most people. You can run it in a shed doorway or yard, it doesn't need a chimney, and the heat is even enough to normalise and harden simple steels. The BLADE Magazine starter guide also favours gas over coal for cleanliness and heat control (BLADE).
Coal has a real case. Kevin Cashen suggests starting on coal or an improvised forge so you learn fire control, then moving to gas (ABS forum). If you have space and tolerant neighbours, it's a fine way to start.
Compare all three in gas vs coal vs induction.
How do gas forge burners work, and how many do you need?
Most budget forges use venturi (atmospheric) burners: gas jets out of a small orifice and drags air in with it. They are simple and need no power. Blown burners use a fan to push air in, which gives more control and tends to suit longer forges; forum smiths favour Darren Ellis's blown forges for blades (iForgeIron).
Burner count follows chamber size, not ambition:
- One burner heats a small chamber well. Good for small blades and for heat treating knives that fit inside its hot zone.
- Two burners suit most knife makers. They give a longer, more even hot zone for chef's knives and longer blades.
- Three burners are for long blades and bigger work. One forum report describes a 3-burner forge that delaminated and used a lot of gas (iForgeIron).
Which gas forges are worth buying?
Vevor propane forge, double burner, complete kit
Pros
- Cheap
- complete kit
- two burners give a usable hot zone for most blades
Cons
- Unsealed ceramic fibre lining
- build quality varies
- US regulator won't suit UK bottles
Verdict: Good value if you budget for a seal coat and a CO alarm. UK buyers should fit a UK regulator.
Prices from Vevor, seen 28 Oct 2026.
Devil Forge 2-burner propane forge (DFPROF2 range)
Pros
- Forum-recommended bargain for a first forge
- 140 × 140 × 400 mm chamber on the DFPROF2
- ships from Lithuania
Cons
- Still needs a seal coat
- multi-burner versions criticised by some
- EU regulator fitting
- possible import charges to the UK
Verdict: A sensible UK starter forge. Check the regulator thread before buying and plan to replace it.
Devil Forge details are from eBay listings and an undated iForgeIron thread (eBay.de; eBay.com; iForgeIron).
Atlas knife forge
Pros
- 2.5" × 11" (64 × 280 mm) cast refractory chamber (Plicast LWI-24)
- stainless 30k BTU burner
- includes a 0–20 PSI regulator
Cons
- Often sold out
- US only
- small chamber limits long blades
Verdict: The upgrade we'd watch for in the US. The cast liner avoids the fibre-sealing job.
Spec from Pop's Knife Supplies. Other names forum smiths rate: Diamondback ("dependable and hot enough") and Chile Forge burners ("the hottest you can buy", but expensive). Majestic's 2-burner was criticised as not getting hot enough (iForgeIron). These opinions are undated.
Victory Forge Force induction, 15 kW
Pros
- No combustion fumes
- fast, targeted heat
- quiet
Cons
- Needs 220 V single phase at up to 32 A and water cooling (sold separately)
- coils limit the shape you can heat
Verdict: A serious upgrade, not a first forge. Check your supply with an electrician first.
Spec from Forged Ironmongery.
Do you need to seal a gas forge? Refractory, Satanite and ITC-100
Yes. Most budget forges are lined with ceramic fibre blanket. Loose fibre is a long-term lung hazard; one experienced smith's warning is to "cover the wool with a refractory cement unless you want to develop silicosis or mesothelioma in 20 years" (iForgeIron, 2011).
Two different products get confused:
- Castable / mortar seal coats such as Satanite (rated to 3200°F / 1760°C) form a hard layer that seals and protects the fibre (Blacksmiths Depot). Mizzou is a castable used the same way.
- IR-reflective topcoats such as ITC-100 reflect heat back into the chamber. They are high-emissive coatings, not sealers, and give no mechanical protection (iForgeIron, 2022; iForgeIron, 2011).
The usual approach is to seal first with a refractory, then add a reflective topcoat if you want one.
Satanite application, per the seller's instructions (Blacksmiths Depot):
- Mix with water to the consistency of sour cream.
- Mist the fibre lightly with a spray bottle, then brush the mix over every exposed surface.
- Air-dry for a few hours. Fire briefly, shut down, and repeat with longer burns to drive off water.
- Apply at least two coats over a couple of days, building up to about ¼" (6 mm).
- Fully cure before adding any topcoat.
Satanite was $25 for 5 lb (2.3 kg) at Blacksmiths Depot in Oct 2026: Satanite refractory mortar 5 lb. Amazon mostly lists rigidisers, which stiffen fibre but are not a seal coat.
UK propane: regulators, hoses and storage
How do you stay safe from carbon monoxide?
Every fuel-burning forge produces carbon monoxide. A US bladesmith died from CO from his gas forge, and another smith suffered brain damage. Kevin Cashen found dangerous CO levels in the room next to his forge while the detectors in the forge area stayed silent (ABS forum, 2016).
What to do:
- Ventilate. Smiths use roof extract fans, wall openings and open doors (ABS forum). Forge outdoors or in a doorway if you can.
- Fit more than one CO alarm. One in the forge area and one in any connected room, especially one where people sit or sleep.
- Place them correctly. A typical EN 50291 alarm manual says: on a wall, high up but at least 150 mm below the ceiling, 1–3 m horizontally from the source, and not directly above heat (FireAngel manual).
- Know what the alarm can and can't do. EN 50291 alarms sound after 60–90 minutes at 50 ppm, 10–40 minutes at 100 ppm, and within 3 minutes at 300 ppm or more. Replace the alarm after its rated life, 7 years for that model (same manual).
- Know the symptoms: headache, dizziness, nausea, tiredness. Turn off the forge, get into fresh air and get help.
Suitable alarms include the FireAngel FA6813 portable CO alarm or Kidde CO alarm. A CO alarm is a backstop, not a substitute for ventilation. See CO alarms and ventilation.
What about coal, coke and charcoal forges?
Solid-fuel forges are cheap to build, from a brake drum or a "just a box of dirt" (JABOD) forge with air from a fan or bellows (iForgeIron; iForgeIron).
Coal smoke needs a chimney or an outdoor site (Make:). Charcoal is cleaner but you burn a lot of it, so fuel costs eat a small budget.
See coal forges.
Should you build a DIY forge?
For heat treating small blades, yes: a two-brick forge is cheap and works. Use soft insulating firebrick or ceramic wool, not barbecue bricks; pottery suppliers stock both (BushcraftUK). UK forum advice is grade 23 soft firebricks, under £5 each (BladeForums).
Makers carve a round chamber into the bricks, drill a hole of about 1" (25 mm) tangent to it so the flame swirls, and keep the torch tip about ½" (12 mm) back from the hole (BladeForums).
Shopping list: soft insulating firebricks and a MAP or propane torch. Note that vermiculite stove boards are not soft insulating firebricks.
A gas forge with home-made burners is a bigger job. Forum veterans warn that building a gas forge is hard without experience (iForgeIron). See DIY forges.
FAQs
What is the best forge for knife making?
For most beginners, a sealed one- or two-burner propane forge. It's easy to control, clean, and good for both forging and heat treating simple steels. Coal suits smiths with space and a chimney. Induction is excellent but costs £1,800 or more. For heat treating only, a two-brick torch forge does the job.
Can I use a propane forge indoors?
Only with serious ventilation and CO alarms, and the bottle must stay outside. In the UK, Calor says propane should always be stored outdoors. Gas forges produce carbon monoxide, which has caused deaths in workshops. Many smiths forge in a doorway, under a lean-to or outdoors.
How hot does a propane forge get?
Hot enough to forge and to forge weld when well built and sealed. Vevor's listing for its 3-burner forge says 2600°F (about 1425°C). Knife Steel Nerds ran an Atlas forge at roughly 2000°F (1095°C) on low pressure for heat-treat tests. Actual temperature depends on burners, lining, pressure and chamber size.
Do I need to coat the inside of my forge?
Yes, if it's lined with ceramic fibre blanket. Seal it with a refractory such as Satanite to stop fibres becoming airborne and to protect the lining. A reflective topcoat such as ITC-100 can go on afterwards, but it isn't a sealer on its own.
What regulator do I need for a gas forge in the UK?
An adjustable high-pressure propane regulator, typically 0.5–4 bar, that fits your cylinder. Calor's 0.5–4 bar regulator fits its 3.9–47 kg propane bottles. A 37 mbar barbecue regulator won't run a forge, and EU W21.8 regulators often don't fit UK bottles.
Sources
- https://blademag.com/knifemaking/how-much-money-do-you-need-to-start-making-knives
- https://www.americanbladesmith.org/community/tools-equipment-and-jigs/beginners-shopping-list-for-tools/
- https://www.iforgeiron.com/topic/61532-commercialy-manufactured-propane-forges/
- https://www.vevor.com/s/home-propane-forge
- https://www.ebay.de/itm/205590025070
- https://www.ebay.com/itm/254977410903
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- https://blacksmithsdepot.com/products/satanite-refractory-mortar-5-lb
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- https://gov.uk/guidance/domestic-solid-fuels-rules-for-local-authorities-in-england
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