Some thoughts on using the LPG (propane) forge, is it not meant to be a definitive guide and it is to be used at your own risk.

 

Safety

  • Please use common sense and be careful

  • The use of a gas powered forge can be hazardous if not done correctly. Serious burns, explosions and worse are possible if the forge is misused.

  • Always use in well ventilated area – toxic gasses can quickly build up in enclosed spaces.

  • It gets hot in there€“ - over 1000 degrees C, sometimes despite the insulation the outside gets hot too, be careful.

  • Remove all flammable materials from around the forge. Do not leave unattended when lit.

  • Have a fire extinguisher handy.

  • Don't open the regulator too much, most forging can be done around 70kPa with welding done a little higher, use just what you need with the pressure -€“ your gas will last better.

  • Use approved gas bottles

  • Check for leaks with soapy water. Use tape thread to reduce leaks in joints. Any hoses with leaks should be immediately replaced.

  • Wear good fitting PPE (personal Protective Equipment) including sturdy boots, eye protection, gloves, apron and sturdy cotton or woollen clothes. Do not wear synthetics!

  • Staring at the inside of a lit forge can cause permanent eye damage - there is a lot of IR radiation being generated. If you need to look into the forge often, acquire safety glasses which protect your eyes from IR radiation.

 

Lighting the forge

  • Switch the tap on the burner to the off position.

  • Switch on the gas tank tap. The hose should be charged with gas now.

  • Place a piece of crushed up newspaper in the forge.
  • Light the paper with matches.

  • Stand to the side and gently turn on the tap.

 

Turning off the forge

  • Turn off the burner tap.

  • Turn off the gas tank.

  • Open the burner tap to release the gas in the pipe.

  • Remove the burner from the forge to avoid heating up.

  • Allow the forge to gently cool off

 

Preparation for first burn

  • To help protect the inner lining, fill the bottom third of the forge with clay cat litter (not recycled the paper type!). This will catch any flux before it eats the lining and protect agaist dropped items. Periodically replace the cat litter especially after using flux.

  • Alternatively a kiln shelf can be used.

  • There maybe some paint burning off in the first burn.

 

Adjusting the “atmosphere”

  • By twisting the cylinder (above the burner tap) in the burner assembly you can change where the gas jet points. This will vary the amount of air sucked in with the venturi process.

  • A reducing atmosphere has an excess of fuel and is indicated by visible flames coming out of the front of the forge. This is often important for forge welding.

  • An oxidizing atmosphere has more oxygen than fuel and will build up scale faster.

  • A neutral atmosphere has a balance of fuel and oxygen.

  • Sound is also an indicator of how the forge is going.
     

Repair of lining

  • The lining is fragile. Be careful and avoid breaking the crust un-necessarily. The outer crust protects the inner fiber, which does most of the insulating). The inner fibre can cause lung damage if inhaled.

  • Flux, such as Borax, is very caustic when heated and will eat through the lining. If you are doing a lot of forge welding and fluxing. Look at installing a sacrifical piece of fire brick or kiln lining to protect the bottom. Always check you lining after a welding session when it has cooled.

  • Broken bits of the hard outer crust can be repaired using RTZ washcoat, mixed with water and painted on. Please allow a couple of days to dry. On first firing up, run only for a few minutes then shut down to allow the RTZ to dry. Then a forging session can be started. 

  • R.T.Z. can be purchased (about $30 litre) from -
    Mathews Industrial Products P/L
    58 Gordon Rd

    Osborne Park

    Western Australia 6017

    Phone (08) 9242 1800