Restoration of a PETROMAX 829 lantern

http://www.dr-bommel.de   : Jan Moeller, Germany 


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Lighting instructions
Chapter 10
- Burning the mantle
Chapter 11 - Pre-heating lantern w. Rapid / pre-heater cup
Chapter 12 - Adjustment of mixing tube paddle
Chapter 13 - Put out lantern 


Chapter 10 - Burning the mantle 

The lantern is now prepared. Now open (!) the pressure relieve screw of the pressure gauge.
It’s advisable to burn the mantle outdoors as it generates strong fumes and odor.
Fill the pre-heater cup with alcohol (Ethanol) and light. The mantle starts to burn or glow until completely burned white. Only now it’s ready to use. If it doesn’t burn completely put some more alcohol in the cup and continue.

Burning the mantle with the Rapid (in case of non-existing alcohol cup) is different.
Here the valve and the pressure relieve screw on the pressure gauge must be closed. Pump the font up to a lower pressure, just enough to get the Rapid to burn. Now open the Rapid with the lever and light the gas stream with a lighter or small gas burner. Let the mantle burn until completely white.

A properly burned mantle should look as seen in the pic 31. below.
After burning let the mantle set and cool down some time before lighting the lantern.

Pic. 27: Filling alcohol in the cup w. bottle 

Pic. 28: Burning the mantle

Pic. 29: Pump up to suitable pressure 

Pic. 30: Ignite 

Pic. 31: Nicely burned

Chapter 11 - Pre-heating lantern w. Rapid / pre-heater cup

Pre-heating the generator before lighting the lantern can be done in two ways:
1) w. Rapid pre-heater using kero from the font, or
2) w. pre-heater cup and alcohol.

For pre-heating with the Rapid one has to pressurize the font first. Close the valve (arrow ‘up’) and the pressure relieve screw on the pressure gauge (#149). Pump up until the pressure is between 1 … 1.5 bar. Usually the Rapid pre-heater works best in that range.

Now open the Rapid lever and immediately light the kero / air mixture (see pic. 30) . Sometimes the pressure from the nozzle blows the Rapid out by itself. Then try again with some higher or lower pressure.
When the Rapid is firing (pic. 32; don’t be afraid, it’s quite noisy)), constantly watch the pressure and keep slowly pumping to maintain a suitable pressure level in the font.
Pre-heat for abt. 60-90 seconds and make sure the flame reaches the upper part of the gen and the connections to the generator loop(pic. 33).
Now slowly open the valve. As soon as the mantle starts to form and to give a bright light, flip the Rapid lever down.
Check that the little rubber seal securely tightens the pre-heater nozzle(pic. 9).

Let the lantern run with lower pressure for a short time, watch the lantern behaviour (tightness etc.) and check, if the mantle is not damaged. Use welder’s goggles or dark glass (pic. 35).

Pre-heating with alcohol takes more time but is a ‘softer’ start and is more gentle to the mantle.
In this case the valve and pressure release screw might be kept open. The pre-heater cup must be filled with alcohol and lit. If the burning time is considerably less than mentioned above, the gen is most probably not hot enough and a second fill is required.

Before the alcohol is fully burned, close the pressure release screw on the pressure gauge and start pumping to a suitable pressure. Slowly open the valve and let the rest of the burning alcohol light the lantern.

Let the lantern run with lower pressure again and watch proper operation before adding pressure up to the red mark on the pressure gauge.


Pic. 32: Rapid firing 

Pic. 33: …to gen’s top 

Pic. 34: Burning ok 

Pic. 35: Check mantle

Chapter 12 - Adjustment of mixing tube paddle

Put the ventilator on if not already done and make sure, the little screw in the mixing tube can be seen from outside. Otherwise turn the vent horizontally by 180 degrees.
Now, only the final tuning is left. This is done using the mixing tube ‘paddle’ inside of the mixing tube (#33). Now turn the screw with a flat screwdriver forward and backward until the lantern gives the brightest light (pic. 36) .
That’s it folks!

Pic. 36: Adjusting the mixing tube ‘paddle’

Pic. 37: Voila, the perfect result ! ☺

Chapter 13 - Put out lantern 

To put the lantern out, simply close the valve. If the generator foot valve was properly maintained and is tight, the lantern should stop delivering fuel, vaporize the remaining fuel in the gen and go out almost immediately.

The pressure can be kept in the font if one wants to resume operation very soon. However the lantern should be checked for leakages or dripping frequently.

If it’s not going to be used in the very near future it’s best to put it out by just fully opening the pressure relieve screw on the pressure gauge. The lantern will dim and go out within a few seconds.

Let the lantern cool down, close the main valve, screw the release screw tight again and store away.


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Content  PDF Version