Problem with Petromax halo and bad brightness.

Hello all,
I lit my Petromax tonight while working on something outside and it is not burning bright and the mantle is black with a decent sized flame around it coming through the mantle. I know for a fact that the burner frame needs to be adjusted, but I do not know the height needed between the orifice and mixing tube. If anyone knows what it should be that would be appreciated.
Also is there anything that would be causing it other than that?

 

Also the lantern is a 500cp and my little Coleman 200a is much brighter than it at the moment.

 

The height between the jet/orifice and the J-tube inlet rim should be at least 14.2 to 14.5mm. It can be wider than this. I usually make it around 15 to 17mm.
The symptoms in the photos normally suggest a worn/enlarged jet/gas tip orifice or a loose jet. What's the operating pressure in the fount? Should be around 30psi or 2 bar.
The internals of the vaporizer should preferable be as clean as possible. Make sure the mixer/J-tube is not too corroded and clean.
I'd assume you using kerosene as fuel.

 

Well, the lantern is brand new and has only been lit about 15-20 times, so unless it came with a messed up part I don’t think it is worn, but the jet may be loose. And yes the operating pressure is 2 bar. And I do run it on kero. Do you know if there is a way to easily measure 14.2-14.5 mm? I don’t have any tools that measure anything other than inches and the like. Also one it is at that distance how tight should it be tightened?

 

Normally new lanterns would have a universal key as they call it.
On the end of it is a kind of measuring part.

 

A common 3/8" nut uses a 9/16" wrench which is 14.3 mm. My Aida lantern came with no tools so I use a nut as the gauge for mine and it's fine. I also experience a blackened mantle like that sometimes. It can be from kero tgat has gone bad from storage in a plastic jug. Or it can be from insufficient preheating of the vaporizer. The best cure is to pump it on up a bit more and let it run, it will eventually burn the carbon off the mantle.
As for tightening the jet just a bit tighter than hand snug should do it. Also the same for the adjusting screw for the burner assembly gap. Check it after running a while and if the gap has gotten smaller then the adjuster screw has lost grip with the heat expansion and needs to be tighter.

 

As mentioned by Rùstytank, a 9/16" across the flats nuts would be convenient enough. You can usually increase the gap further if you suspect the kero's a little on the heavy side. 1" = 25.4mm.
Did your lantern ran well earlier when it was first bought?
If you have some copper antiseize compound, you can smear it on the jet/gas tip's threads before screwing and tightening it back to the generator. That'd somewhat reduce chances of it coming loose after a number of lighting cycles. At the time, it'd seal better too.

 

Ok, that makes measuring a lot easier. And I will see if the jet is loose too.

The lantern ran perfectly when I used it the first 10 or so times, but a while ago the clay burner broke so I got a new steel one to replace it. It started getting dim and also noticeably quieter right before the burner broke. After I put on the new burner and a new mantle it burned as well as it did just before the clay burner broke, not too well, but not as bad as it is now. Should the distance between the orifice and j tube affect how loud the lantern is? Or is that because it is not burning as bright?

 

The noise has nothing to do with the light output. But off coarse any air disturbance beyond the normal will cause noise and will affect the light output. But not in the way that you get black spots. The mixing paddle is causing the noise.

I wonder if your pressure is kept on the 2bar and if the 2bar is actually 2 bar.

Also it is normal that the pressure will drop over time so you must use the hand pump every now and then.

I wonder if the metal burner head will expand and contract more then a clay one and therefore loosens easier.

 

Who knows, I will check and see if the burner is loose.

But yes, I have noticed with a full tank the pressure does not last as long as more fuel makes for less air space and liquids compress less than gas, so the losing of pressure faster from a full tank makes sense.

And the noise I was talking about is the characteristic whoosh/hiss of a lantern. The hiss is not as loud as it was when I first go it, as others have said the jet needs to probably be tightened and the pricker might need to be tightened as well.

 

Well petromax lanterns especially the 500cp version make a lot of noise. That is the characteristic part of these lanterns.
So doe yours have the mixing paddle in the J-tube and if so what is its direction?
What you also could check is if there is debris in the tank. Did you "needle" when the light was dim? That is: quickly moving the needle up and down again.

 

Wait, there is a paddle inside the j tube? I don’t know. I have not checked. Yes I did do the needle up and down a few times, but it did not help.

 

If there is one, should I be pointing in a certain direction?

 

It*

 

Also does anyone know what mantles are good for 500cp? Petromax ones are harder to find and coleman no longer makes 1111 mantles so they are expensive. Are the Peerless good?

 

The large Peerless are ok.
Or Butterfly 4D.

But check the burner flame without mantle before.

Gap from jet to mixing tube should be 14 to 18mm. For a worn jet rather 18mm. I believe google will tell you corresponding inches.

The stainless steel burner is rubbish. Better replace it with clay or ceramic burner. Steel burner will widen the mixing chamber irrevokable until burner falls out.

You might get this undefined flames and corona if the flame fell backwards behind burner and burns partly within mixing tube. Tube turns visibly red.

This can have various reasons and a few options to mitigate.

Only when flame burns correct at the burner front, then mount a mantle.
Because too rich/fat mixture burns with too low temperature and this will shrink the mantle too small. Too small mantles cause mixing tube burn again.....

 

Ok, the mixing chamber has burned red after a while every time I have used the lantern, is that not normal?
My Colemans burner glows red very very dimly after it has burned for a while as well.

As for the steel burner, brass expands more when heated than stainless steel. So yes, it will form the brass but unless the brass or steel are of bad quality neither should break. Although that also depends on the brass alloy type.

Good Suggestion on doing it without the mantle, although since I sadly have limited amount of 500cp mantles I will try my best to fix the problem without taking the mantle off, but if that fails to solve the problem i will take it off and fix it then.

 

Any 500cp mantles would be fine for the testing. There are still plenty of inexpensive mantles from China you could get. Butterfly, Anchor, etc. Some without brands. They might not the strongest but a lot of them still get pretty bright. Some are still thorium-based. Peerless should be fine as well. They are no longer made in the Philippines. They are made in India now.
In terms of price, it'd be hard to beat Asian ones.
Since you're in Texas, I'd believe it shouldn't be too difficult to get Coleman mantles. But their mantles are not like what they used to be. The Peerless #111 should be the equivalent for the old Coleman #1111.

 

Alright, so I took the jet off to check the little pricker and it turns out that the pricker was broken and bent up. I replaced it but broke the replacement as well. Anyone know an easy way to replace them without damaging the needle after putting the jet back on? When I put the new one on it seemed to be on good and tightened all the way down where it should be, but when I put the jet back on it bent up the new one too when I tried turning the valve to make it go back up. Any suggestions or advice?
That may have also been causing problems along the j tube not being properly adjusted.

 

Yeah Myn, I can find Coleman ones, but not any that would fit a 500cp. They are all too small sadly because they are a brighter white than the common Petromax mantles, although I have not tried the Helox ones. (But luckily It is easy to find the mantles for my little Coleman 200a.)

 

Check first if the needle will go through the jet before placing them on the lantern.
Also did you do any adjustment to the needle rod?

 

Adjusting the Petromax pricker is a little more complicated than the Coleman because, its variable. First, you need to check the pricker control rod in the generator to see if its loosened in any way. If it is, it'd be off-centre. The needle height is adjustable by adjusting the pricker rod. When the the pricker control knob is at the 'up' position, the needle should protrude about 1 to 1.5mm from the orifice of the jet. Try screwing the jet down when the pricker is at the 'up' position and see if you can still tighten all the way in. That way, you'd get the tip of the needle into the conical guide behind the orifice first before the threads engage.
Anyhow, you better check that the pricker rod isn't bent too much off-centre before getting on to the rest of the assembly.

 

I thought the rod itself looked off center, but I did not really know how to fix it. And the needle did not really seem to want to go through the jet anyway.
So the rod might be bent or need adjusting, so how would I fix that?

 

I would not know if I would need to replace the jet though.

 

There really isn't anything to keep the rod exactly centered in the generator/vaporizer. As long as the pricker rod hasn't come loose on the eccentric block, you're pretty much ok. It only needs be adjusted to the right overall length to suit the vaporizer/jet dimensions.
The needle itself might have a burr or slightly bent at the tip. How far have you dis-assembled the lantern? It might be helpful to refer to the following restoration guide to see that you aren't too far off:-

 

Even though you do not actually need to take apart the entire lantern to get the problem resolved, I'd suggest you might as well take this opportunity to get thoroughly familiar with the Petromax and similar clones.
Essentially, its very handy for us collectors to be able to completely take apart any lantern we own and be able to re-assemble them together correctly at any point of time, so that they become functional again.

 

I always say that these are machines burning folatile fuel with an open flame. You SHOULD know how these function and how to operate them.

In stead of wrecking needles you can first check if the jet is 100% ok and if the needles you have fit and also belong to the jet you want to use. For this you don't need the lantern at all.
Simple put the needle through the hole, carefully!
Check if you have a 500cp jet and 500cp needle.

 

I checked the needle and jet and they both said 500 on them, although I think there may have been a bur on the needle.

I checked the rod and took it out and made sure it was straight and reassembled it, now I am just waiting for my pack of new needles to come in.

How would I know if the jet needs to be replaced or cleaned? I can see through the hole if I hold it up to a light, and it seems clean.

 

The 500cp jet would be 0.24mm in diametre and the needle is 0.23mm diam. I don't think anyone would be able to differentiate between a worn and a good jet just by looking at it with naked eyes unless he is Superman. Its not easy to measure the jet orifice without special tools but you can just use a new needle to approximately gauge it. You can easily measure the needle's diameter with a vernier caliper. A digital one is easier to read.
When you've already got the rest of the lantern in good working order, a worn out jet would produce a larger than normal flame which, is usually orange or yellowish. There'd likely be a flame halo outside the mantle as well. The light would be a lot less bright. You can prick the jet anytime you feel its dirty or partially clogged by operating the tip cleaner. You can also light up the lantern as usual without the mantle attached. This way, you should get a clean, pale blue flame from the burner if its working correctly.
You might need to make final adjustments on the pricker rod once you attach a new needle on it, so that the needle's tip doesn't protrude too much from the jet orifice when in the 'up' position.

 

Ok, how would I adjust the rod? I saw it has threads on the lower half but they did not seem to want to move.

And the rest of the lantern works perfectly.

Once the rod is adjusted the needle should go inside lot easier and not get broken as easily right?