Petromax CP500 issue

OK Henry - So you know and your own are running right!

 

Well you may not have to open every window, it depends on the size of the room. Although it's been a while since I had a 500 HK lamp burning in the house, the last time I had a few burning outdoors, they all worked well.

Under normal circumstances, I display some of my collection at various vintage rallies through the summer months and always have a few burning in the evening, large or small, they are there to work and if they don't, it's maintenance time. So yes, the vast majority of lamps in my collection work as they should.

Henry.

 

Yes, indoors!

I have a couple of my P'Max clones fitted with frosted globes to reduce the glare and when the power goes out, we crack open a window a little, light an Anchor or a Golden Globe and let the light flood the room. Plenty of folk in the highlands of Scotland once relied on Tilley lamps and table lamps for their lighting and it wasn't that long ago. Last year we found a small stone cottage miles away from mains electricity and as it was empty I looked through the window. What did I see... a X246b and a guardsman, both obviously well used workhorses that provided all their lighting needs.

 

Hi thanks for the thoughts
I have not yet totally given up ....
The lamp has run very little, I would guess 20 or so hours, I brought the lamp brand new and never used
It did run well and burn brightly the first time I used it
I guess I am just frustrated at the time I have had to spend after such little use
The fact than the manufacturer must accept there are issues as they supply some gauze to modify
I have wrapped copper wire round the needle holder - this has made things better but not a full fix
It seems if everything is perfect they may work well but seems it takes so little to upset them, I am not sure what has changed on mine
It does run and pulses less but is still pulsing it is bright but if I increase the pressure it gets brighter but there is a lot of burn outside the mantle
The mantle supplied as I remember was like a long thin tube with quite straight sides
I ordered replacements from petromax and they are much more bulb shaped I now have a handful of mantles that are similar but way cheaper and seem to work the same as the petromax replacement ones
We sit in the garden of an evening and love the heat and light if I go to the shed and grab the vapalux or Tilley we have a relaxing time nice even sound etc if I grab the petromax, not so much
Maybe I need to strip to component parts ultrasonic all parts and rebuild
Just seems crazy after such little use ?
Thanks to all for support ideas and suggestions
I would love it to work properly I was quite frustrated in my earlier post ! have a great weekend 25 degrees here today so will be topping up our tans

 

I can understand your frustration. Forking out hard earned money on something that won't work is not conducive to glee in the warren.

A complete strip down and rebuild may not be necessary. In spite of the fact that your lantern is relatively new, I'd be tempted to try a new jet. Also, check that the needle is attached firmly to the needle rod.

 

+1 on the new jet. You can find cheap jets on eBay. I've used them and they work for me Here are a couple of links to them and pricker needles as well...

2 Pcs Vergaser-Düsen for Light 500 Hk, Kerosene Lamp | eBay

2 Piece Düsen-reinigungsnadeln Light 500 Hk, Kerosene Lamp | eBay

 

Glad to hear that you've not given up.
Sometimes, the harder it is to get it sorted out, the more interesting it becomes. If you've not stripped it down again, I would suggest you try to light it up without the mantle in place. You can post some pictures that could indicate the type of flame you've been getting all along. If its long and slightly yellowish, you'd know something's not right about the fuel-air ratio. That could also mean that the jet is enlarged, an unnoticed leak around the jet or an air gap that's inadequate. Less common, even a poor batch of mantles could accentuate the flame-outside-mantle problem.
About the pulsing, I've personally experienced that it could also be caused a tiny(unnoticeable) crack on the vaporizer. In that case, undesired air had been drawn into the fuel path, causing erratic flow, severe pulsing and even dimming.
On one previous instance, I've used a copper wire coil around the pricker rod. It didn't work very well. I replaced that with a braided nickel-plated copper screening/shield from a thermocouple cable, which worked far better and practically solved the pulsing problem. This could be packed more densely inside the vaporizer tube than a simple wire coil, providing better conduction from the tube wall throughout the internals. That's not all. It actually provided a more restricted fuel fuel flow compared to a simple coil. This way it sort of dampened off any back flows into the fount. The dynamics of it could be much more complicated, of course.
Other designs like the Coleman 237, have a coil within a coil; which are wound in opposite directions with one another. This too, provided a unique means of fuel flow restriction, which is somewhat different from what a simple coil could realize.

 

@spike589715 It sounds like you have had a similar experience to myself in respect of a new Petromax 829. I purchased mine April last year, and no matter what I did at first, I couldn't seem to get it to run. The solution for me was the purchase of a Anchor Lantern to use as spare parts, to test and use on the new Petromax (Swap a piece, see if it makes a difference, and so on until it works). The Anchor Inner Hood fitted on the new Petromax saw it running as sweet as can be.

Moving forwards 10 months, a fettle and play or two later (when not frustrated with a new not working lantern that cost significant bucks) and I now have the original Petromax Inner Hood back on the original lantern, and it works fine. It still hunts a little, which I'll sort with the brass gaze in due course. It turns out I had a damaged/small dent in the original J Tube (#33 Mixing tube) that caused all my problems - this I have replaced from the Anchor Lantern.

Good luck with nailing the fault, these are good lanterns, and it will be well worth in the end. Regards, Alex

 

I have made a collection of Chinese and Hong Kong Petromax clones including a brand new Sea Anchor that only cost me £20 inc delivery plus 2x Anchor 950s an Anchor 909, an Eye brand, Airoplane, Golden Globe, Solar, Light brand, Relum Magnalux... and they all work well and give a tremendous amount of light. Recently I bought a modern Petromax 829 for a very good price because the owner couldn't get it running. No problem I thought, I have loads of clones so the real thing must be better. Well, I did get it to run (almost everything that could be set incorrectly, had been!) but the damn thing stinks and I can't find out why! I've checked all the seals and performed a dunk test but it still smells of kero whenever I run it, which isn't often. It's crazy that the only genuine Petromax is the one that performs the worst... and the rapid heater spring isn't as tight as it should be although that's not what's causing the smell. You might imagine it's because it's a Chinese made Petromax, not a German original but I have 11 Chinese clones and they all behave perfectly!

 

Sorry to jump in, but I have a thought, so this copper or brass spiral to be fitted inside part 152, I take it you want it so it presses out against the inside wall of the tube which would hold it in place and help with heat conduction into the wire, whilst still allowing 101 to be able to move but be quite close to the wire spiral to prevent all the fuel bypassing the spiral up the centre.
This would cause the fuel to spiral up the tube through the now restricted path which would create a narrower stream of fuel albeit moving at a faster rate, so this should gain heat quicker due to all the mixing and additional contact with hot surfaces with all this happening before it even gets to the P ring and therefore vaporize more fully by the time it came out of the nozzle at the top.

So, what is the ideal wire size for this?

I used a similar approach to cool hot gasses in a project years ago actually identical to be honest, and it worked really well, same principle, just instead of heating, it was cooling, but same design, a spiral around a central rod with the spiral pressing against the inside of the tube the whole thing sat in.

 

I always say: a pressure lantern is a machine. The petromax is by design the most complex. All parts must perform well as the fuel.
Temperature of fuel, size and shape of the mantle, pressure in the tank, dirt particles, all play a role in the the total picture.
The " Leidenforst" principle makes that the lantern may pulse. An extra piece of mesh in the vaporiser may help.

 

I also wonder about the Chinese version J tube. It does not have a waisted entry so will not accelerate the air causing a low pressure at the restriction which would help to draw air in.
I know the petromax Lanterns of old have this wheras the modern Chinese versions do not.
If it were not needed then why does the original design have this, could this help prevent back burn in the J tube?.

 

Absolutely!
I had similar experiences.
By tightening and loosening the jet a few times, makes it seat and seal fully.

 

I also used extremely fine stainless steel sieve mesh, used in irrigation system filters, successfully.
It is important that the mesh makes good contact with the tube, in order to conduct heat away, as well as to prevent "free flow" of kerosene between the tube and the mesh.
The mesh is more effective in the "hot zone" near the mantle.

 

Hi Myn,
I read in some places, that brass wool does as good job, especially in white gass lanterns, like the Coleman 335, 285.
In can't find brass wool in South Africa.

What is your experience?

 

Just difficult to see the preheat bowl, to fill it...

 

Hi Jacob,
Brass or bronze wool would work fine. So are steel or stainless steel wool and braiding.
The idea is not merely to conduct or distribute heat evenly thoughout the fuel in the vaporizer. The metallic wool / mesh/braiding takes up considerable space within. This reduces the total mass of fuel residing in vaporizer at any one time and in effect, contributes to:-
1. Reduction in the amount of required heat to gassify the fuel completely.
2. Prevention of excessive amounts of fuel vaporizing at any one time. This reduces the chances of the excess, which cannot be fullly discharged through the jet or gas tip orifice, from seeking another escape path of lesser resistance which is back to the fount.

Vaporization in a capillary media is apparently easier, more controlled and less erratic as compared to bulk media in this case.

 

Myn,
Thanks for your quick and thorough answer.
Your suggestion to use steel wool actual makes sense...
My gut thought it would rust...?? Would there not be some oxidation...?

I did some research on the Leidenfrost effect, which also happens in generators. Your answer also touches on this.
I had good success with both s/steel and brass mesh, rolled around the pricker rod.
I thought filling the generator tube with brass wool, would be easier. Now you recommend steel wool as well. I will use 0000 steel wool that I use to polish founts, to fill a generator and see what happens.

PS
I am running a 285 very successful with only a copper mesh around the pricker rod; from top to bottom, (no paper cylinder), but I get some oscillations. By adding pressure, it gets better, obviously because of the higher pressure the "oscillation wave" has to overcome.

Your reasoning makes perfect sense, thanks.

 

Jacob,
It would take quite awhile for the steel wool to rust within the generator tube. Especially so if the lantern is in frequent use.
Yes, it would eventually rust if the lantern falls into long disuse.

While pure copper mesh or wires works very well for the basic reduction of pulsations, I have found that it tend to catalyse the thermal degradation of kerosene in the generator and somewhat hastens carbon buildup. Others might have different experiences though.

 

Thanks Myn.
In try to burn a different lamp/lantern every night, hence the frequency of burning a specific lamp/lantern is low. I do remove all fuel after every, run, though. Doing this removes the water droplets, forming when pumping up the fount. Rust formation tendency is thus lower, I hope.
U mitigate carbon buildup, by using the Amish blend, (3+1), and using coal derived paraffin.
Not only does it burn cleaner, but starting is also much easier.

 

Thanks Jacob