New Petromax owner - couple of questions please if I may

Hi folks, just jumping over from the stove forum having picked up a Petromax lantern. I've looked on the reference forum and couldn't believe the array of lanterns there. I'm not some purist when it comes to these things but I would like to know a little more about what I have (impulsively) gone and bought.

I've had it to bits and replaced the seals, jets, needle (complete) valve packing - well just about most things really. And it's firing fine.
Q. I saw the the wrench is supposed to work like a feeler gauge to set the air gap but the genuine one? I bought is far to think for that. Is there a measurement I can use to check the gap?

Q. Does the height that I tie the mantle at on the ceramic make a difference to the output?

Q. Looking at the pics can anyone shed any light (see what I did there..) on the lamp itself. It has everything but a date on it. Every component has Made in Germany stamped on it an there's no other name/brand at all.

In short I have no detail whatsoever from the seller. I kind just bought it and thought, hmm, do I need a lamp? Given that I have several and more stoves than fingers. Hey, no pockets in a shroud as they say.

It looks a bit battered and bruised but that's OK and from looking at the reference section I can tell that it's fitted with the short NRV that isn't serviceable like the later ones. It also has no spirit cup.

I'd like to think that I whould be able to get it to be brighter, it's not really much better than my modern Coleman if I'm honest.

Really appreciate anyone's time in answering any of this from a newbie..

 

Chris that's a mighty fine lantern you have there. I'm a Petromax fan myself but only have the Aida and Hipolito variants. As to the wrench as the spacer gauge, the gauge is the width for the end of the handle, not the thickness. The gap is supposed to be approx 14mm or 9/16". I don't have the wrench myself so I use a 9/16" nut from the hardware store to set the gap and they run just fine.
When I got my Aida I was new to this design. Go to this website and read the whole thing through like I did.
Doron Papo's Lanterns Site-technical stuff petromax

 

Welcome aboard!

 

Cheers. Esso blue, blimey there's a blast from the past. And Pink Paraffin too, eh?

Sorry folks, just seen that the pics have repeated themselves. Grrrrr.

 

Hi Chris, Welcome to CPL !

Very nice lantern

 

Cheers PB. It seems good quality, but I don't know soot from sawdust on these things. It could be 100 years old or made last week. I have always fancied one (oh I have way too much kit) and I saw this on the Bay and they sent ME an offer. Huh? And I figured, hmm too good to miss. and before you know it, it was mine. It's in used condition as it were but as it's well made it's just fine and dandy. It leaked and was badly sooted up so I threw some spares at it. And there we have it.

 

Hello Chris, there was also Regent Green paraffin and Petromax lanterns are well made and the link below shows relevant information. Jeff.

Restoration of a PETROMAX 829 Lantern

 

14.2 mm. Excellent thanks Jeff. That's one down

 

Thanks Rusty, I wasn't using the thickness of the wrench, trust me. I couldn't get the U tube to drop that far but after a bit of wiggling it freed up and dropped to the width of the wrench. I used calipers to check it too and it's now 14.2 mm. I also needed to adjust the length of the needle rod thingy as well as the wire wasn't poking out of the jet enough. So its better, but still doesn't feel like 400 watts!

 

These are as good as it gets as far as light output goes. I would say 50 - 75% brighter than your average Tilley/Vapalux, so if you're not seeing it then there is something wrong.
I know that doesn't help but at least you know you're concerns are founded.

 

Hi Chris ... have a look at the below named site on these lanterns made in Germany / Asia ... you can examine yours and look at the markings ..... I have an actual German Petromax lantern which I purchased in Germany sent from Bavaria ... and it is fine well made lantern conforming with what is indicated .... just a thought

Distinguish between European made petromax an asian made

good luck

 

The brightness of any lantern depends on how much the vapouriser has been used, in the Preston ring vapourisers the carbon builds up in the actual ring and it's difficult to clear, but not impossible, check out the cleaning instructions in the link in my previous post.

The jet in your lantern may be worn.

 

On the contrary, it does. Mine's definitely not as bright as it should be. I'm just looking the various trouble shooting things. I have to say it's sounding right, holding full pressure, turning on and off smartly and there's no smoke or fuel dribbling anywhere. It's a little subtle fettle needed I think. The mantle has been white on occasions but that was pre -rebuild and there was fuel everywhere. The mantle is dull enough to look at and is more orange than anything. I mean it's working as a lantern sure but it's not something you'd see and say Oooh I have to get one of those. Not yet anyway

 

Thanks Alby, I was never in any real doubt that it was German but reading that thread confirms it. Thank you. I'm just curious as to how old it might be.

 

Is it stamped "Made in Germany" or Reg Germany??

 

Made in Germany as per the guide posted by Alby. And has 10 points on the star

 

A small breakthrough. What I had not seen or seen mention of is the small damper sitting inside the top mixing tube. It's a simple external screw spindle with a rotating block on the inside of the pipe. It spins 360. If you turn it vertically it allows more flow and suddenly my lamp burned much brighter.

 

Hello Chris, that's good news and did you see my previous post?

 

Actually No Jeff. It's going to sound odd, but replies don't seem to be coming through in order. I've had a couple where I've already checked and replied and then a new post has appeared half way up!! Need to read up on what you're talking about. I've cleaned it pretty thoroughly and changed pretty much all the serviceable parts. Back in a tick...

Still no one has had a crack at how old it is...

 

Nope not following Jeff. Every time I look at a write up or a parts list people call things by different names. The needle is new. The jet cap is new, the long stick with the needle on top is new. I cleaned the inside tube of the carburettor? And the round tube thing at the top of that where the preheater aims. So.. vapouriser? Preston ring? They're not mentioned in the write up. It's burning well just not that bright as I say. I may be expecting too much of course but I wouldn't describe it as white hot that's for sure.

 

One thing I can say is that when I turn the valve 1/4 turn that is max brightness. Turn it to 6 O'clock and nothing more happens. It will 'simmer' very nicely with a very small glow (standby position) and turns off instantly when I go to 12 O'clock

 

Hello Chris, it's not called a carburettor, it's called a vapouriser, because that is what it does, it vapourises the fuel and air mix when it's heated sufficiently and that type of vapouriser is called a Preston ring vapouriser.

Cleaning the straight part of the vapouriser does not clean it's ring and if carbon has built up in the ring then the lantern will not perform as it should.

The link below shows cleaning instructions and stated there is the use of an ultra sonic bath and citric acid.

Just because a jet is new, does not mean that it's perfect and if your lantern is working better with the pricker wire turned up a bit, then that is a classic sign of an enlarged jet.

There may be some scratched numbers on the base plate and if there is then that is a date code.

This link shows more relevant information.

Do let us know how you get on.

PS., could you post a photo of your vapouriser, just in case your lantern has been fitted with a different type of vapouriser.

Restoration of a PETROMAX 829 Lantern

 

@Chris J You got a nice dependable German made Petromax! These are a great lantern, enjoy!

 

I have a few new needles and a few jets. They're all fine. I'm new to these lamps by the way but not stoves. Preston ring, thanks there's a new one for me. I did clean that too as per a vid I watched. I took the top off and watched the performance of the jut into the mixing tube. Perfect. Not a sign of anything at all. So I'd say it was vapourising pretty well. I'd expect spray or droplets etc if it was not running well

No date code I'm afraid that's why I was asking. Would have made it easier. Vapouriser exactly the same. Seems to be all very original without the usual tool marks you'd expect to find. Well it was ha ha. I'll give it all another go

 

Well, it's all about marginal gains here. Had another go at the vapouriser and it seems really clean. But I stuck my fibre optic camera in there and the bottom half of the tube was much more fouled than I'd thought. So I cleaned it with a small rifle bush until it was spotless. Fired it up and it's a little brighter again. Late now so I'll play some more tomorrow after work. Can't be that hard. Must just be missing something simple. I mean it's good enough but not what I'd expect.

 

I assume that you are pumping plenty of pressure into the tank.

 

To the red line Jeff, yes. I'm using a standard Petromax mantle and burning odourless kerosene. Not petrol, not diesel but kerosene. Pressure holds really well so I've no leaks that I can detect with soap spray.

 

Are the jet and the ceramic nozzle tightened properly?

If the pricker rod is set properly, then when the pointer on the pricker operating knob is at 6 o'clock, then the jet is fully open, the closer the pointer gets to 12 o'clock, the higher the rod lifts the pricker and at 12 o'clock the pricker is right up through the jet which is how the jet is cleaned.

If there is still carbon in the Preston ring, then it will not heat properly and the paraffin will not vapouriser properly and the light will be duller and more yellow and at times a bit orange.

I prefer to preheat the Petromax type of lantern with meths in a meths cup and sometimes they need two preheatings one right after the other, especially if it's cold weather.

That is also the case for most paraffin pressure lamps etc..

 

Yes all nice and tight Jeff. Preston ring seems clean, no traces of anything that I can find. I don't have an ultrasonic bath, but I used carb cleaner and 100psi air line, then a wire and there was nothing coming out. Looked using fibre optic and it looked clean.

The pricker is through the jet at 12 O'clock by around 0.5 mm which is within spec. I can make it more if you think I should. It's through the hole does it need to be MORE through the hole? I could end up with the pricker blocking the hole even when the valve is fully open. Incidentally, it's not cold here. I'm doing it inside in my 'hobby' space. Cough - spare bedroom.

Let's just go back over some basics -
does it make a difference with different mantles
Does the tying of the mantle height make a difference
Is there better fuel that I should try - does it make any difference

I've not seen this mixing tube damper mentioned anywhere else. Is this a bit unusual?

 

Hi @Chris J
Welcome to the light side. Everything that has been said so far is true. Also true is that different manufacturers used different terminology (often translated literally from the name in that country) so many of the things here do have more than one name.
The pricker serves only to clear small blockages that may happen at the jet or nozzle. It has no role to play in restricting/blocking flow.
To answer your immediate questions above, 1) yes a thorium mantle may be a little "whiter". 2) no, the mantle within reason finds it's own size on first lighting 3) do not use anything other than paraffin - the lamp is not designed for it.
The "damper" or "Air mixing screw" or "paddle" is a common feature on most petromax type lanterns. I would set it up directly upwards (least resistance) and once other issues are fixed then play with it.
Other things to look at: seal of thread between J tube (mixing tube) and Gas chamber, (mixing chamber) and the seal between ceramic nozzle and gas chamber. I use a .45cal brush to clean inside the tube.
You can retrofit a spirit cup.
The pressure guage may not be telling the truth. Take the pressure up a little - say 2.5.
I have just rebuilt one like yours. There were many issues and it was a case of eliminating things one by one. It is worth persevering as "they don't make them like that anymore"
it is probably from the 1960's - are there no markings at all on the underside ? The short non-servicable NRV seems to be comensurate with that age.
Chris