Gold Mohar Lantern

Hi everyone,
I am new here. I just bought presure lantern Gold Mohar made in India. I disassamble the lamp clean everything and put it to gether.
1. My first question is: I cant make any pressure in the tank. what could be wrong?
Are there any seals accept the one under the filling cap?
Iam sorry there are sure these questions somewhere...
2. Do you know something about them? Historie, value?
Thank you very much for answers

 

Hello and Welcome.

Your lantern looks like a Petromax clone; so it should use the same seals. If you take the shiny hood off and take off the inner burner head; the vaporizer will be pointing up. Look at the nipple that screws in the top and hopefully it will be marked 500, 350 or 300.

Take the pump out, it will unscrew and oil the cup on the bottom of the shaft; this may correct the no building pressure problem. If not you will need to investigate further.

 

Made by Optimohar Industries, apparently. 1960’s judging by the artwork. (Photo of tin sign courtesy of CCS ‘Stove Reference Library’)

 

Welcome aboard!

 

Thank you for the answers...

1. Yes, on the niple there is a sign:G.M 350
2. Why is the number important?
3. I dont know if I understand that about the one way valve... should I take it out or should I put there oil?
4. What kind of oil? with what to preheat? And what is the proper fuel for this beuty beasts?

Thanks again for your advises. Iam new in this and I love it... but I am upset that it dont work... but they was out for a long time(I bought two of them right away

 

Welcome Lubos. The number on the nipple indicates the power of the lantern, example 350 = 350 candles.
The leather washer in the pump is sometimes known as a cup or bucket and it must be soft and pliable for it to work properly. You can use vegetable oil (but not ľanový olej) or light mineral oil.

It is good practice to replace the seals on an old lantern, there is a small rubber seal inside the valve which may have gone very hard and will not make a good seal, there is no need to buy a new valve, just the small brass cup with rubber seal (part number #17) this site may be of help
Restoration of a PETROMAX 829 Lantern

Use spiritus / denatured alcohol / bio - ethanol to preheat the lantern.
The correct fuel is kerosene (petrolej). Never use benzín.

 

Thank you Henry
If I understand it correctly I should only replaced the whole #17 brass cup? Where can I find spare thing like this... ?

 

Also I dont think I find spare lead washer... can I replce them with something similar? I know there is one where the tank and brass tube is mounted on top of the tank

 

Welcome Lubos.
The Gold Mohar you're having looks kind of well-made...judging from the pictures. Petromax-styled.
You don't have to replace the whole #17 brass cup. Only the rubber pip if its very hard and not sealing. You can punch out a piece from a sheet of fuel-resistant 'rubber' such as Viton. You can also use cork if you can't find suitable 'rubbers'. It needs to be soft enough to seal with the force resulting from the weak compression spring inside the non-return valve.

 

Hi @Lubos and welcome !

Thank you for showing your nice lantern

Have you any experience with lamps before or is this your first one?

Good luck with everything

 

I only have one Indian lantern, a Prabhat so my experience is not from a large sample size, but...

Check the central boss on the tank where the brass control valve screws in. On my Prabhat, this was loose and had to be soldered into place! It was a blooming nightmare but it worked... in the end! This probably isn't the problem on your Goldmohar but it's worth checking.

 

Thanks @ColinG you mean where the pisten is screw on the tank? That is solid...

Thank you @podbros yes thats my first lantern but I bought two of them right away... I want them for camping...

Do you have a clue how should I unscrew

 

If you can not find fuel resistant rubber or cork as Myn suggests, you can buy part #17 (Ventileinsatz mit Gummi - 350 HK) from here
Detailseite: Ersatzteil- und Zubehörliste "Petromax 350 HK

You can get a lead washer #90 from the same place.

To unscrew the valve, you will need a special tool. You can buy one (Check Valve removal Tool Petromax Vapalux Optimus Primus Multipurpose wrench | eBay) or you can make your own. Cut a 5mm wide slot in the end of something that is a close fit in the tube, an 18mm bolt is good. There are two different examples here
Check valve or NRV or whatever its name is

 

No, at the top in the very centre of the tank! On my Prabhat this was so loose you could spin it round it was so badly made!

 

That is solid also there is lead washer wich cause tight fit...

 

Hallo my teachers
I have few updates...
1. new skin to the pump works I was able to make pressure.
2. Manometer on the filling cap doesnt work...
3. I was bit unpacient and fill the tank with petroleum and by the pressure it was all over the lantern so for safety reasons I didnt fire it up...
4. Petroleum is out and I'm thinking about pressurized it empty and sink it to the water how it was written here on forum...
5. Is it normal that petroleum leaks from somewhere or by the pressure it has to be with out any leaks? I think it leaks up in the needle and maybe in the middle and where the tank and rest is mounted...
Thank you for you suggestions or thoughts and answers

 

Is there any odorless petroleum on the market?

 

Hello Lubos,

Your lantern does not have a ON / OFF valve. You can turn the wheel so that the needle is up but petroleum can still leak from the nipple.

It is a good idea to pressurize the lantern and put it in water but you will have to put a finger or thumb over the nipple (which is also called a jet or gas tip) or the air will leak out too fast. Do this test and tell us where the leaks are so that we can help you fix them.

I can't help with the odourless petroleum but when these lamps are burning correctly they do not smell much and if you use them when you're camping they will be outside so what little smell there is won't be a problem.

 

The name of different fuels in different countries is confusing but just to be certain, all the Petromax clones I've seen fun on paraffin/kerosene. In the UK the name petrolium is the same as gasoline in the US. If you run a kerosene lantern on gasoline/petrol/Coleman fuel it can be extremely dangerous as it does not have the correct safety features that a Ceman lantern does. Only run your lantern of kerosene!

 

Yes it can be confusing. What the British call paraffin, the Germans call petroleum. I have been told you can get paraffin in Germany but it is a wax.

 

Be sure to use only kerosene for the lantern. I think in Slovak, its called "petrolej" if I'm not wrong. Germans usually called them "petroleum".
Do not use gasoline or petrol or coleman fuel or light naphtha on this lantern because it is very dangerous (this lantern is not designed to operate with these volatile fuels).

 

Ok sure thank you for warnings...

 

*Correction*

Ceman lantern = Coleman lantern

Apologies... I sometimes don't spot the nonsense autocorrect has made of my typing in time - often the last millisecond before I hit post. I'm sure you were all able to translate but I thought it was worth mentioning.

 

Hi there
So I spray some soapy water on it... and the result is:
1. The jet(needle and also where is the niple screwed on to the tube with loop)
2. The top of the nut which screws the loop tube with the bottum part
3. The pisten there I heard the visle sound
4. The nut behind the wheel which hides the needle

 

That are the leak points... can I isolate them and with what... thank you

 

Have you started dis-assembling the lantern already? If not, you can start the following but do it one at a time in stages so as to reduce chances of messing up more points than necessary:-

1. Not a problem with the needle orifice/hole since its not supposed to seal totally. The jet or vaporizer threads or seat may be worn. Unscrew, inspect or replace if you have a spare. Otherwise, you may try wrapping a mantle tie-string around the threads and smear some copper antiseize compound on it before tightening it back in.
2. Loosen a little and then tighten further the generator nut and see if it'll seal. Use two spanners to hold and prevent the lower generator part from spinning on the fount while tighten the nut with the other spanner.
3. Have you replaced the rubber or pip of the the non-return valve?
4. Loosen a little and then tighten further and see if it still leaks.
Proceed patiently, no rush. Others would offer help along the way.

 

Hi
Yes I had the lamp dis assambled. Then I clean it and I put everything back together...
So there is only mantle string for sealing? It have to be heat resistant...

 

Mantle string is resistant enough. It won't burn inside the threads but might char. That's not a problem once it's sealed. You can also use graphite string or expanded graphite cord/packing if you have them. Some guys use hard soap. Some use muffler cement.
Sometimes just the copper antiseize would do when tighten sufficiently.

 

Hi I have a question about rubber sealing in the one-way valve in the cerosine tank...
Does it have contact with cerosine can I replace it with a piece of silicon tube?

 

I'm not sure exactly what you are considering, but you can't replace any of what is called the NRV or Non Return Valve with a tube of any description. The NRV will have a small pip in it that stops the kerosene flowing up the pump tube when pressure is added via the pump. For replacement pips and other seals, try the Fettle Box (link at the bottom of the page) or base camp online. If you send some photos of what you are trying to do someone here will try to assist.