1962 Petromax 829 Unserviceable NRV

Hi all, i have been fettling my 829 today and apart from the most carbon that i have ever removed from a lantern the one piece NRV is leaking and as it is larger than the normal sized Optimus etc NRV i don't know where to get a replacement, i spoke to basecamp but they hadn't heard of one before, i found a thread on here a while back about one but now can't find it,
This was what came out after around twenty cycles of heat and quench so i had already removed a lot of carbon, the brass cleaning needles rod was jammed solid in there too, it took hours to remove!

 

You really shouldn't have a problem finding a new NRV. I believe you can get them from Tilley Lamps and Stoves.com. There is a very good site in Germany that sells parts for Petromax lanterns, too. I just can't remember the name. I'm sure one of our German members knows what site I'm talking about.

 

Thanks George, the trouble is it is a different size than the standard ones i believe, basecamp has a large stock of all things Paraffin and are very knowledgeable but he'd not heard of one of these although i am sure i read a thread on one on here somewhere.

 

www.starklichttechnik.de/onlineshop/petromax-ersatzteile/

or

Hytta.de

 

Thanks Willi, are the Petromax NRV threads larger in diameter than Optimus NRV's do you know? i was told that normally Petromax and Optimus NRV's are interchangeable.

 

Basecamp looks to stock 10-83 - Pump valve complete but he said it wouldn't fit my lantern because of the size difference.

 

Have a look at Starklichttechnik.de. Martin speaks English and has the spares you need and will
help you.
Just email him.

Matthias

 

Ok will do, thanks.

 

@MG
If it's the one on the left with a slotted head? It looks like one of the Austramax NRV's. They have a larger dia thread (9mm from memory).
Austramax 3/300 Lantern with a stainless steel based font

But why is yours unserviceable?

 

@ROBBO55
Yes its the left one, my cheap digital gauge says 7.83 mm but i don't think i trust it,

It either looks to be one piece/crimped together and i've tried to take it apart but it just deforms it.

 

@MG
Is it an odd ball design like this crimped NRV.

Note the nut on the screw is swaged on after the NRV was assembled. It would be better to replace the seal by prying the old one off rather than disassembling the NRV

 

@ROBBO55

No it looks like a Vapalux NRV at the slot end and all you can see at the base is the spring, it definitely won't come apart without me destroying it, i may just buy the one from basecamp, maybe we got our lines crossed over the dimensions, i might get some heat on this one to see if i can get it apart that way.

 

@MG

Could the tube have a left hand thread?

Tony

 

@Tony Press

I had my hopes up then but sadly no, i don't think its meant to come undone as it is so soft, you can quite easily get purchase on an Optimus etc NRV but this one just ovals as soon as you put a decent amount of pressure on it.

 

@MG I had an NRV like the one you are having trouble with, it was on a PICOSTAR 500cp lantern - definitely not serviceable !

Before ordering parts; have you a spare NRV you could try / borrow from another lantern to make sure it will fit ?

Henry.

 

@MG ,
Could you show some pictures of the bottom end of that NRV? It looks different from the usuals on a Petromax.
It appears to me(from the first picture) to have some deformation or crimped markings at the lower end. And perhaps also having an end plug with a couple of flat sides to be held with a wrench? You might want to magnify the image of the bottom end to inspect it.

 

@Henry Plews

I wish i could find the thread on here that i read before, it looks like the same NRV as i have, was also from a Petromax and they also said it was unserviceable too, this is my first Petromax so i do not have any spares for them other than the items you mentioned that were also good for Optimus lanterns, as a complete NRV is only £6.95 from basecamp i might as well order one, i could do with some Tilley NRV springs so will try some of theirs plus there are other items i can add to make the order worthwhile,

@MYN

I think most of the shape/marks is damage caused by me rather than crimps but it does look like there is a join near the very end that wasn't as noticeable before i attacked it with the grips and there is no way in my opinion that you could get any sort of purchase on such a thin part as to be able to unscrew it.

 

Looks like some press-fitted end piece if it was not screwed in.
Perhaps a regular Petromax NRV should make your day (provided that the threaded part in the pump tube had not been altered).

 

That is what i am hoping Myn, i will be ordering some Petromax parts today so will find out soon enough.

 

I've never seen an NRV in a Petromax like that one.

 

Maybe it was a limited run George? i've ordered a new Petromax NRV so keep your fingers crossed that it fits or i am going to have trouble sorting this one out too!

 

I am not a fan of limited or special runs. I think that some one found a matching valve and has used it.
I have found these non serviceable valves too in old lamps. All be it not many.

 

I agree with WimVe, I've been collecting the Petromax lanterns about 30 years. Didn't start with these, Coleman since 1979/80, was the starting point but I have never came across an NRV like this. I really find it hard to accept this part as anything other than a "make do" part. I'm wrong more then right most of the time but this seems strange, never in 30 years and I never came across one like this. I bet the one you ordered will fit without a problem.

 

Well its my first Petromax so i must be really lucky then i will be cursing if the replacement doesn't fit but i can't imaging they would change the actual size as well as design?
Apparently they are like race horses and can be difficult to get running properly but i've also heard they are a decent reliable lamp so we will see, if its anything like the Optimus 1550 i have then its going to be a pain!
I have also ordered the cross bar and screw for the mixing tube as mine was seized solid, can anyone tell me what the measurement between the jet and base should be please? thanks.

 

Once you get used to them, Petromax lanterns are no more difficult to fettle than most other brands.
The Optimus 1550 is much improved by adding a spirit cup which sits higher up the vapouriser.

The gap between jet and bottom of mixing tube is around 14.2 mm (14 to 15 mm). Use item 66 from here : www.base-camp.co.uk/Petromax/Petromax%20Spares%20Price%20List.htm or a 14 mm drill bit. Make sure the needle is down.

Henry.

 

@Henry Plews

Thanks Henry, that's good to know, i ordered a Petromax spirit cup today with other spares on the off chance it might fit the 1550 (i can't remember if you said it would fit or not) but i still haven't got round to doing anymore to it as i keep buying other lanterns to mess around with!
I have got one of the Petromax tools but the drill bit may be easier to use, i have bought a new needle but i don't intend on breaking the original...hopefully.

 

Well a standard Petromax NRV fits so we are getting there, shame the new NRV leaked but luckily i have stocked up with spare pips/cones so a quick swap and the pressure gauge has held steady overnight, i did perform a dunk test on the other fittings except the gauge as i didn't think it was waterproof, with any luck i shall be able to get the lantern up and running over the weekend,
Thanks all.

 

Progress is being made, I like your tenacity ...... looking forward to seeing the money shot (first light).
Cheers
Pete

 

Thanks Pete, i am also looking forward to it

 

The pressure indicator is waterproof.
Although after a dunktest is woul be a good idea to dry the inside >> remove the cap and blow water away.
There is a change the spring will leak air. In that case though, the indicator will not work either.