Austramax 3/300 - Burner - Repair or Replace?

@Pauly

It sounds like your problem is not enough pressure in the tank to feed fuel to the burner.

If you privately send me your phone number (“Conversations”) and a time to call, I’ll talk you through some tests.

Cheers

Tony

 

Thanks Tony, I've sent you a message now.
Cheers, Paul

 

Thanks for your help today Tony. So we've worked out that the no return valve had stuck shut. I then disassembled it using your trick of putting the bottom end into a drill chuck, which worked really well.

Having pulled it apart I was able to clean out all the grit and rubbish, but the seal in there has deteriorated badly. I gave it a try anyway, ie, reassembled the whole thing and installed back in the lantern. As expected the pump itself is working really well now and feels right, the tank is pressurizing as expected, but the pump handle starts to pop out which confirms that the NRV is now not holding. Here are the photos of the dissassembled NRV. I don't think you can just buy the seal by itself. Maybe next step is a new NRV?

Thanks, Paul

NRV Disassembled



Close up of the seal part

 

I have removed the rubber, cut a small piece of a slightly oversize o ring and inserted it into the holder. I then chucked it in a drill and using progressively finer water paper, shaped it into a bubble. So far it has worked on my stoves and lanterns.

 

@Pauly

What diameter is the inside of the brass pip holder?

I can send you a viton pip.

Cheers

Tony

 

There are rubber pips available for Primus and Petromax type non-return valves so very likely for the Austramax too. It is also very easy to make your own from a piece of 3mm viton rubber using a leather punch of the correct diameter. It is important to clean the sealing lip which mates to the rubber before putting it back together. Rotating it by hand on a wad of fine steel wool should do the trick.

 

Thanks guys for the replies. For what seem like simple old lanterns, it is really fun learning new things as I go. While it's not quite there yet I'm really enjoying the journey. Before this I didn't know what viton was, that graphite was a thing for glands, etc etc. In fact, I didn't really even appreciate what a "gland" nut was although I'd used them for some plumbing fixes before - but I'm all too familiar with that now.

@Tony Press , I reassembled the whole lot for testing it so will have to get this back out again. I'll be back in touch with that diameter when I can get back to this in the next day or three and will take you up on your kind offer as I'm keen to have this up and running properly for Christmas if I can. I can see from last night and then once the NRV was unstuck and how it pumped that I'm really just a whisker away from having a good old lantern running like a charm.

@phaedrus42 and @goldwinger11 - you have me thinking. I might look at getting some viton sheet and punches for later.

 

Oh, yer can't beat a generous application of graphite to yer glands...

 

@Tony Press , the inner diameter of the brass holder is 4mm. The depth to the face of the brass holder is approx 3mm and I don't know but maybe the original seal was sitting proud of the brass face.

 

@Pauly

Ok. When I get back from Antarctica (next week) I’ll send you a couple of pips.

You could make one if you had viton or good quality cork. The pip sits slightly proud of the brass cup.


Cheers

Tony

 

Hi @Tony Press , I spotted a place on ebay where I can get a pack of 4mm and 4.5mm ones for $5 delivered so I've just gone with that. They should arrive mid next week.

 

@Pauly

I hope this helps you.
I have been doing a bit more work on my Austramax and have tried a couple of options regarding the gauze replacement.

As a benchmark here is a pressed metal burner / nozzle from a later model.



I found another kitchen strainer made of stainless steel mesh. The wires were 0.22mm Dia with approx 1.5mm between wires.
The mesh was too large and the flame kept shooting back into the burner resulting in underburn. So no flame shot.



I went back to the very fine gauze that came with the lantern. The gauze is too fine for me to measure with any accuracy. @Lamp_Doctor suggested it was from a kitchen tap filter and I think he is right.
I did get it to work when I increased the pressure significantly. But I still think it’s not right.



Tried a brass Pipe filter but it was to fine and burnt through very quickly. no flame shot

I found another kitchen strainer made of stainless steel mesh. The wires were 0.22mm Dia with approx 0.7mm between wires.
No underburn but there is still a little red in the flame. Good enough to give a mantle a go.
I did flatten the gauze off a bit to get rid of the peak before fitting a mantle.



With a mantle there was a nice bright light.

 

Below is a selection of Coleman burner caps and stainless steel mesh that I have used successfully to replace the original mesh.

From left to right: 220F (?) 242, 249, 639, 237. A good test for the durability of the mesh is to heat up a piece red hot with a blow torch and see if it can survive the heat for a minute or so. If it still looks intact after that, it is lkely to last on the lantern. Too fine will tend to burn away, but too coarse may allow the flame to burn back into the tube.

 

Awesome pictures @ROBBO55 and @phaedrus42 !
Martin, the original mesh that I pulled out of mine (if it is the actual original mesh) had gaps of approx 1mm. I spotted a couple of really cheap kitchen strainers at the local cheap shop with slightly under and over that spacing so I think I'll do some experimenting. Having seen the flame that comes out of my Tilley x246 now I know the really coarse mesh I was trying in the Austramax is probably not right - I think I was observing blow back but I might not have been achieving the right pressure either with my NRV issue that should be sorted next week.

So do you think that the 0.7mm gap mesh you have settled on gives a better output than the pressed metal burner from the later models? The photos look like it would.

 

G'day @Pauly

It's hard to say. But I don't think there is much in it. Austramax lanterns are bright with a matching mantle. And picking the mantle can be trial and error.

 

So my new stockpile of pips arrived today. I've put one in and am still losing pressure through the NRV. The pump handle is pressing out. I've removed the NRV again and blowing through it with my mouth and holding my fingers over the two little holes on the side walls of the lower part of the assembly two things happened.
1. I can tell even with the new pip it is leaking back through the brass screw top
2. I recalled the very first time I siphoned petrol when I was a kid.

I've noticed the fine rim surface on the top part of the assembly that seals against the pip looks a little ragged. The other issue could be that maybe the spring isn't giving enough push to make a seal. Thinking maybe I could sandpaper that rim but there is very little meat on it. Any suggestions?

 

@Pauly

Have you fitted a washer to the NRV to make a good seal between it and the bottom of the pump assembly?

Tony

 

Hi @Tony Press , yes it has a new lead washer installed.

 

@Pauly

It needs to be cleaned up. Hopefully this can be done without removing the lip completely.

2. check the pip is sitting square. some of those pips are cut on an angle and wont sit flat in the pip holder.

3. is the new pip flush or slightly raised above the lip of the pip. If it isn't it won't seal.
If not try another pip or a very thin slice of another pip inserted into the base of the pip holder will help. but not to thick.

4. give the spring a little stretch but not too much.

5, is the pip and pip holder moving in & out smoothly in the NRV. Sometimes they can catch if there is a but or the pip is to large in diameter.

6. do a dunk test in hot water with the pump removed to see where the air is coming from.

7. Don't give up.

 

Clean the brass sealing lip with fine steel wool using circular motions. You are likely to damage the lip with sandpaper.

 

very fine wire wool idea.. I like that.
How do wire wool grades work?

I have had anything from a scouring pad grade - 1-2mm wide flat ribbons of it - bad I should think.
To a fuzzy cloud of maybe 40 awg or less in a ball or similar.

I do remember if you don't remove any lost strands of it they only cause you merry hell later.

My advice is remove the NRV valve seat if you can, do the wire wool treatment well away from the lamp, careful to keep the lip of it true.
Wash it clean. Then put it back.

Don't put wire wool down the pump tube - Time bomb!
It will work but not for very long.

 

@JonD

“Wire wool”, or “steel wool” as it’s known in Australia, is graded. 0000 is the finest, at 0.03mm; 000 at 0.04mm; and so on through 00, 0, 1, 2, 3 and 4 (4 being very course).

See here:

Steelwool Grades and Applications

Cheers

Tony

 

I find 000 or 0000 grade steel wool indispensible when cleaning and fettling lamps. From shining up enamel vents to brass to nickel plating. It is a royal pain near anything magnetic though.

 

@phaedrus42

I have rolls of the stuff in my workshop.

Cheers

Tony

 

Thanks for the replies. Haven't been back on for a while. Will have to try the steel wool idea when I get back home.

 

Hi all,

Well it is a rather special occasion tonight. I was never previously a collector of anything and thought people who collected things (like you if you are reading this post) were strange. Now I'm one of those strange people. It is now at the point where, when friends ask how many lanterns I have, I tell them it's hard to know - it's like counting chickens - they move around so much. After going on a detour with a bunch of Tilleys and some Colemans I've finally come back to this very first pressure lantern that was the gateway into my unexpected pressure lantern habit. Tonight I got her working properly for the first time. I didn't do the steel wool idea after all - with the passage of time I've picked up a few other Austramaxes (none other working by the way) including one that I've decided is just too far gone and has become a donor for the rest. So with a donor NRV and a brand new pip this pretty little 1950s Austramax I, with help of a number of you here, have brought her back to life. Thanks to everyone who contributed to my posts about this Austramax and especially to @Tony Press who did the phone conversation that pushed me forward through the initial hurdles and confusion.

 

@Pauly

!

Cheers

Tony

 

That's a fine piece you've got there, Pauly.

 

Looks good @Pauly , congratulations

 

Well done ..