Tilley and similar designs - Vapouriser failures

Hi JonD, good observation. I'd agree on that. Heat patissipated from mantle and spigot must be distributed along the vaporizer to avoid carbonization of kero .
Heat is partly led via vaporizer to tank. But on other end via direct Contac at the rim to the burner.

Another source of overheating the vaporizer at an individual spot, can be flames reaching into the gap between burner and vaporizer, if spigot is a bit loose.
Just my ten cents
Regards
Willi

Ps I use brass vaporizer, as messing has better heat transport, distributing heat evenly, avoiding carbon build up.

 

I'd be interested to know whether that's opinion or fact - have you any evidence to back it up?

My feeling is that the exact opposite is correct - the hotter the vapouriser, then the less likely there will be carbon build-up because vapourisation of the fuel will be more complete and the vapour will be more likely to be swept out of the vapouriser jet, particularly if the tank pressure is kept high. Now that's only my opinion based on simple scientific principles and NOT fact - I have absolutely no evidence whatsoever to back it up...

 

Thanks for the input @bp4willi !

To @David Shouksmith that is something I meant to mention in my post and I missed it out so thanks for the reminder!

Of course while I was dealing with the stuck vapouriser I took a look at the carbon buildup on the pricker wire.
On a previous attempt when it had burned about this long and then started to misbehave I found a lot of carbon on the wire.
I think I mentioned that somewhere in the earlier posts.

This time there was just some discolouration of the wire at what I guess is now the hottest point - near the middle.
It would fall just below the bottom of the spigot I suppose. The top part of the wire still looked like new. I'm sorry but again I was naughty about taking pictures.
That might be an excuse to go down the shed...maybe I can post some later.

 

Here is the red stuff that develops between the spigot and vapouriser.
Luckily quite easy to remove burner & hood this time.



Here is the pricker wire. Now a bit blacker at the hotspot than when I last looked.

 

@JonD & @David Shouksmith @bp4willi

I’m with David on his logic.

The only “Tilley” vapouriser failure I’ve had was a German-made all brass vapouriser that swelled up in the spigot through heat distortion. It was clean of carbon build-up inside.

I regularly clean my user Tilley vapourisers, as I do my Colemans. I see no greater carbon build up in my Tilleys than kerosene Colemans.

Mind you, I don’t use Tilley X246Bs: Maybe the fact that they can’t be pumped up as hard as an X246 is an issue...

Tilley sold of thousands of their X246s in rural Australia. Most of the ones I buy have good or OK vapourisers.

Jon: sorry I’ve not got to fiddle with my Koreans yet. I’ve got a tricky Gloria in pieces on the bench.

Cheers

Tony

 

No worries @Tony Press !
I think the point we are trying to sort out here is why heat distortion happens - since that it what all the swelling is about never mind what the vapouriser material actually is.
If carbonisation is related to heat that is interesting too. I think it is some kind of cracking happening. It isn't vapourising then - it is the fuel splitting apart and we are only burning the remaining components of it. They will of course burn but it is the gunk that leaves behind we don't like.

I don't have nearly enough experience with earlier X246s or lamps based on those principles. I only have what I have. It does seem to me that cooling of the top end really does matter.

@loco7lamp made a great effort with using the hex headed nipples but they did not have any heat path away at the top. They worked but then failed due to overheating. Stu blamed his brazing but I reckon that would not have failed had it not been running so hot.

You have a lovely looking brass ended vap from Korea - that's the one I have been bugging you about. Looks like it should be very fine to me. I want one but seller kkn4602 seems to have variable feedback.
I'm not sure a repeat order would get you the same thing.

I started here trying to work out why the X246B eats vapourisers, partly that is because they are not made like they used to be - that is for sure. But I wonder if there is something else. I can get no further than it is the vapouriser simply runs too hot. (It can hardly run too cold and fail can it?)

Did the earlier X246s, Guardsmans etc have slightly shorter cages so that the burner sat in contact at the top more or less no matter how they were assembled? Could be.

The X246B has 2 cage designs, one is a simple dished plate on the tank top and the cage legs are welded to it (see my gold one of 1964) but later the dished plate acquired four pressed ridges (see my red one of 1973). The cage attached to the later one was lifted by 3 or 4 mm - but why? Did they shorten the legs to compensate? Did saving some metal off the leg length cheapen it by enough to make the stamping out of the plate more complex? I am totally stumped by that....can't work it out at all.

Anyway I suspect the X246B cage is actually marginally too high for the length of the 606 vapouriser in many cases. I have shimmed up the 1973 one by using a fatter washer than standard between the control cock and the tank. (You can't do that to the washer at the bottom of the vapouriser without affecting pricker operation).

That one is going very happily. We are playing, hopefully we are learning.

 

Hi David,
Pls have a Look at Wikipedia, thermal cracking.
Cracking (chemistry) - Wikipedia
"An overall process of disproportionation can be observed, where "light", hydrogen-rich products are formed at the expense of heavier molecules which condense and are depleted of hydrogen. ....
Thermal cracking is currently used ... to produce light fractions or distillates, burner fuel and/or petroleum coke. Two extremes of the thermal cracking in terms of product range are represented by the high-temperature process called "steam cracking" or pyrolysis (ca. 750 °C to 900 °C or higher) ... and the milder-temperature delayed coking (ca. 500 °C) which can produce, under the right conditions, valuable needle coke, a highly crystalline petroleum coke"

That Petroleum coke is the deposit, which blocks and bursts the vaporizer.

Seems to happen more often with Iso-paraffine.

This is chemistry, not physics.
Regards
Willi

 

@JonD

Don’t buy the vapouriser until I test one; but I’ve had only excellent service from KKN4602.

Cheers

Tony

 

@Tony Press thanks for the advice, I wasn't going to buy one until I need one, even though I would like one for research purposes.

What I see in the listing picture today looks quite different from yours. I would not mind parting with the cash for one identical but not sure about this one.
I see no brass at the jet end so I suspect it is not renewable. It looks like a direct copy of the original Tilley - that said it is a nice job.
The point of spending the extra cash was that the jet could be replaced.

 

Spread the love. It was time to check the red one from 1973.
All was completely free and easy on this one between vapouriser and spigot/hood. All it needed was some preheating.
It is back on all the original bits from 1973.


This picture is stopped down to prevent flaring - it is bright.

I think I would recommend an addition to the lighting up procedure.

Do everything you would normally do, check fuel, clean the glass etc.

Before you light the preheater, can the top assembly swivel on the vapouriser?
Is it catching on the cage - or does it turn smoothly?
If not find out why.

If the vapouriser or spigot have crud attached to them which restricts the movement - clean it off. It will only build up and weld them together next time you burn.

If the height of the burner and hood is determined by catching on the cage not by sitting on the vapouriser then increase the height of the vapouriser.
Add more (or thicker) washers between fuel cock and tank top. Vapouriser must have good contact with the burner.

Shimming this up too much will make the rim of the hood interfere with the handle when it is folded - there is 3-4mm of leeway.

I am checking this on mine each time as I light up. It is serving me well so far - only time will tell.

Still looking for inputs about the dished plate the cage legs are welded to? Why did it acquire the four
pressed up dimples?

 

I have just joined. Absolute noob.
My vapouriser tube has a bulge that stops the burner from being lifted off. Is this a "parts failure, or a design feature?? I have never seen a Tilley like it before. (I used them years ago)
The tube is 5 inch.
The lamp worked when I was first given it, but the mantle failed. I had a spare mantle that came with the lamp. Now, it does not work. I am happy to get a new vapouriser.

Thanks for any help/advice, I am not even sure what the model is!! (X 246B ??)

 

Hello Alan and welcome to the forum.
If you check out Tilley in the Lamp Reference Gallery, you'll see that the frame legs on an X246 are straight, the legs on an X246A are bent inwards and the legs on an X246B are bent inwards and welded to a disc which is held down onto the tank by a round aluminium nut.

Henry.

 

Thanks, Henry.
And I thought a Tilley lamp was a Tilley lamp!!
I have to go to the mailand tomorrow, just about to go to bed, so I will check out the gallery Tuesday.
(Fairly surenow that, I have an X246B !!)
{I had bought 2 "Tilley" lamps 40 years ago, when my ex wife had horses....I let my brother have them when I went to Uni!!}
[ ~ £15 each!! ]

Thanks
A

 

G'day @Alan Gale and welcome to CPL.

The sides of the vapouriser should be parallel so if there is a bulge then the vapouriser is buggered and needs to be replaced. If the bulge is severe and jammed in the spigot of the burner then the spigot may also be buggered and need replacing.

 

Thanks. The spigot is lose on the vapouriser, so it should be just a hacksaw job to get it off!!

 

Good luck with it Alan, If you read the different opinions here (and in the earlier threads linked) about why it happens you can make up your own mind about what to do when replacing it.
For my 5 pence worth I would take every precaution to make sure the next one has a long life. They are becoming hard to obtain and expensive.

Whole lamps may be had for less than the price of a new replacement vapouriser. The trouble is knowing whether you have bought another one which is just as bad...and of course you will want
to get that one going too. Then it all spirals out of control!

 

On making a burn of my red one tonight something happened...

I accidentally put the clear Ethanol, meant for the pre-heater, in the tank by mistaking it for my clear Kerosene...I realised before firing it up.

Should I get it out? (devil on one shoulder - it will be OK) (saint on the other shoulder - you should ditch it - because it might go bang)
I got it out and filled up with clean fuel.

It lit up in the normal way. All was going well - except - while looking into the flame and listening to the hiss, I got to thinking (a very bad idea).

In spite of what I have written before about my clear kerosene (sold as BBQ lighting fluid, described as C11-C14 on the label).

Thinks - it does pour more easily than the smelly yellow prepack stuff in 4L plastic cans - so it has to be cleaner - yes? Nothing wrong with that idea I concluded.
But then it is of a thinner consistency - no question about that.

Then I thought - what does it take to make it vapourise? Not so much, it completely disappears after a day or two when you spill it.
Hmm - and petrol/gasoline does that in an hour or two. More thinks....

I want to backtrack on the idea that the BBQ lighting stuff is good for Tilleys. Once I happened on that thought I extinguished the lamp straight away.
Thin fuel vapourises easily - not much energy is required. It follows if you are using it then less heat is needed to make vapourisation and the vapouriser will run hotter and is
much more likely to bulge as a result.

I think there is a need to try thicker fuel than this for preserving vapourisers. I see I made a mistake a long while back - my apologies for any past argument to the
contrary (and there were some @David Shouksmith - sorry!). Looking for some 28sec heating oil to compare with or else it is back to the nasty smelling pre-pack stuff.

Thanks to all who have commented so far.
There must be many more who could add. Please do! The truth is out there...

 

Keep the quest going mate.

 

Thanks for the encouragement. It is very much appreciated.

I can see the only proper way to be sure of this is to measure vapouriser temperatures in the different cases.

Isn't it a pity that thermal imaging cameras are so expensive - it would be great to be able to see hotspots and compare running temperatures on different fuel types.
I might be able to borrow a "point and shoot" measuring gun but you are never sure of your target with one of those. A picture with coloured gradients would be so much more valuable.

 

I have ordered a spare from Tilley, but having had the chance to read all the posts re Vapourizer Failures; I am thinking of sucking some of the kerosine from my AGA tank, and using that.
Thanks
A

 

Welcome Alan, I reckon you could do worse than that!
Since my boss won't let me buy the spendy IR camera (not yet anyway ) I have resorted to a very crude test.

Tonight I filled two laboratory watch glasses. One with the BBQ lighting juice and the other with the last of the pre-pack paraffin from the Mega-store.
Exactly the same volume to the best of my efforts. Now I am watching them. They are sitting in the same environment.
I want to see which is gone by evaporation first. It might show something up or else nothing at all?

Meanwhile my Gold 1964 X246B has run very well for 4hrs tonight on the Mega-store stuff. As bright as anything could be expected to be...

One piece of advice... when you get your new vapouriser, please check out the rim for smoothness. And also that your burner has a shoulder inside which is intact.

If the vapouriser outer rim has no high spots and the burner shoulder is sitting down in contact with it and not on the outer cage I reckon you are well set for success and a long life from it. If the handle is lifted up, so not in contact with the hood, the whole upper assembly will spin easily on the end of the vapouriser. I check mine will do that before I start pre heating - every time now.

Good luck..

 

I am very puzzled by my watch glass experiment.
I put equal volumes of BBQ lighting fuel and pre-pack paraffin in two watch glasses, side by side, and I left them for 24 hours.

I reckoned the pre-pack was more viscous than the BBQ lighting stuff.
Then it must contain heavier oil fractions and so it will be around when the BBQ stuff is long gone - Y/N?

It turns out...No. Most of the BBQ stuff remains while the pre-pack has nearly disappeared to about 1/4 the original volume.
I could almost think I mixed them up. I can't explain it.

Can it be that one has both light and heavy oils - and the light ones have departed? The other one is a closer mix, all being somewhere around the mid-range?

I was thinking that maybe one was better to use than the other. I don't know what to think now.

 

@JonD

I re-tested my Korean-made steel-with-brass-nipple vapouriser today and compared it to a modern Tilley vapouriser. The rsults are at the bottom of this thread:

Korean Tilley Vapourisers


Cheers

Tony

 

@JonD , I’ve followed the discussion with interest.

If Tilley vaporisers were sensitive to fuel composition I’d expect swollen vaporisers would be common, and to my knowledge they aren’t.

I can’t see loss of heat due to vapourising a slightly heavier fuel would cause a vaporiser to be cooler. There is so much excess heat in a lantern - the heat required for vaporisation is a tiny fraction of the heat released in combustion and the amount of fuel being vaporised in any moment is tiny.

I am also skeptical about the ridge in the hood, or whether the hood weighs down on the vapouriser being an important factor, again because of the large amount of available heat all around the vapouriser, spigot and burner.

I’d wager a mantle that bulging vapourisers are caused by a fault in materials or manufacture, rather than conditions of use.

We won’t settle this with evidence unless someone posts instructions describing how to cause a generator to swell, and the effect is reproduced by other members. I hope no-one posts instructions as I’m not keen to sacrifice a vapouriser!

 

Hehe - it has been quite active today.
In this thread and the other one - we haven't reached any sort of consensus about it. I don't think that matters.
I know what I have learned and what I will do differently from now on.

Fuel - I don't care much so long as it is clean. The prepack stuff I tried actually disappeared completely before the BBQ lighting stuff which is still there today.
An unexpected result but there it is. For burning no difference - except for odours and trivial stuff.

Vapourisers should have a flat and smooth top to make contact with the burner which itself should have a rim inside to mate with it.

The lamp should be assembled so that the burner assembly sits on the vapouriser rather than on the cage.

The vapouriser and burner spigot can tend to "bind" on one another after running. Better to free them off before lighting. If allowed to continue like that they will become impossible to free from one another without major force. I think it is much better to check they will part before lighting, some light rocking of the burner will free them from one another without breaking the mantle if you are careful.

Before lighting I check they are in contact with one another.

Light and enjoy.

The X246B was made with some short cuts. The principle of operation is exactly the same as what went before. The tolerances were maybe not so great. That is why some care in assembly is a good precaution before running them.

My apologies but the idea that they can be thrown together and still work might be successful in some cases but I reckon it results in wrecked parts.
They are your lamps - so do with them what you will. I have no more to say on it. Think on the physics and work it out.

I am still most interested about cages and dimples on X246B.
Does anyone have comment to make on that?

 

Disaster strikes again... The red one has swollen it's vapouriser and stuck in the spigot. So the answer is not yet found here in any of my precautions.

That lamp was an absolutely stock X246B, it was almost unfired from the day it was made in 1973 but it has failed now after about 10hours of total running.
While it was running it was apparently burning perfectly, very bright and little smell. A few nights ago I came to light it and the burner would not come off the vapouriser for the
now customary check of the vapouriser mating surface. Just a little crud in there I thought, it will come. Well it didn't. It was free to move for about 25-30mm but right at the
top of the vapouriser, just before the burner should come off, it jammed fast.

After struggling with it for some hours it was obvious I had to kill the mantle and remove the spigot to see what was going on. Vapouriser was swollen over the top 10mm or so.
(I was much too cross about it to take any pictures- sorry!!) It was not swollen by much. The main tube of the vapouriser measures 9.5 - 9.6mm where the top end was up at 10.5mm.
The spigot hole is 10mm by my reckoning so of course it could not pass. I spent some time squashing it down in a machine vice and eventually had to remove the last high spots
with a diamond file to allow it to pass through the spigot. Spigot saved. Vapouriser I might not want to try again. Thinking on it.

So we are back where we started. Why did it do it? All the previous arguments come round again such as was it the fuel?
The pricker wire is clean - no significant carbon. The jet is clear. So it must have distorted because of heat. Why?

I did say it was running extremely bright - some others have reported this too - some X246B are white hot while others lag behind somewhat yellow.
White means hot. We all know that flame temperature depends on mixture - lets bear with the idea this one was running at peak temperature and probably so are others that
burn perfectly white.

The top was bearing down on the vapouriser clear of the cage - I assembled it like that following my theory that contact between vapouriser and burner will take away some heat.
I still stand by that idea but... It was also putting the weight of the burner down on the vapouriser - if the vapouriser got hot enough to soften the downward force would cause
the bulge and we have explained the problem. But plenty of early Tilleys worked exactly like this...?

I can say at this point that I have very much gone off this as a design for a lamp. What a weak point. I should be throwing them all in the skip!!

The design has been used for years in all sorts of lamps by Tilley and others. It must work when it is right. So I come back to what is wrong with X246B?
Yes I could assemble it so the weight of the burner is supported by the cage instead but i still think that invites failure from the vapouriser overheating in another way.
So why does it run so hot?

Can it be that the X246B burner is smaller than the ones that went before? I don't have any X246 or X246A, bowl fires or what have you to compare.
All I have is the juliands replacement burner which is definitely bigger. Bigger means more surface area and more ability to lose heat by radiation or convection.
Please could someone comment about that? Is it only the X246B fitted with a mini version? Can it be the small burner cannot cope with the dissipation needed
to run at high output with perfect mixture and not overheat the vapouriser?

I know I will be told to put them in the skip but I remember Grandpa Potts and the line "From the ashes of disaster come the roses of success"


.

 

@JonD , pitty but I miss the part about fuel, what did you feed her with ?

 

This post is puzzling and interesting. I have no knowledge of Tilleys but do you think that the mantle size has anything to do with the problem?

 

I did miss describing the fuel - my apologies.

I have used two types. Pre-pack paraffin from the local hardware chain and Barbecue lighting fluid described as follows (I am not much of a chemist)
Hydrocarbons C11-C14, n-alkanes, isoalkanes, cyclics, <2% aromatics, EC926-141-6. It was running the BBQ lighting stuff when this happened.

That fuel runs everything else I have (except the petrol fuelled kit) very well. It works perfectly in (wicky alert)Aladdins, Gaudards, Karlskronas etc, Primus Stoves Roarer and Silent and
my Hipolito 502. Reading earlier up the thread I did an evaporation test between it and the pre-pack. The prepack was the more volatile of the two (unexpected) but the difference
was very small.

I can't lay blame at the fuel - at least not any more than the composition of it affects the fuel-air ratio slightly and so the whiteness of the burn and operating temperature.
If you could vary the fuel/air, maybe with a vane like in some designs, you could achieve the same thing another way. I was not running it at high pressure - I didn't need to.
10 to 20 strokes of the pump and it was quite bright enough. I thought it was running really well so it was quite a shock when this happened.

Mantle was a Peerless DT140 this time but I have had the same thing happen with Tilley 164Xs - I don't think the mantle is a factor.

I'm looking for further info about burner sizes please. What else shares the small size burner of an X246B - anything?

 

Hi Jon,
In Case you'll throw away the generator anyhow, make a cut at the swollen section. You should find hard carbon deposit inside. This is not only deposit. The carbon swells inside the generator and creates enormous power which deformates the steel.

As said further up, this carbon crack products happens more easily with iso alkane. Less carbon with n-alkane.
Regards
Peter