Today I’ve managed to lose an otherwise probably/good Tilley vapouriser to the damaging side effects of the heat & quench process so many people recommend as a way of removing carbon deposits. This is the second time this has happened to me, and most probably the last time I’ll subject any of my vapourisers to this sadistic form of shock therapy. I used a basic propane torch and kept the flame moving smoothly from end to end, not focusing much on the jet end, and not heating very long at all. When I quenched the workpiece I heard both a sizzle and a pop. A huge amount of material was thrown off the jet end of the vapouriser as you can see in the picture below. A thick layer of the steel is now missing from the tube. Ironically, even with all this material having been removed, the tube will not fit inside a burner spigot. Evidently the whole tube has expanded in diameter and there is nothing to do other than chuck it in the metal recycling. Has this ever happened to anyone else here? From what I’ve seen so far of the heat & quench practice in general, I think it’s extremely overrated and that it often does more harm than good.
Just one week ago using heat & quench I managed to separate mixing chamber from mixing tube of old Petromax 828. I was very happy from the result, beacuse nothing else worked. These were brass parts and they survived intact. But the small steel disc located just above the mixing chamber indeed lost some small bits during the process. Maybe old, rusted steel parts are more prone to damage using this method? Thanks for sharing your example, I will bear in mind that and use this method only when necessary. Piotrek
It would appear that the carbon inside the vapouriser has probably ignited and made the wall of the vaporiser swell. This sometimes happens when old Tilley vapourisers that are choked with carbon are used in a lamp: they swell and get stuck in spigot. I’ve never had happen what you experienced, though, and I’ve done a fair few Tilley vapouriser heat-and-quenches. Cheers Tony
@Jaska The layer that flaked off the jet-end of the Tilley vaporizer was likely the scale that had formed on the surface of the steel by 'high temperature oxidation'. That is similar to the mill-scale on the surface of hot-rolled steel channels, bars or plates produced in steel mills. The layer is usually formed on steels that had been subjected to a highly oxidizing atmosphere and when red-hot or hotter. This is normal around the mantle area of the lantern, especially when part of the tube is actually inside the hot mantle, (like that in a Tilley). This flake is composed mainly of black iron oxide(Fe3O4). It forms as a product when iron is actually burned. Such as those produced when you burn a piece of steel wool. It isn't the normal hydrated iron oxide(red rust). It might or might not adhere very strongly to the steel. The heat and quench sometimes would separate the layer. It isn't as tightly bound as those produced by controlled blackening process of steel. I don't think the vaporizer tube is much expanded by the heat and quench. It is more likely that too much scale has formed or the tube was slightly deformed/bent. When you perform heat and quench for steel or iron parts, try to reduce the amount of air or oxygen to the torch so that it produces a slightly yellower flame(but not sooty) instead of clean pale blue. This will produce a 'reducing flame' instead of an 'oxidizing flame'. It has a lot less tendency to further oxidize and 'scale-up' the steel piece. The thicker the scale formed, the more likely for it to flake off during quenching. It is also very important that you only heat the piece to a dull red and not to a bright, cherry red, orange or yellow/white hot. The brighter it becomes, the more scale it'd produces. Some guys use oil for quenching for a reduced thermal shock but it isn't as effective as water quench for carbon removal.
Based on this it almost seems like a catch-22: a chocked-up vapouriser will either swell and fail in situ or, if serviced with heat & quench, will ignite internally and fail as mine has here. In my own experience, every Tilley vapouriser I’ve subjected to heating & quenching has ignited at some point and had a flame emanating from the lower end. Whether that’s usual or not, I have no idea. It doesn’t take much heating, even with a crappy propane torch, to make them ignite this way. If the ignition of the internal carbon deposits is what causes the part to fail, then this suggests to me that heating & quenching should be avoided. I don’t like buying replacement parts when reasonable service is an option, but I can’t be bothered to “save” a few bucks in this fashion when new parts are available.
Tilley vapourisers always seem to cause much discussion. They were designed to be a consumable, but now of course we try to repair them rather than reach for one of our precious unused "new old stock" examples that we all have saved up. The new made ones often leave much to be desired. It is safe to say the heat and quench is rather a last-ditch attempt to keep one going, rather than a regular service option. The other thing to appreciate is that as hobbyists - we do not use our lanterns for hours on end, unlike the way many that were used when they were new. We also tend to use them mainly outside, where we may tolerate a less than perfect vapouriser. I take the view that I will never wear one out with the few hours I use one for over a year. Badly coked up vapourisers can swell and be difficult to get in/out of the mantle support/spigeot. I have had two like this, one on an R1 and one on a guardsman sourced from ebay. If I detect swelling or deformation they go in the bin, as they will be difficult to use and even more difficult to get out of the mantle support.
Some sound advice Have you tried just tapping on a piece of hardwood until no more carbon comes out? That doesn’t take that long.. Or perhaps invest in an ultrasound cleaner.. they give good results regards pb
I haven’t tried the tapping without having first heated & quenched, no. Should that alone allow anything to be dislodged and released? I haven’t considered an ultrasonic cleaner for the reason that I’ve read many times, here and there, that it isn’t effective at clearing up the type of carbon deposits one would find in a Tilley vapouriser. Are there others here who use this method with good results?
After recalling some past experiences with the Tilley vaporizer, I just realized that the tube can actually expand if the jet orifice area is badly clogged. This is usually not so apparent for vaporizers with removable jets. The Tilley steel vaporizer isn't one of them. The expansion I experienced was due to that caused by rapid expansion of residual fuel trapped within. Since the badly clogged jet couldn't relieve the pressure buildup fast enough, that was the result. The jet end of the Tilley is merely a shaped piece of sheet metal, crimped-formed in place. It actually slightly ruptured during heat-quench as well. I had to actually silbrazed it(with some difficulty) back to seal off a tiny fuel leakage around that spot. It was messy but I had no other choice since, I do not have a spare vaporizer at that time.
I guess I’m not a hobbyist by that measure, then. I have a couple of favourite Tilleys that I use very frequently—many hours per week. Rather than wear out all my good vapourisers, I tend to move one vapouriser from lamp to lamp and use that one exclusively. Keep in mind that it gets pitch dark outside here at around 2:45 PM this time of year where I live. I acquire all my lanterns for the purpose of either using or passing on to someone else.
Hmm, my sons and I have thought about investing in an ultrasonic cleaner for other purposes, so maybe this will finally get us to make up our minds about it. Does this one look good enough for lantern-related stuff such as Tilley vapourisers? Is it overkill? I assume anyone checking out the link will translate the webpage from Finnish to English.
hi @Jaska I have used one with a heater using the water based ultrasound/ carburettor cleaner and it worked well It looked similar to the one you showed. I would try the tapping method first and see how you get on you may get results using something as simple as an old rectangular oven loaf baking tray, some dishwasher fluid and a camping stove for heat? Get a few in at a time ? Always worth trying other ways I think
Judging by your picture I am certain that @MYN is correct in referring to this as scale. I frequently come across it when cleaning up an old vapouriser on the outside with a rotary wire brush and quenching several times. Sometimes I file one spot a bit to 'crack' the scale for the wire brush to remove it properly. In any case I am a big advocate of the tried and tested heat and quench and I tap the vapouriser on white paper and it is staggering how much carbon is released from inside. My challenge is usually to get it almost clean and to be able to see through the vapouriser and to see a little 'circular' hole at the end. Sometimes this is assisted by ensuring I have water in the vapouriser and putting a thumb over one end and heating it and often a good jet of water comes out of the jet before I have to drop it because the hot water is starting to burn my thumb. However, just beacuse the jet may be clear temporarily does not mean that any carbon left behind will still block the jet in use. The main idea is to get rid of as much loose carbon as possible and then have a clear jet. I have generally about 1 in 20 that I cannot get right with this traditional heat and quench method. Sometimes the carbon is out in a few cycles and other times it can seem like forever and perhaps need more than ten cycles.
