Does the wick have to have the copper wire in it? Could I use a 3/16 or 1/4 round cotton wick instead? The round wick would be long enough to lay around the bottom of the tank and would be tight inside the generator/riser tube. Thoughts? Sean
The wire is there to allow one to get the wick all the way up the tube and also have it be somewhat tight so that it doesn't fall out and allow just the right amount of fuel that will vaporize easily. The wire is usually brass, but I've seen copper ones for sale. I've not ever pulled out a copper wire from an original setup, that I know of. I can also see that the wire will tell you right away that you've put the wick in as far as it needs to go, because it is rigid and will stop, where without one, how would you really know? I guess, on the other hand, you could experiment with the idea. My question would be, how would you get the wick in without using something to push it up into the tube? When I replace wicks in my Sveas, it is tight enough that I have to use needle nose pliers to get it done. 2 cents, Sam
Using the wire allows you to set the 'tightness' of the wick. When you wind the wick around the wire, you can control how tight you wind it. By inserting the wick using the wire, the set tightness is maintained during insertion. If you just stuff the wick in, you have no control over how tight it is. Too tight, fuel won't flow properly resulting in poor performance. As Sam says, a wire also aids insertion/removal and depth control. Trying to remove an old wick sans wire, is one of life's great frustrations. Terry
I found some brass wire and cotton string at my local hardware store. I made a couple wicks. When my cap seals get here I'll test them out. Thanks for the info Sean
Is there a "correct" length for the wick to be? I would guess it should be long enough to reach the bottom outside edge of the fuel tank. Is that sufficient?
i have recently got a 123r and i took the wick out for inspection - found it to be clean and uncharred so it is going back wick is about 100mm long overall and the top 20mm goes in the wick holder i now understand that the wick holder is a seperate brass tube, quite heavy and soft soldered into the riser this is a safety feature and should the stove overheat the solder will melt and the wick drops off allowing fuel to escape unimpeded by the wick thus preventing excessive pressure which might cause the tank to burst it does mean that burning fuel will envelope the outside of the stove, so still dangerous but not as bad as the tank bursting - i assume the more i see of these stoves the more i realise the thought that gone into them to make them as safe as possible
it would be fuel vapour unless the overheating occurred because of overpriming with an overfilled tank, in which case liquid would be expelled i was drilled in the safe use of these stoves years ago by my uncle who told me horror stories of the svedish hand grenade - myth? similar tales can be found on this august website
I am thinking myth (Based on my own experience, not stories). I have seen boiling/bubbling fuel in a tank and before the fuel cap was removed, it was only a small flame at the cap.
i think fact, liquid gasoline expands a lot when heated, a lot more than water does, the deeply dished base of the 123 is designed to accommodate the expansion of a full ( or overfull ) tank of liquid fuel, to prevent the tank bursting. it is not vapour pressure that will burst the tank it is hydraulic pressure because liquids are not compressable - heat a liquid and it will expand and if it is tightly contained then that container must expand too or burst / split i also believe that the base of these stoves can be popped out with such force that the stove will 'jump' off the ground, perhaps by an inch or two, possibly more, i do not need to see it happen to see that it could be possible if the liquid fuel expands fast enough to overwhelm the safety valve. i have never seen a stove explode and i hope never to see it - but that does not mean it cannot happen
Ive seen a primus 71 type stove explode some 40 years ago I was still at school and the owner was someone else in the same hut. All I know is the stove developed a large flame not from the burner and the owner got it to the open door before it went bang leaving him holding a tank and case. We did search for the burner but never found it. It left him a bit red faced but no real harm done apart from the stove.
glad to hear that you and your friends were unscathed but i am also glad to hear a first hand account of this happening with a self pressurising stove not glad that it happened of course but your account is worth a hundred unsubstantiated stories of this happening i think the key thing is to avoid overfilling the tank and overpriming the stove - to that end i think priming with meths is highly advisable
