Radius 42 - tank overpressurized

Discussion in 'Stove Forum' started by SMolson, Jul 3, 2013.

  1. SMolson

    SMolson Subscriber

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    Some may be interested in what an over-pressurized Radius 42 looks like, well here's one example. These two old pups I obtained yesterday, likely pre-war due to the Radius star logo and the winged fuel cap on the bottom of their fuel tanks. These 2 with SRV's on their fount.

    1372891133-IMG_4151_Radius_42_opt.jpg

    It appears the user was melting lead with this one and some dropped onto the SRV. Not a good idea to seize the SRV on one of these, which no doubt led to her catastrophic failure.
    1372891145-IMG_4152_Radius_42_opt.jpg

    Bloated out bottom, melting her fuel-cap gasket to the tank.
    1372891160-IMG_4154_Radius_42_opt.jpg

    Here she is on the right, next to the 'normal' one on the left.
    1372891169-IMG_4155_Radius_42_opt.jpg

    1372891180-IMG_4156_Radius_42_opt.jpg

    1372891189-IMG_4158_Radius_42_opt.jpg

    A 'normal' spirit well/moat on the 42
    1372891197-IMG_4160_Radius_42_opt.jpg

    Bloated one from overpressure
    1372891204-IMG_4161_Radius_42_opt.jpg

    The wick carrier can be heard rattling around inside the fuel tank, it has fallen from its held position within the vaporizer. Not sure if anything other than her burner bell can be recycled, haven't tried opening any of her caps (fuel/SRV) yet. I'll be working on the non-overpressurized 42 and will post her in the gallery once finished.
     
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  2. David Shouksmith

    David Shouksmith Subscriber

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    :shock: Someone came very close to a potential disaster with that one... :doh:
     
  3. itchy

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    Amazing that it is still in one piece.

    You are a nicer guy than I. I am not so sure that a previous user did not intentionally plug the cap with solder after it had failed to hold pressure.
     
  4. David Shouksmith

    David Shouksmith Subscriber

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    :-k Exactly the same thought passed through my mind too... :whistle:
     
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  5. Murph

    Murph United States Subscriber

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    Bugger! That's one knocked-up stove!

    Murph
     
  6. geeves

    geeves New Zealand Subscriber

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    Knocked-up stove! Thinking back to another thread I can see its almost due.

    Normally I would ask for flame shots but in the picture of the priming cup there appears to be a crack in the riser tube. A possible scenario for the demise of this stove would be SRV leaks. Solder up. Overheat stove and riser cracks or riser cracks just through bad luck. High pressure burning fuel all over tank. That's when the excitement would begin.

    I've seen a stove of this style explode a very long time ago. It started with a riser crack and ended with the riser and burner bell going places unknown and a huge bang.
     
  7. G1gop United Kingdom

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    I know that it would be 'unwise' to do, but if say it was a very rare stove indeed, would it be possible to repair the tank?
    I.E. take it apart and reshape it then put it back together?
    Way beyond my capabilities, but I was just thinking that if it was a stove that was just to rare to not try, could it be feasible?
    Alan
     
  8. Trojandog

    Trojandog United Kingdom Subscriber

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    Wow. That was one lucky user!

    I don't think there is much you can do to repair it. Even if it were possible, I wouldn't trust it given the stresses have gone through that tank.

    What I would do:

    Keep the bell, jet, spindle, stuffing box and the base cap. Those base caps are sometimes missing (I have one which came with a short bolt. Still using it with the bolt, I just replaced the white plastic washer with a viton one):

    1342336688-Radius05_opt.jpg

    Then cut the tank up and make some flame spreaders out of it :thumbup: .

    Terry
     
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  9. SMolson

    SMolson Subscriber

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    I never considered the user would have poured lead purposely to seal a leaky SRV, you may be right.

    lol Murph.

    I also noticed on her tin green, much abused Radius case that its heat shield is absent, so a perfect storm of events...

    I managed to get the winged fuel cap off, and her carrier/wick were still in place in the fuel tube. The wick was burned and is no longer usable but the carrier looks fine. The 'rattling' item in the fuel tank may be the safety rod that poked into the SRV. It may have broken away.

    Trojandog - your post on fixing your Radius's SRV was very helpful. I replaced the gaskets in mine, made a new wick and carrier for her and now she (the non-pregnant one) runs fine.
    1372954581-IMG_4173_Radius_42_opt.jpg

    I'm going to leave the bloated stove's tank as-is, keep it as a reminder/example. I'll test her jet to see if it's not too worn (hole big), but its burner bell is sitting on the 'good' one as its original had a crack at the thread join.
     
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  10. mr optimus

    mr optimus United Kingdom Subscriber

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    Hi SMolson, I have never seen a tank over pressurised like that before, i have only seen the base plate balloon out on Tilley lamps.
    The whole of the tank on the 42 has ballooned, the sides and the spirit cup, it was a miracle it never exploded.
    I am in agreement, the previous owner has plugged the safety valve with solder.
    the owner was using the stove for purposes beyond it capability, so the valve would constantly release pressure so it was plugged so it could be used beyond its safety level.
    A very stupid but lucky owner.
    The reaction of the tank over pressurising, probably put the fear of god in the owner.
     
  11. tetley

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    As soon as I saw that first pic, my thoughts were also that someone had badly 'fixed' a leaking valve.

    As for what to do with it, why not half fill it with Coleman fuel, seal it up and cook it on top of a very cheap stove. make a video with a good lens from far away* just to show us what does (and I suspect almost did) happen.

    *and then some way further, obviously. 8)
     
  12. geeves

    geeves New Zealand Subscriber

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    That cap looks pitted as well as plugged. More like bad arc welding? Are we certain this hasn't been in a fire?
     
  13. SMolson

    SMolson Subscriber

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    The orange-cased Radius 42 stove, after getting her back to safe operational condition, is shown here .
     
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  14. myford

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    Plugging the pressure relief valve sure seems like a bad idea, but considering that some of these stoves were made without relief valves it is isn't neccessarily a recipe for certain disaster.

    Bruce
     
  15. SMolson

    SMolson Subscriber

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    That's true Bruce, in this case we can't say for certainty what happened, but if the SRV was working properly the stove's pregnant status most likely would have been averted (or at the very least had a much better chance to avoid it). As mentioned above the heat shield from its battered case was also missing, which didn't help the situation.
    I have a few 42's without an SRV, including this one , and due to the risk they pose will not be firing her up for any length of time if at all. I'll stick to a SRV'ed model on trips/use.
     
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  16. myford

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    I have no great background of experience with these matters, but I am surprised that a stove could generate the sort of overpressure required to balloon the tank and invert the base just through normal operation. Given the general look of it I wonder whether the stove has been involved in a larger fire. As for relief valves, I am all for them but they have their own issues. Thankfully I have only had one of my stoves vent itself while cooking, but that was enough, as it got a bit exciting due to it being close to my tent. It is good that the valve is positioned close to the burner. If the vented gas were not ignited immediately I could imagine it forming a cloud that would be quite dramatic when it did eventually ignite.
    Bruce
     
  17. geeves

    geeves New Zealand Subscriber

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    The original owner of my 42 told me to always position the tank so the valve pointed out one way and the cap the other. Also said don't simmer for long periods as this overheats the tank. He described the valve opening as a candle flame that grew over a few seconds to a meter long which was extinguished by turning the stove to full noise.