Might the Kovea Spider be run on Naphtha (white spirits/coleman)?

Discussion in 'Stove Forum' started by Rif, Sep 22, 2020.

  1. Rif

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    Seeing kits available from Primus eg. Eta Spider/Express Spider, Gravity to make them multi fuel and seeing Koveas line up of Booster Dual Max, Booster +1 and Hydra whom are jetted for dual fuel (Naphtha and Iso-butane), has me wondering if, with the aid of a bottle and pump, the Kovea Spider with its ability to burn liquid butane (inverted canister), might be run on Naphtha?

    The thought came about due to needing a pump/bottle combo for my Primus Omnilite (long story, don't ask) and picking up a Kovea pump/bottle on a local online auction as a make do attempt on the cheap (around $25 US delivered).
    I'll need to source a Primus hose for the Omnilite once my bottle/pump arrives but that's a question for another day.

    Any thoughts on the matter or might someone have already tried this? (Kovea Spider on Naphtha)

    My first thought on issues would be ability to heat enough in a prime, the spider, and I'm interested in knowing others thoughts.

    I've kept the Omnilite mostly as a multi fuel option for my Trangia 27 despite not using it for quite some time, preferring the quiet of my Trangia butane burner and original alcohol burner as well as a parting of the ways with said bottle/pump.

    I spotted and won the Kovea bottle/pump yesterday and hopefully arriving in the next couple of days being shipped today.

    I'd read in here somewhere of a Kovea burner head being used on another stove as a silencer and it got the creative thinking going and enjoying reading this communities forum thought I'd see what others thought.
     
  2. Reflector

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    I would be careful in trying to convert the Kovea Spider as the Primus Spider actually started life off as the ExpressLander VF (as far as I know, since I own the ExpressLander before Primus "discontinued" that variant) which is designed as a liquid fuel stove from the start before Primus made it into a gas stove that can do liquid feed (and then sells you back the conversion components to make it a liquid stove.) It seems like the Gravity MF also predates the "gas only with a multifuel conversion option" Gravity that you see today.

    You can get a silent cap built into the bell for the OmniLite that replaces the OmniLite bell from Primus (~40USD) or you can get a 3D printed or machined ("saucer shaped") one from other sources. I own both and I prefer the Primus one because I have converted one of my jets on my Omnilite to run off alcohol (isopropyl 91% and/or with any ratio of denatured alcohol in there as needed) and the screw on cap from Primus doesn't underburn with alcohol. The Primus cap is supposed to be not OK to run with Kerosene so the other ones may be a different story.
     
  3. Rif

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    Thanks for the caution.
    I made mention of the Primus units due to a multi-fuel kit (bottle/pump) being relatively recently made available to stoves sold as iso-butane users in order for them to utilise liquid fuels which piqued my interest, given I was already looking for a replacement bottle/pump.

    The "multi-fuel" Kovea stoves are single jet gas/naphtha stoves.

    Given that, it would be reasonable to concur that given the Kovea spider is jetted for gas, it might be possible to make it burn naphtha (like the others, with the addition of a bottle/pump combo) was my thinking albeit likely not well articulated.
    It might not, hence my request for thoughts on the matter.

    Thanks for the reply by the way.
     
  4. Rif

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    Great to hear about the options - thank you.
     
  5. Reflector

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    You might be able to but I think the problem is the thermal feedback and what might be something like a braided metal cable inside the loop or other design elements for a dedicated liquid fuel stove. I own a MSR Simmerlite, which MSR "discontinued" and reintroduced as the isobutane WindPro. I have heard the WindPro is missing the braided metal cable and it can "chuff" (fuel delivery pulsates) when delivering liquid butane in some conditions but it will work as an inverted feed canister stove.

    You might be able to but I don't think the Spider was designed "day 1" as a liquid fuel stove. If you look at the ExpressLander, Gravity and Simmerlite a large amount of the loop is exposed to the flame. The Expresslander has a 180 degree U bend, the Gravity has two 180 degree U bends. The Simmerlite has close to a 180 degree sweep that runs across the fairly wide burner head.

    In contrast the Spider has a little vertical section of the tube that is in a U bend, but it is only exposed to a tiny fraction of the flame like a finger. It might be enough to boil butane reliably when it is operating as an inverted feed stove but I would wonder if it puts enough heat in to ensure the vaporization of white gas.

    Edit: And maybe potential clogging due to the tight bend for cleaning the preheat loop out. I think it might be able to put a lot of heat into the base given the copper U pipe and thermal feedback from the head into the base.
     
  6. Rif

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    Hi Reflector,
    thanks for your thoughts.

    The Kovea bottle/pump combo I won at a local online auction arrived in what appears to be like new condition.

    Whilst these were bought to see if they might act as a make do, for my Primus Omnilite, I feel at least equiped now should I want to take the idea forward with the purchase of a Kovea Spider.

    I'm a little surprised that no one else has at least tried out the idea as I'm often late to the party to have an idea rather than trend setting.

    You make some good points regarding "potential clogging" and "vaporisation of white gas".

    Yeah, no suggestion from me that "the Spider was designed "day 1" as a liquid fuel stove", twas merely curiosity aroused by my newly acquired Kovea combo and too much time on my hands whilst I awaited its arrival.

    Given the Spider is a firm favourite of many cycle tourers due partly to its low weight/low bulk easy packing I'll likely pick one up at some stage to see if it might earn a place in my panniers.

    I'm sure then I'll be tempted to connect the naphtha bottle/pump combo for a test and will rewaken this thread to bore everyone with my findings and possibly requesting ideas to help unclog the then blocked preheat tube.

    I appreciate you taking the time to put some thoughts together - thank you.
     
  7. Reflector

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    I know that MSR uses a braided steel cable in the Whisperlite and Simmerlite that can be pulled and pushed to help clear out any potential blockages that build up in the generator tube. Looking at the Spider I would be most concerned by how tight that bend is, in contrast to a lot of liquid fuel designs that relatively large radius bends (approx 1"/25mm). I don't know how confident I would be in running a wire through but it would work as something to abrade the inside of the generator. You probably should check if you find any success in running white gas through to see how much build up occurs.

    Also you may want to disassemble the base where all the connections converge into the jet and see if there's anything vulnerable to heat before going off. I don't think it should be too bad given that it already has the copper tube in the design but if you do try to run it: Use a little preheating pan (like a metallic bottle cap) with alcohol in it or teacandle to warm the base up first before running white gas through. Otherwise a jet lighter to "massage" the tube to get it to the point it has a good deal of warmth in it would work too.