Optimus Trapper 81

Discussion in 'Optimus No:81' started by Knotty, Feb 25, 2014.

  1. Knotty

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    Optimus Trapper 81 purchased on ebay. Stove had never been fired and pot lifter was still in its plastic bag. Unfortunately the box was pretty mangled.

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    The year is unknown but it’s one of the older ones, lacking the weep hole that indicates when you’ve added the maximum amount of alcohol it can hold. The red fuel measuring cup doesn’t have the sticker seen on some kits, explaining that it holds 1 dl and you should fill an empty stove with three measures. Oddly, that procedure contradicts the printed instructions which say that maximum fill is 250 ml. Perhaps the 300 ml fill became the standard after the fill indicator was added.

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    The stated weight of the stove is 970 g but my postal scale put the complete kit at 941 g. Component weights are as follows, in grams:
    Base 327
    Windscreen 97
    1.9 l Pot 126
    2.0 l pot 128
    Pan 152
    Pot Lifter 58
    Plug & Filler 30
    Strap 23

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    The pots are listed as 1.9 and 2.0l. They lack volume indicators but filling them to just below the beltline takes 1 l. For storage, the smaller pot nests snugly inside the larger but reverse the order and they can be used as a double boiler.

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    The alcohol stove is built into the base, unlike a Trangia 25 or 27 which utilize a separate brass burner. Also unlike the Trangia, the flame is adjusted via an external lever in the base. Moving the lever slides a plate across the circular opening at the bottom of the burner, acting as an air shutter. More air allows the fuel to burn hotter and faster, and closing the shutter completely adjusts the flame to a minimum. If the shutter is closed before the stove fully warms the flame may accidentally extinguish. Combustion air for the flame comes from two sources, up the center through the shutter and in from a circumferential gap in the base plate just below the top of the burner. This creates a dual flame front, which probably improves efficiency.

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    Fuel is held via absorption into a fiberglass like foam material that surrounds the burner tube. Filling is accomplished by inserting the red plastic fill adapter into the tube and pouring fuel down the center. The adapter has a bottom to it and holes in the side. The fuel simply wicks into the fiberglass. The stove base becomes surprisingly warm during use, again unlike a Trangia 25/27. Once the stove cools, the red plastic fill plug can be inserted and capped to retain leftover fuel for the next use.

    A couple of burn tests with water straight from the tap boiled 1 l in 10:30 and .5 l in 5:30. An additional test was run with .5 l and the shutter only 50% open. Surprisingly the boil time remained the same at 5:30.

    It’s a little surprising that this cook set is no longer produced as it offers an experience similar to the Trangia 25 but with the advantage of much easier flame control and lighter weight. Some comparison pics with the Trangia 25 and also the Svea 123 powered Sigg Tourist and Optimus 88 kits.

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    Last edited by a moderator: Jun 26, 2015
  2. DAVE GIBSON

    DAVE GIBSON Subscriber

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    Knotty..good thing i'm not looking at ebay these days or we would have bid each other into bankruptcy!!!
    Allan did a demo of his on a winter camp out a few years ago and i have lusted after a trapper ever since....
     
  3. Knotty

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    Dave, this one was listed as a "buy it now." That plus it's unused condition made it irresistible. I wasn't sure I'd ever find one, let alone a new one.
     
  4. geneislucky

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    Great photos and presentation, Knotty. Thanks. My previous fever for an Trapper has been re-ignited.
     
  5. Stoveuser

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    Knotty, I almost hit the "Report post" button on this one! The way you present this set really makes me want one :mrgreen:
    Kidding aside, its a thorough, in-depth, report with exellent pics. Keep up the good work :thumbup:

    Best regards
    Stoveuser
     
  6. shagratork

    shagratork United Kingdom Moderator, R.I.P. Subscriber

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    Hi Knotty, what a great post.

    Wonderfully set out and well explained.

    I do not have a Trapper but saw one in use some years ago.
    At the time I was very impressed with it and thought it was an improvement over my Trangia and decided I should get one.
    I was outbid a couple of times on eBay and then I got interested in other stoves and forgot all about the Trapper.

    After looking at your post I am now regretting that I did not get one.
     
  7. Doc Mark

    Doc Mark Subscriber

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    Morning, Knotty,

    Excellent report and photos, of one of my most favorite stoves! I have a few of those, three to be exact, one an older model and two of the later ones with the weep hole. Both are great stoves, but the weep hole is a huge improvement when it comes to refilling the stove, without over-filling it. SB and I actually started a grass fire, once, when I overfilled the older version of that stove and flaming fuel spilled out the bottom!!!! :shock: :shock: :oops: :oops: ](*,) ](*,) Best to be very cautious when filling those older model versions.

    Another tip you might consider, is making sure to keep the o-rings on the "Safe Fill" device lubed up a good bit. Otherwise, inserting and removing them from your Trapper WILL cause them to eventually crack and that, too, will allow the stove to leak. I use lip balm, which is always in my pocket, on our o-rings, and that seems to work nicely. Spit will do, if you have nothing else, but lip balm is far better.

    As you know, turn the holes in the base, into the wind, for faster boiling, and I've also found that simmering can be enhanced a tad if you turn the base holes away from the wind, too.

    Last, I have no idea what sort of Meths you have where you live, but I have always used Methylated Spirits (Marine Stove Fuel), and it works perfectly. The stove burns hot and clean, and simmers well. I did have to use HEET, once, during a trip to Alaska, and got the "wrong" bottle by mistake (there are two different kinds of "HEET"). The stove worked, but smelled horrible, and our food had a bad taste, too!! :shock: :shock: :thumbdown: =; As soon as we could access good, clean, Meths again, we were back in business, with no problems at all. I have found that, with the Meths we use, our pots do not get sooty, at all, but they do build up a nice brownish-colored patina, which does not easily rub off. In fact, once in place, the boiling times for our Trapper stoves have markedly decreased, which is a very nice byproduct of leaving the patina on your pots, instead of scrubbing it off when washing them.

    Have fun with your Trapper 81, and enjoy using it. We certainly have used the whey out of ours, and love them quite a lot!! At altitude, or down in the desert; deep Winter, or blazing Summer, they have never let us down!!

    Thanks for the great report and photos, and God Bless!

    Every Good Wish,
    Doc
     
  8. Doc Mark

    Doc Mark Subscriber

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    Hi, Knotty,

    Just thought of one more thing: After breaking a couple of o-rings on my first Trapper, I got a few spares to keep with the stove, "just in case". Probably a good thing to do, I'm thinkin'. Again, have fun with your stove, and God Bless!

    Every Good Wish,
    Doc
     
  9. Knotty

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    Thanks for the kind words gents. Hearing of the interest in this product makes me all the more glad that I was able to nab one before the rush. ;)

    Doc, I generally buy Kleen-Strip SLX Denatured Alcohol by the gallon or HEET in the yellow bottle. Both always burn clean for me. Will be interested to see if I get that brown patina. Also thanks for the advice on the o-rings. After opening the package I treated them with pure silicone grease. Should go a long way to protect them but lip balm is a great field maintenance option.
     
  10. Chef BC

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    Intriguing demonstration and one that is a clear benefit to this site. :thumbup: :thumbup: Asking strictly from inexperience with both, how similar is the Trapper to the Swedish Meta 50? :-k
     
  11. snwcmpr

    snwcmpr Subscriber

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    Great detailed and informative post. I too now want one.
    Ken in NC
     
  12. brassnipplekey

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    Morning .
    Knotty ... V nice presentation .. excellent pics and a quality post . Thanks.

    The tip from Doc re- lube yer 'o' rings is a top tip . I'm reckoning (like you )silicone grease is the way ... but lip balm ... or spit, at a pinch :-).
    I've burnt various brands of meths in my 81 , burnt methanol and Docs correct .. the pans turn a lovely light brown colour .. no carbony mess , almost an anodised looking coating .
    Very interesting stove/cook set .Thanks for your thoughts and well worked (Pro) presentation .
    Take care and keep the flame blue .

    Nick
     
  13. presscall

    presscall United Kingdom SotM Winner SotY Winner Subscriber

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  14. Knotty

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    Chef, I don't have and have never seen a Meta 50 in person so I'm unable to compare based on experience. If I had more disposable income, I'd pick up a Meta just for fun but right now it's not high on the list. Someday...