I recently purchased the Primus Express Spider for several reasons - largely based around the fact that it is a far more suitable stove for winter use:
- it has a pre-heat tube meaning that, at cold temperatures, the butane in canisters will still become vaporised and therefore continue to fuel the stove;
- it is a tube-fed stove which has two benefits - the canister can be inverted to assist vaporisation and the stove is more stable which permits use within the porch of a shelter in inclement weather;
- it is lightweight, packable and comes with several decent reviews under its belt which indicate that it is likely to be an effective winter cooking system.
On opening the box, you can immediately descry a superbly manufactured stove. Once the various, annoyingly obstreperous, tags are removed, the stove can be played with. At 193g, alongside a stuffsack which weighs an additional 12g and with which I shall dispense, placing instead the Spider inside my Titan Kettle, it is sufficiently lightweight. A canister top stove (the Gosystem Fly-Ti or Monatauk Gnat, for example) would be lighter but for the reasons I have espoused previously when considering my winter overnight system, it is impractical for cooking inside a tent and it does not have pre-heat advantages. There is also a small, flat, circular disc of metal which is a heat shield. This is a superfluous bit of gimmickry as far as I can see and my intention is to shelve it until I see the need for it.
Boil time is billed at 4.5mins for 1 litre of water going from 20C to 100C and power output is 2000W/7150 BTU/h. Dimensions are 105 x 85 x 55 mm. I did not do my own tests as this will change in real-world conditions anyway which are impossible to recreate at home.
The stove has three legs, with broad, teethy grips, which unfurl reassuringly smoothly into solid stantion points and provide a very stable tripod base. They do not clip into place, they simply slide in, but the whole system is still very well-balanced. The pre-heat tube, fashioned in an agreeable and efficacious brass, curves around the perimeter of the stoves fire-pit flame system. The tube from the gas canister to the stove itself is a woven, steel mesh measuring 28cm and culminating in a solid and elementary flow-adjustment system to be screwed into a canister.
Initially, I was quite concerned about stability - because the hose of the system is so robustly substantial, as is the gas-inflow tube (also crafted from brass) the stove lists backwards if there is nothing on it. This did not seem particularly stable to me, but the simple weight of the empty box placed on the legs (perhaps as little as 50g) was enough to stabilise it. A Titan Kettle with 500ml (600g or so) will keep it stable. The footprint of the stove, when unfurled, is sufficiently diminutive to permit cooking within the porch of the Akto - perhaps (heaven forbid) the Fly Creek UL1...
The Spider does not have a Peizo ignitor which features on most canister stoves. The attractions of this simpler setup however are both a consequential weight saving and improved reliability (there are fewer complicated parts to malfunction in wintry freezing conditions). Most of us carry a lighter or matches anyway, so why have an piezo? It becomes redundant.
I am looking forward to testing this stove on a 3-day trip in Snowdonia, or the Lakes (destination to be determined) in January 2011 when the temperatures will likely be very low indeed. I have some confidence it will perform admirably on the evidence so far.