MYOG – A Winter Canister Stove using your Summer Upright Stove and the Brunton Stove Stand

You may have jumped the gun on assuming I hadn't researched this earlier…

I have been following this thread for quite awhile. And have read most of the other articles you referenced. I have even purchased a brunton stand to replicate the original MYOG stove in your article — available time to come up with something nicer than the primus express spider stove (FYI I have also read that article) have kept me from proceding.

I had actually requested the spider for christmas — didn't get it so was planning to purchase in the coming weeks… and then Stuart provides this update. This appears to definatly be the eloquent solutions I was looking for as far as MYO inverted cannister stoves go.

Anywho, thanks for consolidating all of those nice articles / threads and of course all of the quality info you have provided through the years re. canister stoves.

James

Edited to add "and of course…" at the end

There are many people making MYOG gas stove　in Japan.

"SRS" he is one of them.and on blog.

http://pclv9161.blog84.fc2.com/blog-category-6.html

Photos of a named person.
Japanese is garbled and fear. However, you will see from the picture file.

Elementary years ago,in　Australia, Tony has previously made a MYOG gas stove.
That was very shocking debut in Japan.
Japanese here and there and then to increase the people who own a gas stove.
I am also a very simple mechanism to YouTube MYOG has published a gas stove.
(Angel stove, @dutro76 on YouTube)

If you don't have the resources to make the parts as shown I had success using copper wire from some old electrical wire I had laying around. Something a little more flexible would have been easier to use, but I just went with what I had at my disposal. Worked well in the field.

I found this similar Gelert stand, but it has no control at canister end:
is that OK?
Note the extra adaptor to allow use of the cheap male butane picnic narrow cannisters (shaped for gas mode).

EDIT: Rereading article, it seems might be dubious for liquid feed or at best wasteful (of 1 minutes gas), as liquid = much gas would remain in tube because must turn off at burner 1st, then disconnect: however I am puzzled by the articles suggestion to turn off at canister 1st so that liquid in tube is burnt off— surely there is now no pressure driving it; but it obviously works.

> however I am puzzled by the articles suggestion to turn off at canister 1st so that liquid in tube is burnt off— surely there is now no pressure driving it; but it obviously works.

There is still pressure driving it; the evaporating gas in the fuel line.

The point of using a liquid feed burner it to enable the lower boiling point propane to drive the propane/butane mix out of the cylinder as liquid (and have it evaporate in the pre-heat tube), largely preventing the fractional distillation/evaporation that can occur at low temperatures, which would result in the propane boiling off preferentially, leaving the higher boiling point butane behind, and thus having no gas pressure below 4C.

If there's some liquid propane/butane mix in the gas line, this will evaporate and reach the burner.

Roger Caffin (to Stuart Robb)
"You are right – valving the liquid is very tricky. That's why mounting the whole stove on the Brunton stand has some merit: you get a valve at the gas feed. But it is extra weight.

Oh yes – you NEED the valve at the canister as well, as a safety on/off."

Does this apply to both liquid and gas feed modes or just liquid mode?

(Does unscrewing the cartridge not count as safety on-off?)

If a valve is needed for both modes, then Gelert stand shown is dubious: does anyone sell replacemment hoses with cannister valves?

A valve at the canister is not essential for eithe gas or liquid feed but as Roger said, it's a safety feature – if the fuel tube could rupture or detach from either end, then it would be nice to have a means to quickly shut off the gas.

BTW, using pure Butane in liquid feed mode gives little advantage over gas mode. The boiling point of pure Butane does not change (unlike a butane/propane mixture), so the only advantage of liquid feed in this case is the avoidance of evaporative cooling of the canister contents.

But I wonder if turning the (fully on) cannister valve off is actually any quicker (possibly slower?) than unthreading/unclipping the cannister itself:

Is there anything inherently dangerous about disconnecting the cannister whilst stove is still lit (in an emergency only) as the cannister seal will activate.

Edit: I suppose liquid mode means more gas/liquid in tube, but the canister end should be colder, and if liquid mode cos cold weather…. so in emergency remove canister and run; should be safe enough? EDIT: DEFINITELY NOT — see Roger Caffins
response: "Re: Valve at canister ….? on 09/26/2011 17:48:08 MDT" …NO! NO NO NO!…

EDIT The following question is now irrelevant, see above
In normml use, for liquid mode when cold, with no remote valve, before turning off, perhaps you could uninvert the canister (back to gas mode), letting the liquid in tube burn off (1minute?), then turn off at stove end, and optionally unscrew cannister if packing up.

I mis-titled my previous post which asks the above question.

Just `Bump" ing

Hi Alan

Sorry – I was overseas for 2 months.

> Does this apply to both liquid and gas feed modes or just liquid mode?
Liquid feed only.

> (Does unscrewing the cartridge not count as safety on-off?)
Yes, BUT …
It is a lot faster to flick a valve than to unscrew a canister. Also, unscrewing the canister can, in some cases, release some gas from the canister half-way through. That could be a shade exciting.

Cheers

Hi Christopher

Yeah, NEAT!
My only concern would be how well the copper wire contacts the brass tube: does it get loose over time. But with heavy copper wire, the cost of replacing the heat shunt is pretty close to zero anyhow. And if it works, who's complaining?

Cheers

Hi Alan

> Is there anything inherently dangerous about disconnecting the cannister whilst stove
> is still lit (in an emergency only) as the cannister seal will activate.
> …. so in emergency remove canister and run; should be safe enough?
OH GOD NO! NO NO NO!

You CAN get liquid fuel leaking out of the connection while the canister is being unscrewed. Happens with some combinations of stove and canister, not all. But that's liquid fuel – it expands about 250 times into a gas.
Obviously you have never seen a BLEVE – a fire ball from spilt LPG. (BLEVE = Boiling Liquid Expanding Vapour Explosion) Think fire ball engulfing your head.

> perhaps you could uninvert the canister (back to gas mode), letting the liquid in
> tube burn off (1minute?), then turn off at stove end, and optionally unscrew
> cannister if packing up.
This is usually safe enough. A small amount of gas might escape, but if there are no flames anywhere nearby it is unlikely to be harmful.
Key to this is to unscrew the canister fairly fast, so the internal valve gets to seal off quickly.

Cheers

"> is still lit (in an emergency only) as the cannister seal will activate.
> …. so in emergency remove canister and run; should be safe enough?
NO! NO NO NO!"

Thanks, I'm convinced, a can side valve seems a requirement!!

I wonder if a can side on/off only valve would be lighter as well as quicker to operate, or, in liquid mode, if stove has its own valve, do you only turn the can valve on partially .

It seems odd gelert will sell a remote stove adaptor without a can valve (I suppose they presume gas mode only: that the threaded canister is kept upright (and doesnt topple)).

(in liquid mode, if (someone else's) remote stove (with no can valve) was lit and in trouble before stove valve, eg hose leak, do they have any options other than running away?

"Obviously you have never seen a BLEVE "
No, but I do want to avoid one!! The tube on remote stoves always worried me, (I worried about hidden damage underneath the braid), so I just have a can top stove, hence I definitely wanted to know all the remote stove safe shut off methods before buying one.

Now that low cost remote stoves are available at, for example, 235g (GoSystems TriSpi), it is probably just as cheap to modifiy these, especially with the copper wire idea.

Did the copper wire get used to restrict the tube as well?

You could, altho' that stove
a) does not have a convenient brass tube to mount a heat conductor on, and
b) the valve at the canister is not designed for the fine control of liquid, and
c) is not particularly light

You'd be better buying a Primus Express Spider @ 198g which already has a pre-heat tube, altho' the control knob is a bit inconvenient for inverted canister use.

Alan Bradley wrote
>>> How did you connect the Gnat to the hose?
The Gnat screws onto the centre of the stand (and unscrews for packing). I made this centre piece from a TNC connector which has the requsite thread. The vapouriser tube is brazed in this and the fuel tube is clamped onto the other end.

>>> Is the cannister connector (shown in other threads) a Roger Caffin special?
No, I made that also.

Stuart,

If I may ask, what is a TNC connector?

HJ
Adventures in Stoving

In some circles, a TNC connector is the threaded equivalent of a BNC connector.

I thought you would never ask.

–B.G.–

It's a type of electrical connector sometimes used for high frequency signals.
TNC = Threaded Neill-Concelman connector, similar to
BNC = Bayonet Neill-Concelman connector.
Strictly speaking, I used a RP-TNC, where RP = Reverse Polarity.

Interesting. I suppose the smaller diameter end is used as a hose barb and the other end as the threaded connector (after being gutted), yes?

HJ
Adventures in Stoving

Hi Alan

Sorry – I missed this.

> It seems odd gelert will sell a remote stove adaptor without a can valve
As to why they only have one valve on a remote canister stove – COST.

> I worried about hidden damage underneath the braid
We have recently seen cheap Chinese stoves with really unreliable hoses, so that can be a concern. But the 'good' stoves usually have a far better plastic (something like PFA) inside the braid which very rarely suffers any damage.

Cheers

Jim – the vapouriser tube is brazed into the narrow diameter end, the nut on the threaded middle section holds the legs and the stove screws onto the threaded end.

>> It seems odd gelert will sell a remote stove adaptor without a can valve
Roger Caffin responded "As to why they only have one valve on a remote canister stove – COST."

I had thought they(gelert) might worry about being sued:
if the hose/stove goes wrong and the user has no canister side valve to stop gas flow, they might try to disconnect the canister which, as you explained earlier, might not go so well due to a possible small amount liquid gas escaping before cannister seals.

I don't think its made anymore.

Jim – the vapouriser tube is brazed into the narrow diameter end, the nut on the threaded middle section holds the legs and the stove screws onto the threaded end.

Nice. Very nice. Thank you.

HJ
Adventures in Stoving