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Heat transfer for picnic stove?

PostPosted: Wed 21 Jul, 2021 9:04 am
by Moondog55
Just wondering about the best way to make a heat transfer system for the little butane picnic stove to make it more usable in snow season.
Something that works like a Moulder strip
Would simply using thick copper wire work in the hot flame or would it be better to use some NiChrome resistance wire for the small section in the flame path?
Just enough added heat to counteract the evaporative cooling so I was thinking that putting the heat under the steel shell of the stove body not under that gas canister

Re: Heat transfer for picnic stove?

PostPosted: Wed 21 Jul, 2021 8:14 pm
by icefest
I've stopped messing around with warming up gas canisters using fire since I had one explode...

I think either a liquid feed gas stove or shelllite stoves are best used in the snow.

Blade 2 by fire maple weighs 135g, and tolerate liquid feed
https://www.aliexpress.com/item/32793644574.html

Re: Heat transfer for picnic stove?

PostPosted: Wed 21 Jul, 2021 11:02 pm
by Moondog55
I actually have the 117T, but the little picnic stove is much faster and when using in a hut so much easier/more convenient to use.
If the Iso-Pro canisters work when cold I won't bother but N-Butane is so much cheaper

Re: Heat transfer for picnic stove?

PostPosted: Thu 22 Jul, 2021 8:13 am
by stry
With the section that is actually in the flame, you could try brass as a balance between conductivity and ductility.

Re: Heat transfer for picnic stove?

PostPosted: Thu 22 Jul, 2021 8:29 am
by Moondog55
stry wrote:With the section that is actually in the flame, you could try brass as a balance between conductivity and ductility.


I was thinking of using a bent Titanium tent stake forced into a circle the same size as the burner but I may have a brazing rod somewhere. I really don't want to buy a metre length of 1mm NiChrome wire when I only really need 100mm

Re: Heat transfer for picnic stove?

PostPosted: Thu 22 Jul, 2021 12:39 pm
by GBW
Aluminium has 10x the thermal conductivity of titanium; copper over 20x.

Re: Heat transfer for picnic stove?

PostPosted: Thu 22 Jul, 2021 1:22 pm
by Moondog55
Yes but the trade-off there is that the Aluminium will degrade very very quickly and using too much copper might add too much heat to the canister.
I left the stove in the hut at Pretty Valley so it's not here to play with but I was thinking od spending $20- and getting another.
A deep winter solution might be to use PowerMax canisters but those are $9- each and that makes no sense in terms of economy.
Also I can't find any 2.5mm<2 copper wire, only multistrand stuff which burns out quickly

Re: Heat transfer for picnic stove?

PostPosted: Thu 22 Jul, 2021 2:42 pm
by CraigVIC
These stoves are easily damaged/caught on fire/overheat, boil the canister etc. Just a slightly too wide pot will do it. I have done it myself even though I was aware they are prone to it. No reason not to muck around with one but they aren't good candidates for mods imo.

Re: Heat transfer for picnic stove?

PostPosted: Thu 22 Jul, 2021 2:49 pm
by Moondog55
Heard and understood Craig. The new "Safety" models are better in this regard but nothing is proof against stupidity, I've had that happen with my old Primus 111B in the past

Re: Heat transfer for picnic stove?

PostPosted: Thu 22 Jul, 2021 6:29 pm
by GBW
Have you tried resting the canister in a rectangular tray of water to keep the temp above freezing?

https://www.youtube.com/watch?v=vbuhwHfhR18

Re: Heat transfer for picnic stove?

PostPosted: Fri 23 Jul, 2021 11:34 am
by johnrs
Heh Moondog
Try the combination of a liquid fuel stove and a convenient gas stove like the Firemaple Blade 2 mentioned above.
The Blade 2 is a really great stove and you can buy cheap low temp canisters at Kmart or online.
There is a thread about the cannisters somewhere on this site.
John

Re: Heat transfer for picnic stove?

PostPosted: Fri 23 Jul, 2021 11:42 am
by johnrs
Cheap gas cannisters.
Moondog here are some details



Thank you for choosing Outdoors Domain for your recent online purchase.
Your Order
Cart Items Qty Item Price Item Total
Gasmate 230G Iso-Butane Cartridge (24 Units)
1 $69.95 AUD $69.95 AUD
Subtotal: $69.95 AUD
Shipping: $0.00 AUD
Grand Total: $69.95 AUD
GST Included in Total: $6.36 AUD
The Outdoors Domain Team
Phone 1300 794 839 Email [email protected] Website www.OutdoorsDomain.com.au
Shop 28 Lionel Road Mt. Waverley Victoria 3149 ABN 21 052 510 022

Re: Heat transfer for picnic stove?

PostPosted: Fri 23 Jul, 2021 12:33 pm
by Moondog55
I did that last year
It's now $105- for the carton with shipping
K-Mart still has them for $4- each
But if you read the MSD for the standard Gasmate hairspray cans even those are now composite it seems
https://delivery.bunningscontenthub.bun ... v=f0a61b15

Re: Heat transfer for picnic stove?

PostPosted: Mon 26 Jul, 2021 2:56 pm
by Moondog55
Somebody on another forum just told me about Iwatani stoves
https://www.iwatani.com/va-30
These have a very small heat exchange that does what I need so I can see now how to knock up something similar

Re: Heat transfer for picnic stove?

PostPosted: Wed 11 Aug, 2021 1:22 pm
by cjhfield
Iwatani.jpg
Iwatani stove
This is the heat exchanger of my Iwatani. Its aluminium. After 5 minutes running the stove it is warm but not uncomfortable to keep your fingers on it.

Re: Heat transfer for picnic stove?

PostPosted: Wed 11 Aug, 2021 2:02 pm
by Moondog55
Thanx for the close up It helps a lot. I can do something similar with what I have around the place