Moulder Strip Directions

[David Thomas]

“Could the strip be permanently applied to the canister with JB Weld and considered a consumable? Several canisters could be prepared ahead of time in that fashion and have no need to do change overs of the strip in the harsh climate conditions. Does this idea have any merit?”

Dan, the idea has merit, and would offer the following benefits

• marginally better heat transfer
• no need for a strap / scrunci / cozy
• possibly one could downsize the MS a little bit

OTOH, there are drawbacks:

• if it might get knocked off as you assemble the stove/canister or pack it, you’d bring the strap anyway
• while from 0-ish to 20F, a CMS only suffices, a cozy really helps below 0F so maybe you have that along anyway
• some of us refill from 450-gram canisters and that would be more bothersome if an MS is bonded to the 110-gram or 220-gram receiving canister.

On balance, we have a proven, lightweight solution, easy to transfer from canister to canister.  JB Weld is really not very thermally conductive at all, as I found out with one of my attempts to combine an aluminum rod with a rounded section of Al sheet metal.  Air is 0.024, JB Weld 0.59, Copper 401.  So while JB Weld is 25 times more conductive than air, it is 700 times less conductive than copper.  I suspect that where the CMS is pressed to the canister, virtually all the heat is transferred at the contact points and travels laterally in the copper to those points.  Any heat conducted to the steel canister is then very quickly dissipated by the boiling of the butane/propane inside.

[Roger Caffin]

As David notes: equilibrium is reached fairly quickly, and at sub-zero ambient it is not ‘hot’ ime.

Cheers

[Roger Caffin]

JB-Weld:
Quite apart from the inconveniences David has mention, I suspect that the surface of a canister may not take JB-Weld all that well. I suspect that the bond to the paint will be rather poor. But I might be wrong: that needs testing and I don’t have any JB-Weld. (Limited availability in Oz.)

Cheers

[Jerry Adams]

You can solder copper to canister.  You have to scrape off the paint first.  I suggest emptying it first.  Not that I’d recommend that, I think like Bob said it’s not that important to have a super good thermal contact between strip and canister.

[David Thomas]

Jerry for the win in understatement!

Here’s how to clean a pistol. . . .  “I suggest emptying it first.”

[Jerry Adams]

yeah, but really, when you solder the wire on the side it’s pretty quick.  There really isn’t time for the butane inside to get all that hot.

I did this before anything about Moulder strips by the way.  Back when Bob Gross brought up using thick copper wire.

[David Thomas]

And since you’d rotate the canister so the sidewall you’d solder would be on top and only in contact with vapor (not liquid), I suspect you’d be fine.  Sand it.  Flux it.  Solder it.

[Gray T Kinnier]

I have used that tape for two winters in the Sierra for my Moulder strip. I cut a length of the silicone tape that matches the height of the vertical wall of the canister. The 1.5″ width allows room for the 1″ copper strip. I secure the silicone tape to the canister at home with clear packing tape wrapping it once and a half around the canister with the overlap covering the silicone tape area. Before attaching the silicone tape I apply a generous layer of silicone plumbing grease to to the side facing the canister, this allows me to slide the copper strip in and out when breaking down the stove between uses. When wrapping the canister with the packing tape have the copper strip in place, wrap without much tension over the silicone tape area to allow for removal and replacing the copper strip. This has worked fine in temperatures to 10 F that I have used it. I thought of trying other tapes but this has worked well and is probably as light as possible. All the canisters for the trip are prepared like this at home and I use the same copper strip as I cycle to a new canister. After the canister is empty I have reused the silicone tape on a new canister. I can try to upload a photo tomorrow if that would help.

[Roger Caffin]

PHOTOS!

Cheers

[DAN-Y]

Rough up the surface of the canister with sandpaper/emery cloth and then apply JB weld.

Plumbers Putty Epoxy, comes in a tube. Cut off amount needed, knead with hands, apply over top of MS. Use sandpaper on surface first. Easier to use than JB Weld.

Or just use Velcro Strap :-)

 

[JCH]

David – re: “Classic Moulder Strip”. Please allow me to respectfully disagree as I feel no modifier is required.

A Moulder Strip is precisely the configuration that Bob devised, tested, and published. Of course anyone is welcome to add/delete/revise/bastardize to their hearts content…but then it is not a Moulder Strip.  It then becomes a “<insert-your-name> Strip” :)  It may be best to remember that the Moulder Strip is but a blip on the cosmic path of enlightenment…revered in it’s time, it will garner many devotees, but shall be doomed to being cast aside at first appearance of the new hotness.

Also, all you guys are killing me with your modifications to the Moulder Strip that make it more complicated, less efficient, heavier, or all 3.  The goal is not to change it.  The goal is to improve it! Simpler, lighter, more efficient or why bother?

[DAN-Y]

As long as you canister guys are refilling, solder the strip onto the refilling canister. Lightweight is there to the ultimate. No hassle with velcro strap or string and spring.

[Roger Caffin]

Gray Kinnier in #3496650 inspired me to try a simple idea. One should be able to permanently bind a thin pad to the canister with tape, leaving you able to slip the Strip underneath. Light weight, no hassles in the field, easy to assemble.

You don’t even need a silicone pad for this. I used a second bit of the tape to block the adhesive in the region of the strip. To be sure, this would mean the second bit of tape could get hot – but somehow I don’t think it is likely to get very hot. I used PCB masking tape with a silicone adhesive, but any other high temperature tape would do: Al foil, copper foil or Kapton for instance. In extremis you could simply use DUCT tape. Oh, the wonders of duct tape!

I should add that after I had put the tape on with the strip in place (that is actually the tricky bit!) and run two layers around the canister, I found that the strip was held rather tightly against the canister – but it was easy enough to slip it out and then back in place. A single turn of tape is probably not enough (duct tape excepted).

When the canister is empty you could transfer the tape and silicone pad (or whatever) to another canister. No suggestion of refilling the empty canister of course …

Edit: the strip shown is a bit of an overkill. It’s 1.6 mm thick by 20 mm wide, and the heat pours down it. 1.2 x 15 mm should work I think.

Cheers

[Casey Bowden]

What happens when you screw the stove on the canister and the arm of the stove conflicts with the Moulder Strip (MS)? Unscrew and try again? Is this not an issue with your MS and stove combination?

[Roger Caffin]

Hi Casey

arm of the stove conflicts with the Moulder Strip
Not a problem at all.

The strip is not in place when you screw the stove on, because it comes off for packing.

The strip does not conflict with the arms on the stove, either because the Velcro strip can be rotated around the canister, or because the adhesive tape fitting was done with the stove securely mounted first (and some excess width for movement was allowed anyhow).

Cheers

[Casey Bowden]

…(and some excess width for movement was allowed anyhow).

That would take care of it. Thanks.

 

[Bob Moulder]

As long as you canister guys are refilling, solder the strip onto the refilling canister. Lightweight is there to the ultimate. No hassle with velcro strap or string and spring.

Dan, this will not work with some stoves because stove arms or valves get in the way when screwing on the canister. Also, it is best to position the strip opposite the fuel valve, and this will end up in a different spot on the canister’s circumference if a different model of stove is used. And while there is some latitude for strips to be a bit too long or short, ideally the strips are of different lengths to match different stoves’ burner heights.

Soldering on a strip definitely will not work with the pot supports of the MiniMo, and it can make packing tricky as mentioned above, and should something go wrong with the canister’s Lindal valve it’s nice to be able to quickly and simply switch to another canister.

As for the life of Lindal valves, some of my online reading suggested that perhaps refilling the canister should be done a limited number of times — say a dozen, just to pull a number out of the air — but I have a Primus 110 canister that I have refilled many dozens of times, both for testing and for use on the trail, and it is still going strong. At first I kept count but after a few dozen lost track, but it is fairly large number by now.  :^)

 

[DAN-Y]

The Moulder Strip works, that’s the important thing. Use whatever method is convenient for you guys for attaching it. Stay warm in those frigid conditions where the MS is needed ;-)

[Bob Moulder]

In your experience is there an upper limit on the number of minutes you can continuously run the stove (As in melting dry western powder snow into several litres of water/ melt water for a group) before the canister gets to the point where you dont want it to safely get any hotter?    IIRC your trip reports are often solo for a night or two, so I’m wondering if there’s a diminishing rate of return where at some point with longer trips and more snow melting/stove usage  required where it would be preferable to bring an inverted cylinder stove?

I was out hiking for a couple of days and missed this….

Short answer: No

I have used this setup continuously for snow melting on several occasions and it keeps working until all fuel is expended and it does not overheat.

The only limitation is the size of the pot. Since it’s a “topper” stove, pot volumes larger than 2 liters might cause some instability, especially with some of the tiny stoves such as the BRS-3000T, Fire Maples, SP Gigas, etc.

In any event, a pot with a flux ring is vastly preferred for fuel efficiency, which is why my go-to setup is the MiniMo with the Sumo 1.8 liter pot. I have found this adequate for 3 people when all water is obtained by melting snow. If solo, IME the MiniMo pot is plenty.

MiniMo with Sumo pot at 4°F….   no problem! (JB canister stabilizer legs in use)

[DAN-Y]

The 1.5″ silicone tape was tested in 3 different configurations. It would not pass the rigid expectations of the canister world users ;-)

The silicone tape was used to protect an extension cord connection used outdoors for the winter months. It has found a place in my plumbing/electrical box ;-)

I had in my box of goodies 2 velcro cinch straps that were 1″ wide and wrapped 1-1/2 times around a small canister. Held the 1″ wide copper strip beyond expectations. I’ll try to find a link to the velcro straps.

[Roger Caffin]

Hi Dan

Thanks for feedback on tape. Ah well, at least it had other uses.

Cheers

[DAN-Y]

The silicone would be good enough for me but not canister diehards ;-)

The velcro straps are used by the RV industry for awning securement. Worked wonders for mine. Tougher than nails. :-)

[Bob Moulder]

Dan, although your earlier idea of soldering the strip to the canister would prove unworkable, and the silicone tape didn’t pan out, it did get me thinking about something I had not previously considered.

The high-temp silicone sheet material I got from McMaster-Carr has a very tenacious adhesive on one side. So I thought, Why not simply stick the silicone to the canister, leaving a little ‘pocket’ for inserting the copper strip?

Well I tried this today and it is working out better than I had expected. I rather anticipated that the adhesive might loosen and creep once it got fairly warm, but that did not happen.

Today I sanded the paint off the canister where the sticky-backed silicone would be applied and cut a piece of the material such that it looked like a big Band-Aid. I left the backing material on and applied it to the canister at the proper location for the copper strip when used with the BRS stove.

Glitch #1 occurred when I fired up the stove and the strip got hot enough to melt the backing material, after which the copper strip stuck under the silicone… not good. So I made another silicone strip and put some Ti foil in the area where you see the backing material. This worked very well.

I ran the setup for 3 test boils (ambient temp 73°F!!) and the although the copper/silicone area of the canister reached about 140°F the silicone sheet did not creep and the copper strip maintained good contact with the canister.

With no field testing it’s too early to give this a full-on recommendation but it certainly looks quite promising. Getting mighty close to Zero for the fiddle factor!   ;^)

[Jerry Adams]

“Glitch #1 occurred when I fired up the stove and the strip got hot enough to melt the backing material, after which the copper strip stuck under the silicone… not good. ”

My favorites are always the failures.

Best if spectacular.

[Roger Caffin]

Hi Bob
According to Dow Corning, the upper WORKING temperature limit for the siloxane adhesives used on these sorts of silicone polymer sheets is about 200 C. So your sticky silicone sheet should stay stuck on for a long time.
I would imagine that the adhesive on your stuff could be similar to the adhesive on my green tape.
Cheers

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