Wind Screen

[Marc Eldridge]

For you stove guys, what do you think of this wind screen setup?

[Matthew Black]

Is that a Vargo Ti stove?

[Jerry Adams]

Is there enough airflow out the top?

How much does it weigh?

You can't roll it up for easier storage.

Will the canister overheat?

[Paul McLaughlin]

Don't use that with that stove! That Coleman has plastic parts that are going to melt with that rig – including the bit that connects the control handle to the valve. If that melts YOU CANNOT TURN IT OFF!

[Jerry Adams]

hmmm… take pictures?

[Delmar O’Donnell]

Is your windscreen galvanized? If so, warning. Research the health effects of over-exposure to galvanization. The concern is zinc poisoning and "metal fume fever" which gives flu-like symptoms. Welders avoid welding on galvanized material, and you should likewise avoid getting it hot (especially near food).

[Tad Englund]

Delmar, I was thinking the very same thing

[James Marco]

Yeah, avoid galvanized.

[Hikin’ Jim]

Is that a Vargo Ti stove?

Looks like a Coleman F-1 Ultralight.

HJ
Adventures In Stoving

[Hikin’ Jim]

For you stove guys, what do you think of this wind screen setup?

Marc,

Looks like there are some good things about it, but it looks like it might be resting on the canister, yes? If so, you could get some serious heat conduction to the canister. Whether or not it's resting on the canister, you need to feel the canister by hand when the stove is in normal operation. If the canister feels hot, turn it off. An overheated canister could be a very bad thing.

As others have mentioned, I'd be worried about plastic parts melting and about the galvanization. Pretty simple innovation you've got there with the clothes pin. I like it. :)

Lastly, how heavy it it? It looks maybe a bit heavy? "Heavy" of course varies by the person. If you're saving a lot of gas and don't have the hassle of wasting an entire canister of gas to boil just two cups of water, then of course even a relatively heavy windscreen can be a wonderful thing.

Just a few thoughts. Keep experimenting!

HJ
Adventures In Stoving

[David Thomas]

+1 on avoiding galvanized metal in situations where it is heated. Especially since there are so many options of mild steel, SS and Ti to choose from. This could include heating a galvanized nail to melt a hole in nylon webbing. Just find a non-galvanized hunk of metal instead.

If you're at home (or in a field of diary cows), and you opt to heat or weld something galvanized, FIRST sand/file off the zinc layer before heating it, and SECOND drink a lot of milk. Welders have long observed that they have fewer issues as the calcium helps displace the zinc.

But better to heat zinc at all.

[Bob Gross]

"But better to heat zinc at all."

Or NOT.

–B.G.–

[Roger Caffin]

> For you stove guys, what do you think of this wind screen setup?
Errr… not good. Way overboard imho.

The gap around the exit as shown is too small. The limited air flow will give lots of CO.

The inside photo shows an extreme lack of air inlet holes as well. More CO.

The stove is going to get very hot inside there. Much too hot in my opinion: dangerous for any plastic and rubber in the stove.

Zinc fumes in the cooking, as well as up the nose. Seriously not good.

Carting a bucket around – too big, too heavy, and quite unnecessary too.

You simply do not need a windshield like that anyhow. It is gross overkill.

Sorry, but…
Cheers

[Bob Gross]

"It is gross overkill."

Just exactly what do you mean by that?

If you are going to use terminology like that, then reserve it for the really serious stuff.

–B.G.–

[Paul McLaughlin]

Just to clarify my post about the melting parts, I had the same stove (Coleman F1 Ultralight) and my son borrowed it, and using it with a foil windscreen halfway around the stove, he melted that plastic bit on the handle. Fortunately one of his buddies had a leatherman with pliers and they were bale to turn it off by grabbing the valve spindle with the pliers. As my son put it, "our next option was to fling the thing into the lake".

[Jerry Adams]

I have a Coleman F1 Ultralight

Either because of user error or design defect, it started leaking between stove and canister, flamed up, melted those plastic parts a little, but it still works

Then, several times, I carefully screwed it onto canister and left it overnight, it cooled off, started leaking fuel, empty in the morning. I got a new stove.

[Redacted k]

I like the concept, the execution needs work as others have noted. The attachment to the valve is clever, although not viable long term. Not sure if the valve plastic would melt of the sticks burn first, I think the plastic melt.

As said, galvanize and flame dont mix. This advice I even got from a blacksmith, who was very casual towards safety. "Eye protection? Squint!"

You will get the best effectiveness with aluminum as a material. It is very light, and reflects the most heat back towards your pot, of the common materials. Better than steel, better than titanium.

I have been working on a similar concept for my coleman white gas stove, but using a disposable aluminum pie pan.

Do make sure to keep the aluminum out of the flames though.

If you are going to continue with that stove, the heat shield/wind screen will need to locate between the bottom of the burner but above the valve.

[Delmar O’Donnell]

>You will get the best effectiveness with aluminum as a material. It is very light, and reflects the most heat back towards your pot, of the common materials. Better than steel, better than titanium.

Really! This is news to me. I thought heat reflectivity was more a function of the finish. For example, that a shiny surface would work better in theory than, for example, flat-black stippled surface, etc. I was unaware that the metal of the shield had anything to do with its effectiveness as a reflector. I'm aware that aluminum conducts heat better than steel or titanium, but it's surprising to me to learn it's a better reflector!

I recollect someone saying that titanium has been used as a heat shield on aircraft or spacecraft, and that would make me think it would be good at reflecting (and dissipating) heat away from its surface.

Now, if you consider a shield to be a heat SINK, then I can see aluminum (or copper) being superior. In theory. The aluminum we use for a wind screen is pretty darned thin and would not act as much of a heat sink.

Interesting. Not arguing, just trying to understand. The above quote puts in doubt my understanding of heat reflection.

[Jerry Adams]

yeah, finish is what matters, any polished metal is pretty reflective

table of emissivity:
http://www.engineeringtoolbox.com/emissivity-coefficients-d_447.html

emissivity = 0 means it absorbs no heat (so it reflects all),
emissivity = 1 means it absorbs all heat (so it reflects none)

Titanium is a little bit worse than aluminum but not that much

but reflectivity of windscreen probably isn't that important, it's supposed to block wind so it doesn't blow the flame around and make burning inefficient

[Delmar O’Donnell]

Well how did I get to be this old, and remain so ignorant, to never see an emissivity table before? This is fascinating. So an ideal heat-reflective windscreen would be made of Aluminum Foil (.04) or Electroplated Nickel (.03) or Polished Silver (.02), and a really bad reflective windscreen would be made of Concrete (.94) or Pyrex (.95) or Ice. (Your comment about the real purpose of a windscreen (to shield the wind) notwithstanding.)

This table also has "old galvanized steel," and it's pretty bad at .88

[Jerry Adams]

aluminum or whatever, covered with soot would be pretty bad : )

[Delmar O’Donnell]

> aluminum or whatever, covered with soot would be pretty bad : )

Sure would. Soot would be equivalent to "lampblack," on the list at .96, about as bad as it gets.

Thanks for the education, Jerry. Where do I send the check for my tutelage?

[James Marco]

Well, we can agree that the galvinization is bad for you.

There are a lot of design components to screens. For such a simple device you would think they don't do a lot. Heat losses right through a wind screen are a fairly minor component. Heat from the stove comes from two major sources: Infrared radiation from the chemical reactions (actually drives the next) and conduction through heated air/combustion byproducts.

Absorbing the IR, the heat is then radiated outward again, so, an insulated screen would be slightly more efficient than a non-insulated one. The neoprene sleeve on a JetBoil, for example, also traps heat in the pot.

Ti is not a great conductor, so, functionally, might be closer to aluminum in performance that raw emisivity suggests for stove screens. Aluminum is lighter, though. FThe or example, a typical "grease" pot at 1 liter capacity is still the lightest pot out there at 3.5oz. Removing the lid handle gets it down to 3.25. Only by changing capacity does anything else beat it for weight. My two person pot (about 1.85L) heighs about 5.625oz including lid. An equivalent Ti pot always weighs more.

I would guess the same applies to wind screens. A slightly heavier ti foil one would work about as well, and be more permanent…but, it would cost more and be heavier.

[Redacted k]

Yes, that table is what I gained the knowledge from. Even heavily oxidized, the aluminum is decent. Covered in black carbon soot, not so much. So keep it clean.

On paper, polished gold plating is superior. In reality, I found that it cannot withstand having a flame lick against it, and quickly burns off. (A completely different application, but the result is relevant).

Take note of the oxidized labels for the metals. Most heat reflectors for a stove will become oxidized, that open flame nearby is pretty effective at it.

Also note the numbers for the black paints, this is why a black pot is particularly good at heating up. A sooty pot is actually quite effective (although the stove running sooty is not). Anodized aluminum is pretty good too, for absorbing heat.

[Valerie E]

Now I've heard it all: a gold-plated UL windscreen! LOL!!!!

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