Help solve sharp edges on DIY thin windscreens

[Eugene Hollingsworth]

<p style=”padding-left: 30px; text-align: left;”>I am making a 1-2 oz fold up windscreen using disposable baking pans. Aside or in addition to folding the edges, any ideas for blunting and reinforcing the edges and rounding the corners? I haven’t figured out a good solution to keeping such thing edges from cutting into whatever bag the windscreen is jammed into. Also I want to stiffen the screens by reinforcing the edges.</p>
( pictures to follow)

 

[Eugene Hollingsworth]

Paper connector to hold into setup shape or use sticks. These go in the little holes in the bottom. One wing to hold the tab so it doesn’t get lost, the other wing holds to overlapping base pieces.

[Jerry Adams]

I dunno, yeah, fold edges

If you remove the disk on top of the canister, there will be a lot of radiative heat getting down to the canister.

That will allow you to operate maybe 10 degree F colder temps

On the other hand, if it’s warm, it could overheat.  Make sure and put your fingers on the side of the canister, lower down, where the fuel is.  If it’s warm, turn off the stove.  In an extreme situation the canister could burst.

I made something like that for car camping, not foldable, fairly thick aluminum.

I made it more so my pot doesn’t tip over and spill onto the ground.  Your pot supports are pretty wide though, so that shouldn’t be an issue.

[Mike B]

The simplest way is to fold the edges, and if needed add stiffening ribs in the direction you are trying to stiffen. Adding a rib makes it almost impossible to put a fold line perpendicular to it though.

[Eugene Hollingsworth]

Jerry, Mike:  what did or would you use for hinging the pieces – I’m considering metal silver duct tape on the back side (where it will stay cooler)  and the tape to thicken and smooth the edges, but am thinking the tape would be short lived.

I might just leave the tall verticals unfolded, but will still need to fold under the stove. The screen is held in shape either by small sticks into the dirt, or use those old fashioned small brass paper button thingies with the long wings.

I could try to fold the most critical edges over small dia piano wire (like the very outside edges) for rigidity, fold other edges w/o wire just for simplicity, and then use soft brass wire loops for hinges.

 

[Jerry Adams]

Mine is non folding because it’s for car camping

You might be able to just fold the aluminum.  It will metal fatigue after a while but it might last long enough to be useful

[Eugene Hollingsworth]

Yeah, just folding the panels might work well enough to see if I like the whole idea or not. I would’t have trouble setting it up because of the paper tabs or sticks in the folded base. (I added a picture of the bass 2-wing paper button.)

 

[James Marco]

A little more technical, but you could roll the edges around a wire, then remove the wire. You could also *try* putting the metal in a brake, then carefully melting the edges back with a propane torch. I have done small stuff that way. Carefully because you don’t want to heat the jaws too much, but gives you a growmited effect.

[Mike B]

I would start with heavy aluminum foil and double or triple fold it over on itself. You may not need more then this to figure out how it all folds up and over it self. Foil is also easy to roll the edges around a thin wire for stiffness or to fold over on it self. If you use aluminum baking trays you can cut it with a pair of scissors and tape it together with metal tape for HVAC duct work to see how it works. Depending on the thickness of your sheet stock you can try to sand the edges some so they are not as sharp.

[Eugene Hollingsworth]

Yeah, the pans are thin enough to cut easily with scissors, which makes soft / smooth non-cutting edges a pain.  I think I’m going with cutting up one of those, maybe folding over wire,  and using HVAC silver tape. (because I have some…) for folding just the bottom pieces. The verticals I’ll just lave as one piece not fold them so tight.

I’ll post pictures when I have it working in the field.  Thanks!!!

[James Marco]

As far as the vertical sections go, you will find that they will continue to fold/bend tighter. Just sayin’…

[Eugene Hollingsworth]

Hmmmm…folding tighter as I use it, curious to see how many folding cycles I get before the metal fractures.

Upside: the only way to find out is cut up, tape, bend a $1 baking sheet and use it until failure.

Win.

[Jerry Adams]

I like $1 baking sheet : )

[BC Bob]

I fold the edges and sand down any pointy corners a bit.  I use the fancy feast cat food can stove so my wind screen is short and fits inside my pot

[Eugene Hollingsworth]

I have one completed and will try to post pictures this weekend. The only concern is the windscreen is only 1 1/2 inches above the burner. I might have made it too short to be effective.

[Jerry Adams]

You could try it when it’s windy

[William N]

For stiff paper, use about 220 grit sand paper– no more paper cuts. (an emery board the orange side is ab out a 280 grit) Folded sheet metal…. that’s always a tough one, because of all the sharp corners. Haven’t figured it out. Even hammering them down probably won’t do it. If the metal is stiff enough, don’t fold the edges you probably don’t need to.

For straight sheetmetal edges, sandpaper, start about 180/220, maybe 120.. and work it up. So the steps might be 120, 150/180, 220, 320, 400, 600. It it’s the thin aluminum shim material from HomeDepot, it’ll never cut you.  If you’re holding the sandpaper, work across the edge, if the sandpaper is on another surface than along the edge is faster.

[Eugene Hollingsworth]

Here’s the completed windscreen. It’s just tall enough with a 110 G canister. True to all the education about safe canister temp I spent quite a bit of time and a full canister making sure I had a safe solution.

Using a heatshield above the tank, the top surface never got more than slightly warm to the touch, while the exposed top part of my finger got slightly burned by reflected heat. (this was indoors and 10 minute run time, with a pot on the stove)

Outdoors at 24 deg, no heatshield, the canister did not feel cold, no frost, and not more than lukewarm on the top.

Many thanks – there is enough learned in this thread to improve the windscreen after it wears out at the seams… :-)

Link to my successful finger test:

Video of finger test indoors, running 10 minutes.

 

 

 

[James Marco]

Looks good Eugene!

[Eugene Hollingsworth]

Thanks James!   My son commented that even folded it looks large, so I put his phone on top of it… heh. That ended that discussion.

:-)

[James Marco]

Ha, hey…yeah some of the new phones are really big. Food stuff and me go back a couple years. I really like to eat even if I only eat once per day, but, I am willing to spend time (and weight) on my cook gear. A SVEA and taller windscreen (though nowhere near as elaborate as yours) helps immensely. Good job! You’ll get good service out of it.

[Mike B]

Very Nice I am glad that you got something that is safe and that you like.

[Jerry Adams]

That looks great.  I like flattening the aluminum tray.  I bet that will work good.

[James Marco]

BTW, after some use, you will notice the folds on interior corners starting to “work harden” from being bent/unbent. You can simply heat the metal to anneal it, removing the work hardening. What happens is that the inside surface compresses the molecules of the aluminum (most metals do this) and pick up a temper. Repeated folding in the same spot will make the metal quite hard and brittle…it’ll eventually break. Usually, cake tins are already work tempered from the rolling mill. So, you might want to do this before you head out. The joints you want flexible, removing the work hardening by reheating those areas will soften the metal again. I put a little candle soot on it and when it burns off with a torch, I’m done. Just let it cool. You can also do it in your oven, I think. By the book, about 550F (high/broil) for about an hour will do it, but this softens the whole wind screen. Using a propane torch is more localized and faster.

I’ve done this for many years with my aluminum wind screens and they last a hell of a lot longer. I have a couple thin ones from cake pans/cookie sheets I have used for about 15-20 years. Before that, I would break them every year and it got a bit annoying. I also applied the same concept to my cooking pot to add a series of concentric rings in the bottom as a heat exchanger. (It works about 12-15% better than plain.)

https://www.tinmantech.com/education/articles/aluminum-alloys-annealing.php
http://www.millerwelds.com/resources/communities/mboard/forum/welding-discussions/24717-annealing-aluminum

[Eugene Hollingsworth]

Marco – I’m going to have to try annealing some aluminum pans. Thanks for that – I would never have considered aluminum could be annealed.

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