Forum Index » Make Your Own Gear » I want to make a heatshield


Display Avatars Sort By:
Zack Freije
(oldskool) - F

Locale: Ohio
I want to make a heatshield on 06/11/2010 02:24:25 MDT Print View

I bought a new lightweight backpacking stove and cook kit. I want to build a heat shield for it. I have a reference design, but I am having a difficult time sourcing the components used in that build and I think it can be done lighter.

I need your input/advice.

Cook kit is GSI Pinnacle Soloist:


Here is my reference for the heat shield:


It is make of a cookie tin lid, some aluminum flashing, and a few pieces of bent coat hanger to lock it all together.

I have been unable to find a 4.5-5" diameter tin lid in order to start the build. I also got to thinking that perhaps that was the most sturdy option but not the lightest. I am thinking that I can make something else, with your help, that will be just as good and possibly lighter. The rolled lip on the cookie tin lid helps hold the flashing in place at the bottom.

The goal is to get it to fit easily inside the stow bag that holds the kit together.

Do you have any suggestions?

Kronos Master of Fate
(kthompson) - MLife

Locale: Behind the Redwood Curtain
Re: I want to make a heatshield on 06/11/2010 06:45:45 MDT Print View

Heatshield as in pot cozy, or heatshield as in windscreen? If you are making a cozy why not use Reflectix, aluminum covered bubble wrap?

Kevin Beeden
(captain_paranoia) - F

Locale: UK
Re: I want to make a heatshield on 06/11/2010 09:12:29 MDT Print View

This looks to be a windshield for a canister-top gas stove, where the cookie tin lid sits somewhere between the burner and the canister. Is that right?

In which case, why not simply make a cylinder of flashing, and support it on a three-legged wire (or folded flashing) support held in place somewhere between burner and canister? I don't see that the solid lid provides any useful function other than supporting the wall of the windshield.

The advantage of an open base to the windshield is that you don't restrict the air supply to the burner, allowing you to make a fully cylindrical windshield, which you can lock together with simple slot-and tab fastenings (upper one with tab on outside, lower one with tab on indside). This joint allows you to roll the windshield up for storage inside the pot. If you make the slot/tab joints in the right place, and the right size, they can allow clearance for access to the valve.

Tim Marshall
(MarshLaw303) - MLife

Locale: Minnesota
Re: Re: I want to make a heatshield on 06/11/2010 10:31:35 MDT Print View

i believe the reason for the closed bottom is to keep from overheating the canister, i think thats pretty important!

-Tim

Zack Freije
(oldskool) - F

Locale: Ohio
windscreen on 06/11/2010 10:53:04 MDT Print View

The lower pan is necessary for reflective heat and to keep from overheating the canister. The cylinder portion cannot be fully wrapped around because of the pot handle and the flow control valve of the stove.

Here is the Soto Micro regulator stove I have:


The opening on the side for the handle and regulator should supply sufficient air flow for the stove. If not, I could always perforate the bottom of the windscreen.

The guaze looking ring is to be placed between the canister and the bottom of the heatshield/windscreen to keep from overheating the canister. This is an issue that some people have concern about in the winter especially.

Kronos Master of Fate
(kthompson) - MLife

Locale: Behind the Redwood Curtain
Re: windscreen on 06/11/2010 13:27:56 MDT Print View

OK How about this version.

http://www.freewebs.com/jasonklass/beltbuckle.htm

I didn't notice the hole in the tin disc. I hadn't had my coffee yet!

John Nausieda
(Meander) - MLife

Locale: PNW
Different setup on 06/11/2010 14:11:11 MDT Print View

I have a similar stove Snowpeak giga and I am running a 2 liter pot with a clamp on handle that REI made. I am using a stock Trail Designs 4 inch windscreen. I hang the windscreen off the pot and hold it together with a Bobbie pin. My handle actually clamps it in place. In position, the windscreen ends right above the control valve . There is plenty of air circulation to keep the gas canister from overheating, but I'm trapping all the upward heat to the pan. In my case if i gently release the pot holder I can drop the heat shield and place the pan down on any surface, It is also safe as you can feel the gas canister so you can judge its temperature. Very Cheap too.windscreen

Edited by Meander on 06/11/2010 15:22:29 MDT.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: windscreen on 06/11/2010 18:12:16 MDT Print View

> The lower pan is necessary for reflective heat and to keep from overheating the canister.

Except that very few people ever use a 'lower pan', mainly because blocking all the heat of the flame from reaching the canister is usually a bad idea anyhow. You need some thermal feedback to keep the canister warm, especially in cold weather.

All you have to do for safety is to make sure the canister never gets too hot to touch. That, and read our many articles on the use of canister stoves in winter and what makes a canister explode.

Cheers

Zack Freije
(oldskool) - F

Locale: Ohio
Re: Re: windscreen on 06/11/2010 19:44:36 MDT Print View

If the bottom pan is not required, I have an idea for a design that rests on the handle of the pot and is lifted up with the pot, to pour the water.

It would extend 1" below the bottom of the pot itself. This 1" measurement will place the bottom of the windscreen even with the point at which the vertical tube meets the bottom of the heating element.

Will this provide sufficient windscreen and sufficient airflow? The pot supporting legs of the stove are flush with the outside edge of the pot, for a total OD of 4.5". I figure the windscreen will be very nearly snug to the OD of the pot itself.

This design will give me free access to the fuel control valve and the built in ignite button. It will end 2.25" above the point at which the stove connects to the canister.

Do I need to consider a disc of aluminum to sit between the canister bottom and the ground?

Anything else I need to consider?

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: windscreen on 06/11/2010 21:06:38 MDT Print View

> I figure the windscreen will be very nearly snug to the OD of the pot itself.

Where will the flames and hot air go?
I suspect that this might lead to rather high CO levels. We leave a 1/2" gap between the pot and the conventional windshield for a good reason.

Cheers

Zack Freije
(oldskool) - F

Locale: Ohio
Re: Re: Re: Re: windscreen on 06/12/2010 02:03:27 MDT Print View

I don't have flames lapping up the side of my pot without the shield. There would be an air gap between the shield and the pot, however, it can't float in space. It needs to be supported by something, so as it rests on the handle, it will invariable tip at a slight angle and touch the pot at the lower position opposite the handle. I don't want the gap to be so large that this becomes particularly pronounced. It will of course be adjustable so, I can experiment to find that perfect setting in the field.

In the past, I've used stoves with the external fuel bottle. Those stoves sit on the ground and the heat shield is large. I believe this application will be different. I guess time will tell.

Mark Fowler
(KramRelwof) - MLife

Locale: Namadgi
Conical Windshield on 06/12/2010 23:07:38 MDT Print View

My solution to building a windshield for a MSR Superfly was to make a truncated conical windshield which rests on the valve stem and rises to about 1 cm above the base of my pot. This should work for most gas stoves. You need to cut the conical section to suit the diameter of your pot.

I punched a series of 12mm holes around the base of the cone for air supply to the burner and there is a gap of around 1cm between the pot base and the windshield. The windshield is made from aluminium flashing and weighs 20g. This weight could be pruned slightly.

I store the windscreen as a flat sheet and curve it into shape secured at the top with a small paper clip.

Where the cone is truncated the diameter of the opening is 30mm. You need to design the cone to suit individual pots and stoves. A hunt around the internet will provide the relevant spreadsheet to do this.

Edited by KramRelwof on 06/12/2010 23:08:53 MDT.

Kevin Beeden
(captain_paranoia) - F

Locale: UK
re: overheating on 06/21/2010 11:26:23 MDT Print View

> i believe the reason for the closed bottom is to keep from overheating the canister

My thinking is that, with no windshield at all, there's nothing to protect the canister from the heat of the flame. And, since all canister stoves are supplied like this, and do not explode, I figure it's safe to operate like this. Practical experience also tells me that the canister doesn't overheat.

If we add a windshield around the burner head and pan, that doesn't entirely enclose the lower part of the burner or the canister, I see little reason why the canister should get any hotter than with no windshield; there's nothing extra to reflect heat downwards. All the windshield does is prevent the flame being blown about, and hold the hot gases close to the pan to increase efficiency.