

Starting Fire With an Ice Lens

by Bob Gillis

Use clear lake or pond ice. To practice, boil water for 10 minutes to remove gas. Let it cool, then boil 10 minutes again. Let it cool again, then freeze slowly.

Create a foil container 2" deep and freeze slowly. Or buy a clear block of ice. To make fire, the ice must be clear.

Shape the ice lens for fire making. First shave with a knife to get the rough shape of a lens.





You can also grind your ice fire lens on cement or a stone.

Finish shaping your ice fire lens by using the heat of your hand to melt the ice lens smooth.

The edge of your lens should look something like this.

Locate tinder that is completely dry and finely divided. With the sun at its highest in the sky hold your lens perpendicular to the sun and move it up and down to focus the brightest spot of light onto your tinder. Be careful to avoid dripping water onto your tinder. The tinder will first smoke and then ignite. Carefully add more tinder and very small sticks until a good fire is established.

E-mail from Elijah Cobb:

Hi Bob;

I would be happy for you to use the images that Linda Raynolds took of my fire with ice making. Enclose are some others. These are taken by other folks. A local paper ran a story that was not very informative. The other local paper may do a story also - perhaps it will be worth sending to you.





I used professionally made ice that was very clear. I have not been able to freeze a good size piece of clear ice outdoors. I don't live near a lake so I really have no idea how often you would be able to find a nice clear piece of ice. Because I had a large piece I went for size - maximum light gathering / concentrating. My focal the focal length of the lens was about 10 inches and the diameter of the focal area was about 50cent size. The focal area was not very coherent but seemed to have quite a bit of depth. It would produce smoke on dark paper in less than thirty seconds, and you could not hold your hand in the focal area for more that twenty plus seconds.

I carved the lens with a 2" chisel and smoothed by hand with a flexible sheet abrasive for tile work. I was amazed that it worked on my first real try. I thought it would need to be much more accurately focused.



I assume a much smaller lens could be made to work. I tried to make a smaller lens with a flat side and deeply curved surfaces - almost a sphere. I have not gotten it to work yet but I think this is the way to go - no double convex surfaces to line up with each other. I accidently destroyed it by exposing it to too much sun light which fogs, crazes and makes bubbles in the lens so that all the light scatters instead of focusing.







After using my two big lens for about four hours each they were both useless. The shape was fine but the ice was to bubbly and crazed.

Just before trying to make a fire I usually ran a bit of cool water over the surface of the lens to clarify it. (water too cold if freezes in rivulets - too warm it will make thermal stress crack through the whole lens/ block of ice)

Many folks assumed that I had made a mold and frozen water in it. My experience with making ice for fun sculptures is that I could not get ice that was any where near clear enough. Perhaps it would work in a freezer with distilled and boiled (deoxygenated) water with an insulator on the side away from the cooling coils.







Elijah Cobb: ecobb@tritel.net

Cody, Wyoming

Watch a short video of Elijah Cobb making fire from his ice lens.

Other fire from ice articles: http://wildwoodsurvival.com/survival/fire/ice/index.html