Solar ignition

If you find yourself in a situation when you want to light a fire but don’t have a lighter or matches, or even if you want to try different fire lighting techniques or show off at a family BBQ; then you should give solar ignition a go. Solar ignition is a great tool to have, and be able to use especially as you can light natural materials with it. It’s a free and renewable source that unlike matches and lighter fluid won’t run out… you just have to avoid the rain and cloudy days, which here in the UK is easier said than done. So when its nice and sunny it’s the perfect time to get out and try it.

I’m sure most know that you can use a magnifying glass to light a fire. But you can also use the concave bottom of a normal drinks can too. If you can get the bottom shiny enough. This works the same way as a magnifying glass by focusing the sun’s rays to a single point but where a magnifying glass refracts the light the parabolic shape reflects the sun’s rays to a focused pint in the middle of the dome shape.

All you will need is;

• A drinks can,
• A polishing compound.
• Some easy to light materials i.e. charcloth, dry grass, punk wood etc
• A sunny afternoon
• A little patience
• And sunglasses

I used metal polishing paste, that I use on my stropping leather when I hone my knives. But any finely abrasive compound should work. Using the same method you would to polish any other metal, like car parts, brassware or your best silver cutlery. Work the polishing paste in, round and round in circles with a piece of cloth. Until it is as shiny as possible.

One of the easiest things to light with this solar ignition technique is pre charred materials such as charcloth. Which can easily be made by placing 100% natural materials, such as cotton or fibrous seed heads like thistle down or cat tail heads, into a tin with a small whole in and place so that they burn without the presence of oxygen. Charred materials are always easier to light with any fire lighting method, but the blackening helps to absorb the sun’s heat radiation were as a white or shiny material will reflect them. But this technique still works with natural unprepared materials like fine dry grass balls and dry punk wood it just takes a little longer.

Once you have your can polished and your tinder ready to go you need to find the focal point of the can this is where the can creates on point of pure white on your, this can be achieved by varying the angle and distance between char cloth and can until you find the brightest spot.

If you are using char cloth on a sunny day this will not take very long to ignite, and you can transfer the char cloth into your tinder bundle and blow it into flames just like you were lighting a fire with a flint and steel or a bow drill. If you are using non prepared materials like dry grass you will need to wait a little longer and mover the ball of grass around a little so that a larger area starts to smoulder and burn, before it will be sustainable to blow into flames in a tinder bundle.

Sadly due to littering You find drinks cans nearly everywhere now so this could definitely help in a survival situation, providing you have enough sunlight and a fine abrasives material to polish with – even toothpaste works.

I can see this being a fun technique to try with younger people such as scouts or forest school, and is a bit of fun but educational as well involving bits of science as well as awareness of the litter we throw away.

Maybe have a race see who can get the char cloth to light first is it better to spend longer polishing the can or trying to light the fire?

(Warning looking at the Suns rays can be dangerous and can damage your eyesight. When practicing solar ignition always wear sunglasses.)

Hopefully we have enough sunny days over the coming summer months to get out and experiment with solar ignition