Coke Can fire
- Thread starter TeeDee
- Start date
-
The awesome MakerMoot is coming up (13-15th Nov 2026), Visit the TORM & ARM markets,and have space back at camp to work on projects and enjoy great company. PLEASE CLICK HERE for more information.
Not successfully!
Back in the early days of the internet I remember an article about starting a fire with a can of coke and a chocolate bar.
I tried it.
The chocolate was to be used as a polishing agent to make that mirror surface.
I failed.
I tried buffing with better products - toothpaste, autosol, can’t remember what else.
I failed.
Probably should have retried this summer!
Back in the early days of the internet I remember an article about starting a fire with a can of coke and a chocolate bar.
I tried it.
The chocolate was to be used as a polishing agent to make that mirror surface.
I failed.
I tried buffing with better products - toothpaste, autosol, can’t remember what else.
I failed.
Probably should have retried this summer!
I seem to remember giving it as an activity to my eldest quite a few years back too. Child labour rather than me having to do it.
Such a small amount of reflection and really small focal range.
Such a small amount of reflection and really small focal range.
Post in thread 'What fuel do you use?'
https://bushcraftuk.com/community/threads/what-fuel-do-you-use.170151/post-2124845
https://bushcraftuk.com/community/threads/what-fuel-do-you-use.170151/post-2124845
I completed the coffee cup challenge with erm some improvisation.
The goal was solar ignition. Using a suitable container such as a coffee cup, and reflector like a crisp packet or mylar sheet ignite a piece of tinder. After a couple days I was using tub of animal feed with a mylar sheet on charcloth... The moral I can tell you is a credit card size fresnel lens works A LOT of better.
I've lit charcloth on the winter's solstice (w/ credit card size fresnel lens)... you still need STRONG sun casting hard shadows. But it works, and it was easier.
In terms of the coke can, nothing is stopping you from using a dremel tool and some car polish for proof of concept. While I wish everyone success... I'm not sure it's really big enough. The quality of finish matters way too much. I'd get sun burn before getting the charcloth to light
The goal was solar ignition. Using a suitable container such as a coffee cup, and reflector like a crisp packet or mylar sheet ignite a piece of tinder. After a couple days I was using tub of animal feed with a mylar sheet on charcloth... The moral I can tell you is a credit card size fresnel lens works A LOT of better.
I've lit charcloth on the winter's solstice (w/ credit card size fresnel lens)... you still need STRONG sun casting hard shadows. But it works, and it was easier.
In terms of the coke can, nothing is stopping you from using a dremel tool and some car polish for proof of concept. While I wish everyone success... I'm not sure it's really big enough. The quality of finish matters way too much. I'd get sun burn before getting the charcloth to light
The difficulty is that the bottom of a coke can is not parabolic, merely spherical and as such does not have a sufficiently concentrated foci to generate the heat required, especially in our climate.
Have tried to know the art is in finding the focus point.
Did think to have another go this summer given how fierce that sun was given I for reasons unknown had earlier polished the concave end of an aerosol can to a mirror finish, but in the end I didn't
Materials to polish to a mirror finish - 800 grit abrasive paper with water followed by well worn 800 grit with water and finally autosol
I'd just like to say I have just been out there with my aerosol can with the mirror polished bottom to try the idea out, to report, it's tricksy to get the angle to the sun right but the focus point, that is the point where the dry leaf I was going at started to smoulder and burn holes through was about 40mm from the bottom of the dish ( dish diameter = 65mm and depth = 15mm. And so I tried it with a bit of char cloth and yep, viable fire starting embers were created.
That's a lot of things to find/have to hand when busting a lens out of my torch, for example, might be quicker.
Is the coke parabolic lens more something you make in advance rather than in a pinch? Nice subject, though.
Are aerosol cans botties deeper and more concave than coke cans. I think they are. The more pressure to contain. And steel as well. So maybe gets a better reflective surface?
Am going to try a beer can bottom next to describe an excuse to go and buy beer.
But the deeper the dish should shorten the focal point to also provide some wind breaking of which might in fact aid matters.
How it was I came to polish the end of an aerosol can was because I'd used a section out of an aerosol can to make a melting pot for liquifying sulphur in a bid to make brimstone matches (Lucifers),to have just had the thing on my desk to end up polishing it as I watched movie on the desktop (can't just sit down and watch anything, have to be doing something with my hands else I get bored of watching).
These aren’t so much bigger than a can bottom but they are parabolic. They focus much tighter than a spherical can bottom might.
If I were interested in solar fire lighting I’d but one and carry it.
I don’t think I’d thrash around trying to polish a chance found can with whatever abrasive I could find - like grass I suppose. Long job.
If I were interested in solar fire lighting I’d but one and carry it.
I don’t think I’d thrash around trying to polish a chance found can with whatever abrasive I could find - like grass I suppose. Long job.
i found a rusty axe head an hour ago so i'll give it a try when i'm back at my shack
i found an old axe head an hour ago, so i'll give that a try when i'm back at my shack
to get back on topic: no success with soda cans myself, only parabolic mirrors from old flashlights... might be an idea to check out David West on YouTube, i'm sure he has something on this subject
