How do you start a fire with a magnifying glass?

E

Evolute

Joined
Mar 19, 2001
Messages
4,769
Alright, let's say that I've gathered some dry tinder. Then I take my magnifying glass and make the angle and the distance just right for the sunlight to come to a very small, bright spot. Then my tinder starts to smoke....

Up to that point is easy. But how do I get the smoking point to erupt into flame? I only seem to be able to burn tiny holes through my tinder.

Thanks in advance for any help you can provide.
 
Tinder is a funny thing in that different tinders react differently than others to the various ignition sources. Many tinders need to be blown on to produce a flame. If it were me, I'd focus the lens on a piece of punkwood, which would generate a coal that would smolder without help, then touch the coal to my tinder bundle, and blow on it until it flames.

Mike
 
What you need to do is focus it to where the dot of light becomes smaller almost like a laser dot. At which point if you use tender it will start to smoke in a short period of time.
 
When I was a kid, we used to have a lot of fun scorching ants, roly-polies, and various other bugs with a magnifying glass. We'd also take them to school and try to get a seat by a window in the sun and burn little red spots on the kid in front of us.

OK, I know it was off-topic and all, I just hadn't thought of any of that stuff in years.

Reminiscing about the good old days...
 
Thanks, Michael.

As an addendum:

I was wondering whether a fresnel lens could work like a regular magnifying glass for fire starting. The answer appears to be "yes". I still haven't even started a fire with a magnifying glass, but I can burn holes through tinder with a fresnel lens just like with a regular magnifying glass.

If I can learn reliable firestarting with the magnifying glass method, then a credit card sized fresnel lens in the wallet seems like a great little bit of survival gear that could be carried very conveniently.
 
Hi Evolute,

YEP, the fresnel credit card pocket fresnel lens in its protective sheath is a GREAT survivaltool :)

Just remember that using it to start a fire works only from ONE side and if my memory is correct you'll have to hold the "ribbed" side towards the sun.

Still, getting a fire burning with the help of a fresnel lens or classic magnifying lens requires a lot of practice and patience.

I never go without my credit card Fresnel lens anymore, it's also great for reading maps as I'm well in my fourties ;) and also when removing nasty little splinters it's unmissable.

Best Scouting wishes from Holland,

Bagheera
 
For all you survival-minded people - take a look at American Science & Surplus - they have a lot of stuff that could be useful, in the right hands ;)
They have regular lenses (various types) as well as pocket fresnel lenses, 4 for $2, and large Fresnel magnifiers for $12.50 (these are 10"x13")


www.sciplus.com

Sam
 
my 2 cts...
The only thing I ever managed to "light" with a CC-sized fresnel lens was the naugahide seat in my truck when I first got the the "survival card". :eek: Something I discovered after a few years of wallet-carrying is that the lens collects dirt and lint and stuff in the ridges. *yuck* Cleaning it in warm water and mild dish soap works, but now it sits in my BOB kit. I feel like I know enough other (more reliable) ways of fire-starting that I don't need to carry the "survival card" on my person everyday. I've found I'm usually trying to start a fire (in the woods) in the rain, under cloudy skies, at night: precisely when there's no sun!

Matt in Texas
 
You must log in or register to reply here.
Back
Top