how to make a 50mW laser burn ??

[wesdaman14]

my true 50mW from dx used to burn
but now it don't burn with fresh batteries :'(
so i heard of using a magnify glass to make it burn
what kinda magnify glass do i need, and how far does it need to be away from the laser head >?
Thanks a bunch

 

[Razako]

Just about any magnifying glass should work. They work best if they are the type that has an extra thick "bulge" in them for extra magnification. Just shine your laser through the glass and put the object that you want to burn where the dot is smallest.

btw goggles are highly recommended when doing this.