Okay, here's my first post after leeching off the site for information. Special thanks to kyratshooter for the posts on oil cloth and tin cloth.
I bought a Zippo lighter because it's made in the U.S.A., keeps lit in the wind, and because it's old school.
I also discovered that the fluid in a freshly-filled lighter evaporates after after about a week when kept in the pocket 9not the first one to discover that).
I did some Internet research, and found suggestions like: "Put one of those wide vegetable rubber bands around it to keep it from evaporating." Well, they stopped using those wide rubber bands (at least everywhere that I've looked). It was also suggested to use a piece of an old bicycle tire tube in place of the rubber band. The tire tube I had was too big, so that didn't work. I haven't gone to a bike repair shop yet to get a smaller tube, but that will work, I am sure.
I also looked into what king of small container would work to keep a backup supply of lighter fluid in. The least helpful comment I found about that was: "Why is this an issue? Just keep it in the original container. That obviously works." Not really an exact quote, but pretty close.
Anyways, the preceding was to head off repetitious advice (well, to attempt it at least). Here's my input:
TO PREVENT EVAPORATION
Wrap some sort of tape around the lighter to seal the division at the flip-top/body interface (if you haven't gone by the bike shop yet).
I only tried two types. Electrical tape, and masking tape.
Electrical tape works, but the fumes interact with the adhesive, and it starts slipping around after a couple of days. Of course, I have Harbor Freight electrical tape, which sucks generally.
The masking tape worked well, and kept the lighter sealed. It leaves residue when you take it off, but that's not a survival/emergency issue. It kept the fluid from evaporating, and stayed sealed without slipping off (for a week in my pocket, at least).
TO CARRY A SMALL SUPPLY OF FUEL
To start with, the above referenced advice about keeping it in the original container is not good advice. I started looking into this whole thing because the original container that I kept in my car bulged out and became brittle. The original container is plastic, and has a rectangular cross section. When it gets warm, the fluid inside evaporates inside the container (technically, the vapor pressure increases) and pressurizes the container. The pressure causes the rectangular container to swell at the narrow dimension. This stresses and stretches the plastic material and causes it to become brittle, so it cracks easily (not just theory, but experience, too). This makes the original container unsuitable for varying environmental conditions. The older-style metal containers would probably work, but the fluid isn't supplied in those anymore.
So, I tried various other types of containers. I put some fluid in them, then left them in my car's center console to see if the fluid would evaporate out of them.
I tried a small, plastic flip-top container (the lid has a little fold-up spout). It didnít leak liquid, but it wasnít vapor-tight (if you squeezed it, you could hear the air coming out). The fluid evaporated very quickly, and it wasn't even summer.
I also tried small, thick, glass bottles (like childrenís aspirin come in - or came in - not sure). Glass sounds risky, but these bottles are pretty hard to break unless you really try (famous last words). The fluid didnít evaporate. I thought I had found an acceptable container. However, I accidentally tipped them over and left them lying on their side on the console. After the weekend passed, I found that half of the fluid was gone. The low surface tension fluid leaked out slowly, even though they didnít leak when you tried shaking the container to test it. In a BOB, this would soak into whatever else you had in the bag. Not good.
Others have suggested using empty eye drop bottles, or glass bottles with eye droppers in the lid. I haven't tried these yet. Maybe the gasket in the lids is better than the one in the bottles I used.
Does anyone have actual experience with small containers that donít leak lighter fluid (vapor or liquid) or time, in any position?