Just sticking this here in the thread - I know I keep seeing the suggestion to make a sparking rod to slip into the corkscrew, but I can't find the most recent suggestion to do that... anyway:

The spark-rod-in-the-corkscrew has been suggested many times here and on other forums and keeps getting re-invented. I have yet to actually hear of it being done. I just checked two SAKs with drill rod and it appears that the largest diameter that will slide into the corkscrew is a 3/32 inch rod (~ 2.38 mm).

So I put calipers on a Zippo brand cigarette lighter flint and guess what size it is? 2.37mm - almost exactly 3/32 inch. That's a pretty slender diameter if one is thinking of scraping along the side of the rod. It might work if someone can obtain a long enough piece of rod this diameter, although I have mental pictures of the rod snapping after just a few uses.

Has anyone actually done this? Theory is fine, but I'd like to see pics/read how it works - maybe it is a good idea; maybe not.

For the terminally curious:

I am so certain the following will work that I'm not even going to try it out, but suggest it here for other tweakers:

Purchase an eyeglasses screwdriver "replacement part" for the corkscrew. Make a 2 part plaster of paris mold of it (if you've never done this, there are plenty of how-tos on the web). Decide what "tool" you want screwed into the corkscrew - maybe a small drill bit, maybe a small phillips, maybe a skinny sparking rod, maybe a little allen wrench - you get the idea. Just keep the inscribed outside diameter no more than 3/32 inch. If it is larger than the screwdriver blade, scape the impression of the blade in the mold to fit - check by closing the mold on the part. Now mix up a little ball of epoxy putty. Stick on the end of the selected tool, set in the mold (grease the mold first with a release agent like Vasoline or oil) Press the mold halves together to form the epoxy ball into the shape of the screwdriver insert. You may have to fiddle a bit with the volume of putty required - probably about "1/2 pea" size, I'm estimating. A little too much should not be a big problem - trim the flash after it sets. In about 10 minutes you should have a nifty new gadget that slips securely into the corkscrew. Minor polishing can be accomplished two ways: 1) after the putty sets up but before it reaches full set (perhaps 30 minutes), run the tool in and out of the corkscrew many times - that will burnish the mating surfaces. 2) Let it cure overnight and then polish/ tweak the mating surfaces with needle files or rolled up fine abrasive paper or cloth.

Worst case, you now own a tiny screwdriver that stows in your corkscrew. And some epoxy putty. Both good.

QUESTION FOR LOUIS: Could you do this with geltrate (SP?) and then cast the insert with liquid epoxy or casting resin?

Man, I hope somebody tries this and comes up with some neat ideas! (OK - I'm thinking of a couple already...)

Tom