Tim Wescott wrote:
I've got a little 3oz fuel tank (model airplane) made out of thin
tinplate (a Dole Pineapple Chunk can, actually). So, maybe about 10 or
15mil, with corrugations.

I need to drill a 1/2" diameter hole in it, to solder in a fitting. I
know that if I use a regular 1/2" twist drill I'll just rip out big hunks
of tin -- so that's a no-go.

This is a last-minute rework to get me to a contest this weekend, and
I've spent out the modeling budget this month. So I'd like to be able to
do it with tools I have in the shop rather than spending time or money I
don't have to order something, or even nip around to Horror Freight.

I have a nice stepped drill that goes up to 1/2 inch, but it's longer
than the tank. I may just go ahead and drill through and patch up the
far end -- but if there's a better solution, I'm open to suggestions.



grind a twist drill like the picture in the below url. Test it on
another piece of metal.....they work great on sheet metal.

John


http://www.wlfuller.com/html/brad_point_drills.html