How do I use a stopper-borer?

Question

I need to bore a small hole in a rubber stopper (bung) like this:

I have a set of tools called stopper-borers like these:

But I can't figure out how to use them. Simply pressing on the borer doesn't get me very far as the rubber is hard enough to resist the sharp end of the tool, but soft enough to absorb the pressure I apply and simply deform momentarily.

The tools didn't come with any instructions and I can't find any on the web. Does anyone have any experience using stopper-borers on rubber stoppers?

Answer 1

The idea is that you have to slice, not push. Also these do not work for silicone rubber stoppers, they do work for natural rubber and cork stoppers.

Well, I should say under human power. If you take the handle off the tube end of the borer and put it into a drill, like a bit, and use it that way, you will be able to drill through the silicone bungs.

Important Use lubrication, other wise you won't even get close to making a hole. It would be like trying to go down a slide made of velco while wearing a sweater.