Anyone got a "cork borer"?

[Garak]

I finally have a line on some #12 stoppers for my pyrex carboys but they don't have any holes in them for airlocks, temperature probes, CO2 lines, vacuum lines, etc... So I need to drill some holes in them.

I've already done a few test on the old #13 stoppers that came with the pyrex carboys but the drills I tried just made a mess. It seals ok but I've noticed bits of rubber breaking off into my HLT from moving the racking cane. The old stoppers are kinda rotten and starting to break down anyway which doesn't help.

I've been googling around and on one of the machinist forums they suggest using a "cork borer". Anyone got one or a set?

The other thing they suggested was making one from a piece of pipe. You simply sharpen the end of a pipe and chuck it up in a drill press and press it through at low rpm. I don't think I have access to a drill that could chuck up a piece of 1/2".

There is also freezing the stoppers but I've found they warm up too fast from freezer temperatures. There is a big tank of liquid N2 at work... I should ask around and find out who can show me how to safely handle that stuff.

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Garak

[mr x]

What about just using a piece of 1/2 tubing by hand? Sharpen it up well, use lots of lubricant, and push and turn...

[Jmac00]

Keep an eye at PA for a cheap hollow punch set (6-8 bucks on sale). Some smaller ones might already fit in the end of a drill, not sure, but if not, try and get the ends cut down to fit. They should work.

Bit off topic, but i know guys that get these turned down to fit a drill, sharpen a bit, then use them to sipe or re-groove tires...work great and its heavy rubber....so should work for your stopper.

[Garak]

The 1/2 O.D. pipe just fits in the chuck of my little drill press so I cut off a 2" piece of the stainless that x gave me and sharpened it up. Worked great now I just need to figure out how to get the core out of the piece of pipe. The hole is alittle on the big side, so I'm going to take down the outer wall of the pipe and try again. That is if I can get the core out...

[mr x]

Screw?

[Garak]

The first core was jammed in there pretty good, pulling on one end with vice grips and pushing the other end with a screwdriver eventually got it out.

The second time around I used more dish soap as a lubricant got an very clean hole. Looks like it could of come from the factory. The cores pop out very easily and fit back in the stopper so well it would be hard to find the hole.

I also made a second core cutter from some ~1/4" tube, that one works even better and creates a tapered hole that seals very well. I think its alittle bigger than 1/4" at the start, as 5/16" airlocks will squeeze in. The bottom of the hole gets down to maybe 3/16".

I love when things work out way better than I expected. I wish I could post a few pics but I can't find the usb cable for my phone at the moment.

EDIT: Found the cable

2011-05-07 18.19.34.jpg

[KMcK]

I finally have a line on some #12 stoppers

Did you order them yet? I'm still looking for one.

[Garak]

Winekitz brought them in for me but I have one more than I need. You can have the extra one. You were also looking for some malt, what was it again?

We can meet up after work some time this week. I'm usually off around 5 but that my vary this week as we are installing a new exhibit.

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Garak