Well, at least I hope not!   I am looking for a way to bore or core clean holes in balsa.  I use the tried and true sharpened K&S brass tube, but I am looking for something I can use in a drill press.  I have seen in the past something called Gaskins Softbore tools, out of England but a google search turned up nothing on this side of the pond.  What do people use when they want to make a lot of clean holes with no breakout on the back side of balsa?  Short of soldering tube to a home made mandrel what options are out there?  Has laser cutting and ARFs killed the market?

 Might look for Forestner Bits (spelling)??  They have several different sizes..

How clean & how big?

Forstner bits work well, but to get them smaller than 5/8" or so you need to go to Fleabay.

Brad-point bits work OK, but they tend to like harder wood -- contest balsa may not be the best for 'em.

I've had good but mixed success with making "sorta Forstners" out of regular twist drill bits -- basically I grind them hollow, so that the edge of the bit is slicing through the balsa.  You need good bearings on your drill press, though -- without the Forstner's centering brad they really want to wander.  And they don't self-clean the hole at all -- you need to peck, then blow them off, then peck, then blow, maybe going 1/32 of an inch each time.

None of these make a hole that's knife-edge straight on the backside, but all of them do way better than twist drills.  The Forstner bits do best, and the sorta-Forstners come in second when they're sharp and I'm not impatient.

Here's a picture showing what I mean, with a 3/16" sorta-Forstner and the back sides of two holes that I drilled with it.  The one that's a bit torn up is the one that I did first, and re-learned the meaning of "slow enough" -- I got impatient on the last peck and went too far.  The bit could use sharpening, too -- from all accounts balsa is incredibly abrasive for being as soft as it is, and I certainly know that I need to sharpen my tools a lot when I'm not just using disposable blades.

Thanks for the replies.  I have some Forstener bits and some brad point bits(admittedly old and dull) and they work OK when I flip the work over like Bootlegger suggests.  But they both are designed for harder woods. Ideally I would like to find some steel tubing with similar wall thickness to the K&S brass tubing.  Something that will hold an edge.  I'm looking to make holes from around 5/8"-1" range.

if thats what you want to do - get the dremel diamond ege cutters - they do just what you are looking for and go right down in size

Try applying masking tape to the backside of the mterial in which you are drilling this has worked for me in the past.

Thanks for the replies.  I have some Forstener bits and some brad point bits(admittedly old and dull) and they work OK when I flip the work over like Bootlegger suggests.  But they both are designed for harder woods. Ideally I would like to find some steel tubing with similar wall thickness to the K&S brass tubing.  Something that will hold an edge.  I'm looking to make holes from around 5/8"-1" range.

If you are going that big with the holes, go get new Forstner bits.  Yes they are expensive.   I myself being a cheap skate, still use brass tubing and keep sharpening the edges.   

Try some old steel golf club shafts.  They will give you holes in the 5/8" and a touch bigger.  Easy to sharpen and will hold an edge for quite a while.

I love that idea!  It will give me a great deal of satisfaction cutting up my old clubs!  Now, if I can just straighten them out...