Oh yes, there was supposed to be some connection to Primitive Skills!

So, how do we get a tube in "nature" to do sphere polishing?

How about some moose bones?

The inside of this bone is almost circular.

It is the inside edge of the cylinder that does the polishing.

Here is the end of the bone with the hole rounded out.

This tool did work - but bone is not as sharp as steel and it took a long time to polish a sphere.

Now, if we could only find something like this in an archaeological dig....

Here are the tubes used for the experiments that I did.

The largest tube is 1½" ID (inner diameter), the middle tube is 1 1/8" ID and the bone tool  is 7/8" ID.

Here is a view of the inside edge of one of the tubes.

A "square" edge on the tube works - but is very slow in shaving down the ice.

I put a "hook" on the inside edge of the metal tubes.

This is a close-up of the "hook."

At first, I just burnished the bottom edge of the tube.  This worked better than a square edge.

The hook shown here worked even better - i.e. it was the most aggressive in removing material.  At least in the early "rough" stages of polishing, an aggressive edge is a good thing.

I ended up making one end of the tube "very sharp" for the initial work. The other end I left burnished for final polishing.

The biggest problem with ice lenses so far has been the ability to make a lens that has a tight enough focal point to light tinder.  There was always the trade-off between the quality of the lens and the size of the lens.  To compound this problem, if we needed to make a big lens, then we needed a big piece of ice.  As described in the first fire-by-ice articles, getting clear ice isn't very easy.
With this tube-polishing technique a number of new avenues have been opened:

1) We only need a small piece of clear ice - which is much easier to find and/or create.  In the above photos, where the smallest sphere was made, the starting point was something that looked a lot like an icicle.  Very often, icicles are perfectly clear - and they're easy-pickin in the winter.  The icicles are already in an almost cylindrical shape - so much of the work is already done!  An icicle provides: clear material, a hand-hold, is partially preformed, and is on display.  Wow, what a starting point!

2) Since this tube-polishing technique guarantees a perfect sphere - we have removed much of the skill element to this technique.  The better the original roughed-out sphere, the less polishing  required.  A very poor original sphere will still end up being perfect, one just needs to polish longer.

There is still exploration that can go into sources for the tube.  A longer tube is nice, since it is easy to hold.  I also tried various sized "rings" and they also worked well.  One could also use a sheet of material with a circular hole in it.  Other natural materials might include: coconut shells, sea shells, nut shells etc.
The cutting edge on the tools can also be optimized.  Maybe a serrated edge for the rough polishing, and then the hook-edge/burnish for the final polish.  In a survival situation, one could use cans, jars, lids, pieces of pipe, rings, bracelets etc.

And now for something completely different...... While sitting and polishing the ice spheres, I couldn't help but think about the monks and their Sand Mandelas.  Both tasks involve lots of labour that produces something that is beautiful.  Also, in both cases, the beauty is impermanent - the sand is brushed away - the sphere melts.  Starting a fire from a perfect ice sphere is magical.  These ice spheres are as much art as they are survival!

On a final note - this whole fire-by-ice project has been a great example of the power of the internet and the sharing of ideas.  Keep those emails coming and let me know about your ideas, experiments and results: Email Rob

Fire from Ice #4:     Page 1      Page 2      Page 3      Page 4