Re: [ATM] question about tiles on a beveled glass tool

[Mark Holm <mdholm@telerama.com>]

Bob May wrote:
> The thing with tile tools is that they are to do the finish
> grinding with.  You don't want to start a project with them as
> they do tend to grind themselves to nothing that way.  Start with
> an end cap for plumbing or something like that and dig the inital
> hole in the glass to about 80% of the depth you want and make it
> sort of spherical and you will do a lot better with the tile
> tool.

The tutorial at gotgrit.com shows a hogging tool made from a cat food
can, or something similar, filled with dental stone to stiffen it up and
make it easier to hold and press down on.  Steel is tough enough that
even a thin tool like that will apparently be enough for smaller
mirrors.  Even if it wears out before you are done hogging, a new one
isn't any big deal.

A pipe cap does have the advantage that you will be very hard pressed
indeed to wear it out.  Pipe caps I have seen sometimes have a couple of
nasty bumps on the rim where the mold wasn't too good.  You would want
to avoid one like that, because, what with the aforementioned toughness
of steel, bumps would be slow to wear down.  You could file them off,
but better just not to have them to begin with if possible.

Mark Holm
mdholm@telerama.com


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