New Tool Issues

Hi all,

I have been grinding with a dental stone tile tool using #120 SiC for
a while.

My sagitta has gotten deeper but it appears there are still large pits
on the surface which are not going away.

My tool seems like it may be to blame. I poured directly onto a tile
mat. And in some places the tile has worn down to the stone. Has
anyone had this problem?

I am considering making a plaster/epoxy tool. Am I going to run into
problems since the individual squares will not match the spherical
surface originally? Or can I just continue at #120 until the pits
disappear and proceed from there?

Any advice would be appreciated!

--

Paul

On Sep 26, 2:16 pm, pku wrote:
Hi all,

I have been grinding with a dental stone tile tool using #120 SiC for
a while.

My sagitta has gotten deeper but it appears there are still large pits
on the surface which are not going away.

My tool seems like it may be to blame. I poured directly onto a tile
mat. And in some places the tile has worn down to the stone. Has
anyone had this problem?

I am considering making a plaster/epoxy tool. Am I going to run into
problems since the individual squares will not match the spherical
surface originally? Or can I just continue at #120 until the pits
disappear and proceed from there?

Any advice would be appreciated!

--

Paul


Hi
It shouldn't make too much difference. I've seen people work with a
tool
missing a square of tile. Work with tool on top to keep from making
your sagitta any deeper or if working with a smaller tool than the
mirror,
use a pattern that doesn't over work the center. You might end up with
an F3 before you stop.
Also, make sure your actually grinding out these pits and not just
creating new ones. Mark the back of the mirror so you can compare
before and after.
When adding new grit, one often gets surface chips. These are not
always deep and may appear large in diameter. Each time you
add grit, you may just be making new ones.
Dwight

You remove the 120 pits with 220, not with more 120?


pku wrote:

Hi all,

I have been grinding with a dental stone tile tool using #120 SiC for
a while.

My sagitta has gotten deeper but it appears there are still large pits
on the surface which are not going away.

My tool seems like it may be to blame. I poured directly onto a tile
mat. And in some places the tile has worn down to the stone. Has
anyone had this problem?

I am considering making a plaster/epoxy tool. Am I going to run into
problems since the individual squares will not match the spherical
surface originally? Or can I just continue at #120 until the pits
disappear and proceed from there?

Any advice would be appreciated!

--

Paul

The 120 pits yes, but there are bigger ones which seem to move around.

Thank you both for the advice. I am going to proceed with a plaster
tool.

--

Paul

On Sep 26, 11:02*pm, jerry warner wrote:
You remove the 120 pits with 220, not with more 120?

pku wrote:
Hi all,

I have been grinding with a dental stone tile tool using #120 SiC for
a while.

My sagitta has gotten deeper but it appears there are still large pits
on the surface which are not going away.

My tool seems like it may be to blame. *I poured directly onto a tile
mat. *And in some places the tile has worn down to the stone. *Has
anyone had this problem?

I am considering making a plaster/epoxy tool. *Am I going to run into
problems since the individual squares will not match the spherical
surface originally? *Or can I just continue at #120 until the pits
disappear and proceed from there?

Any advice would be appreciated!

--

Paul