Need to cut a round hole in some indian stone paving to house a gully
grate (approx 10" hole required).

I was thinking of doing it in 2 halves and first slicing at 1" spacing
from the edge to the perimiter (4.5" grinder) and then slicing at right
angles to remove the bulk, then nibbling from the inside of the
semi-circle and cleaning up with a sharp chisel and/or bolster.

But has anyone got a better way of doing this?

TIA,

Alex.

But has anyone got a better way of doing this?

Is it possible to find an oversize core drill for hire somewhere?

Finding something over 150mm might not be easy, however, and even if found
will be more expensive than the grinder solution.

Christian.

On Fri, 8 Jul 2005 14:22:31 +0100, "Christian McArdle" wrote:

But has anyone got a better way of doing this?

Is it possible to find an oversize core drill for hire somewhere?

Finding something over 150mm might not be easy, however, and even if found
will be more expensive than the grinder solution.

Christian.

Maybe you could use a smaller core drill to drill several overlapping holes - but don't drill quite
through so you have some support for the pilot drill.

Maybe you could use a smaller core drill to drill several overlapping
holes
- but don't drill quite through so you have some support for the pilot
drill.

The problem is that this negates the main advantage of the method, which is
to make a nice smooth hole. Using several holes results in the hole still
needing tidying up afterwards.

Christian.

AlexW wrote:
Need to cut a round hole in some indian stone paving to house a gully
grate (approx 10" hole required).

I was thinking of doing it in 2 halves and first slicing at 1" spacing
from the edge to the perimiter (4.5" grinder) and then slicing at right
angles to remove the bulk, then nibbling from the inside of the
semi-circle and cleaning up with a sharp chisel and/or bolster.

But has anyone got a better way of doing this?

I wonder what happens if you take a carbide woodworking bit in a router,
and start cutting.

Christian McArdle wrote:
But has anyone got a better way of doing this?


Is it possible to find an oversize core drill for hire somewhere?

Finding something over 150mm might not be easy, however, and even if found
will be more expensive than the grinder solution.

Christian.



I thought about core drills and etc, but have never seen one that big &
specialist means expensive, I'd guess.

Ta,

Alex.

Ian Stirling wrote:
AlexW wrote:

Need to cut a round hole in some indian stone paving to house a gully
grate (approx 10" hole required).

I was thinking of doing it in 2 halves and first slicing at 1" spacing
from the edge to the perimiter (4.5" grinder) and then slicing at right
angles to remove the bulk, then nibbling from the inside of the
semi-circle and cleaning up with a sharp chisel and/or bolster.

But has anyone got a better way of doing this?


I wonder what happens if you take a carbide woodworking bit in a router,
and start cutting.

Novel. But guess it might go through a few bits (and routers too)!

Ta,

Alex.

Hi Alex
But has anyone got a better way of doing this?


Don't! Leave a square aperture for the gully grate and infill with
decorative gravel/slate chippings, pretending all along that it's an
artistic touch. Add a few more spots of gravel/slate and claim they are
decorative highlights.

Dave

Christian McArdle wrote:
Maybe you could use a smaller core drill to drill several overlapping

holes

- but don't drill quite through so you have some support for the pilot

drill.

The problem is that this negates the main advantage of the method, which is
to make a nice smooth hole. Using several holes results in the hole still
needing tidying up afterwards.

Christian.



However this might (err not) work.

Making the paving stone rotate, around the centre of the desired hole
(centered 'pivot' hole) with a fixed drill (SDS pedestals ... do they
exist?) with the core drill set away from the centre at the desired
radius. Index the stone round to remove most of the material with full
holes and then offset and index again for the remainder and so on until
an acceptable profile is cut?

Sounds complicated though, and I am not sure how a core drill would fair
when cutting the remainders after the full holes are cut. And could
I get all this stable enough etc?

Alex.

David Lang wrote:
Hi Alex

But has anyone got a better way of doing this?



Don't! Leave a square aperture for the gully grate and infill with
decorative gravel/slate chippings, pretending all along that it's an
artistic touch. Add a few more spots of gravel/slate and claim they are
decorative highlights.

Dave



Now there's an idea!

Alex.

David Lang wrote:
Hi Alex
But has anyone got a better way of doing this?


Don't! Leave a square aperture for the gully grate and infill with
decorative gravel/slate chippings, pretending all along that it's an
artistic touch. Add a few more spots of gravel/slate and claim they
are decorative highlights.

Dave

that's the best idea and the most simple (kiss)

you could also cut the square hole, infill with mortar and press decorative
glass beads / slate / pebbles / whatever floats your boat into the almost set
mortar to avoid having to sweep gravel back into the gap at regular intervals.



RT

you could also cut the square hole, infill with mortar and press
decorative
glass beads / slate / pebbles / whatever floats your boat into the almost
set
mortar to avoid having to sweep gravel back into the gap at regular
intervals.

Or use a square grate?

Christian.

Christian McArdle wrote:
you could also cut the square hole, infill with mortar and press

decorative

glass beads / slate / pebbles / whatever floats your boat into the almost

set

mortar to avoid having to sweep gravel back into the gap at regular

intervals.

Or use a square grate?

Christian.



Grate is inside gully. Gully round.

Suppose I could dig up and replace gully put in by the conservatory
company though.

Alex.

AlexW wrote:
Christian McArdle wrote:
you could also cut the square hole, infill with mortar and press

decorative

glass beads / slate / pebbles / whatever floats your boat into the
almost

set

mortar to avoid having to sweep gravel back into the gap at regular

intervals.

Or use a square grate?

Christian.



Grate is inside gully. Gully round.

Suppose I could dig up and replace gully put in by the conservatory
company though.

Alex.

doncha just love usenet :-)


RT

In article , "AlexW"
says...
Need to cut a round hole in some indian stone paving to house a gully
grate (approx 10" hole required).

I was thinking of doing it in 2 halves and first slicing at 1" spacing
from the edge to the perimiter (4.5" grinder) and then slicing at right
angles to remove the bulk, then nibbling from the inside of the
semi-circle and cleaning up with a sharp chisel and/or bolster.

But has anyone got a better way of doing this?

I'd have thought that scoring it on both sides with the grinder then
whacking it in the middle would stand a fair chance of working, but I
might not try it if I didn't have any spare stone.

In uk.d-i-y, AlexW wrote:
Christian McArdle wrote:
But has anyone got a better way of doing this?
Is it possible to find an oversize core drill for hire somewhere?
Finding something over 150mm might not be easy, however, and even if
found
will be more expensive than the grinder solution.
Christian.


I thought about core drills and etc, but have never seen one that big
& specialist means expensive, I'd guess.

We hired a man and machine to drill 12-inch holes in the (private)
concrete pavement outside our house - for bollards. I don't remember how
much it was, but not a lot. This was a seriously heavy-duty machine,
with built-in trolley. I was happy to leave the job to an expert. Try
Yellow Pages? In this case you could presumably save money by taking the
job to them - not an option for our job.

--
Mike Barnes

AlexW wrote:

Need to cut a round hole in some indian stone paving to house a gully
grate (approx 10" hole required).

I was thinking of doing it in 2 halves and first slicing at 1" spacing
from the edge to the perimiter (4.5" grinder) and then slicing at right
angles to remove the bulk, then nibbling from the inside of the
semi-circle and cleaning up with a sharp chisel and/or bolster.

But has anyone got a better way of doing this?

TIA,

Alex.



Only thing that seems to touch it is a diamnd blade in an angle grinder.

Now I've made holes - semi circular - in slate using a tile saw.

You simply remove MOST of the material and use the edge of the disk to
blend it all to shape.

Should work with the angle grinder to...

Rob Morley wrote:
In article , "AlexW"
says...

Need to cut a round hole in some indian stone paving to house a gully
grate (approx 10" hole required).

I was thinking of doing it in 2 halves and first slicing at 1" spacing
from the edge to the perimiter (4.5" grinder) and then slicing at right
angles to remove the bulk, then nibbling from the inside of the
semi-circle and cleaning up with a sharp chisel and/or bolster.

But has anyone got a better way of doing this?


I'd have thought that scoring it on both sides with the grinder then
whacking it in the middle would stand a fair chance of working, but I
might not try it if I didn't have any spare stone.

Got a cut feeling this aint going to work from previous failed attempts
at doing profiles the same way a couple of years ago. But its /is/ worth
a go as the stone whilst not cheap aint all that pricey.

I suppose I could try and segment the centre with a grinder too and
knock through in small segments.

Ta,

Alex.

The Natural Philosopher wrote:
AlexW wrote:

Need to cut a round hole in some indian stone paving to house a gully
grate (approx 10" hole required).

I was thinking of doing it in 2 halves and first slicing at 1" spacing
from the edge to the perimiter (4.5" grinder) and then slicing at
right angles to remove the bulk, then nibbling from the inside of the
semi-circle and cleaning up with a sharp chisel and/or bolster.

But has anyone got a better way of doing this?

TIA,

Alex.



Only thing that seems to touch it is a diamnd blade in an angle grinder.

Now I've made holes - semi circular - in slate using a tile saw.

You simply remove MOST of the material and use the edge of the disk to
blend it all to shape.

Should work with the angle grinder to...

Will bear the blending biz in mind, probably use ordinary disk for that
bit?

Ta,

Alex.

In article , "AlexW"
says...
Rob Morley wrote:
In article , "AlexW"
says...

Need to cut a round hole in some indian stone paving to house a gully
grate (approx 10" hole required).

I was thinking of doing it in 2 halves and first slicing at 1" spacing
from the edge to the perimiter (4.5" grinder) and then slicing at right
angles to remove the bulk, then nibbling from the inside of the
semi-circle and cleaning up with a sharp chisel and/or bolster.

But has anyone got a better way of doing this?


I'd have thought that scoring it on both sides with the grinder then
whacking it in the middle would stand a fair chance of working, but I
might not try it if I didn't have any spare stone.

Got a cut feeling this aint going to work from previous failed attempts
at doing profiles the same way a couple of years ago. But its /is/ worth
a go as the stone whilst not cheap aint all that pricey.

I suppose I could try and segment the centre with a grinder too and
knock through in small segments.

That's what I meant - basically a cartwheel design, and maybe
drill/chisel through the "hub" first. Be careful how you support it
before you started bashing, too - maybe worth cutting a circle in a
bit of scrap board to suport it right at the edge of the cutout, you
could even bed it in a bit of mortar.

Rob Morley wrote:
In article , "AlexW"
says...

Rob Morley wrote:

In article , "AlexW"
says...


Need to cut a round hole in some indian stone paving to house a gully
grate (approx 10" hole required).

I was thinking of doing it in 2 halves and first slicing at 1" spacing

from the edge to the perimiter (4.5" grinder) and then slicing at right

angles to remove the bulk, then nibbling from the inside of the
semi-circle and cleaning up with a sharp chisel and/or bolster.

But has anyone got a better way of doing this?


I'd have thought that scoring it on both sides with the grinder then
whacking it in the middle would stand a fair chance of working, but I
might not try it if I didn't have any spare stone.

Got a cut feeling this aint going to work from previous failed attempts
at doing profiles the same way a couple of years ago. But its /is/ worth
a go as the stone whilst not cheap aint all that pricey.

I suppose I could try and segment the centre with a grinder too and
knock through in small segments.


That's what I meant - basically a cartwheel design, and maybe
drill/chisel through the "hub" first. Be careful how you support it
before you started bashing, too - maybe worth cutting a circle in a
bit of scrap board to suport it right at the edge of the cutout, you
could even bed it in a bit of mortar.

Tried the method without dicing into segments and it nearly worked! But
I only used a small bit of stone (not willing to nail a big flag).

Using the "cake cutting" technique, and about 10 segments, scoring 1/3rd
the way through each side, used a cold chisel and club hammer in the
scored grooves ... worked a treat.

The 4 1/2 inch grinder had a diamond blade on and actually made the
curvature quite well, in the end this was a lot easier than I thought
and the result is fine for my purposes (when pointed in).

See http://putfile.com/pic.php?pic=7/18916160871.jpg&s=x3 for result.

Cheers,

Alex.

AlexW wrote:

The Natural Philosopher wrote:

AlexW wrote:

Need to cut a round hole in some indian stone paving to house a gully
grate (approx 10" hole required).

I was thinking of doing it in 2 halves and first slicing at 1"
spacing from the edge to the perimiter (4.5" grinder) and then
slicing at right angles to remove the bulk, then nibbling from the
inside of the semi-circle and cleaning up with a sharp chisel and/or
bolster.

But has anyone got a better way of doing this?

TIA,

Alex.



Only thing that seems to touch it is a diamnd blade in an angle grinder.

Now I've made holes - semi circular - in slate using a tile saw.

You simply remove MOST of the material and use the edge of the disk to
blend it all to shape.

Should work with the angle grinder to...


Will bear the blending biz in mind, probably use ordinary disk for that
bit?

Nah. Diamond all the way.
Nothing else touches it.

Ta,

Alex.

AlexW wrote:

Rob Morley wrote:

In article , "AlexW"
says...

Rob Morley wrote:

In article , "AlexW"
says...


Need to cut a round hole in some indian stone paving to house a
gully grate (approx 10" hole required).

I was thinking of doing it in 2 halves and first slicing at 1" spacing


from the edge to the perimiter (4.5" grinder) and then slicing at
right


angles to remove the bulk, then nibbling from the inside of the
semi-circle and cleaning up with a sharp chisel and/or bolster.

But has anyone got a better way of doing this?


I'd have thought that scoring it on both sides with the grinder then
whacking it in the middle would stand a fair chance of working, but
I might not try it if I didn't have any spare stone.


Got a cut feeling this aint going to work from previous failed
attempts at doing profiles the same way a couple of years ago. But
its /is/ worth a go as the stone whilst not cheap aint all that pricey.

I suppose I could try and segment the centre with a grinder too and
knock through in small segments.


That's what I meant - basically a cartwheel design, and maybe
drill/chisel through the "hub" first. Be careful how you support it
before you started bashing, too - maybe worth cutting a circle in a
bit of scrap board to suport it right at the edge of the cutout, you
could even bed it in a bit of mortar.


Tried the method without dicing into segments and it nearly worked! But
I only used a small bit of stone (not willing to nail a big flag).

Using the "cake cutting" technique, and about 10 segments, scoring 1/3rd
the way through each side, used a cold chisel and club hammer in the
scored grooves ... worked a treat.

The 4 1/2 inch grinder had a diamond blade on and actually made the
curvature quite well, in the end this was a lot easier than I thought
and the result is fine for my purposes (when pointed in).

See http://putfile.com/pic.php?pic=7/18916160871.jpg&s=x3 for result.

Cheers,

Alex.

"'Kinaida, you done well there, buoy!"

As they say in Suffolk...;-)

In article , "AlexW"
says...
snip
Using the "cake cutting" technique, and about 10 segments, scoring 1/3rd
the way through each side, used a cold chisel and club hammer in the
scored grooves ... worked a treat.

The 4 1/2 inch grinder had a diamond blade on and actually made the
curvature quite well, in the end this was a lot easier than I thought
and the result is fine for my purposes (when pointed in).

See http://putfile.com/pic.php?pic=7/18916160871.jpg&s=x3 for result.

Looks like a round hole in a square slab - excellent :-)
I think the soil needs a load of well rotted horse manure though.