I have a few holes to drill and so does a friend so we bought a 127mm x
150 diamond core drill between us, it came with a 200mm sds+ core drill
arbor and a 10mm x 200mm tapered guide drill.

I bought a Titan 1250watt sds+ drill with safety clutch from Screwfix
and today attempted my first hole through single skin brick.

I first fitted the pilot drill to the arbor and drilled that hole right
through, then fitted the 127mm core to the arbor and attempted to start
drilling.

What a mess, it was just like trying to drill the core out without a
guide drill fitted at all. The 10mm bit only sticks out 15mm in front of
the core and after just a few seconds that had opened the pilot hole up
so far that the likelyhood of ever getting the core to stay in one
circle is remote to say the least.

What did I do wrong?

My thoughts are that the pilot drill as a guide with just 15mm
protruding is just not enough to guide the core.

I understand that once the core is into the brick by 20mm or so the
guide is probably best removed, but how to get to that stage!

Having tried it I would have thought a 13mm x 250mm or more guide drill
would be the ideal to keep everything going neatly until the core is
deep enough.

Suggestions please.

Never used such a large core drill, but with a 45mm I always go
striaght in with guide bit and core as one. I can't see why you wanted
to pilot the guide bit right through first.

On June 28 2006, " wrote:

Never used such a large core drill, but with a 45mm I always go
striaght in with guide bit and core as one. I can't see why you wanted
to pilot the guide bit right through first.

The plan was that I could then cut from either side if one prooved too
difficult (just above a shelf) as it was a big lump of brick flew out of
the outside so I had nothing left there to guide the drill core anyway.

I have used plenty of metal cutting hole saws up to 75mm and know that
the guide drill is paramount to cutting a clean hole in metal but this
is my first attempt at brick cutting.

"MikeT" wrote in message
...
I have a few holes to drill and so does a friend so we bought a 127mm x
150 diamond core drill between us, it came with a 200mm sds+ core drill
arbor and a 10mm x 200mm tapered guide drill.

I bought a Titan 1250watt sds+ drill with safety clutch from Screwfix
and today attempted my first hole through single skin brick.

I first fitted the pilot drill to the arbor and drilled that hole right
through, then fitted the 127mm core to the arbor and attempted to start
drilling.

Did the instructions say to make a pilot hole right through? Done a few of
these, too long ago to remember the exact procedure but checking the
Marcrist
support page it says drill with the pilot drill until the core is 5mm into
the material then remove the pilot drill. Maybe that is the problem.

Jim A

"Jim Alexander" wrote in message
...

"MikeT" wrote in message
...
I have a few holes to drill and so does a friend so we bought a 127mm x
150 diamond core drill between us, it came with a 200mm sds+ core drill
arbor and a 10mm x 200mm tapered guide drill.

I bought a Titan 1250watt sds+ drill with safety clutch from Screwfix
and today attempted my first hole through single skin brick.

I first fitted the pilot drill to the arbor and drilled that hole right
through, then fitted the 127mm core to the arbor and attempted to start
drilling.

Did the instructions say to make a pilot hole right through? Done a few
of
these, too long ago to remember the exact procedure but checking the
Marcrist
support page it says drill with the pilot drill until the core is 5mm into
the material then remove the pilot drill. Maybe that is the problem.

Jim A




My Hilti DD rig has a clip on pilot bit, which starts the hole to a depth of
between 3-4mm. Then through the wall like a knife thru buttER

Steve

On June 28 2006, "Jim Alexander" wrote:

Did the instructions say to make a pilot hole right through? Done a
few of
these, too long ago to remember the exact procedure but checking the
Marcrist
support page it says drill with the pilot drill until the core is 5mm
into
the material then remove the pilot drill. Maybe that is the problem.

Jim A

Be nice to have got that far in Jim

With it all thrashing about all I have done is make a big mess on the
brick surface with the core cutter tips. There were no instructions with
it but I would have remover the pilot if I ever got far enough into the
brick to do so.

The only thing I can think to do now to recover the job is to either buy
a 13 x 250mm taper drill and use that to get a good clean pilot hole to
guide the core in, or grind down an sds shanked 13mm drill I have here
to fit the arbor and use that as above. 3rd alternative would be a bit
of 10mm silver steel rod and grind a taper on that to fit the arbor to
get the core started clean.

Another slightly worrying thing is the safety clutch, no mention of it
in the sds+ drill manual, but is was spec'd on Screwfix's discription. I
emailed screwfix and they replied a day later to say they had asked the
manufacturers and yes it did have a clutch, I guess I will find out if
it tries to snatch on me.

"MikeT" wrote in message
...
On June 28 2006, "Jim Alexander" wrote:

Did the instructions say to make a pilot hole right through? Done a
few of
these, too long ago to remember the exact procedure but checking the
Marcrist
support page it says drill with the pilot drill until the core is 5mm
into
the material then remove the pilot drill. Maybe that is the problem.

Jim A

Be nice to have got that far in Jim

With it all thrashing about all I have done is make a big mess on the
brick surface with the core cutter tips. There were no instructions with
it but I would have remover the pilot if I ever got far enough into the
brick to do so.

I guess there is no easy way to suggest his but you did have hammer off,
didn't you?

Jim A

The only thing I can think to do now to recover the job is to either buy
a 13 x 250mm taper drill and use that to get a good clean pilot hole to
guide the core in, or grind down an sds shanked 13mm drill I have here
to fit the arbor and use that as above. 3rd alternative would be a bit
of 10mm silver steel rod and grind a taper on that to fit the arbor to
get the core started clean.

Try a wooden plug in the pilot hole. You'll be surprised how an sds bit
is able to push into wood nicely.

On June 28 2006, "Jim Alexander" wrote:

I guess there is no easy way to suggest his but you did have hammer
off, didn't you?

Jim A

Yes Jim I did I did read some other instructions on line about using
core drills even though mine didnt come with any.

Mike.

MikeT wrote:

With it all thrashing about all I have done is make a big mess on
the brick surface with the core cutter tips. There were no
instructions with it but I would have remover the pilot if I ever
got far enough into the brick to do so.

The only thing I can think to do now to recover the job is to
either buy a 13 x 250mm taper drill and use that to get a good
clean pilot hole to guide the core in, or grind down an sds
shanked 13mm drill I have here to fit the arbor and use that as
above. 3rd alternative would be a bit of 10mm silver steel rod
and grind a taper on that to fit the arbor to get the core
started clean.

Maybe bang a piece of scrap metal tubing into the pilot hole to make a
discardable liner?

wrote:

Never used such a large core drill, but with a 45mm I always go
striaght in with guide bit and core as one. I can't see why you wanted
to pilot the guide bit right through first.

Two reasons for drilling a pilot: it lets you drill from both sides and
still have a fair hope of meeting in the middle, and it also *can* make
drilling quicker in some materials.

(I have found dome types of brick that cut rapidly with the diamond of
the core bit, but take forever to drill without hammer action on the drill)

--
Cheers,

John.

/================================================== ===============\
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|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

MikeT wrote:

Another slightly worrying thing is the safety clutch, no mention of it
in the sds+ drill manual, but is was spec'd on Screwfix's discription. I
emailed screwfix and they replied a day later to say they had asked the
manufacturers and yes it did have a clutch, I guess I will find out if
it tries to snatch on me.

For anything but the simplest single skin walls there is no "if" about
it IME!

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

MikeT wrote:
On June 28 2006, "Jim Alexander" wrote:

Did the instructions say to make a pilot hole right through? Done a
few of
these, too long ago to remember the exact procedure but checking the
Marcrist
support page it says drill with the pilot drill until the core is 5mm
into
the material then remove the pilot drill. Maybe that is the problem.

Jim A

Be nice to have got that far in Jim

With it all thrashing about all I have done is make a big mess on the
brick surface with the core cutter tips. There were no instructions with
it but I would have remover the pilot if I ever got far enough into the
brick to do so.

The only thing I can think to do now to recover the job is to either buy
a 13 x 250mm taper drill and use that to get a good clean pilot hole to
guide the core in, or grind down an sds shanked 13mm drill I have here
to fit the arbor and use that as above. 3rd alternative would be a bit
of 10mm silver steel rod and grind a taper on that to fit the arbor to
get the core started clean.

Another slightly worrying thing is the safety clutch, no mention of it
in the sds+ drill manual, but is was spec'd on Screwfix's discription. I
emailed screwfix and they replied a day later to say they had asked the
manufacturers and yes it did have a clutch, I guess I will find out if
it tries to snatch on me.


I drilled a couple of similar large holes, same method as you , but I
kept the drill bit in place until core bit was at least 30mm into
brick.
If you have tct then hammer on ... diamond then hammer off.
Slow, with even pressure.

Now to get you going again ... why not fill the hole with a rapid
hardening compound, plenty on sale in B&Q etc, or mix brick dust with
cement and grout fill hole and leaver over night.
Then start again.

Mathew Newton wrote:

I'm no core drilling expert however when I hired a 150mm core drill it
came with a pilot drill bit AND a *smooth* guide bit. Hence, I drilled
right through with the pilot drill bit and then used the core drill
along with the smooth guide bit to do the biggie. The smooth guide bit
obviously didn't do any further damage to the pilot hole hence the
whole thing went through cleanly...

Mathew

Forgot to mention... here I am getting ready to do the drilling...

(Yeah I know what you're thinking - the bit does look somewhat on the
large side)

http://www.theservicepeople.com/web%...eb%20Large.jpg

Mathew

The message .com
from "Osprey" contains these words:

I drilled a couple of similar large holes, same method as you , but I
kept the drill bit in place until core bit was at least 30mm into
brick.
If you have tct then hammer on ... diamond then hammer off.
Slow, with even pressure.

I found that water helps. The slurry seems to act as further abrasive.

--
Skipweasel
Pay no attention to that man behind the curtain.

On Wed, 28 Jun 2006 10:25:50 -0700, wrote:

Never used such a large core drill, but with a 45mm I always go
striaght in with guide bit and core as one. I can't see why you wanted
to pilot the guide bit right through first.

Because it's often useful to be able to check where the hole will (or
should) come out.

It can be a bit of a pain to get the core drill started if the surface
layer (plaster or whatever) is too flakey to guide the centre drill in. I
suppose a longer centre drill or some sort of rod might be nice, but I
usually find I can get the main core drill cutting to the point it
self-stabilises by carefully offering up the rotating core drill to the
wall slightly off-axis so that just one part of the rim starts to cut at
first, and then straightening it out as it cuts deeper.

Industrial grade language may also help :-)

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Mathew Newton"
saying something like:

obviously didn't do any further damage to the pilot hole hence the
whole thing went through cleanly...

Mathew

Forgot to mention... here I am getting ready to do the drilling...

(Yeah I know what you're thinking - the bit does look somewhat on the
large side)

http://www.theservicepeople.com/web%...eb%20Large.jpg

Nice choice of safety gear.
--

Dave

MikeT wrote:

Another slightly worrying thing is the safety clutch, no mention of it
in the sds+ drill manual, but is was spec'd on Screwfix's
discription. I emailed screwfix and they replied a day later to say
they had asked the manufacturers and yes it did have a clutch, I
guess I will find out if it tries to snatch on me.

Not teaching you to suck eggs but be very careful until you find out.

A pal of mine ended up in A&E when he found out his cheap SDS didn't have a
clutch. He was up a (short) ladder drilling a core, the core bit snagged and
the drill swung round at full speed smacking him square in the face. He was
very lucky it didn't shatter his cheek / eye socket - the broken nose was
seen as a lucky escape.

That particular drill is now consigned to chiselling only....

"Mathew Newton" wrote


I'm no core drilling expert however when I hired a 150mm core drill it
came with a pilot drill bit AND a *smooth* guide bit. Hence, I drilled
right through with the pilot drill bit and then used the core drill
along with the smooth guide bit to do the biggie. The smooth guide bit
obviously didn't do any further damage to the pilot hole hence the
whole thing went through cleanly...

Bang on.
Have done a couple of similar jobs recently but had forgotten about the
solid centre guide.
Going through breeze was OK, but the external brick leaf took forever (guess
that's the price you pay for being a light weight office boy instead of the
rufty-tufty building site dweller).

Phil

On Wed, 28 Jun 2006 17:17:11 +0000, MikeT wrote:

I have a few holes to drill and so does a friend so we bought a 127mm x
150 diamond core drill between us, it came with a 200mm sds+ core drill
arbor and a 10mm x 200mm tapered guide drill.

I bought a Titan 1250watt sds+ drill with safety clutch from Screwfix
and today attempted my first hole through single skin brick.

I first fitted the pilot drill to the arbor and drilled that hole right
through, then fitted the 127mm core to the arbor and attempted to start
drilling.

What a mess, it was just like trying to drill the core out without a
guide drill fitted at all. The 10mm bit only sticks out 15mm in front of
the core and after just a few seconds that had opened the pilot hole up
so far that the likelyhood of ever getting the core to stay in one
circle is remote to say the least.

What did I do wrong?

My thoughts are that the pilot drill as a guide with just 15mm
protruding is just not enough to guide the core.

I understand that once the core is into the brick by 20mm or so the
guide is probably best removed, but how to get to that stage!

Having tried it I would have thought a 13mm x 250mm or more guide drill
would be the ideal to keep everything going neatly until the core is
deep enough.

Suggestions please.

Instead of using the a guide drill it would have been better to use the
blunt guide rod. The surface you wanted to start in must surely be quite
weak (not brick like) to have opened out so much. I don't think the guide
rod protrudes much more than 20-25mm from my core drills. Most of the kit
was obtained from Screwfix although I've added some stuff to it later.

I suppose you may have been trying to drill from inside. I don't suppose
you can get access to it from the other side? Perhaps that was why you
were drilling 127mm?

If all else fails and you are really shafted then I guess you can fix a
couple of battens on the wall in a V so as to support the drill until it
starts.



--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html
Gas Fitting Standards Docs he http://www.makewrite.demon.co.uk/GasFittingStandards

On 28 Jun 2006 10:25:50 -0700, " wrote:

. I can't see why you wanted
to pilot the guide bit right through first.

Thats where the arbor goes.

"marvelus" wrote in message
...
On 28 Jun 2006 10:25:50 -0700, " wrote:

. I can't see why you wanted
to pilot the guide bit right through first.

Thats where the arbor goes.

Genuine question; when 'producing' a wide hole through a cavity wall (
plaster, brick, cavity, brick, rendering) should one drill a (narrow) pilot
hole all the way through -then, and only then, widen the hole using the
'big' bit with its 'guide bit' fitted centrally.?

--

Brian

Brian Sharrock wrote:

Genuine question; when 'producing' a wide hole through a cavity wall (
plaster, brick, cavity, brick, rendering) should one drill a (narrow) pilot
hole all the way through -then, and only then, widen the hole using the
'big' bit with its 'guide bit' fitted centrally.?

If you want to be able to drill from both sides then that is the way to
go. Alternatively you can just drill from one side, either using the
pilot bit all the way through, or just to get you started after which
you remove the pilot altogether and rely on the already cut section to
guide you. (the inner leaf acting as a guide for the outer leaf etc)

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/