SDS Core Bit - 110mm - hammer or just rotation?
bookieb
I'm fitting a 4" extractor fan through a solid block wall.
Rather than faff around with drilling lots of parallel holes, then
attempting to chisel out the middle (as I've done previously), I
decided to lash out and buy a suitable core bit.
It's an SDS TCD core bit, with a smaller guide bit in the middle.
110mm outside diameter.
Should I use hammer+rotate with this bit, or just let it "grind" on
rotate only?
Planning to start on the inside, cut to the 75mm depth the bit allows,
drill through the guide bit hole to find the spot outside, then drill
back in from outside.
If this doesn't join up, and I don't think it will, I'll chisel out
the centre of the cut, and go again.
Does that sound reasonable?
On the inside, the wall has been faced with 50mm insulated dry lining
board, but not yet taped or skimmed.
I'll have to cut through that first before reaching the inside face of
the block.
Any reason not to use the core bit at slow speed and no hammer to make
that cut first?
Any other advice or tips much appreciated on using this bit much
appreciated.
Regards,
bookieb.
Andrew Mawson
"bookieb" <tsgte...@yahoo.co.uk> wrote in message
news:c893a19d-07ab-4379...@g26g2000vbi.googlegroups.com...
Drill all the way through the wall with an sds drill of the drill
guide diameter, then drill from both sides with the 110mm core drill,
that way you get a neat hole on both sides of the wall that does line
up. If your core drill is diamond impregnated then it just needs to
rotate, but if it has tungsten carbide teeth then it needs to hammer
as well.
AWEM
Tabby
<andrew@no_spam_please_mawson.org.uk> wrote:
> b"bookieb" <tsgtest...@yahoo.co.uk> wrote in message
>
> news:c893a19d-07ab-4379...@g26g2000vbi.googlegroups.com...
>
>
>
> > Hi All,
>
> > I'm fitting a 4" extractor fan through a solid block wall.
> > Rather than faff around with drilling lots of parallel holes, then
> > attempting to chisel out the middle (as I've done previously), I
> > decided to lash out and buy a suitable core bit.
>
> > It's an SDS TCD core bit, with a smaller guide bit in the middle.
> > 110mm outside diameter.
>
> > Should I use hammer+rotate with this bit, or just let it "grind" on
> > rotate only?
>
> > Planning to start on the inside, cut to the 75mm depth the bit
> allows,
> > drill through the guide bit hole to find the spot outside, then
> drill
> > back in from outside.
> > If this doesn't join up, and I don't think it will, I'll chisel out
> > the centre of the cut, and go again.
> > Does that sound reasonable?
no, drill all the way from one side. Its normally easy to knock the
central masonry plug out once you've drilled around it.
NT
John Rumm
Depends on how long your arbour is - on thick walls the drill won't fit
through the 4" hole ;-)
--
Cheers,
John.
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harry
If you buy the better expensive diamond drill,no hammer action. Some
need water cooling-ask.
TCT needs a hammer action, is not as expensive but usually there is a
breakout hole unless you drill from both sides.
It's very easy for a big drill like this to jam. Take extreme care. it
can break your wrist. Be sure your drill has a safety clutch, some
don't.
Many small SDS drill won't handle it. Ask before you buy.
harry
your can drill some more. You can buy extension pieces for deep holes.
ARWadsworth
It depends how high up on the outside wall the hole is!
--
Adam
The Medway Handyman
Errrm. My TCT core drill set says definately no hammer in the destructions
& thats how I've always used it.
--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
Tabby
I got the extension bit with mine. And the hex shanked arbour as well
- dont try using that unless you have to.
NT
John Rumm
> On Dec 20, 5:00 pm, John Rumm<see.my.signat...@nowhere.null> wrote:
>> On 20/12/2010 15:00, Tabby wrote:
>>
>>
>>
>>> On Dec 20, 2:06 pm, "Andrew Mawson"
>>> <andrew@no_spam_please_mawson.org.uk> wrote:
>>>> b"bookieb"<tsgtest...@yahoo.co.uk> wrote in message
>>
>>
>>>>> Hi All,
>>
>>>>> I'm fitting a 4" extractor fan through a solid block wall.
>>>>> Rather than faff around with drilling lots of parallel holes, then
>>>>> attempting to chisel out the middle (as I've done previously), I
>>>>> decided to lash out and buy a suitable core bit.
>>
>>>>> It's an SDS TCD core bit, with a smaller guide bit in the middle.
>>>>> 110mm outside diameter.
>>
>>>>> Should I use hammer+rotate with this bit, or just let it "grind" on
>>>>> rotate only?
>>
>>>>> Planning to start on the inside, cut to the 75mm depth the bit
>>>> allows,
>>>>> drill through the guide bit hole to find the spot outside, then
>>>> drill
>>>>> back in from outside.
>>>>> If this doesn't join up, and I don't think it will, I'll chisel out
>>>>> the centre of the cut, and go again.
>>>>> Does that sound reasonable?
>>
>>> no, drill all the way from one side. Its normally easy to knock the
>>> central masonry plug out once you've drilled around it.
>>
>> Depends on how long your arbour is - on thick walls the drill won't fit
>> through the 4" hole ;-)
>
> I got the extension bit with mine. And the hex shanked arbour as well
> - dont try using that unless you have to.
The normal 6 or 8" arbour is ok on the diamond cores by itself, because
they are usually 6" long themselves. I normally drill out with 8mm bit
first to set the position, but then core back from the outside to keep
most of the mess there! (unless its too far up that is)
bookieb
> Any other advice or tips much appreciated on using this bit much
> appreciated.
>
> Regards,
>
> bookieb.
Thanks to all who replied.
Will take it easy and keep the pressure light and speed moderate.
I'll try no hammer first - no great hurry anyway, and I'd sooner take
a bit longer than risk a bad jam.
If no/very limited progress, will try hammer.
Regards,
bookieb,
Andrew Gabriel
harry <harol...@aol.com> writes:
> If you buy the better expensive diamond drill,no hammer action. Some
> need water cooling-ask.
> TCT needs a hammer action, is not as expensive but usually there is a
> breakout hole unless you drill from both sides.
Always try without hammer action first. If the brick is soft
and cuts easily, you get a better cut, and you may avoid
problems some bricks have when exposed to SDS hammer, where
the whole brick instantly disintegrates. Don't use hammer
on thermal blocks either, or to cut through the plaster layer.
> It's very easy for a big drill like this to jam. Take extreme care. it
> can break your wrist. Be sure your drill has a safety clutch, some
> don't.
A friend had two nasty incidents doing this with a cheap SDS with
no saftey clutch.
First time the core jammed, the drill spun a part turn before the
drill body hit the adjacent wall, and then it wound up the arbor
like it was made of plasticine.
Next time, the drill body spun, whacked him on the chin, and
resulted in a visit to A&E and a few stiches.
> Many small SDS drill won't handle it. Ask before you buy.
--
Andrew Gabriel
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