Best way to cut 100mm hole in besser block?

[alpsy]

Hi guys,

I need to cut a 100mm hole in besser block to run a pvc tube through. I need a neat hole and once pvc tube is through, I'll need to seal it (that is between block and tube).

Can anyone please advise me what's the best way to do this and what tools "ill require?

Thanks,

Julie

[commodorenut]

Best looking hole will be made with a 'core drill'

Expensive option for just one usage though.

Do you know someone who installs air-conditioning? A lot of them have core drills ranging in size from 60/70mm up to 100mm

Otherwise you could do a messy hole & fit a skirt around the pipe to hide it.

[memphis]

you want something like this

http://cgi.ebay.com.au/110mm-PRO-diamond-hole-saw-core-drill-4-3-8-pilot-bit_W0QQitemZ180197833982QQihZ008QQcategoryZ50892QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

[Ivan in Oz]

If you can,
go bigger than the 100mm.

Cut a section of the 100mm Pipe, about 250mm or 350mm long;
depending on Block Width;
slit it,
and open it up and slip it over the Main Pipe where the Pipe goes through the Block.

Seal around the Sleeve.

[echnidna]

I cut a 100mm hole through a block wall so i could put my dust extractor outside.

I just drilled a series of holes around the perimeter and knocked the centre out.
I smoothed the hole up for a neat fit with a cold chisel & hammer. (tapping the chisel - not belting it hard)

The whole job only took an hour or so

[Barry_White]

you want something like this

http://cgi.ebay.com.au/110mm-PRO-diamond-hole-saw-core-drill-4-3-8-pilot-bit_W0QQitemZ180197833982QQihZ008QQcategoryZ50892QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

That would be great at a reasonable price but you would want a decent drill to drive it and you would really want to hang on if it grabbed. You would want a drill with a clutch in it like the old 1/2" Blue Bosch that I have.

[Planned LScape]

As echidna said. There was a thread on this a few weeks back, but into house bricks, same applies.
Just trace you pvc piece onto the block and put a masonry bit around the perimeter as close as possible without it dropping into the hole you've just drilled.

[gsouth]

can you take your block somewhere?
There's a mob that do core drilling and concrete sawing in sydney (diacore I think they were called) - I was looking at getting some blocks core drilled to install lights.