Drilling a 30mm hole in 30mm thick slate

[SR71]

As the subject title suggests, can someone point me in the direction of a tool that will drill a 30mm diameter hole in 30mm thick slate?

I need to make the holes for some LED uplighters to be mounted in the patio tiles?

In addition, is there a reasonably priced slate saw/cutter that will cut 30mm slate on the market?

Thanks.

 

[Symptoms]

SR - I've used a diamond core drill in the past but you should be able to do the job with a TCT (tungsten carbide tipped) core drill. You can get both from Screwfix. These should go in a SDS drill.

Slate saw/cutter? Diamond disc for an 9" angle grinder.

 

[SR71]

Symptoms,

I was wondering whether I needed a SDS drill of a particular power rating (800W?) in order to turn what would be a pretty hefty drill bit to drill a 30mm hole in slate?

For example:

http://www.screwfix.com/prods/15148...TCT-Core-Drills/Armeg-TCT-Core-Drill-Bit-30mm

Or do I need one of these:

http://www.screwfix.com/prods/72062/Drill-Bits/Tile-Drills/Diamond-Core-Drill-30mm

I presume either option in a SDS drill?

What arbors and/or pilots would I need?

Many thanks.

 

[Deluks]

If you have an SDS drill get the sds arbor, if normal chuck then get the hex arbor. You should also use the pilot drill bit.

What's the tolerance on the holes, do they need to be exactly 30mm?

 

[SR71]

Deluks,

Tolerance?

Well I am merely going to drop a few of these (http://www.thegardenlightingshop.co.uk/products.asp?c=198&d=3) into the holes, and they look like they have significant flanges, so I don't suppose they need to be exactly 30mm....

Do the core drills cut a hole of significant +/- ?

 

[Symptoms]

SR - I checked the link but, unless I've missed it, can't find a ref to the hole dia needed ... 30mm???

Anyway, follow advice from Deluks. If you get the Armeg tackle (good make so that's what I'd get) get their matching arbor & pilot drill as they all fit together. If you don't own an SDS get the best you can afford but even a shed cheepo will do if funds are tight. If you are likely to ever need to drill larger holea with a core drill, say 110mm, get a SDS with clutch (otherwise you'll risk a broken wrist when the tackle jams in the hole & the SDS spins).

 

[SR71]

Symptoms,

Thanks.

The LED link I presume? The first uplighter @ £11.49 requires a 30mm hole.

When I thought about it some more, this is a tiny light, so I'm now aiming for a 110mm hole.

I'll get the relevant SDS drill (with a clutch - I've already broken other bones this year!), drill bits and arbor etc. and see how I get on...

I'm making the budget up as I go along! Just don't tell the wife....

 

[SR71]

For one reason or another I've only just reached the stage where I'm ready to go with this project.

Just to clarify for the DIY patio-installing newbie...

The "SDS" arbor (as opposed to a "hex" arbor) is essentially just an adapter which sits in the "SDS" drill chuck and mates to the core drill bit correct? Via a screw thread it seems....

Will a TCT core drill bit do for slate or do I need a diamond core drill bit? I only need to make 9 x 100mm holes to deal with these recessed LEDs: http://www.litecraft.co.uk/Products/Product.asp?id=3899.

Also, how do I use the pilot drill bit? Does it sit inside the core drill bit somehow?

Thanks.

 

[marshman]

Also, how do I use the pilot drill bit? Does it sit inside the core drill bit somehow?

.

Yes, its a tapered spline just push it in then give it a light tap so it doesn't fall out.

 

[oilman]

I need to make the holes for some LED uplighters to be mounted in the patio tiles?.

Light pollution

 

[SR71]

marshman,

Thanks.

oilman,

At 0.12w each, I think it'll be minimal. Compared to the airport I live next to which I can see from 150 miles away on approach, I'm fairly sure I won't be able to see my patio illumination.

 

[SR71]

FWIW, here is the patio now...

Untitled

• SR71
• 1 May 2010
• 1

It took me 5hrs to drill 9 holes for the uplighters.

A question, however...

I capped my wall with 10mm slate tiles which I'd cut down to size...

However, 6 months on and some of the tiles are loose.

Untitled

• SR71
• 1 May 2010
• 1

What did I do wrong?

I used a "strong" 4:1 builders sand:cement mix...

Any suggestions?

Thanks.

 

[r896neo]

Was it very cold when you laid them? How is the mortar left on the wall? Hard soft crumbly not adhered well etc?

 

[SR71]

Cold? Not particularly I don't recall....

The mortar is hard, well bonded to the wall, but fairly easily chipped off the slate (which is a good job bearing in mind I have to re-do it.).

I wondered whether the bed of mortar was just not thick enough although I'm not sure why the depth of the mortar bed should affect the bond between the slate and the mortar? It seems to me that this is the key to understanding the problem.

I was thinking about just using some old Rewmar second time round to do the job even though this is a flexible wood adhesive?

 

[Thermo]

clean off the mortar and either rebed them on a 25mm bed and wet the back of teh slate first, or use a decent external tile adhesive, or use silicone.