Masonry Drill Bits

[Nearly Retired (I am now)]

What am I doing wrong drilling into my french house walls? It's much harder work than in UK. At home, my masonry drill bits last a few good holes before giving up the ghost. But here in Charente Maritime with 2ft 6ins thick walls of chalk (?) and sometimes render I wear out one bit per hole.

 

I put up a Sky dish at the weekend. It needed 4 x 10mm holes each 65mm long. Well, I used one bit per hole - that's 16 Euros of bits alone.

 

PS I'm not using cheap bits.

[Nick Trollope]

Blimey, this is an obscure one, but I'll give it a go;

a) 4E for a 10mm drill bit is pretty cheap. I would expect to pay 12E for anything of reasonable quality - more so if we are talking SDS (and who uses anything else for masonry nowadays?)

b) I doubt if your house is built of chalk - not a popular building material, I'd guess. Around here, everything is granite (or concrete) - UK houses are make of man-made bricks, which generally speaking are alot softer than most stone or concrete.

c) If your drill is knackered (eg. the bearings supporting the chuck are duff, allowing the chuck lateral movement), then the bit will wear faster.

d) Masonry bits are meant to turn slowly. A modern, decent SDS drill turns at 100-ish RPM. A 80's B&D hammer drill probably goes at 1000 rpm. Heat is the enemy of any bit and high speed = high friction = high temperatures.

Are you allowing the drill to clear the dust (by withdrawing the bit every few seconds)? If not, you are just drilling the same dross again and again. I assume that you are at least using a hammer drill - modern masonry bits won't work in "drill" mode.

The real reason is probably elsewhere - consider Occam's Razor...

 

[Dave&Olive]

hi

           agree sds is the only way to go, brought a cheap sds with me from axmi....er (not going to give the site will only get slated again) and my trusty hammer drill......result for charente stone........go and buy one of those €49 sds drills from one of the diy sheds in france it will save you a shed load of money on drill bits......

               dave

 

[Nearly Retired (I am now)]

Oh well! You live and learn. I thought 4.55 E was lot of money per bit. The priciest in Bricomarche (yes, yes, overpriced - but with 1 hour to go on a Saturday before the shops shut and a 10 mile journey, what is one supposed to do!).

I though SDS referred only to the chuck type, i.e. 3 flat sides to the bit rather than round. Anyway, I think I've been drilling too fast - max revs at the highest speed - with hammer action on. 

So next time it'll be slow speed and expensive bits  -  I'll leave the SDS until I need loads of holes doing.

By the way, putting up and aligning the dish was a piece of cake. If you've never done, or are worried about trying it, just please give it a go - it's so easy...10 minutes and we were watching the football.

[Julie & Steve]

I agree. SDS is definitely the way to go. Even the cheapest rotary hammer knocks spots off any percussion drill. I wouldn't waste the time on even one hole in granite without one. An expensive masonry drill 'bit' doesn't really make drilling the hole any easier, it just allows you to go through the same grief in drilling more than once!. If you don't drill that many holes, get one of the cheap (under 30E) but big, heavy and cumbersome SDS mini breakers. They usually come with a selection of drills and a couple of chisels and some even have a standard chuck adaptor to allow you to use your metal and wood drills (your masonry drills won't work in it). It's no Rolls Royce and primitive compared with more expensive machines but, like double chocolate chip ice cream, you don't know what you're missing until you've tried it! 

Steve

[Dave&Olive]

this might or might not work in france

       my son who is a self employed builder in the uk . his £650 sds+ drill gave up the goat on the week end , so all the pro places shut he went to Argos and bought a £44 cheepie sorry no 2 with a 2 year warrantee he has hammered them as soon as one breaks down he takes it back and they give him a new one and then uses the spare he reckons most of the pros are now doing this ...

             wonder if it works here

                              dave

 

update returned my b+d drill back to bricomache 3 weeks ago and they have just given me a brand new next model up one so try it

[Alcazar]

I've recently been using special drills I bought through Screwfix here in the UK and exported to france. They are made by "Irwin", and will drill anything, from wood to brick to concrete to stone to glass!

They will often drill without using hammer action.

They are now becoming available in SDS as well.

I paid around £10 for a set of four, 5, 6, 7, and 8mm, and also have one-offs of 10 and 12mm, which were around £4 each.

They are so good I'd use nowt else now.

Alcazar

[Julie & Steve]

Yes, I've seen these but never actually tried them. They appear to be a compromise between all three but not being particularly good at any one. How long do the last? I would be pleasantly surprised if one could drill 20 holes in engineering brick and then drill a couple of clean holes through the back of an iron conduit box more than a few times. (Fixing armoured cable to a wall - in case you were wondering!).

Steve

[Alcazar]

Dunno about compromise: Mine drilled engineering brick, (more than twenty holes) when I did my conservatory here in the UK, and are still going strong. 6mm drill bit on this occasion.

Oh and the self same bit was loaned to a window fitter here in the Uk when his wouldn't drill a concrete lintel, hammer or no. It suffered no apparent ill-effect. Give 'em a try.

Alcazar

[Julie & Steve]

Already added to the list for the next order.

Ta

Steve