Hole in joist - at an angle?

Builders have always uised and still use whatver is to hand, although as materials get cheaper and fixed price jiobs get mre common, they are trading their own time for materials cost not theoir employers.

By the sound of it your flat bit is probably blunt @ £1.50 for a replacement seems hardly worthwhile taking a file to it to sharpen. Alternatively use an auger the screw thread on the tip tends to help pull the drill through, originally these had a square tapered shank to fit a brace but these days they come with round parallel shanks for machine drilling. Just be careful as they cut through quite rapidly and can easily over drill a blind hole.

Richard

Sharpen it, it's trivially easy

NT

This is what I have often done, though I agree with other posters that your spade bit sounds to be blunt.

A stubby auger is a much easier way IME:

Yes, also of course if it was relatively new wood the stuff in the resin can suddenly stop a drill when it clogs up the grooves. Brian

Similarly the quad-flute bits are very fast when they start to bite

ask my thumbnail just /how/ fast the drill burst through the wooden flooring I was drilling for a radiator pipe ...

I went out and bought a brand new 18mm spade bit just to see, and it went through quite happily at a shallow angle. Two wires fit through comfortably.

I have a set of fluted bits but they only go up to 10mm. Used one to drill the four corners of the box shape in the floor boards before linking up the holes with a jigsaw. The drill bit went through without any trouble.

I've always had problems with the larger spade bits; I think it is the extra drag of all that metal.

Then again, sharpening might help.

Then again life's too short when new ones are cheap.

Anyway, wires run through the joists (apart from the last couple which were so notched for previous versions of plumbing there was no point), boxes sunk into the floorboards, and mainly now the Ethernet to extend.

Cheers

Dave r

I put all the bits to be sharpened in a pile. When I eventually get a round tuit I reckon I must get well over 100 an hour done, give or take a fair bit. It would probably take longer to buy new ones.

NT

Been there, got the Tshirt (and a right angled adaptor).

What you need is SPEED. I use an old B&D orange drill with its metal

The numpty electicians who wired up my 1976 house just drilled the centre of the joist but at an angle, i.e. didn't have or bother with a right-angled adapter, where the joists are spaced by 18 inches.

Where 65 mm joist were doubled up they drilled from each side hoping to sort-of meet in the middle, and then hacked away with a wood chisel to get the cooker cable through the mis-aligned hole.

This technique made an effective 3 inch hole (measured vertically) in an 8 inch joist.

I think he is using a flat blade drill, Brian (25 mm diameter) not a high-speed steel type of drill.

Flat blade drills need to rotate very fast to get through old, dry, hardened wood.

Don't forget that new drill bits are for some reason more likely to hit a nail or screw than old drill bits.

I now only use the wood beavers for most jobs. Probably the best on the market if you have serious joist drilling to do.

Then regarding your point about them acting as nail-finders

I don't have an angle-drill, so between joists I use them in the shortest drill body I have, which is the impact driver

Should have said, OK for a single hole, but if you have a long run then pull-through is much easier if the holes are all parallel and aligned. Stubby augers are best. It all depends on how much you have got to do. My big rewiring jobs were in the distant past, in the days before nice compact cordless impact drivers with their hex chuck, that is what I would be using these days.

or fingers too :-)

We had triple joists on some new builds last year. I spent £50 on new bits for that job. Start off with stubby and work up to longer sizes and we still had to drill from both sides (nothing that a tape measure stopped us from doing properly) so the holes were straight and in line.

As long as you have a powerful enough drill. A lot of diy cordless drills will just stall trying to get those through an old, hard lump of timber.