Got any recommendations? The Makita 8406 seems to be the most popular, though the 1400Watt 8406C is little more expensive and has two gears.
Anyone got an 8406C? The speed range quoted for it starts at 900rpm whereas the 8406 is 0-1500rpm. Any other favourites?
I know Les uses a Hilti which I daresay is marvellous - at a price!
I still believe a dedicated core-drill gun is best. The only reason I use my Hilti is because I own it. I use the TE 22 which has a clutch. I also have a TE 17 often called a damp course machine and also have a Hilti breaker. Iíve hired bigger breakers in the past and still ended up using the Hilti.
I was looking at core drill guns at PHEX but have not made a decision yet. Part of my reason is that I now have a 152mm core drill. Got that for RS gas fires but the 152mm is actually too big so I have to mount the fire on non-combustible board. The 152mm is superb for taking soil waste 110mm collars.
The core drills do wear so my most popular sizes are now duplicated. They seem to take ages (weeks) to re-tip them.
Both machines are dedicated to diamond cores. Even the smaller one claims to be suitable for up to 152mm, though a similar power De Walt quotes 90mm max.
Chris, I use an Hitachi DC120V dedicated core drill with variable speed & clutch. Very nice bit of kit.
Saw quite a good offer available v soon at BSS - or is it BOSS - the bigger-pipe brother of Plumbing Trade Supplies chain. If I rem correctly you get Marcrist 117, 52 and 38 plus an adaptor or two for £118 + vat ish. I'll be having one of those.
STILL haven't decided on which machine to use! Mate with the Peter's Hitachi AND a Makita 8406 reckons the Makita is quicker because the clutch is set to allow more torque! I did see in one web scan that the Hitachi was discontinued. Still using a Bosch 24v if I'm up a ladder, and a Bosch multi-drill if I'm not, which is a bit slow on the rpm.
Plumbcenter had a similar offer when I got my set and about the same price plus yah boo I got a Plumbcenter dinky toy of their big wheeler.
Snag is that diamond cutters are like drugs. Once you've tasted 'em you want more and I now have a good set including the wapping 150mm for soil pipe knuckles and Brazilia whatnots.
I use a Hilti TE 27 (no hammer obviously) as that has a clutch.
Get two of your popular sizes:
(1) Daddy bear for flues
(2 Mummy bear for waste pipes
(3) Baby bear for sleeving gas pipes et al
Don't forget a 'cutting charge' per leaf on your modest bill.
PS - Try the water attachment. Marcrist are usually at PHEX and that season kicks off in Eire next month. Anyone got a spare room ?
Oops - Belfast then Dublin for PHEX
.. and they've got a posh new website.
By the way I use a normal drill - a diy one in fact, with 28mm diamond bit for things like going through tiles at max speed. It never seem to jam. I do have a plastic stepped plug which goes in the end of the bit to centre on a smaller hole but I managed to get that stuck once. So now I just hold the bit steady against the tile with my hand round it. Not quite as bonkers as it sounds.
In a former existence I did a study of machine-shop grinding materials. All hard bits embedded in a softer matrix, like our diamond core bits, but with other exotics as well like boron nitride. Fascinating how the relative hardnesses of the hard, the matrix and the drilled have to be right or you get an expensive mess. That was for tougher subjects than London stock bricks, of course. I wonder how much it matters on those.
The really exciting bit was grinding the diamond etc inserts down to a polished surface so they could be looked at under a microscope!
The only problem I had at first was the length of the pilot drill used for starting.
Modern homes have dot and dab walls (unfortunately) and the diamond cutter would start to bite on the plasterboard before the drill had touched blockwork.
Marcrist kindly sent me a longer bit which was fine for that purpose.
I was then having trouble with the 150mm cutter wobbling about. Spoke with my mate Dr Powertool at the Hire-Center and he advised the shorter bit. And he was right. Stopped it wobbling.
A mnufacturer of the bits near me advises you ditch the guide rod (similar idea to central drill but you drill the pilot hole first)asap. . That stops the wobble of course, though the hole IS more likely to drift off. I have some dust extraction kit which relies on the central hole being unoccupied by drill bit or guide rod.
Timely perhaps to remind our reader of the technique of using a bit of ply or similar with a hole in it the size of the core bit, to put it where you want, perhaps overlapping another hole.
I've wondered about using a mod of that technique - with a hoover on it - to catch the inevitable dust whirl.
I always drill the pilot hole first as you recommend.
Thanks for the timely reminder in re the plywood. I've successfully used that technique myself.
If anyone (new entrants) does not understand this I'll draw a sketch.
Les could you please knock up a sketch showing the method of core drilling using a a bit of ply as a guide. Also on a recent job i was core dilling a wall,cut through the iner wall and was faced with a huge cavity/hole?? a core drill would not reach the outer wall and could`nt safely drill from the outside as we were three floors up. Had to stich drill the hole and knock it out from the inside. Anyone ever been faced with the same problem?
With huge cavity unexpected, place a piece of plywood over hole with wee hole in middle. Using long bit drill through outer leaf. Re-introduce core bit, with extension bar from inside.
The Sparky from Screwfix & others is very nice. 2 speed mechanical gearbox, electronic speed control, safety clutch which seems to be at about the right torque, fairly long front handle and light weight (about 2kg I'd guess - similar to standard SDS). Cheap too - I think it was about £140. How long it'll last is anyone's guess but at least it doesn't feel flaky.
Aldi are selling a cordless air pump.
Have been using one for a while. Quite handy.
Re the Aldi air pump - is that a car tyre inflator compressor, a lilo inflator or what? And what do you use it for that's so handy?!
(Me I have a car cigar-lighter socket wired in to my Elu 14.4V worklight which takes batteries from my deWalt 14.4V drill. Means I can plug in a car tyre compressor for pressure testing pipework or pumping up pressure vessels, a 12V diaphragm pump for squirting inhibitor etc into sealed systems or a 12V 'whale' type pump for pushing acid through PHEs for descaling.)