Angle grinder discs

[Roger]

Follow-up really to my 'lintol' thread.

I have a 230mm angle grinder.

If the last bit of gritstone I cut is anything to go by my diamond cutting disc is very close to being worn out. The local shop where I bought it cheaply has since closed so it looks like a Screwfix order is getting close but Screwfix has a large range of diamond blades with a large range of prices.

The disc will be mostly used for cutting gritstone, some of which is very hard indeed, but I don't want to spend a small fortune so will the "Star Buy" Titan on the medium/hard page be up to the job or should I raise my sights a little and if so, to what?

On a related matter ISTR Fred Dibner, in one of his earlier programs, using a thickish grinding disc to bevel off a piece of stone to use as a mullion. I can't see anything like that in the Screwfix catalogue so is my memory at fault or is it a gap in the Screwfix range?

[The Medway Handyman]

Aldi do 'sets' of diamond discs every now & then, cheap as chips & they work OK. Worth a look.

[Dave Plowman (News)]

It may not be of help, but I bought a Titan plain diamond wheel replacement from Screwfix for my Plasplugs tile cutter, and it has lasted far longer cutting porcelain tiles than the original. So I'd call it good value as it's cheaper too. Of course Plasplugs recommend a grooved cutter for porcelain but I was disappointed with the edge it gave - rather too chipped.

[Bruce]

My local branch has them in stock at the moment. £4.99 for 4 (2 each of 2 different types) if I recall correctly.

[Roger]

The message from Bruce contains these words:

Thanks Bruce and Dave. I will have a lookin if I can tomorrow. Up to now I haven't used my local Aldi as I am usually home from weekly shopping before Aldi opens.

[Roger]

The message from "Dave Plowman (News)" contains these words:

Thanks Dave. If the Aldi ones wear out too fast (assuming I can find some) I will get Titan on spec but I will try Aldi first as I don't have a long enough shopping list with Screwfix atm (to get free carriage).

[auctions]

I've been using these, which have lasted well enough.

[The Wanderer]

Hmm, cheap angle grinder discs? Somehow that's a doubtful combination. Perhaps my outlook is tempered by a fatality I had to attend some years ago where it was thought initially that the guy working on the roof of a new industrial unit had been electrocuted. After I'd made sure all the electrics were safe, the fire and rescue service got him down. The HSE report afterwards concluded that it was a cheap disc in a 9" angle grinder that had shattered and part of the blade embedded itself in his skull. Never really liked angle grinders since then......

[Dave Plowman (News)]

I very much doubt a diamond disk could shatter. They are a simple steel disk with diamond coating. Very different from ordinary ones.

[Andy Dingley]

Cut it wet, and use monocrystalline diamond. You'll probably want to hire a 12" / 15" saw (even better is to do it on a bench), rather than a 9" electric.

Cheap diamond disks are cheap primarily because they use cheap diamond. This is polycrystalline - each diamond abrasive grain is actually many diamond crystals. They're grown as crystals rather than bonded, so the joins between crystals are discontinuities rather than gluelines, but they're still weaker than crystalline diamond. They cut fine when new, but they have nothing like the lifetime of the monocrystalline diamonds. On hardstone, you'll notice.

The "typical" angle grinder disks (both grind and cut) have always been made in range of grades from soft to hard, depending on metal to stone. They're pretty easy to find, even from Screwfix. If it's hardstone though, and you're doing a lot of it, it's worth talking to the tech desk at a real supplier (CSM are helpful and sell stuff, or will pass on the useful numbers for Hermes / Norton).

[Roger]

The message from Andy Dingley contains these words:

At the moment it is single stones to be trimmed to fit. I am doing some with bolster and club hammer but the thicker ones can be sods to cut that way.

There is a large variation in hardness between stones which is particularly noticeable using the angle grinder. Some cuts seem to take for ever while others are almost like a knife through butter.

I have some flags to lay sometime (several round tuits down the pile) and if I have to trim many of them I may well go for something more extreme but for the moment it will be the angle grinder or lump hammer.

[Pete C]

Is wet cutting with a normal angle grinder 'frowned upon'? :)

Would a plug in RCD and thick rubber gloves be enough.

cheers, Pete.

[sm_jamieson]

Any idea how this compares to the following ?

[mike]

Toolstation have free carriage on all orders at the mo' if that's any help.

[Harry Bloomfield]

The Wanderer presented the following explanation :

Even the best quality ones can shatter if maltreated.

[Andy Dingley]

Yes! Hire a real wet grinder.

Apart from which, there's no water feed on my angle grinder. There needs to be a pump, just to give enough flow. Otherwise work underwater (easier than it sounds, as the extra buoyancy makes larger pieces handleable).