On Sun, 08 Aug 2004 22:49:19 GMT, "Matthew Durkin"
wrote:

I need to buy an angle grinder to cut some decorative concrete slabs.

Buy a 9" and buy a cheap one (like the 20 quid Kinzo).

A 9" angle grinder isn't very useful. It's big, it's heavy, and the
discs they use have an incredible gyroscopic effect. They also rotate
more slowly than a small machine, so the cutting speed isn't actually
that much different. As an "angle grinder" for use on metal, it's just
not as handy as a 4 1/2".

What it will do is turn a big stone cutting disk, so it will slice
bricks and slabs for you. A 4 1/2" just doesn't have the reach.

So take you 20 quid, and buy it. Get one each of stone/metal grind/cut
disks. If you're doing anything that needs a clean cut, get a diamond
disk too.

You'll kill it eventually. But for a 9" grinder and "typical" use, I
really don't think you'll do it in a hurry.

If you are working a lot of steel grinding, then use 7" flap disks
instead and buy a grinder (like my Makita) that costs about £80 and
upwards. The advantage is that they weigh around half of a cheap
grinder, and for 9" machines that's significant.

The 7" flap wheel is because it's lighter than a 9" rigid disk, and
you don't suffer the gyroscope problem. I also prefer flap wheel to
rigids, for almost all tasks.

What I really wish I had is a 7" grinder. But it looks like those
only come from Mafell or Fein, and cost around £200.



Now for 4 1/2" grinders, it's a whole different story. These are
really useful machines and I keep them out on the bench permanently (I
might do an hour or two's grinding a day, if I'm in the metal
workshop). I buy the good Bosch ones, and I wear those to death fairly
rapidly. I just can't see how under a tenner can be a good investment,
because there _is_ a reliability difference, even on the better ones.

If you get a 4 1/2" grinder, then buy samples of every abrasive disk
you can find for it. They increase the versatility enormously. Most of
the time I use flap wheels, or twisted wire cup wheels. Sometimes (for
working inside corners) I use a rigid disk, usually a cut disk. The
others see a range of use, but it's the flap wheels that do most of
the work.

Screwfix is a decent source for abrasives, but also try the 3M Beartex
from RS, the non-round sandpaper disks(sic) from the same source (they
don't leave scratches from the edge of a disk). The best flap wheels
are from CSM - they have a lighter backing than the Garryson, they
offer 120 grit, and they also have a top-quality range with a top
dressing - these are clogproof on most materials.

Comfortable goggles and earmuffs are a must. I like a faceshield
instead of goggles, but this needs a fabric chin cover, or sparks can
go underneath. For ears I like mil-surplus Peltors (about a fiver or
so - get a bagful for workshop visitors too). Get the artillery or
cook's version (big cups) not the squaddie version with the thin cups
to fit under a helmet (and no sound deadening).

I used to use anti-vibration gloves with angle grinders, but now I
just use neoprene grips stuck to the machine handles and
leather/canvas rigger gloves. I don't think that either the gel or the
air gloves gave me enough hand protection for grinding. Neoprene grips
give as much vibration reduction as the gloves too - air gloves were
particularly disappointing, as they only cushioned the palms.



--
Smert' spamionam