Quick one...

For some historical reason I have a rectangular gully in my drive,
which has (and probably always has had) a standard square cast iron
grid over it, which overlaps the gully by about 2", so it looks crap,
wobbles, and lets rubbish in.

I thought I'd try and cut off the offending overlap; however knowing
the propensity of cast iron for shattering I thought I'd check here
before diving in. Would an angle grinder do it OK? Ot would it need a
hack saw (which might well mean 'sod it ;et's have a plastic grid
instead!!)

David

"Lobster" wrote in message
oups.com...
Quick one...

For some historical reason I have a rectangular gully in my drive,
which has (and probably always has had) a standard square cast iron
grid over it, which overlaps the gully by about 2", so it looks crap,
wobbles, and lets rubbish in.

I thought I'd try and cut off the offending overlap; however knowing
the propensity of cast iron for shattering I thought I'd check here
before diving in. Would an angle grinder do it OK? Ot would it need a
hack saw (which might well mean 'sod it ;et's have a plastic grid
instead!!)

The plastic grills are very good, I'm sad to say. No point in messing about
with cast iron. Even Spouse wouldn't, he was a ferrous metallurgist.

Mary

"Mary Fisher" wrote in message
t...
SNIP

The plastic grills are very good, I'm sad to say. No point in
messing about
with cast iron. Even Spouse wouldn't, he was a ferrous metallurgist.

Mary



Isn't he a bit rusty now then ???

AWEM

"Andrew Mawson" wrote in message
...

"Mary Fisher" wrote in message
t...
SNIP

The plastic grills are very good, I'm sad to say. No point in
messing about
with cast iron. Even Spouse wouldn't, he was a ferrous metallurgist.

Mary



Isn't he a bit rusty now then ???

He certainly has a metallic aroma about him when he's working with iron ...
I got used to it fifty years ago!

Today he's been working with birch so it's a different scent :-)

Mary

AWEM

In article .com,
Lobster wrote:
I thought I'd try and cut off the offending overlap; however knowing
the propensity of cast iron for shattering I thought I'd check here
before diving in. Would an angle grinder do it OK? Ot would it need a
hack saw (which might well mean 'sod it ;et's have a plastic grid
instead!!)

Angle grinder will be fine, but take it steady. In a stand would be best.

--
*In "Casablanca", Humphrey Bogart never said "Play it again, Sam" *

Dave Plowman London SW
To e-mail, change noise into sound.

On 24 Jul 2006 08:03:09 -0700, "Lobster"
wrote:

I thought I'd try and cut off the offending overlap; however knowing
the propensity of cast iron for shattering I thought I'd check

Dead easy.

We used to nick it with a saw or grinder, then break it with a
hammerblow and there was a small risk of breakage. Nowadays I'd just
grind all the way through and not worry.

BTW - grinding cheap cast iron is a filthy job, owing to the free carbon
going everywhere.

Andy Dingley wrote:
On 24 Jul 2006 08:03:09 -0700, "Lobster"
wrote:

I thought I'd try and cut off the offending overlap; however knowing
the propensity of cast iron for shattering I thought I'd check

Dead easy.

Hmm...

We used to nick it with a saw or grinder, then break it with a
hammerblow and there was a small risk of breakage. Nowadays I'd just
grind all the way through and not worry.

BTW - grinding cheap cast iron is a filthy job, owing to the free carbon
going everywhere.

Had a go last night; my (little 5") grinder protested muchly, taking
about 10 mins to cut through just one of the 7 elements of the grid. So
I'll reluctantly be including a nasty little plastic grid in my next
Screwfix order!

The one cut it made was adnittedly nice and clean, and the grid got
extremely hot. Out of interest, why wasn't there the usual shower of
sparks while i was using the grinder (this being cast iron)?

David

The message
from Lobster contains these words:

The one cut it made was adnittedly nice and clean, and the grid got
extremely hot. Out of interest, why wasn't there the usual shower of
sparks while i was using the grinder (this being cast iron)?

'Cos cast iron doesn't do that sort of spark. If you'd done it at night
you'd have seen red streaks instead.

--
Skipweasel
Pay no attention to that man behind the curtain.

Guy King wrote:
The message
from Lobster contains these words:

The one cut it made was adnittedly nice and clean, and the grid got
extremely hot. Out of interest, why wasn't there the usual shower of
sparks while i was using the grinder (this being cast iron)?

'Cos cast iron doesn't do that sort of spark.

Yeah but what I meant is why? (one for the Fisher Spouse? :-) )

David

"Lobster" wrote in message
...

Had a go last night; my (little 5") grinder protested muchly, taking
about 10 mins to cut through just one of the 7 elements of the grid. So
I'll reluctantly be including a nasty little plastic grid in my next
Screwfix order!

Honestly, they're good. I wouldn't tolerate a nasty one, I'm well pleased
with ours though.

Mary

"Lobster" wrote in message
...
Guy King wrote:
The message
from Lobster contains these words:

The one cut it made was adnittedly nice and clean, and the grid got
extremely hot. Out of interest, why wasn't there the usual shower of
sparks while i was using the grinder (this being cast iron)?

'Cos cast iron doesn't do that sort of spark.

Yeah but what I meant is why? (one for the Fisher Spouse? :-) )

I'll ask him when he comes back from Lidl - new fire extinguisher and things
I can't remember.

What do you MEAN - I'm not interested???

Of course I am.

Mary
yawning

"Lobster" wrote in message
...
Guy King wrote:
The message
from Lobster contains these words:

The one cut it made was adnittedly nice and clean, and the grid got
extremely hot. Out of interest, why wasn't there the usual shower of
sparks while i was using the grinder (this being cast iron)?

'Cos cast iron doesn't do that sort of spark.

Yeah but what I meant is why? (one for the Fisher Spouse? :-) )

Right, he's back, with fire extinguisher, silicone spray, a couple of other
things and a £10 radio controlled amphibion - says it's for me beaue I've
always wanted a boat but really it's to cheer him up after the session we
had with the oncologist this morning :-) I shan't let him go shopping
without me again.

He says that there are many different grades of cast iron, which we all knew
really if we'd thought about - I'm not talking about wrought iron or steel,
mild or any other kind.

He can't say for sure without knowing the quality of your item but most cast
irons won't send out white sparks because of the lubrication effect of the
free graphite (the carbon Andy Dingley mentioned). Spouse would expect dull
red sparks if anything (as Guy suggested).

The heat generated by the grinding is also dependent on the quality of the
iron - not your equipment or your skill so don't feel inadequate on either
count.

It's not a simple matter - if it were you wouldn't need every batch of iron
to be controlled by laboratory analysis according to the job for which it's
intended. But as with most things we all tend to generalise ...

Does this help?

Mary

David

"Mary Fisher" wrote in message
. net...

He's been thinking about it and said that it might be a ductile iron even
though it's cast, that would make it more suitable for a gully grid where
there would be traffic (even pedestrian traffic).

That adds another element to the matter. I wish I hadn't said anything :-)

Then, of course, there's the type of abrasive you were using ... PLEASE
don't ask for an explanation of that!

Mary.

Mary Fisher wrote:
"Lobster" wrote in message
...
Guy King wrote:
The message
from Lobster contains these words:

The one cut it made was adnittedly nice and clean, and the grid got
extremely hot. Out of interest, why wasn't there the usual shower of
sparks while i was using the grinder (this being cast iron)?
'Cos cast iron doesn't do that sort of spark.
Yeah but what I meant is why? (one for the Fisher Spouse? :-) )


He says

[...]

Does this help?

Excellent! More than I ever wanted to know and more besides: please pass
on my thanks!

David

"Lobster" wrote in message
...
Mary Fisher wrote:
"Lobster" wrote in message
...
Guy King wrote:
The message
from Lobster contains these words:

The one cut it made was adnittedly nice and clean, and the grid got
extremely hot. Out of interest, why wasn't there the usual shower of
sparks while i was using the grinder (this being cast iron)?
'Cos cast iron doesn't do that sort of spark.
Yeah but what I meant is why? (one for the Fisher Spouse? :-) )


He says

[...]

Does this help?

Excellent! More than I ever wanted to know and more besides: please pass
on my thanks!

OK, thanks for saying that. He'll be pleased.

But I know that he'll also say that he didn't say anything really ... :-)

Mary

David

On Thu, 27 Jul 2006 07:26:00 GMT, Lobster
wrote:

The one cut it made was adnittedly nice and clean, and the grid got
extremely hot.

I'm surprised - were you using a metal cutting disk, not a stone or a
grinding disk ?

Out of interest, why wasn't there the usual shower of
sparks while i was using the grinder (this being cast iron)?

You can identify steel grades quite well by "spark testing" like this
(web search for more)

Cast iron is a crude mixture of iron and carbion, not an alloy like
steel. Look with a magnifying glass and you'll see the separate
particles. When you grind it you get these dull red glowing particles
of iron, and very few sparks (burning particles). It's mainly because
the graphite lubricates the cut and keeps the heat down, so not
lighting the sparks in the first place. Also the iron has a relatively
low energy when burning, so tends to go out rather than burning up.

If you grind highly-alloyed high speed steel, then the sparks "burst"
some distance from the wheel. They're hot sparks to begin with, but
their burning causes them to get even hotter as they fly.