A number of bells have been cast in brass. The castings are somewhat
rough, and the outside needs polishing.
I don't see how to do this on a lathe. The castings are not perfectly
round and would need too much metal taken off.
There is a hole in the middle, andI I propose putting a bolt through
and spiinnng the bells slowly in a drill press while using a flappy
wheel on an angle grinder to polish them.
Unless anyone has a better idea!

Matty F wrote:
A number of bells have been cast in brass. The castings are somewhat
rough, and the outside needs polishing.
I don't see how to do this on a lathe. The castings are not perfectly
round and would need too much metal taken off.

well cast them again properly!

There is a hole in the middle, andI I propose putting a bolt through
and spiinnng the bells slowly in a drill press while using a flappy
wheel on an angle grinder to polish them.
Unless anyone has a better idea!

Do it right second time. If you want a proper tone, they need to be
trued up.

On Oct 25, 1:00 am, The Natural Philosopher
wrote:
Matty F wrote:
A number of bells have been cast in brass. The castings are somewhat
rough, and the outside needs polishing.
I don't see how to do this on a lathe. The castings are not perfectly
round and would need too much metal taken off.

well cast them again properly!

The original bell is 100 years old. I don't want them to look modern,
just polished.

There is a hole in the middle, andI I propose putting a bolt through
and spiinnng the bells slowly in a drill press while using a flappy
wheel on an angle grinder to polish them.
Unless anyone has a better idea!

Do it right second time. If you want a proper tone, they need to be
trued up.

They sound fine already.

On 24/10/10 13:35, Matty F wrote:


They sound fine already.

Then leave them alone. You might be able to get some help from the
Whitechapel Bell Foundry but I suspect their advice will be the same as
mine. Bells are tuned before they leave the foundry. If you try to mess
around with them at best you are likely to detune them and at worse
fubar requiring them to be scrapped and recast.


--
Bernard Peek

On Oct 25, 2:14 am, Bernard Peek wrote:
On 24/10/10 13:35, Matty F wrote:



They sound fine already.

Then leave them alone. You might be able to get some help from the
Whitechapel Bell Foundry but I suspect their advice will be the same as
mine. Bells are tuned before they leave the foundry. If you try to mess
around with them at best you are likely to detune them and at worse
fubar requiring them to be scrapped and recast.

They are not musical instruments - they just make a ding ding noise
and llook shiny.
Any pitch will do.It's better if they all make different noises, then
the driver will know which bell is which!

Here's one that somebody else polished:
http://i45.tinypic.com/2h4evxc.jpg

Matty F wrote:
On Oct 25, 2:14 am, Bernard Peek wrote:
On 24/10/10 13:35, Matty F wrote:



They sound fine already.
Then leave them alone. You might be able to get some help from the
Whitechapel Bell Foundry but I suspect their advice will be the same as
mine. Bells are tuned before they leave the foundry. If you try to mess
around with them at best you are likely to detune them and at worse
fubar requiring them to be scrapped and recast.

They are not musical instruments - they just make a ding ding noise
and llook shiny.
Any pitch will do.It's better if they all make different noises, then
the driver will know which bell is which!

Here's one that somebody else polished:
http://i45.tinypic.com/2h4evxc.jpg


Oh just use hand held emery then followed by Brasso or equivalent.


Your hand will 'follow' the eccentricity if you use low spindle speeds.

On 24/10/2010 12:50, Matty F wrote:
A number of bells have been cast in brass. The castings are somewhat
rough, and the outside needs polishing.
I don't see how to do this on a lathe. The castings are not perfectly
round and would need too much metal taken off.
There is a hole in the middle, andI I propose putting a bolt through
and spiinnng the bells slowly in a drill press while using a flappy
wheel on an angle grinder to polish them.
Unless anyone has a better idea!

If you want to do it by machine, rather than by hand, the correct
equipment is a spindle polishing machine with a calico mop and brass
polishing compound. A flap wheel is far too aggressive for polishing brass.

Colin Bignell

"Matty F" wrote in message
...
A number of bells have been cast in brass. The castings are somewhat
rough, and the outside needs polishing.
I don't see how to do this on a lathe. The castings are not perfectly
round and would need too much metal taken off.
There is a hole in the middle, andI I propose putting a bolt through
and spiinnng the bells slowly in a drill press while using a flappy
wheel on an angle grinder to polish them.
Unless anyone has a better idea!

Have a word with this lot... www.thepolishingshop.co.uk/

I suspect that using a smaller diameter flap wheel and not too coarse grit
will take time but produce the result you need prior to proper polishing
with a proper buffing machine. Remember that pre-buffing finish should be as
fine as you can get with whatever method you use as finish buffing will take
longer otherwise. Also the finishing produces quite a bit of heat, so
working the full set of bells in rotation should give you time to let them
cool. even wearing gloves you'll get hot hands...

Obviously you could hand polish them but it is a very laborious process, so
perhaps finishing off with their polishing kits on
http://www.thepolishingshop.co.uk/ac...hing_Kits.html
will give you a proper looking job.

You can make a simple mandrel for the polishing mops and mount in your lathe
so as to make a substitute polishing machine. Using the right soaps and the
right mops and you'll produce a good finish.

When finished you might like to have them sealed with a clear coat of
lacquer

"Matty F" wrote in message
...
A number of bells have been cast in brass. The castings are somewhat
rough, and the outside needs polishing.
I don't see how to do this on a lathe. The castings are not perfectly
round and would need too much metal taken off.
There is a hole in the middle, andI I propose putting a bolt through
and spiinnng the bells slowly in a drill press while using a flappy
wheel on an angle grinder to polish them.
Unless anyone has a better idea!

I'd say you are probably more experienced at this than the rest of us, but,
as it is brass, then I would start off with a brass brush wheel (a good
thick, but fine wired one: not one of the typical 'shed' things, and
definitely not one that is just brass plated!). Then move on to the proper
polishing mops and 'soaps'.

At a pinch - and depending on the bell size - you might be able to make a
reciprocal sander, that can take some of the pain out of hand polishing the
tricky bits. I once made one of these from a 'side to side' type electric
razor, with a half a wooden clothes peg stuck on where the shaver part used
to be. Stuck strips of different grades of emery on the peg with double
sided tape, and used it to get all the casting marks out of a pair of
carbeuretters (never can spell that!) before the final buff up. (Riffler
files are handy too.)

S

On Oct 25, 4:24 am, "Nightjar \"cpb\"@" "insertmysurnamehere wrote:
On 24/10/2010 12:50, Matty F wrote:

A number of bells have been cast in brass. The castings are somewhat
rough, and the outside needs polishing.
I don't see how to do this on a lathe. The castings are not perfectly
round and would need too much metal taken off.
There is a hole in the middle, andI I propose putting a bolt through
and spiinnng the bells slowly in a drill press while using a flappy
wheel on an angle grinder to polish them.
Unless anyone has a better idea!

If you want to do it by machine, rather than by hand, the correct
equipment is a spindle polishing machine with a calico mop and brass
polishing compound. A flap wheel is far too aggressive for polishing brass.

The bells have been cast in sand, so I need to take a lot of metal off
before using the spindle polishing machine. They are plenty thick
enough. I could take 1mm off if necessary. That will alter the pitch
for sure!

Matty F FIRST wrote:

A number of bells have been cast in brass. The castings are somewhat
rough, and the outside needs polishing.

Then LATER wrote:

They are not musical instruments - they just make a ding ding noise
and llook shiny.
Any pitch will do.It's better if they all make different noises, then
the driver will know which bell is which!
Here's one that somebody else polished:
http://i45.tinypic.com/2h4evxc.jpg

Well flippin' 'eck!! Am I the only one who thought Matty was talking
about Bells, as in Church Bells?!?

You're also in NZ Matty (by the look of it), so "local" uk.d-i-y advice
ain't a lot of use to you!

Personally -- seeing the "here's one we did earlier" -- I'd just get the
Brasso out, along with the old tooth brushes.

J.

On Oct 25, 5:56 am, "R" None@don't work wrote:
"Matty F" wrote in message

...

A number of bells have been cast in brass. The castings are somewhat
rough, and the outside needs polishing.
I don't see how to do this on a lathe. The castings are not perfectly
round and would need too much metal taken off.
There is a hole in the middle, andI I propose putting a bolt through
and spiinnng the bells slowly in a drill press while using a flappy
wheel on an angle grinder to polish them.
Unless anyone has a better idea!

Have a word with this lot...www.thepolishingshop.co.uk/

I suspect that using a smaller diameter flap wheel and not too coarse grit
will take time but produce the result you need prior to proper polishing
with a proper buffing machine. Remember that pre-buffing finish should be as
fine as you can get with whatever method you use as finish buffing will take
longer otherwise. Also the finishing produces quite a bit of heat, so
working the full set of bells in rotation should give you time to let them
cool. even wearing gloves you'll get hot hands...

Obviously you could hand polish them but it is a very laborious process, so
perhaps finishing off with their polishing kits onhttp://www.thepolishingshop.co.uk/acatalog/Polishing_Kits.html
will give you a proper looking job.

You can make a simple mandrel for the polishing mops and mount in your lathe
so as to make a substitute polishing machine. Using the right soaps and the
right mops and you'll produce a good finish.

When finished you might like to have them sealed with a clear coat of
lacquer

I'm not after an extremely high polish, although that's easy enough.
The main problem is to get rid of the sand casting finish first.
I just realised that there's a collet chuck that will fit the big
drill press, and that will hold the bolt that I will put through the
bell.
With a three jaw chuck I would have to sand the bell from underneath
so that the pressure of sanding doesn't make it fall out of the chuck.
With the collet chuck I can sand the bell from the top. I propose
running the drill at about 60 rpm. The inside of the bell doesn't need
polishing.

On 24/10/2010 21:16, Another John wrote:
Matty FIRST wrote:

A number of bells have been cast in brass. The castings are somewhat
rough, and the outside needs polishing.

Then LATER wrote:

They are not musical instruments - they just make a ding ding noise
and llook shiny.
Any pitch will do.It's better if they all make different noises, then
the driver will know which bell is which!
Here's one that somebody else polished:
http://i45.tinypic.com/2h4evxc.jpg

Well flippin' 'eck!! Am I the only one who thought Matty was talking
about Bells, as in Church Bells?!?

You're also in NZ Matty (by the look of it), so "local" uk.d-i-y advice
ain't a lot of use to you!

You seriously misunderestimate him.

He has been posting here for quite some time and has impressed us with
his talents and ingenuity.

Dave

On 24 Oct, 12:50, Matty F wrote:
A number of bells have been cast in brass. The castings are somewhat
rough, and the outside needs polishing.

Chuck them in the lathe, using a woooden jam chuck turned up to fit
securely inside. Ideal jams chucks are turned to be a perfect fit for
each bell, but you won't do this. Gluing neoprene foam on can make one
jam chuck work for multiple bells, although it does reduce the
clamping force. Another way is to coat the jam chuck with a spiral of
hot-melt glue before shoving it in the casting.

Then use the lathe to rotate them slowly. Use your favourite angle
grinder and flap wheel to then polish them. Foam backed flap wheels
are even better (foam between the flaps - more conformal). Don't use a
hard disk! Do put a sheet over the lathe, or else use your dedicated
grinding lathe (with the worn bedways). A gentle action with the
grinder and a slow lathe speed will cope with an oval bell. Finish
with a Garryflex block by hand (still rotating in the lathe) to make
neat circular brushmarks.

Plain brass isn't a good bell alloy (goes clunk, not ting!) and you
really want a bit of tin (or modern pewter) in there.

On Oct 25, 10:59 am, Andy Dingley wrote:
On 24 Oct, 12:50, Matty F wrote:

A number of bells have been cast in brass. The castings are somewhat
rough, and the outside needs polishing.

Chuck them in the lathe, using a woooden jam chuck turned up to fit
securely inside. Ideal jams chucks are turned to be a perfect fit for
each bell, but you won't do this. Gluing neoprene foam on can make one
jam chuck work for multiple bells, although it does reduce the
clamping force. Another way is to coat the jam chuck with a spiral of
hot-melt glue before shoving it in the casting.

Since there's a hole in the middle of the bell, it would be easy to
bolt it to the wood.

Then use the lathe to rotate them slowly. Use your favourite angle
grinder and flap wheel to then polish them. Foam backed flap wheels
are even better (foam between the flaps - more conformal). Don't use a
hard disk! Do put a sheet over the lathe, or else use your dedicated
grinding lathe (with the worn bedways). A gentle action with the
grinder and a slow lathe speed will cope with an oval bell. Finish
with a Garryflex block by hand (still rotating in the lathe) to make
neat circular brushmarks.

The chief engineer won't let anyone grind on the new lathe, so I think
that's out. However I think the drill press with a collet check will
do the job. Another way is to put the bell in a portable drill and
rotate it against the saggy part of a linisher. But I can't fit a
collet chuck to a portable drill, and the linisher is a huge dangerous
thing! I'd probably sand a hole in the bell.

Plain brass isn't a good bell alloy (goes clunk, not ting!) and you
really want a bit of tin (or modern pewter) in there.

Well, I call them brass but they are bound to be the right alloy. They
do make a nice ringing sound. I suspect the foundry does them at mates
rates.

I made these knockers for the bells to match the old one that's been
hitting bells for a hundred years and has got a bit flattened.
http://i54.tinypic.com/wa537t.jpg
The bells face downwards and the knockers are hit upwards through a
hole and hit the bell and fall back a tiny bit even if someone holds
on the the pull cord.

This is the first time I've cut a diagonal on the lathe. Nobody told
me to start the diagonal cut near the middle instead of the outside.
So one is not so good. Never mind, it's inside a hole where nobody
will see it!

On Sun, 24 Oct 2010 21:16:45 +0100, Another John wrote:

Matty F FIRST wrote:

A number of bells have been cast in brass. The castings are somewhat
rough, and the outside needs polishing.

Then LATER wrote:

They are not musical instruments - they just make a ding ding noise and
llook shiny.
Any pitch will do.It's better if they all make different noises, then
the driver will know which bell is which! Here's one that somebody else
polished: http://i45.tinypic.com/2h4evxc.jpg

Well flippin' 'eck!! Am I the only one who thought Matty was talking
about Bells, as in Church Bells?!?

Not if you've read most of Matty's posts :-)

You're also in NZ Matty (by the look of it), so "local" uk.d-i-y advice
ain't a lot of use to you!

Why not? I'm in the US these days (coming up on three years now) and this
ng's by far the best when it comes to asking/learning about the proper
tricks and techniques to do various things - it's surprising how little
"UK-specific" traffic there is, and most stuff is relevant no matter
where you are in the world.

cheers

Jules

On 24/10/2010 21:12, Matty F wrote:
On Oct 25, 4:24 am, "Nightjar\"cpb\"@""insertmysurnamehere wrote:
On 24/10/2010 12:50, Matty F wrote:

A number of bells have been cast in brass. The castings are somewhat
rough, and the outside needs polishing.
I don't see how to do this on a lathe. The castings are not perfectly
round and would need too much metal taken off.
There is a hole in the middle, andI I propose putting a bolt through
and spiinnng the bells slowly in a drill press while using a flappy
wheel on an angle grinder to polish them.
Unless anyone has a better idea!

If you want to do it by machine, rather than by hand, the correct
equipment is a spindle polishing machine with a calico mop and brass
polishing compound. A flap wheel is far too aggressive for polishing brass.

The bells have been cast in sand, so I need to take a lot of metal off
before using the spindle polishing machine. They are plenty thick
enough. I could take 1mm off if necessary. That will alter the pitch
for sure!

It is perfectly possible to produce a polished sand finish but, if you
want a smooth polished finish, then you do need to take material off. I
would still do that on a spindle polisher myself, but using a more
aggressive mop and compound combination to start with. However, we are
then getting into the field of which equipment each of us feels most
comfortable with.

Colin Bignell

On 25 Oct, 00:49, Matty F wrote:

Since there's a hole in the middle of the bell, it would be easy to
bolt it to the wood.

I'd still use a jam chuck. It avoids the cantilever aspect and
inevitable wobbliness of clamping through a bolt at one end.


The chief engineer won't let anyone grind on the new lathe, so I think
that's out.

Wise. That's why you need a grinding lathe. They're cheap, because
you can use the clapped out old clunker that the S/H machinery dealer
wants rid of for just the scrap price of the copper in the motor.

On Oct 25, 12:49*am, Matty F wrote:

Plain brass isn't a good bell alloy (goes clunk, not ting!) and you
really want a bit of tin (or modern pewter) in there.

Well, I call them brass but they are bound to be the right alloy. They
do make a nice ringing sound. I suspect the foundry does them at mates
rates.

I made these knockers for the bells to match the old one that's been
hitting bells for a hundred years and has got a bit flattened.http://i54.tinypic.com/wa537t.jpg
The bells face downwards and the knockers are hit upwards through a
hole and hit the bell and fall back a tiny bit even if someone holds
on the the pull cord.

I think that's important - from what I gather the best way to crack
the bell is to hit it with something that's not free to rebound
afterwards. Talking to the chap at the Whitechapel foundry I gather
that bell metal is a copper/tin alloy, though it has more tin than the
more common bronzes, which is why it looks yellow like brass rather
than the normal kind of reddish colour. It's a bit of a compromise -
it needs to be fairly hard to ring properly, but if you put a bit too
much tin in it becomes too brittle and cracks
Mike

On 25/10/2010 14:35, docholliday wrote:
I think that's important - from what I gather the best way to crack
the bell is to hit it with something that's not free to rebound
afterwards. Talking to the chap at the Whitechapel foundry I gather
that bell metal is a copper/tin alloy, though it has more tin than the
more common bronzes, which is why it looks yellow like brass rather
than the normal kind of reddish colour. It's a bit of a compromise -
it needs to be fairly hard to ring properly, but if you put a bit too
much tin in it becomes too brittle and cracks
Mike

I shall share this so you can all suffer.

The "Liberty Bell" in Philadelphia is an American icon. It's famed for
its enormous crack.

http://en.wikipedia.org/wiki/Liberty_Bell

has a long discussion on different metals and their impact (!) on the
sound of the bell.

Now you can all hum the Monty Python theme all night with me. It's
Sousa's march "Liberty Bell"!

Andy

In article ,
Dave wrote:

Well flippin' 'eck!! Am I the only one who thought Matty was talking
about Bells, as in Church Bells?!?

You're also in NZ Matty (by the look of it), so "local" uk.d-i-y advice
ain't a lot of use to you!

You seriously misunderestimate him.
He has been posting here for quite some time and has impressed us with
his talents and ingenuity.

Beg pardon Matty: never noticed you before, probably because your
spheres of interest rarely overlap mine. I _did_ notice your NZ address
though, hence my suggestion that any advice to contact UK firms with a
view to visiting wouldn't be a lot of use. (I wasn't underestimating
him Dave: I wasn't making any judgement at all.)

J.

On 25/10/2010 9:16 a.m., Another John wrote:
Matty FIRST wrote:

A number of bells have been cast in brass. The castings are somewhat
rough, and the outside needs polishing.

Then LATER wrote:

They are not musical instruments - they just make a ding ding noise
and llook shiny.
Any pitch will do.It's better if they all make different noises, then
the driver will know which bell is which!
Here's one that somebody else polished:
http://i45.tinypic.com/2h4evxc.jpg

Well flippin' 'eck!! Am I the only one who thought Matty was talking
about Bells, as in Church Bells?!?

I thought of trains pulled by steam engines.

OT: Anyone see the Russian film Andrei Rublev? A classic, IMO. It ends with
the casting of an enormous bell.

On 25/10/2010 21:22, Another John wrote:

Beg pardon Matty: never noticed you before, probably because your
spheres of interest rarely overlap mine. I _did_ notice your NZ address
though, hence my suggestion that any advice to contact UK firms with a
view to visiting wouldn't be a lot of use. (I wasn't underestimating
him Dave: I wasn't making any judgement at all.)

No offence taken John. The group has been fascinated with his projects.

Dave

On 25/10/2010 22:39, Gib Bogle wrote:
On 25/10/2010 9:16 a.m., Another John wrote:
Matty FIRST wrote:

A number of bells have been cast in brass. The castings are somewhat
rough, and the outside needs polishing.

Then LATER wrote:

They are not musical instruments - they just make a ding ding noise
and llook shiny.
Any pitch will do.It's better if they all make different noises, then
the driver will know which bell is which!
Here's one that somebody else polished:
http://i45.tinypic.com/2h4evxc.jpg

Well flippin' 'eck!! Am I the only one who thought Matty was talking
about Bells, as in Church Bells?!?

I thought of trains pulled by steam engines.


I thought about trams :-)

Dave

On Oct 26, 9:22 am, Another John wrote:
In article ,

Dave wrote:
Well flippin' 'eck!! Am I the only one who thought Matty was talking
about Bells, as in Church Bells?!?

You're also in NZ Matty (by the look of it), so "local" uk.d-i-y advice
ain't a lot of use to you!

You seriously misunderestimate him.
He has been posting here for quite some time and has impressed us with
his talents and ingenuity.

Beg pardon Matty: never noticed you before, probably because your
spheres of interest rarely overlap mine. I _did_ notice your NZ address
though, hence my suggestion that any advice to contact UK firms with a
view to visiting wouldn't be a lot of use. (I wasn't underestimating
him Dave: I wasn't making any judgement at all.)

Like many New Zealanders I'm keen on d-i-y. A hundred years ago, spare
parts from Britain took months to arrive, so my ancestors fabricated
them instead. My father went through the depression of the 1930s and
had no money to pay tradesmen. I've carried on and do almost
everything myself. I'm possibly slower than some tradesmen but I have
the time to do things properly.
Now I have access to a good workshop, with lots of unusual projects to
restore old machinery.
Since the UK has a much bigger population than NZ, it's more likely
that UK people wil be able to suggest solutions to problems.

In article
,
Matty F wrote:
Like many New Zealanders I'm keen on d-i-y. A hundred
years ago, spare parts from Britain took months to
arrive, so my ancestors fabricated them instead. My
father went through the depression of the 1930s and had
no money to pay tradesmen. I've carried on and do almost
everything myself. I'm possibly slower than some
tradesmen but I have the time to do things properly. Now
I have access to a good workshop, with lots of unusual
projects to restore old machinery. Since the UK has a
much bigger population than NZ, it's more likely that UK
people wil be able to suggest solutions to problems.
Just the sort of philosophy you expect from people brought
up with Hobbits all around ;-)

John

--
John Mulrooney
NOTE Email address IS correct but might not be checked for a while.

I used to have a handle on life, but it broke

On Oct 27, 1:37 am, JTM wrote:

Just the sort of philosophy you expect from people brought
up with Hobbits all around ;-)

Isn't that the movie that's going to be filmed in Ireland?

On 26/10/2010 13:37, JTM wrote:
Just the sort of philosophy you expect from people brought
up with Hobbits all around ;-)

John


"Hobbit shooting starts" the headline said...

On Oct 27, 8:47 am, Andy Champ wrote:
On 26/10/2010 13:37, JTM wrote:

Just the sort of philosophy you expect from people brought
up with Hobbits all around ;-)

John

"Hobbit shooting starts" the headline said...

Only announced 3 minutes ago

Matty F wrote:
On Oct 27, 8:47 am, Andy Champ wrote:
On 26/10/2010 13:37, JTM wrote:

Just the sort of philosophy you expect from people brought
up with Hobbits all around ;-)
John
"Hobbit shooting starts" the headline said...

Only announced 3 minutes ago

Oh is it open season on Hobbits?

I'll get me Purdey...