Repair a small cast bell

[gerry maddenParticipant @gerrymadden53711]

Excellent repair, and I can confirm that the pitch is correct !

Gerry

[Trevor Drabble 1Participant @trevordrabble1]

Simon , Excellent job , well done . Regarding the finish you are wanting , suggest you may find it useful to contact Black-it . No connection with company .

Trevor.

[Grindstone CowboyParticipant @grindstonecowboy]

Don't know what it is or where you'd get it, but I believe there is a chemical used to patinate newly cast bronze statues.

Rob

[bernard towersParticipant @bernardtowers37738]

Problem is that any chemical blacking won't take on the bronze repair. you could try a VHT barbecue paint

[simondavies3Participant @simondavies3]

Posted by bernard towers on 31/07/2023 16:50:14:

Problem is that any chemical blacking won't take on the bronze repair. you could try a VHT barbecue paint

I believe that there is very little bronze exposed on the outside – and I can attack it further to leave just the trace of the repair – and its not blackening, its a verdigris finish which in my logical way (meaning unknowledgeable) should also advere/affect bronze thanks to the copper content. But then, I never made any pretence to be a chemist!

I think Rob may have the general idea, problem I have found so far is the torrent of search engine hits referencing painted on patina finishes…

[Michael GilliganParticipant @michaelgilligan61133]

Verdigris [ the real deal, not just a colour] is formed on cuprous materials

ergo … the original colour on the cast Iron is not actual verdigris

MichaelG.

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This Wikipedia page may possibly help: https://en.wikipedia.org/wiki/Verdigris

Edited By Michael Gilligan on 31/07/2023 17:37:10

[simondavies3Participant @simondavies3]

Posted by Michael Gilligan on 31/07/2023 17:34:44:

Verdigris [ the real deal, not just a colour] is formed on cuprous materials

ergo … the original colour on the cast Iron is not actual verdigris

Michael, I totally agree – but I am at a loss to know what else to call it…
As you can see from the original photos at the top of this thread and Gerry's later, it resembles verdigris and I am convinced its a chemical effect since there were no fumes or surface material burning away when I heated it.

If you know what it may be called, I am sure that would advance me in my search…currently 'not-verdigris', is not helping!

[Michael GilliganParticipant @michaelgilligan61133]

Sorry, Simon … not really very helpful was it !

For my penance, I shall go searching on your behalf

MichaelG.

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Edit: __ before I do, I should mention that I did have one idea about it … if the iron bell was first copper-plated then real verdigris could be formed in the plating.

Edited By Michael Gilligan on 31/07/2023 18:32:36

[Michael GilliganParticipant @michaelgilligan61133]

If you decide to try the copper-plating route, this looks a very thorough tutorial on doing that without the use of nasty acids : **LINK**

MichaelG.

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Edit: __ this doesn’t tell us much, but it’s attractive :

https://omotenashi-square.com/products/japanese-cast-iron-temple-wind-bell

 

Edited By Michael Gilligan on 31/07/2023 19:10:39

[simondavies3Participant @simondavies3]

Thanks Michael, good to know that you are on the case!

I did wonder about copper plating, just wasn't sure that this is how it would have been done originally.

Hopefully your penance will reveal all!

Simon

[Grindstone CowboyParticipant @grindstonecowboy]

Well, these might work, or could end in disaster..

Links to https://www.sciencecompany.com/Patina-Formulas-for-Brass-Bronze-and-Copper.aspx

Rob

[Michael GilliganParticipant @michaelgilligan61133]

I think you might do well to ask this bay seller whether it would/should work: **LINK**

https://www.ebay.co.uk/itm/262931185082

MichaelG.

[peak4Participant @peak4]

I wonder if the original was applies hot, such as in the production of these Japanese tea kettles; about 6 minutes in, though the whole video is worth watching

Though I did see this commercial video whilst I was wandering around the net as well

Bill

Edited By peak4 on 31/07/2023 21:31:53

[Michael GilliganParticipant @michaelgilligan61133]

Fascinating video, Bill … thanks for sharing it

Frustrating though, to hear only the word lacquer used in reference to whatever was dusted onto the hot metal

MichaelG.

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Edited By Michael Gilligan on 01/08/2023 07:59:31

[simondavies3Participant @simondavies3]

Posted by Michael Gilligan on 01/08/2023 07:51:55:

Fascinating video, Bill … thanks for sharing it

Frustrating though, to hear only the word lacquer used in reference to whatever was dusted onto the hot metal

MichaelG.

Yes, agree with Michael on both counts….

[Howard LewisParticipant @howardlewis46836]

If you want to copper plate it, being ferrous, suspend it in a solution of copper suphate for a few hours.

Because of the relative position of Iron and Copper in the electrochemical series, copper will transfer onto the iron.

If left long enough, a suffiecient thicknes might build up, and then the copper could be treated with somrthing that will change the surface to green

Vinegar perhaps? A wild guess

Howard

[Jouke van der VeenParticipant @joukevanderveen72935]

I think the copper layer will remain extremely thin.

Copper will deposit and iron will go into solution as long as the iron is in contact with the solution.

Then the process of ion exchange will stop.

On top of this adhesion may be not so good. Cleaning or pickling is important.

The copper ion exchange process is also known for checking cleanliness of iron/steel parts.

Regards,

Jouke

[david bennett 8Participant @davidbennett8]

" Nobuho heats up the kettle and brushes the lacquer on "

Anyone looking for an easy solution for a matching colour will almost certainly fail For centuries the japanese were the masters of decorative metalwork, and their knowledge probably extends to even a simple object like this bell. The wise words – that it is the most skilled work, by the most experienced, should be carefully considered. Oh sure you can find a cheap western alternative, but it will never match the original. Why would they give away their commercial secrets?

dave8

[SillyOldDufferModerator @sillyoldduffer]

Posted by david bennett 8 on 04/08/2023 23:15:37:

" Nobuho heats up the kettle and brushes the lacquer on "

Anyone looking for an easy solution for a matching colour will almost certainly fail For centuries the japanese were the masters of decorative metalwork, and their knowledge probably extends to even a simple object like this bell. …

dave8

Ancient craft-skills are unlikely to have been applied to a Replica bell sold in 1985, and probably still available new!

I agree matching colour is difficult though. Repair Shop used to annoy me because it skipped over important details, but later programmes are more forthcoming. They would fix this with paint. They carefully prepare the surface, cleaning and making good, test various paint types to find the one that sticks best, and mix to get the correct colour, perhaps a range of near misses to improve blending. They make it look easy, but I think a good eye, steady hand, suitable brushes, experience and plenty of practice are needed. I noticed they often apply paint in much smaller quantities than I would, probably taking much longer to build up the effect than TV implies.

I'd be very surprised to find the bell is made of Bronze, because it's expensive. More likely to be Brass in a replica, maybe something even cheaper like plated steel.

Whatever, the patina will have been produced by dipping the item into a hot chemical mix, compounded to create the appearance of ancient Bronze in a few minutes.

Several mixes could do the necessary, but we've no idea what the chemicals used were. It makes a difference – all acids react with Copper to produce green salts, but the greens aren't the same. The green produced by Vinegar on Copper, an Acetate, isn't the same as the Verdigris produced on Copper roofs by Carbon Dioxide, which is mostly a Carbonate. Paint is much more controllable.

Dave

[Michael GilliganParticipant @michaelgilligan61133]

Posted by SillyOldDuffer on 05/08/2023 10:43:20:
.

[…]

I'd be very surprised to find the bell is made of Bronze […]

.

So would I Dave … it was specifically declared to be cast iron

[ which is why I needed to withdraw my very first comment ]

The current problem is one of finding a way to convincingly colour the repaired item.

MichaelG.

[duncan webster 1Participant @duncanwebster1]

Daft idea time:

Electroplate with copper, which might disguise the repair as well, and then dip it in carbonic acid to produce copper carbonate

[simondavies3Participant @simondavies3]

Posted by david bennett 8 on 04/08/2023 23:15:37:

" Nobuho heats up the kettle and brushes the lacquer on "

Anyone looking for an easy solution for a matching colour will almost certainly fail For centuries the japanese were the masters of decorative metalwork, and their knowledge probably extends to even a simple object like this bell. The wise words – that it is the most skilled work, by the most experienced, should be carefully considered. Oh sure you can find a cheap western alternative, but it will never match the original. Why would they give away their commercial secrets?

dave8

Dave (and others) – very true – and if I simply wanted another cast iron bell, I am sure I could find a brand new one though.

However the challenge of returning it to one piece and the pleasure of discovering that it has retained it's tone is, for me, part of the fun.

Equally, there are any number of people on the web describing how to apply verdigris-like paint finishes which would be the simple solution. I enjoy the challenge of trying to reproduce the original finish – even if the initial challenge is to discover what it may have been.

To mis-quote JFK: " I choose to go to fix the bell, not because it is easy, but because it is hard, because that goal will serve to organize and measure the best of my energies and skills…"

[Michael GilliganParticipant @michaelgilligan61133]

[david bennett 8Participant @davidbennett8]

Simon,I applaudd your aims.

I wonder, if we chased the supply-line on these bells, would we find a foundry/factory complex or a family set-up as the kettle maker in the video ? If it is a family set-up, the secret of this patination could be what has enabled the family to survive for many generations.

dave8

Edited By david bennett 8 on 05/08/2023 15:04:15

Edited By david bennett 8 on 05/08/2023 15:19:47

[gerry maddenParticipant @gerrymadden53711]

…except I might add a note of caution. After a lifetime of operating with this abnormal behaviour one ends up with so many damn projects one wakes up in the morning unable to decide which one to start next

Gerry

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