Repair a small cast bell

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

" 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

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

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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.

Daft idea time:

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

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..."

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

...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

Whoops. Either I'm going potty or the forum skipped a post. I won't put it to the vote!

Dave

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As already admitted, Dave … I too missed it at first reading … but there it is ^^^

MichaelG.

Simon, if you are having trouble experimenting with patinas, I would suggest you start with a black colour (liver of sulphur based ) followed by a green one ( ammonium chloride based ) This approach works on copper compounds. I have not tried it on cast iron

dave8