Nickel Key Caps

[d.elliott]

There are several types of metal keys:

 

- wooden bodied with deep drawn metal tops fitted

- solid metal keys, nickel, nickel plated brass or aluminium

- hollow solid or plated keys with caps fitted

 

Many repairers will be familiar with the instrument that turns up with flat topped nickel keys, some of which have their caps missing, others of which have been plugged with soft solder. These are the hollow keys refered to above, and unfortunately, the loss of a key cap or three is far from un-common. Recently I had one to deal with that had eight keys plugged with solder. This last instance has prompted me to post my repair technique.

 

The only course of action has been to contact a source for scrap parts and try to order as closer replacement as possible. This is fine but the keys come in different lengths, and are very much a diminishing resource. Keys too long or too short are unsightly and will throw the action out of kilter.

 

For some time now I have been experimenting with replacement polished stainless steel plug- caps. These caps are the same dimension as the original caps, and have a plug section the same diameter as the key bore (less a clearance). I have tried different lengths, clearances and leads; press fits, sweated fits and bonded fits have all been considered. The following is the resultant repair technique

 

To fit a plug-cap simply cut off the solder (if present) and ream the end of the bore with an appropriate sized drill-bit to remove debris, old solder etc. True up and flatten/ clean the top of the key tube by striking it across some emery paper which is laid on a flat surface.

 

The cap is glued into the key with an industrial grade of adhesive, like the gel-type superglue which also works. If the key body has been worn it may be necessary to blend in with a fine diamond file or emery paper 'on-a-stick' once the glue has cured.

 

The final result is only disinguishable if you know its been done. By now I must have repaired over thirty keys like this, my first 'production batch' of fifty caps has been replaced with a second, I know I let David Leese have some but most have been used by me over the last 18 months, with no failures.

 

Hope that this is of interest.

 

Dave E

[Pete Dunk]

It's of great interest to me Dave. I have a Lachenal with three key tops missing and have been scouting around for suitably thin sheet material and a metal punch that would produce the correct size of 'slug'. We have one such punch at the school where I work but the slugs it makes are too small. So can I either buy some of the tops you have or post the keys to you for repair?

[Theo]

I've also been faced with this situation on many occasions.

 

When I find hollow metal keys with missing tops I replace the tops on the original buttons so as to avoid problems with buttons of different lengths diameters etc. I happen to be a near neighbour of Dave Shaw who makes the well known Shaw whistle. A while back he gave me a small handful of the nickel silver punchings from the holes of his whistles. These are some what oversized, but after soldering in place its a simple matter to remove the surplus either in a lathe, or with a file. When the key tops are not flat I use a doming block and punch to produce the appropriate curve. Once the button with replacement cap is buffed and polished its indistinguishable form the originals.

 

Pete, if you want a few of these contact me off-list.

[d.elliott]

It's of great interest to me Dave. I have a Lachenal with three key tops missing and have been scouting around for suitably thin sheet material and a metal punch that would produce the correct size of 'slug'. We have one such punch at the school where I work but the slugs it makes are too small. So can I either buy some of the tops you have or post the keys to you for repair?

 

 

Hi Pete,

 

give me a bell and I'll let you have a few at what they cost me, or I'll do the keys for you if you wish

 

Dave

[Paul Read]

I've also been faced with this situation on many occasions.

 

When I find hollow metal keys with missing tops I replace the tops on the original buttons so as to avoid problems with buttons of different lengths diameters etc. I happen to be a near neighbour of Dave Shaw who makes the well known Shaw whistle. A while back he gave me a small handful of the nickel silver punchings from the holes of his whistles. These are some what oversized, but after soldering in place its a simple matter to remove the surplus either in a lathe, or with a file. When the key tops are not flat I use a doming block and punch to produce the appropriate curve. Once the button with replacement cap is buffed and polished its indistinguishable form the originals.

 

Pete, if you want a few of these contact me off-list.

Hi Theo,

I have a friend who is a jewelery maker. She taught me how to solder on small pieces of nickel plate. When finished you can't tell which buttons have been repaired (especially when she does it!)

[d.elliott]

I've also been faced with this situation on many occasions.

 

When I find hollow metal keys with missing tops I replace the tops on the original buttons so as to avoid problems with buttons of different lengths diameters etc. I happen to be a near neighbour of Dave Shaw who makes the well known Shaw whistle. A while back he gave me a small handful of the nickel silver punchings from the holes of his whistles. These are some what oversized, but after soldering in place its a simple matter to remove the surplus either in a lathe, or with a file. When the key tops are not flat I use a doming block and punch to produce the appropriate curve. Once the button with replacement cap is buffed and polished its indistinguishable form the originals.

 

Pete, if you want a few of these contact me off-list.

Hi Theo,

I have a friend who is a jewelery maker. She taught me how to solder on small pieces of nickel plate. When finished you can't tell which buttons have been repaired (especially when she does it!)

 

My plug approach makes the soldering etc not necessary, I suppose they could be soft soldered using the clearance as a capilliary fitting, like the good old plumbing technique

 

dave