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Plating sterling silver with fine silver to cover fire scale


#1

I have a small sterling silver teapot, approximately 6" diameter and 6" height. The surface has been planished as well as having some repoussé work. I have fire scale and I am wanting to fine silver plate the teapot.
Do I need to nickel plate the teapot before silver plating it?


#2

Hi Genevieve,
Its almost impossible to give you a good answer till one sees some pictures it. also in the absence of more historical information for example, how old is it? do you think or maybe its got some identifying marks or even its English and has hall marks that will date, and say where and by whom it was made.
Is the firescale recent?? or do you think its old ie from perhaps 50 or 100yrs old? What is best for it really depends on its provenance. You wont get plating to take to firescale, and nickel plating will ruin it.
Sometimes, its better to just give it some tlc and not try to restore it to what it was when new.
If it modern, ie within the past 30 yrs then perhaps some restoration would be worth the effort. Geff Herman is the best person on this forum to advise you if your in the USA and its a US made pot. A final thought, tea pots are mainly English, coffee pots are American…
Ted.
In Dorset UK.


#3

Hello Ted,
Thanks so much for your response. The teapot, and it is a teapot, was made by me a couple of years ago. I truly appreciate your input and will keep it in mind for future reference.

I will get hold of Jeff Herman and see what words of wisdom he might have for me!

Thanks again

Genevieve
Kansas City MO USA


#4

If it is at all possible I would try to polish through that fire scale rather than plating over it.


#5

Thanks so much but my problem is the surface has been planished and I do not want to remove it.
Genevieve


#6

Ted Here again,
Can we have a pic of the pot or of the firestain area??
Theres a flux that will eat out firestain but youd need a proper
fire brick set up and a propane torch 1in in dia to heat the whole pot to the specified temp, applying this flux all over inc the inside , heat till the flux melts and dissolves the fire stain, keep applying more flux till all fire stain is dissolved out of the silver. This comes out as a red opaque runny flux, then when its dissolved all the f/stain turns clear.
ts called Johnson Matthey stainless steel grade brazing flux and can be bought in the US from welding supply stores
Its highly reactive containing active fluorides and has to used in a well ventilated w/shop.
I use it all the time for all brazng or as you call it, soldering.
When its done its job, you boil the item in a very weak solution of h2so4.
Ted.


#7

Genevieve- Before I became a gold and platinum smith I spend about a decade
making my living raising silver chalices, patens, pixes etc for the
churches. I’ve done my fair share of silver plating and antique silver
restoration as well. though not nearly as much as Jeffery Herman has.
That’s for sure. And I will bow to his superior expertise if he weighs in
on this.
Just plate it with fine silver. No base plating needed. It will cover over
your fire scale and any solder seams. I still do this to any silver
eyeglasses or jewelry I make. The fine silver plating will also retard
tarnishing though it will not prevent it forever. I do two platings. I do
one. Then hand polish it with a fine silver polish like Twinkle, Wrights or
even better yet Jeffery Herman’s own brand of silver polish. Then plate
again and hand polish again. Use only a soft pure cotton cloth to apply the
polish as well as hand buffing it. No paper towels, no kleenex, no bare
fingertips. Only cotton.
As for trying to polish the fire scale out…I’ve seen folks literally
polish holes right through silver trying to get rid of the fire scale.
Have fun and make lots of jewelry.
-Jo Haemer
www.timothywgreen.com


#8

Jo thanks so much for the information. I spoke with Jeffrey Herman and have decided to leave the piece as it is and to take more precautions when soldering and finishing. BUT I might try your technique to see how it looks.
Genevieve


#9

Hi Ted,

I really appreciate your information but I am a bit concerned about the flux. I spoke with Peter Johns about this and he himself expressed some concern. So as it is I am going to leave the piece alone, with the fire scale and go about soldering and finishing a bit differently. Again, thank you so much for responding. You can go to my website (http://www.genevieveflynn.com) and look for Tree Frog Teapot. There is an image of the piece.
Take care and thanks!
Genevieve


#10

The flux is only going to be able to do the same thing as the heat,
pickle, brass brush routine that is normally done to “raise the fine
silver” i.e. it will attack and remove the copper oxide on the surface
of the metal leaving only fine silver behind. There is no way to remove
the deep oxide that is the fire stain that does not cause problems with
the metal surface. The oxygen got in there because the oxygen atom is
small enough to fit in-between the metal atoms in the crystal matrix. No
flux or acid or other material is going to be able to do that with the
exception of another gas like hydrogen. Hot hydrogen will indeed flit
in-between the metal atoms until it finds an oxygen atom and it will
reduce the metal oxide but it will also combine with another hydrogen
atom and make water or more precisely steam which has a much greater
volume than the gas and it will form a steam bubble. When you have
enough of them it will form blisters in the metal matrix and basically
ruin your metal. This is a problem that is typically experienced in oven
soldering systems that used a mix of hydrogen and nitrogen or cracked
ammonia which is basically the same thing when the sterling silver has
too much oxygen present in the metal.


#11

Hi James,
I bow to your superior knowledge about the atomic structure of fire stain.
However, if youve never used this chemical flourine based very! active flux, its designed to dissolve chromium oxide! as well as nickel oxides and iron oxides, you may find the flourine will act on deep seated copper oxide. I
Also as a titanium smith, my researches into the production , of titanium metal Flurine hexaflouride is the only chemical that will remove oxygen from this reactive metal base during its reduction under vacumn.
So its use in this flux is justified in sorting out firestain in silver as well as other non ferrous metals.
It is far superior to the heat, pickle and brass brush routine you mention . Try it, youll be surprised.
Ted.


#12

Yes I use that type of flux on a regular basis it is the best flux for
brazing stainless and other difficult metals. It is quite aggressive in
reducing oxides but it still cannot penetrate the surface of the metal,
all its actions will be on the surface.

As an aside I do a bit of titanium work myself and you might be
interested in an even more aggressive flux that will allow you to torch
braze titanium with a silver filler material
http://www.superiorflux.com/titanium-brazing-flux/

Jim


#13

Hi Jim,
Im glad your not afraid to use these aggresive fluxes.!
Ive looked up this co, thanks for the link, and they list they have an agent? or distributor here in the UK.
Shot off an email just now, hope they can respond quickly.
When I get some and run trials with it will report how it works out in my setting.
I currently use tig with argon to join small components down to 15 amps. Still tricky.
Last year was asked to make some titanium wedding rings. Not wanting to turn them up out of bar stock, had some 3/16th cp plate. Had it break press guillotined to 3/16th sq, then hammered it into 1/2 round in a die, was surprisingly hard by hand.

Should have set up the die in my 10 ton fly press!. will do so next time… then coiled it around my tapered steel ring mandrel, cut off trued up them tig’d the joint.
Polished up then fire oxidised to the lovely clear blue. Customer v/happy.
Do you use a standard Johnson Matthey easiflow silver brazing filler rod? thats 55% Ag with other metals inc cadmium. Now not made any more here. Ive enough to last me out. some kilos of it.
Ive read their advice note on this flux, they recommend using their filler rod Do you?
Ted.

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