working with silver

Daniel Koster

Daniel Koster

www.kosterknives.com
Knifemaker / Craftsman / Service Provider
Joined
Oct 18, 2001
Messages
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I need to make some fittings out of silver.

What's the best way to do this?

1 - silver-plating over mild steel?
2 - cast silver?
3 - silver cut/formed to shape?


I've never worked with the stuff - trying to get some cost estimates.


Thanks!
 
I can only help with the cost, I bought eight ounces this Monday to use for fittings and paid eight dollars an ounce. It's stamped with a serial number and " pure silver 999. fine". I havn't worked with it yet but after handeling it I believe it will be too soft for everyday carry. More of a "dress" knife if there was such a thing.
Dave
 
Dan,

Silver is easy to work with. Sterling silver has alloys added to make it harder than fine silver. You can buy it "half hard", or harden it yourself by work hardening. It can also be hardened by heat treating.

I've used sterling silver for bolsters. I make silver and gold jewelry when I have the time.

You can solder it, cast it, roll it, machine it, grind it, etc., no problem.

I have a small folder on my web page that has sterling bolsters and inlay.

Silver plate will wear off fast. :)
 
If you can find some nickel silver, it would be a little harder than the pure kind. I believe that it would be a little harder than brass (not that brass is very hard). If you go the nickel route I would advise machining, but if you go pure casting may be easier. Its not too hard to do lost wax casting on pure precious metals on your own, and if it doesn't turn out right, you can just cook it up again.

Good Luck
Ben C
 
Yes. NS is an option, but only if silver (sterling) ends up being too difficult to work with.

Anybody have a cost for sterling silver?

Is it better to cast it? (save expense/waste)
 
I haven't done any silver work in decades but my wife and a few friends are jewelers, so:

Daniel Koster said:
Anybody have a cost for sterling silver?
Click to expand...

As an official precious metal it's a classic commodity. The price varies with the day.

Daniel Koster said:
Is it better to cast it? (save expense/waste)
Click to expand...

IMHO, casting is a whole investment in equipment and learning of its own. You can get some stunning results that way, but there will still be waste in sprues, etc. and you have to be a bit careful about porosity. Some people reuse the waste silver but you have to be careful about contamination resulting in a weaker alloy (maybe this is more of a concern with gold -- I know my very experienced friend worries about that).

You can also use silver Precious Metal Clay for some things. Basically, it's a mix of silver and binder that you mold like clay then fire to burn out the binder and sinter together. It's a lot more expensive per ounce than silver, shrinks 10-25% (depending on type of PMC) when fired and will never have the strength of a good casting, let alone filed and ground silver stock but it is very versatile, easy to work with and allows a number of tricks which are impossible with other forms of the metal. PMC burns out to fine silver, so it's definitely softer than sterling.

Dan Pierson
 
Dan,
can you carve anything?can you work brass?,if so you can work sterling. what kind of fittings are you wanting to make? PMC is basically garbage for any knife or hard use item. price of sterling....finished goods as in sheet or wire will run $5 or more per ounce over the spot price of silver.casting,no waste if you have a contact caster cast from your pattern,cost.....price of sterling and flask charge. many variables and you didn't state exactly what you want to make. :)
 
sounds like casting would be great, but quite involved.

Maybe I'll just stick with NS for simplicity's sake.


Shakudo - I had hope to use it for a guard, subhilt and buttcap.
 
let's see, you have files,sandpaper,carving knives,knowledge of constuction of the parts in metal,etc. looks like if you want them in silver,get a couple pieces of carving wax.make the models and have a job shop cast them for you.
 
Casting is easy and can be cheap.Sterling for casting can be bought at any flea market or on Ebay.You just buy sterling tableware(check around,you may have plenty).I regularly buy old and damaged silver for $2-3 per ounce.Less than the value of the silver in it.You can buy casting grain from metal suppliers for a couple of dollars and ounce above the spot price of silver.As to the casting- get a block of carving wax from a jewelery of art supply (about $8-10) and cut out a rough blank for what you want.Carve and file it to the approximate shape.Leave extra to file away in the metal.Don't make precision holes in the wax,allow room to fit the holes after casting.When the wax model is done,take it to a jeweler or artist who casts,along with your silver (you will need about 10 times the weight of the wax,plus 1/2 ounce).He/she will often cast it for you for free,or charge you a minimum fee of $10-20.Tell them that you don't need it cleaned up at all.If you offer to make them a cooking knife in trade for casting services,you may end up with lifetime free casting in the trade.
Stacy
 
I like Stacy's advice and may take it myself one of these days. Thanks Stacy! I know a local jeweler who might just do this but I wouldn't have thought of it myself.

As to working silver Dan, go for it. You can buy silver or sterling in about any configuration you can imagine from Rio Grande among many others. I've found Rio Grande to be great folks to deal with and after you've ordered from them the catalogs are free (pretty pricey to buy and browse, but worth the money that way too).

I wouldn't hesitate to take a chunk of sterling stock and work it like you would brass or NS. Especially if fine silver, save your sweeps! They won't look like much for any given project but do accumulate and are worth their spot price less a bit in trade for new material. There are many companies who will buy your sweeps if you use good practice in accumulating them (contaminate free). If you use fine metals very often and always save your cutoffs and file dust you could end up with a nice little bonus when you retire! :D
 
The Rio Grande catalogue in front of me has got fine silver casting grain priced at $9.40/oz and sterling silver casting grain at $8.16.
Silver can be re-cast as long as you use at least 60% new metal each time you cast, or if you use a graphite crucible (which will remove most oxygen). Also, you can put sand over the top of the melted metal when it's in the crucible and still heating up. Silver casts much better than brass or copper, and everything casts better than nickel-silver (which is nickel and copper and zinc. Copper and zinc makes brass).
When silver is cast it will be in its annealed state. You can either forge it or roll it to make it hard again. Or you can actually harden it like steel. To achieve a rockewll hardenss of 47 on your silver, bake it at 700ºf for an hour, or so, then let it air cool. Baking at 1400ºf will give you a rockwell hardenss of 48 but, as silver is hot-short, it will shatter if you drop it.
Silver is kind of expensive as knife-making metals go (brass is about $7/lb, nickel-silver is about $1.30/oz) but compared to the cost of the other junk you're likely to put on your knive (stabilized burl, ivory, damasteel, etc) its downright cheap so I don't see a reason to be miserly about it. Especially if you're casting, I wouldn't worry about sweeping up your fillings - I bet it'd cost you more money in your time than the silver is worth.
I also vote for Rio Grande as your supplier. You can get damn near anything from them and they're very reasonable. If you don't mind waiting a little longer, you can get free shipping, too.

- Chris
 
Chris,
You have given good info! Thanks.
I bought some scrap silver with the intension of casting. In my reading it would appear that a flux (borax?) should be added. I didn't see anything about the need for 'new metal' for casting or the inportance of using a graphite crucible.
Will you elaborate or tell us where to get more information?
Thanks, Lynn
 
you guys are amazing - great information here. restored my faith in the project.

I think I'll search for a jeweler - and go ahead and browse Rio Grande - I have some extra time on this one.
 
If you want to pursue casting, here's an interesting site to check out:

http://www.backyardmetalcasting.com/

He also sells booklets on making casting furnaces, and mixing your own casting sand.

IIRC, when Tim Lively (or more accurately, his Wife) did casting on his video "Knifemaking Unplugged," they alloyed the pure silver with copper wire, at 90% silver, 10% copper.
 
I was going to suggest you check out a casting book,or "The complete metalsmith".The flux is used in all casting operations.A teaspoon of fine ground charcoal added to four ounces of borax makes an excellent casting flux.When recasting old sprues and bad castings it is necessary to use more than half new metal.If you don't pitting may be a problem.It is actually almost cheaper( and far better quality wise) to trade in your silver scrap for casting grain.Most refiners and many suppliers have an exchange ratio.
Tim's video and books are good info.But I would avoid using copper wire to alloy with.It often contains some alloy elements that can cause pitting.It works,but pure copper works better.Unless you already have a lot of fine silver,it is best to purchase sterling casting grain than to alloy your own (too many technical problems to go into).
Stacy
 
amazing the amount of half truths,common misconceptions,outdated info from 40 year old sources,etc............. looks almost like the old blacksmith edge packing discussions. some of you people need to go to school or maybe check the internet for the current and correct information about casting and working silver and it's alloys. :eek:
 
Shakudo,In what things are we out of date?(with the exception of sand as an oxygen shield). I am a master goldsmith,and use several thousand ounces of silver and hundreds of ounces of gold each year.I have taught casting and apprenticed many jewelers, including the owner and head instructor of one of the most high tech jewelers schools in America.
PS,I think PMC is junk ,too.
Stacy
 
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