Silver-soldering loco construction

Giles

Western Thunderer
Hi Mickoo,

Here's a video that shows the type of flame we're after..... actually we usually use a slightly smaller version, but looking very much the same, with the clear, defined blue cone which give you the precision control. Too big a flame will get the whole job too hot which all too often we are trying to avoid. Most often we just want to get the joint hot, quickly.


Incidentally, another incredibly useful tool in our armoury is this stuff - Cool Paste - If you want to make a joint (either silver soldering or soft soldering) close to something that is going to get damaged by heat, you apply some of this stuff to the job in between the bit you're going to heat and the bit you're trying to protect, and it keeps it cool. It works. You can heat something up to red heat whilst holding it in your hand (not recommended.....). Immensely useful.

http://www.cooksongold.com/Jewellery-Tools/Technoflux-Heat-Insulating-Paste---120ml-prcode-999-AAH
 

Giles

Western Thunderer
Another thing that my wife and I have been playing with, is lost wax casting at home. The difference being melting the silver (in this case) brass or bronze in the domestic microwave using a special ceramic furnace.
It's good fun, and adds to the range of stuff that can be done - but is rather too time consuming to be of any use commercially.
One of the brake shoes had gone missing on my 37, so a mould was taken from the remaining matching one, a wax (injected) taken, an investment made, and a new one cast in silver (a couple of other silver things were done at the same time!)

8E93A51D-545F-4C82-8110-090EA1EDCA27_zpsfim6jwap.jpg
 

John Miller

Western Thunderer
Another thing that my wife and I have been playing with, is lost wax casting at home. The difference being melting the silver (in this case) brass or bronze in the domestic microwave using a special ceramic furnace.
It's good fun, and adds to the range of stuff that can be done ..............

Lost wax casting bronze using a domestic microwave? - That sounds very interesting. I wonder If I might be so bold as to request a short tutorial along the lines of your excellent one on silver soldering .... :thumbs:

Many thanks in anticipation .....

John
 

Giles

Western Thunderer
Here's an thorough video explaining the process from the chap who devised the system. Di and I did the days course ( £100 each) and found it very enjoyable.

- Video Tube for YouTube - iPhone/iPad

and another video showing an actual melt.....

- Video Tube for YouTube - iPhone/iPad
 

simon.bolton

Active Member
Hi Giles, not quite started yet. Soon, soon. But first, what is pickling and how much water in the pH Reducer...or the other way around?Judging from the product on ebay the makers haven't reckoned on it being used in a silver soldering related scenario.

Cheers
Simon
 

Scale7JB

Western Thunderer
The Microwave casting is absolutely brilliant!

Thanks for that... Unfortunately the missus blew up our microwave a couple of years back by, wait for it, putting metal in it.. Who'd a thunk it..!!

JB.
 

adrian

Flying Squad
But first, what is pickling and how much water in the pH Reducer...or the other way around?
Pickling is just a mild acid bath used to remove the flux and fire-scale after silver soldering. I use an easy-flo flux in silver soldering and this can leave an almost glassy residue on the surface which can be quite tough to remove.

So dunking the soldered item in an acid bath for an hour or so will remove most/all of the flus and any oxidation scale on the item. There are lots of different concoctions available or to make yourself. Vinegar and salt - even cola! I have a bottle of sulphuric acid which I dilute (always acid to water!) I presume the swimming pool stuff is the same. Try a dilute solution first if it doesn't work that well just strengthen it up a little!
 

Giles

Western Thunderer
....Absolutely - water in a mayonnaise jar or similar (clearly labelled) and then add about two tablespoonfuls of Ph reducer. Stir until it's dissolved.
Many people also use Citric Acid which you can get from the Chemist as a 'green' pickle.

Both the bronze casting and the silver works extremely well, both lost wax, and delft clay (which is a jewellers version of sand-casting). Delft clay is a much quicker process to set up, but is a bit coarser, and unable to cope with undercuts etc..
 

D G Williams

Active Member
Pickling is just a mild acid bath used to remove the flux and fire-scale after silver soldering. I use an easy-flo flux in silver soldering and this can leave an almost glassy residue on the surface which can be quite tough to remove.
A colleague of mine who makes silver jewellery uses vinegar with a bit of salt added. (She was a bit vague about how much salt.) Sorry to be a bit late with this but I only found it yesterday, when she was using apple cider vinegar.
David.
 

unklian

Western Thunderer
Interesting thread. Just one question to return to the original subject for a moment, I have always found that the temperatures needed for silver soldering tends to anneal brass and nickel silver and they become quite soft. As far as I am aware there is no way of hardening these metals other than working them. So how do you put the original strength back into small components you have silver soldered ? I have always preferred soft soldering small components because there is no risk of damaging them in this way, and if you do your soft soldering right there is less cleaning up .
 

Giles

Western Thunderer
I tend to use the 'easy' grade of silver solder, and I haven't had to resort to using multiple grades - and therefore very often one can get the solder to flow below the annealing point of the metals. But to be fair, I've never really had a problem when the metal has annealed either – it's always remained stiff enough (and the newly fabricated component usually has its own strength) and of course the material re-hardens over time as well. So in practise, the problem hasn't arisen for me, at any rate.

One of the nice things about using the paste instead of the flux-and-silversolder, is that the proportions would appear to be perfect, so I find there is rarely any cleaning up to do at all, whereas using borax there is always the glassy residue described.
 

jonte

Western Thunderer
Thanks for taking the time and trouble to make and post this easy to follow video about silver soldering, Giles.

I found it extremely interesting.

jonte
 

Wagonman

Western Thunderer
A colleague of mine who makes silver jewellery uses vinegar with a bit of salt added. (She was a bit vague about how much salt.) Sorry to be a bit late with this but I only found it yesterday, when she was using apple cider vinegar.
David.

A colleague of mine – a goldsmith – uses dilute sulphuric acid. She's away at the moment so I can't ask her how dilute but it's safe to dip your fingers in if you're quick and wash off immediately. Hmm, not very scientific...
 

paratom

Western Thunderer
Giles

Interesting thread. I have often thought if you can use silver paste with a resistance soldering iron. I have one that has several heat settings and the highest setting, which I never use, could probably heat the nickel silver to the temperature required for silver soldering. I am thinking about small parts for this operation. Any thoughts on this.

Tom
 
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