Hi everyone,

I need help very badly for a problem I'm currently facing:

I wish to solder a piece of silver (92.5) on a silver plate (92.5) but when I use hard solder (Silver, copper and very little Cadmium), the plate gets warped (due to brazing). I can't use soft solder because it contains harmful elements like lead/tin/cadmium. The product I am making will be used to serve food and hence I can't take the risk of even using these harmful elements for soldering.

 Can anyone suggest an alternative?

Thanks

Stu

 

If I understand, you're soldering two pieces of sterling with hard solder and the solder doesn't flow?  The first thing that comes to mind is your torch/flame isn't large enough and you're spending way too much time trying to heat up your piece.  Silver is a very good heat conductor so you have to work fast ' ish.  

 I would flux your pieces, crank up the heat, heat from below (if possible), but heat the entire piece - the largest piece is where your heat should be directed, use the tip of the blue flame - once the flux finishes bubbling - put your solder in place and finish.  Don't be afraid of the heat/torch - crank the heat - but keep it moving, don't hold your flame in one position.  Again warping means you're spending too much time, get in and get out.
 

Dear Karen.

Thanks for the fast reply. I am using a big torch (and not the small handheld one) and am giving adequate heat. The problem lies in melting the solder- because its a silver solder and silver's melting point being high, it takes a while to heat the solder, because of which the silver plate also gets so hot that it gets warped.

 

Stu

 Stu,

I understand silver solder, I use hard solder almost exclusively;  flux the entire piece and turn up the heat - use the tip of the blue flame and heat the entire piece.  That warping is because you're taking too much time heating up the piece - and you've probably gotten a wicked case of firescale too. 

 If you're piece is too big to get hot enough with your torch, use two.

 

Try pickling it a few times to bring up the silver so that you have layer of fine silver on top and flux, apply the hard solder and crank up the heat. Big sheets are hard to do. Hard solder starts to flow at almost fusing temps so if it isn't almost orange the stuff just won't flow but be careful or the whole mess will slump on you into one big puddle. If all else fails try medium solder.

 Hi,  The problem might be from the material that is plated.  If it is nickel that is plated it requires a lot of heat and general warps, especially if its a flat sheet. It would be helpful to know relative sizes of the pieces, but it still shouldn't be that big of a problem.  I don't know what you have for equipment but I would try to heat the piece from underneath, also flux your solder.  Think of soldering like baking, try to get both pieces of metal to the same temperature at the same time, if your concentrating your heat at just the soldering point then your soldering all wrong, if you have a very big piece and your attaching a small piece to the middle of it i wouldn't worry about heating up the little piece at all.  You should concentrate your efforts on keeping the bigger piece hot.  If you concentrate all your heat onto the solder itself trying to "weld" your piece, it will burn out the flux before the bigger peice becomes hot enough to solder.  Sometimes it's helpful to create a kiln with firebricks to trap the heat in while you work. There are generally 3 jewelers solders Hard,Medium, and Easy.  These melt at around 1300-1000 F.  There is also an extra easy... which melts somewhat lower.   Then there are Low Temp solders, or what people call plumbing solders.  These melt at anywhere from 100-400 F.  If you are worried about health issues there are plenty of lead free types of low melting solder.  P.s.  Tin is food-safe.  Hopefully you find this helpful, Frank Mueller