Tips for Soldering Silver and Copper
If you want to make jewellery, at some point you will probably need to find out how to solder two pieces together, or to join jumprings. Soldering is an essential part of silversmithing and working with many other metals to make jewellery.
Below are the top tips to follow to make sure that when you solder your piece it creates a good join with the least effort.
Create a Perfect Joint
When you are soldering two surfaces together, your joint must fit together perfectly with no gaps. If you have used a jeweller's saw, check and remove burrs with a piece of folded emergy paper or thin file - this will also clean the surface of oxide or grease.
Molten metal does not stick to oxidised or greasy metal.
If you are trying to make a silver ring and are joining the two ends of wire together, then the way to get a tight joint is to get both ends in pliers, move them apart (like you'd open a jump ring), then move them so they are overlapping slightly. Now move them back into position with the pliers and the two surfaces of the joint should just "snap" together and make a perfect fit.
Solder cannot fill a gap, so it is essential you have a very snug fit.... even if it takes you awhile to achieve this.
Flux the Joint
Most jewellers will use a borax cone and flux, although there are other paste products on the market a borax cone and flux will probably last you years and is much cheaper at the outset too.
Flux, which should be of a milk-like consistency, should be painted all round the joint. The solder will flow where the flux is, so be careful to cover the whole joint all the way round, without straying too far from the joint itself else you'll have a large area to clean up and file down.
Tip: store your flux brush in a drinking straw to keep it clean when you are not using it
Placing Silver Solder Paillons
Although there are solder pastes, most jewellers will be more familiar with using a strip of silver solder and cutting off small paillons (bits) using snips (small, sharp shears).
Before you cut the silver solder, give it a rub with .... then snip the paillons into your flux - if you hold your hand over the end of your silver solder while you're snipping then your paillons will not disappear onto the floor.
The paillon or paillons of solder should be covered with flux - pick them up carefully with some tweezers and place them in place on your join. The silver paillons must touch both sides of the joint to be soldered.
It is most usual to solder your first join with hard solder. Hard solder melts at a higher temperature than medium and easy solder, so if you solder another piece on a bit later then you won't destroy your first joint.
Position Your Piece to be Soldered
Rather than simply placing your silver to be soldered directly onto a soldering block, try to set your work on top of a thin piece of wire to raise it off the ground.
Placing your work above the soldering block allows the heat from your torch to reflect off the surface, giving much more efficient heating and thus allowing your solder to flow cleanly all around the joint.
A simple stainless steel paperclip can be bent easily to help with your positioning. Alternatively, if you have any steel binding wire this will work too.
Beware Stray and Missing Pallions
When you use silver solder, the tiny pieces are called pallions.
It's important that you know where all your silver pallions are. If you have any left over pallions in your flux, pick them out in case you use them accidentally on a future joint as they will be unusable within about 15 minutes,.
Check if you have any misplaced or lost pallions on, or around, or touching, your work - they could melt in the wrong place and cause you problems a bit later on.
15 minutes: Pallions need to be clean and to be used within 15 minutes because the air will start to oxidise them, making them 'dirty' again - so only cut what you need, when you need it.
Gently Does It...
Don't just rush in with the torch straight at your paillons - it'll all fall apart and you'll have to start again.
Heat from your torch should be applied gently at first, to dry out the flux; you will see this bubble up - check that as it's bubbling it's not moving your paillon out of position.
Once the flux has stopped bubbling, you should then direct the torch heat away from the joint and raise the temperature of the work as a whole - heat the soldering block around your piece and then heat the piece from the part furthest from your joint.
Only when your work is a dull red all over should the torch flame be directed directly at the join. You should see a flash of silver as the silver paillon melts and runs along the joint where the flux is. Remove the flame one second or so after you've seen this or you'll get to the stage where you're melting your silver.
Solder Should Melt, Not Be Heated
What you are trying to do is to get the solder to melt by getting the surrounding metal up to a temperature that makes it melt - you should not be heating the solder itself to get it to melt.
Quench and Pickle
Now you need to quench your work - use wood-handled tweezers to pick it up and drop it into a small pot/bucket of water.
You'll see that there are some marks around the soldered area, so now drop your piece into pickle for 5-10 minutes to remove this firescale. When you remove silver from pickle silver becomes a lovely white colour, which becomes a shiny silver once you start to polish it. Copper still looks like copper at the end of this process.
File and Polish
Never underestimate the time you need to take to file down and polish up the joint you made. After soldering, you'll be left with a lumpy area that needs filing down gently until it merges seamlessly with the rest of your piece.
There are several ways to do your filing, including:
- Using needle files
- Using fine grade polishing cloths and sandpapers
- Using a tumbler to give a final shine and polish
Sometimes it can take as long to finish your piece as it did to make it!
If you have any questions about soldering silver or copper, feel free to post them in the comments box below. I'll try to answer your questions as quickly as possible.
Thank you for reading - and HAPPY SOLDERING!