Tuesday, January 21, 2014

Which soldering surface is best?

Choose your soldering surface 
Your choice of work surface can to help you solder or stop it cold, and is a frequently confusing for students. Whether you're annealing or solder, it's good to know what to choose. 

In general, use colder surfaces to slow it down, and hotter surface to speed up heating. For example, for small jump rings, soldering on heat reflective charcoal can make soldering go faster, or make it easier to melt them! If you move them to the solder board, the heat will be dissipated a little, slowing it down enough to work more carefully. For larger work, like anything bigger than a jump ring, I'll usually work on a hotter surface, like charcoal, because it helps me heat the metal efficiently.

Hotter surfaces: charcoal, fire brick, honey comb, solderite boards, magnesia blocks, wire nest

Colder surfaces: ceramic solder board, transite, Silquar, steel mesh screens

Always place your soldering surface on heat buffers to protect your table or bench top from burning, like ceramic floor tiles, lightweight sheet metal, or concrete tile backer board.



Charcoal Block
Charcoal blocks create a reducing atmosphere and reflect heat back on the article being soldered, making the flame more effective. Hard charcoal blocks are longer lasting. Soft charcoal blocks can be used with pins to hold your work in place. When the block gets uneven,  you can grind it flat again on a hard surface like concrete or coarse sandpaper. Wear a dust mask and gloves! Excess flux can be removed by pouring boiling hot water over the brick into a bucket or utility sink to remove flux before sanding.

Pros: Reducing atmosphere, quick to heat. Soft charcoal can be pressed to hold work or used with pins to position your pieces. You can make divots in either kind of charcoal to hold and melt metal into balls. You can carve depressions to pour small ingots. You can fix

Cons: Soft charcoal will crack so tie the block tightly around the edges with steel binding wire before using. Both hard and soft charcoal will wear down over time. Soft charcoal can burn away faster and may need to be quenched to keep it from smoldering away. Black charcoal powder is messy.


Honeycomb block
Clean ceramic lightweight honeycomb blocks reflect heat quickly. Perforation holds pins (18ga.) like sewing T-pins to keep your work in place while heating. Excess flux can be removed with hot water.

Pros: Lightweight, asbestos free, inexpensive. Stays flat. One side is flat, the other often ridged to help keep pieces from rolling around.

Cons: Solder can fall through the holes. Honeycomb blocks can break into smaller pieces, which are still handy to use for soldering. 


Solderite, Kiln Brick
One of the benefits of these materials is that they can be drilled or cut as needed for your soldering projects. Solderite is made as a solder board, but was developed as a synthetic substitute for charcoal. It's reflects more heat back at your work than most solder boards. Solderite boards are available in hard or soft. 

Kiln bricks are readily available from ceramic suppliers - they're used to build kilns. Buy K23 bricks, which are soft enough to cut or press in pins, etc.

Pros: Economical, formable, easy to clean up. 

Cons: Solder can fall into the large pores of the kiln brick. Kiln brick is softer than charcoal and pins can come loose during soldering. Kiln bricks are always dusty with white powder that can get messy.

Solderite can be burned and pitted by the torch, which means the boards can wear out faster than other solder boards. Flux can harden on kiln brick, making it hard to sand back to a usable surface. Try pouring boiling hot water over the brick into a bucket or utility sink to remove flux before sanding. 

Ceramic, Silquar, Transite Solder Boards
I'm always surprised to see jewelers who don't use a solder board, using only charcoal or fire brick instead. Solder boards offer a reliable, easily cleaned surface for soldering, preparing your solder and more. These hardened materials can withstand the intense heat of the torch,  but they dissipate heat quickly. 

What does that mean for soldering? Let's say you have a bezel setting and you're soldering it directly on the board. The sheet metal base will be cooled by the solder board, and so the solder won't flow, or it will flow up and onto the lighter, easily heated bezel wire. One trick I use for soldering on bezels, other than using a tripod to raise it so that I can heat from underneath, is to preheat the charcoal. I'll heat the surface to cherry red and then place the fluxed and prepared setting to solder on top. The hot charcoal heats the work from underneath as I continue to heat from the top.  

Pros: Tough surfaces, easy to clean with boiling water in a utility sink or bucket. Highly recommended. 12x12 boards give you a great big surface to work on. 

Cons: On the pricey side for Silquar, but in general inexpensive. Some Silquar boards come with rubber feet, which can melt, so be sure to remove them. Solder boards get craggy and messed up over time, like all solder surfaces and need to be replaced. 


Pumice & annealing pan
Volcanic pumice reflects heat beautifully, and it's nice to be able to rotate your work as you solder or anneal. But this set up is a nightmare for small detailed pieces and anything else that can get lost in those pebbles! I use a annealing pan for large scale work. 

Pros: Good for annealing large workpieces, can custom position pieces in the pumice, and the rotating pans allow you to quickly move your work during heating.

Cons: Pumice must be held in a container of some sort. Your work and solder can get lost easily in the pumice. 


Magnesia Block
These lightweight blocks are a lot like kiln bricks, but easier to press pins and parts into for soldering. The surface is very powdery and things can get a bit messy quickly when using magnesia.

Pros: very soft material can be pinned into or press objects for soldering into surface. Very inexpensive. 

Cons: Difficult to clean. Can be ground down on a hard surface like concrete or coarse sandpaper, but baked on flux can be difficult to clean. Wear a dust mask! 


Soldering tripods with steel mesh
A tripod is great for raising your work so that you can solder from above and below. Obviously, small pieces will be awkward on the mesh and can fall through the openings. But this is my preferred surface for soldering on settings to a base, like bezels. 

Pros: Great for access to the top and bottom for heating. Easy to clean the mesh with hot water. The steel of the mesh holds the heat briefly, and can keep heating the metal when you take the flame away.

Cons: Soft mesh can warp and be difficult to flatten. If you solder on a warped surface, your sheet can anneal during soldering and warp to match the mesh. Upgrade to a heavy gauge steel screen for a longer lasting surface. The steel mesh is a heat sink and will require a larger, hotter flame to heat both the steel under your work and your metal.


Wire Nest
You can make a fast nest of binding wire to place under your work to boost your heat. I use 19 gauge dark annealed steel binding wire (available at most hardware stores because it's the stuff you use to tie your muffler back onto your car, etc.). Scrunch up a bunch of wire into a flattened pillow. Place it on top of a hotter surface, like charcoal even faster heating. When you aim your torch into the nest, the heat reflects up onto the back of your metal.

Pros: Cheap and fast solution. When it's too gross to use anymore, recycle it.

Cons: It can be a little hard to stabilize your pieces on the open wire nest and solder can fall in there during soldering.


Not appropriate for soldering directly on ever: 
household ceramic tiles, red landscaping bricks, stainless steel, wood, paper (okay, now I'm just getting silly :^).

Learn more about soldering and fabrication at SilveraJewlerySchool.com. Happy soldering!



4 comments:

My Art and My Soul said...

Great info, Joe. Thanks so much:O)

Carmine Bermejo said...

Thank you so much for the well organized info! This helped me decide which board to get!

Harriet Russell said...

Thanks for the side by side comparisons...cleared up a lot of my confusion!

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