Article: Soldering Hints and Tricks

By Charles Lewton-BrainMore from this author

Medical hemostats and forceps make good clips for wire solder. Soldering clips for soldering work may be made from cotter pins, coat hanger wire, piano wire, steel strapping or old clock springs. These may be used to hold parts together.

Soldering weights are good tools to have. Several in different weights are really useful to have around and very fast to use. They hold items down during soldering and can have notched, drilled or grooved holding ends. Traditionally they are made with rectangular blocks of solid steel to which a hold down rod has been attached. These can however be hard to find. Angle iron can be used.

Even a sardine can filled with typemetal or lead will work. One can make them from rectangular thick sheets of steel with 1/8″ or 3mm steel rods brazed (think hard soldered) onto the block using a white paste flux, silver, silver solder, brass or copper to fix it in place.

The end which sits upon the work to hold it in place may be shaped differently for different purposes. Old needle files serve well for the rod. They are much faster in use than any third arm as one has different sized soldering weights and they are rapidly swung onto the work to hold it in place. They are often used in combination with a nest. If one uses a sheet of steel rather than a solid rectangular block one makes a relatively light soldering weight but it allows one to easily stack bricks or other objects onto the flat surface of the weight to have variable weights quickly.

There are many kinds of refractive surfaces one can use to solder on, from pumice chunks to Kitty Litter® (watch out for the latter-it tends to pop when first heated-use safety glasses and wear an apron and don't wear sandals). Some people like ceramic blocks of various kinds, graphite will work, the time honored (and pleasant reducing atmosphere) of a charcoal block is always good-if somewhat expensive.

My preference is to use a light (not dense and heavy) fire brick of the kind that ceramacists build kilns with. It can be easily shaped, sawn apart or into with a wood saw, have wires and pins pushed into it, be cleaned by scraping against another fire brick-in general a useful surface for soldering on.

I have a spray bottle of water like a plant mister near the soldering bench. It is used to put out the charcoal block immediately after using it. This preserves the block far longer than just letting it burn after using it. The spray is also used for quenching if I don't mind a little overspray and want to keep water out of interior spaces in a construction or a folded piece of metal while fold-forming.

In the past with a charcoal block I have taken a metal tin with walls a little lower than and larger than the block and poured some casting or soldering investment into it, then setting the block in place. This prevents the block from splitting as they have a tendency to do and because it is mounted in a metal tray keeps it cleaner and easier to handle than simply a loose block. Some people wrap a block with wire around the sides to hold it together though to my mind this still lets messy bits fall off and does not take into account large cracks.

John Cogswell came up with a great way of making granules or little balls using a charcoal block. He was using them for granulation but there are lots of uses for little spheres. One makes a metal frame for the block as shown in the diagram. The block is tilted on a prop or some kind and a small pan of water is placed next to it. When one heats up small chips of metal as soon as they become round they roll down the surface of the block, maintaining their shape and then landing in the water. The frame guides them off the block into the pan. I have drawn jump rings rather than chips of metal because jump rings are the only way to easily and accurately guarantee identical metal volumes when making small balls.

This is a quick method for small quantities of spheres. Larger quantities are usually made by layering the metal pieces in charcoal powder and heating in a kiln for a time, later washing away the ash.

A soldering nest is a loosely wound bundle of fairly thin iron binding wire. One spreads ones fingers slightly to wind the wire (.016 or thinner) so as not to trap them by binding them too tightly. Several sizes of nest are useful but in general three fingers will produce a good sized nest for most work. One winds at different angles to create a loosely interwoven pad about 4mm (3/16″) thick. This gets the work being heated off the firebrick allowing heat reflected from the brick to work on it. Because iron is a poor conductor of heat it holds heat after the flame is removed elsewhere and acts like an electric burner under parts of the piece one is not heating with the torch because it glows while one moves the flame elsewhere on the piece. It is most useful with broader flame torch types; those professionals working only with a mini-torch would not find it as useful.

Such a nest emulates the action of soldering on a charcoal block and provides more all around heat, albeit without offering the reducing atmosphere conditions of the charcoal block. Thin iron wire is however much cheaper than a charcoal block and lasts for years. If you use too thick a wire for this the subsequent heat sink effect of it in contact with the work may interfere with soldering.

iron binding wire soldering nest.

Kerr® Quickset #2 soldering investment stone is a great assist for holding pieces together while soldering. Doug Zaruba uses half a squash ball as a small mixing bowl for it, makes a clay-like mixture, places it around the parts to be held together, washes his hands and then it is ready to solder with. For a very strong mixture sprinkle in broken sawblade pieces which one has saved or fibrous material like Fiberfax® or fiberglass (agh-itchy and unpleasant). It can be ordered from your local supplier who will have a Kerr® catalog. It is however not listed with the investments but instead is under 'specialty products' and is at the back of the catalog. More permanent soldering jigs can be made with a mixture of one third investment, 1 third Portland cement and a third fiberglass. Such a jig may last 50 solderings or so.

Heat sinks are usually a problem in soldering but can be used creatively to stop previously soldered joints from opening up during later soldering operations. Examples include chunks of steel, washers, nuts and old copper coins-with the latter one must be careful that they are not made with a low melting aluminum core, as with many new pennies. The mark of an accomplished goldsmith is the use of heat sinks instead of solder flow retardants. Heat control is soldering control.

Thin (30 gauge) iron binding wire is very good for binding pieces together. It is important to use cable as it is less likely to burn out during soldering and can expand and contract slightly so that there is no indenting of the bound object-which can occur very easily if too thick a wire is used to bind during soldering. The basic rule is to never use a wire as thick as or thicker than the sheet metal being bound. Two strand cable is usually sufficient.

The twisted wire cable is then looped every 1-2 cm and looped and twisted to make rows of tension loops. It is important to always twist them in the same direction so you don't inadvertently loosen them later at the wrong moment. They may be tightened and allow stress to be spread through the binding system so the wire doesn't give way suddenly just as one gets it tight enough. They also permit more complex wiring situations.

It is important never to wire across open spaces as the metal softens and will bend inwards and collapse. Instead one uses hooks and the presence of tension loops to be able to re-direct pressure against the strongest structures of the object being soldered. Because when hot everything becomes soft and pliable we use structural strength to replace material strength at the temperatures required for soldered construction.

Very difficult shapes to accurately hold together can be wired, for example a sphere. Note how the presence of tension loops allows hooks and wires to be strung through them making almost any object able to be wired.

Some goldsmiths prefer stainless steel binding wire because it can be put into the pickle without causing a plating reaction. I don't like the lack of stretch it has while tightening it but like anything one would get used to it and adjust.

When bridging a seam with binding wire take thicker wire (16 gauge and up) and make a bridge to lift the binding wire up off the seam. This prevents it from being soldered down to the seam. Notice how the bridge wire loops up and away from the seam to avoid contact with it and also how the ends of the thick wire bridge are also bent up away from the metal surface being joined so that like the skids on a sled they do not scratch the surface they are on.

It is better to take an hour to wire a complex job up and then spend less than five minutes for a trouble free soldering than it is to have to go back and repair or fix problems. With experience one needs to wire less often but a proper wiring or soldering set up usually saves considerable time in the long run. That old Aristotle quote: "Well begun is half done" while irritating is accurate.

When one has to solder a ring shank without endangering the stone it is normally packed in some cooling material such as Kerr® #2 investment stone (Quickset #2), Kool Jool®, wet matted paper towel and so on to protect it. In my experience wet paper towel is the best of these because one has better control of its degree of wetness and hence the safety of the stone. My preference however is to have the ring head under water in a crucible and have the ring held down with a soldering weight. One can also make a thin slice of kiln brick which is tucked inside the ring over the water level to additionally reflect heat upwards and slow the evaporation of the water.

This approach is particularly good with silver rings as silver conducts heat better than any of the metals and so requires intense hot heat to carry out such a soldering. In all cases one must keep tabs on the water level so as not to inadvertently have it go too low and so endanger the stone. Another material used is paper clay, a product found in many craft shops and originating in Japan.

A method of protecting gemstones from heat comes from the shop of Robert and Barbara Kaylor in Boise, Idaho. They use a crucible with lead shot in it to hold the ring steady for soldering. This way one can monitor the water level to ensure it does not go too low, as if it does one has a nasty lead mess on the ring, not to mention the potential stone damage (to remove lead one uses muriatic acid; a mixture of hydrochloric and water in varying proportions). Stainless steel shot would be an alternative.

Another soldering trick from Kaylor is to use the hefty round or ring-like magnet from a stereo speaker as a holding tool for the back end of one or more steel self-locking tweezers; the same inexpensive kind used for earring post soldering clamps. They are easily maneuverable, quick to place and remove and hold objects the thickness of the magnet (about 1 cm or just under half an inch) off the soldering surface. The magnets can also be mounted a number of ways on their sides and so on to allow other holding positions for the self locking tweezers.

Just a note that the Benchmate® system comes with the best third arms I've ever seen and has various soldering platforms, clamps and ring soldering heat sinks that are standard equipment with it.

Solder flow retardants are best used when heat sinks will not work. It is usually more efficient and quicker to work with heat control and heat sinks. One may have a false sense of security with solder flow retardants and attempt heating methods which may threaten the piece with damage. Sometimes however one needs a solder flow retardant to prevent a piece freezing when soldering it, such as with certain chain solderings and soldering a trigger for a catch in place in the catch (I still would use a heat sink and speed with this method).

Some people use yellow ochre with water. I find that it has a tendency to "bleed" into the flux and make the soldering problematic. It is somewhat better mixed with a little oil instead of water but I find it difficult to remove from the piece and do not use it.

Some people use a little rouge powder from the polishing machine dust mixed with a small amount of oil which works well.

One can take a small piece of rubber (vulcanized mold chunk, slice off a piece of old torch hose etc.) and, holding it in tweezers, rub it on the metal part to be protected while it is hot. The rubber melts on with a truly nasty smell (use ventilation) and leaves a brown slimy coat on the metal. This too works well.

My favorite is Papermate© correction fluid. There are solvent based and solvent-free water based versions. In my experience the water based version does not come off the metal after soldering as easily as the solvent based one which I therefore prefer. I had heard that it contained toxic chemicals which were released upon heating and wrote to the Papermate company listing all the metals, chemicals and temperatures that their product would come in contact with in standard use by metalsmiths. In their return letter no mention of chemical interactions with the white pigment was made and they felt the main danger lay in the solvent used: 1.1.1. trichloroethylene which is as I understand it a mutagen and carcinogen.

This leads me to think that the white material is something inert like tin oxide or calcium carbonate (chalk). 1.1.1. trichloroethylene breaks down on heating to form chlorine gas, hydrogen chloride and phosgene gas, all of which are highly toxic. Their lab ran evaporation rate tests and found that because it skins over the solvent does not evaporate as quickly as they had thought. It seems that about twenty minutes after application the solvent will for all intents and purposes have evaporated. There is however a safety problem here and it is recommended that alternates to the solvent based material be used. While we are not discussing large amounts of solvent exposure someone will at some point use a lot of it at once or all day and chance personal injury. Potters 'kiln wash' might be good too.

I have a suspicion that Papermate® and similar products are mostly calcium carbonate, what print makers call 'whiting' and what the rest of us call 'chalk'. The cheapest source by volume for chalk in solution is probably Maalox® though I have not yet tried it as a solder flow retardant.

Kaylor uses China White, a standard graphic artists material made mostly of chalk as an effective solder flow retardant. It comes as a liquid in a tube or in a dry cake which one uses like a water color cake with a brush and a little water.

Kelly Clemmer in Calgary uses Papermate® as a resist for reticulation on brass. He paints it on in a pattern, gives it more than adequate time to air out and then reticulates the surface. Where the resist is stays more or less smooth providing smooth figurative (in his case) areas amongst the reticulation.

Some goldsmiths use a disposable type disposable lighter to light their torch with. On the one hand this is great because teams of engineers spent years figuring out the absolute best and easiest way to strike a spark by hand and came up with this shape but if they contain gas they can explode if hit with a spark or accidentally brushed with a torch flame. Rumor has it a lighter has the same explosive power as a grenade and can take a leg off. I suggest then using an empty one and carefully sawing the very bottom off so that there is no chance of any fuel being left around it. If the bottom has a hole in it then one can as I do hammer a nail in next to the soldering area and the lighter sits neatly on it.

An old-fashioned blow pipe which can still be bought from most tool suppliers costs about two dollars, uses an alcohol or oil lamp flame and allows one to get a hot spot in varying sizes that is about 1700oF. A small one is like having a 500 dollar mini torch for under five dollars. Different size holes in different tips give different sized hot spots. One blows gently into the pipe and through a flame onto the work. The air pressure required is not very much. The only trick is learning to keep the air in one cheek like a trumpet player which continues to go through the pipe while you breathe in through your nose in order to keep the air pressure steady. The reason jewellers alcohol lamps have flat sides on them is so they can be tipped slightly and allow a blowpipe flame to more easily go through them for this kind of soldering. One could use a variable silent fish tank pump as an air source. I've seen this once or twice with gas/air torches as an air source. Most of the world still uses this tool.

Some goldsmiths use pipe cleaners as flux brushes. I like a needleless syringe for injecting watery flux solutions inside tubes and other hard to get at places.

Self-locking tweezers may be bought and then reshaped if necessary. A good shape is a half inch right angle bend at the end. This can be filed into so that single wires or prongs can be held during soldering. John Cogswell uses versions of these as extremely useful soldering jigs and heat sinks for constructing prong settings from wire. An example is shown where the tips of the tweezers accommodate two jump ring cross struts and a vertical prong, clamping them together for soldering with a pinpoint hot mini torch right in the tweezers. The setting is assembled one vertical prong at a time.

Pair of the cheaper, chrome plated steel self-locking tweezers with a triangular notch filed in place at each of the ends automatically grips and snaps earring posts to a right angle for quick earring post soldering. To use them one simply throws the earring posts onto the table and they are easily and quickly held at 90o no matter what angle they are gripped from. Note that the ends have been filed so that when using them they smoothly grasp and guide the earring post into its groove. Again, other grooves, slots and holes can be installed to hold various kinds of assemblies together while soldering. If made of titanium or if titanium ends are attached to the self locking tweezers they cannot solder together or to the metals being assembled and so become a superb soldering jig.

Self-locking tweezers may be made from heavy iron wire. Basically they are a kind of tongs with springiness and clamp built in. European tool catalogs offer examples which one can quickly make oneself from looking at the pictures.

A cotter pin and heavy nut can also be used for such clamping purposes. It is bent up after the nut has been slid onto it and when turned the nut bites into the cotter pin somewhat so that it locks as the nut threads itself onto the bent legs of the cotter pin. Similar clamping tools can be designed easily with some thought.

Self locking tweezers and clamps can be made a number of different ways. One can for example put a ring or oval loop around a pair of ordinary tweezers and slide it up the tweezers to tighten them in place. There are literally dozens of home made tweezer based clamping jigs for soldering. Define the soldering problem; define 'what must be' to set up the soldering and there will be some kind of soldering jig solution available.

Some versions may be made to hold ring bands together while soldering or to hold a head. Self-locking tweezers may also be reshaped to various useful forms such as clamps for holding heads in place in a shank during a soldered construction. One can buy some specialty tweezers from tool suppliers.

Tweezers for holding a head onto a ring during soldering

Soldering picks are an essential: they may be made from coat hanger wire. One end is coiled to prevent picking up by the hot end, the other side ground to a point. The last 2 cm or 3/4 " are bent to a right angle. This enables one to pick up items with the pick and also to see what the pick shown is doing when in use which one can't do easily with a straight one. The reason for the shape at the back of the pick is to have somewhere to hang it from and so as to have a handle to control it with. The best material is titanium to which the solder will not stick. One can even ball up solder right on the pick and then have it slide off onto the piece from the pick. I may divide a molten ball of solder with the pick to halve it. A source for 16g titanium wire is Reactive Metals (reactive@sedona.net). Another source for titanium wire for making soldering picks with is your local high tech bike shop-they often use titanium spokes and may have bent ones for free.

Dee Fontans found that using a steel soldering pick on which some solder had been deliberately melted was useful as a delivery method for controlled small amounts of solder onto delicate wire soldered connections such as one encounters with filigree. One can 'wick' away surplus molten solder into a thin wire twisted cable that is fluxed and frayed out at the end.

Some people use a pencil as a soldering pick. The wood gradually burns away with use leaving a graphite rod in a somewhat charred wooden handle. Such a tool can be used to stir molten metal with too.

Artists graphite sticks can sometimes be obtained long enough to work as stirring rods for melts. Quartz rods are also used to stir melts but watch out for heat transmitted up and out the end of the rod - one can get burnt.

Soldering tongs for holding wire solder for soldering large objects are very useful to avoid burning one's hand from radiant heat. They are made from welding rod and are about 14-18 inches in length. They look like miniature blacksmiths tongs with very long handles, one of which is bent so that it locks onto the other one. This provides tension on the front. Several are loaded with wire or strip solder ready to use. Long hemostats will work as well.

Wire soldering is extremely useful for production (an automatic pencil can be used as a handle and feeding device). In Germany one uses a 'Lötblitz', a kind of automatic feeding wire solder pen, it has a thumb ratchet to drive the solder forwards as you use it and you stand with a coil of it over your arm feeding and soldering very rapdily. Wire soldering tends to be messy but an experienced wire soldering person can solder as cleanly as with carefully placed chips.

I have recently taken to using color coded hemostats (used for clamping blood vessels in operations-you can find them at flea markets and Radio Shack type electronics stores) as clamps for different wire solders, hard solder is one color, medium another. The handles are spray painted and they hang, loaded ready for use in the soldering area. I have three of each color/solder type ready when beginning a job.

T pins such as are used by fabric artists and seamstresses can be bent over and pushed into the fire brick to hold things in place in a similar way to how blacksmiths clamp things onto an anvil with a 'hold down tool' tapped into a hole in the top of the anvil.

I'd like to say a couple of words about annealing. Because some books said that metal is red hot when annealed many people do this. In fact it seriously damages the crystal structure of the metal if there is any further extended deformation; drawing, rolling, chasing, raising, forging etc. going to happen to it. Overheating causes grain enlargement which may eventually lead to cracking in the metal.

This will not really matter if the work is only being used for construction or is at the end of its plastic working. The descriptions of glowing red come from the days when there was no electric light and the soldering area was in the darkest part of the shop and consisted of a forge. The actual color is the red you see in Concord grapes, barely red at all. If you see any visible red light coming off a piece of metal under normal room conditions today it is already overheated. Therefore we need other indicators for when the metal is annealed.

Temple sticks and crayons are waxy materials used by welders. If the Temple stick melts you have hit a certain temperature. Messy to clean off.

Borax flux goes glassy but then you have to clean it off.

Blue carpenters chalk turns white.

Ivory soap turns black.

A bamboo skewer or piece of wood leaves a trace like drawn charcoal (David LaPlantz).

A permanent marker will disappear.

My favorite method is to watch the flame color. It will turn distinctly yellowish-orange the moment that the metal surface hits about 800 degrees F. This is the temperature that carbon particles glow incandescent and it means that unburned carbon particles in the flame are hitting a surface with that temperature regardless of what material that surface is made of. This is however below the 900 degrees F that is called 'black body heat' which is the temperature that materials begin to give off visible light. In practice by the time you have recognized the yellow flame and reacted to it the temperature will have risen somewhat and you will be at about the right temperature for all the metals that we are concerned with. (Yes I know they all have different annealing temperatures but given the need for average accuracy and speed of working this is a good approach).

Kaylor has a nice trick for annealing a coil of wire which depending upon one's heat source can sometimes run the risk of being overheated or even melted. He coils it up in a tin can and then heats the can. It functions like a little temporary kiln and keeps any direct flame off the wire thus preventing it from being melted. I've heard of annealing on a hot plate for the same reason.

Charles Lewton-Brain

Master goldsmith Charles Lewton-Brain trained, studied and worked in Germany, Canada and the United States to learn the skills he uses. Charles Lewton-Brain is one of the original creators of Ganoksin.

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