Soldering Bit Maintenance - Summary

If a bit has not been properly tinned, solder will not wet to it. Without solder on the bit heat transfer from the bit to the work surface may become extremely difficult and time consuming, or even impossible.

You must understand that proper wiping and continuous wetting is important and a lot easier than continually having to clean and re-tin the bit, especially at the risk of damage to the plated surface because of accidentally scratching, or over abrading it.

When you notice that an iron is not performing as well as it did when it was new you will find that poor thermal transfer from the element to the work is usually the cause. Improper care and maintenance and the lack of a periodic cleaning of the bits shank can cause a layer of oxides, which will inhibit the transfer of heat through the bit. Always ensure plug style bits are properly seated into the elements before heating the iron. If a bit is not inserted fully into the element there may be a gap behind the bit. This gap can cause a hot spot within the element causing a premature failure of the soldering iron.

Courtesy of American Beauty Tools


Other links to Soldering Iron Maintenance:
https://glasstips.blogspot.com/2019/11/soldering-iron-maintenance.html

https://glasstips.blogspot.com/2010/01/maintenance-of-soldering-bits-periodic.html

https://glasstips.blogspot.com/2009/12/soldering-bit-maintenance-wiping-bit.html

https://glasstips.blogspot.com/2009/12/soldering-bit-maintenance-tinning.html

Choosing the Soldering Bit

An important consideration, when choosing the most appropriate bit, is that thick, short bits will store more heat and deliver it more efficiently than long, narrow ones. This makes the standard chisel configuration the usual bit of choice. The chisel shaped bit is often used for joining flat seems together. The working edge of the chisel bit should be about the same width as (or slightly wider than) the seam that is being soldered.

Usually a solder connection is made in one to three seconds. If the connection takes longer than three seconds, you may need a larger bit, a higher wattage iron or a completely different type of soldering equipment altogether. It is a good idea to familiarize yourself with other soldering methods and equipment that are available in order to ensure that you are utilizing the best, safest, most efficient and economical means available to perform your soldering application.

Courtesy of American Beauty Tools

Soldering Bits

Type
The bit type is determined by the soldering iron it is used on. There are screw type bits (bits that screw onto, or into the solder iron element), slip on bits that slip over the element and plug type bits that slide inside of the element. There are even bits that are a permanent part of a replaceable element/bit assembly. Regardless of the type of bits required it is always important to have them fully seated to the element and periodically cleaned, in order to maintain proper heat transfer from the element into the bit.

ConfigurationThe bit configuration to use should be determined by the intended application requirements. Some of the basic bit configurations available include ballpoint, conical, diamond (pyramid), chisel, and spade. You will find that there are usually a variety of styles, or modifications available, within each of these basic configuration families, to accommodate specific application requirements. Although less efficient, a more narrow configuration is sometimes required to obtain accessibility, or to achieve the desired results.

SizeThe bit size to use (regarding the working portion) should also be determined by the intended application requirements. The bit body, or shank must be matched to the iron it will be used with (always select a bit that was designed, or approved for the soldering iron you intend to use on the application being considered). As with bit configuration though, there are usually a variety of modified working diameters available within each family of standard bit sizes that are available. These modified bits are generally referred to as turned down bits, because the working area of the bit has been turned down to a smaller diameter than the body, or shank diameter. Turned down bits are not as efficient, but are sometimes required to solder in otherwise inaccessible areas.

Courtesy American Beauty Tools

Tack Soldering

Tack soldering is the placing of a small amount of solder on the foil to hold two or more pieces together, so the main soldering can be performed without disturbing any placing of the remaining pieces.


The advantage of tack soldering is it can allow you to completely eliminate framing. You can just hold two pieces together with one hand and spot a dab of solder to hold them together. You don't have to do this for all pieces - just enough of the outside pieces to hold the whole project together. Once you've tack soldered, everything will be held in place and you can just run the beads without further considering the placing of the pieces.

For free form shapes, tack soldering is always quicker. You may want to use nails or tacks to hold all the glass in place while you tack solder.

With big foil projects or ones that have to fit into a predetermined dimension, tack soldering ensures there is no growth through movement of the pieces.

It's a quick way to avoid having to fiddle with each piece to make sure each is exactly lined up before starting with the running of the beads.

Soldering Bit Composition

Most bits are made of copper, which is suitable because of its excellent thermal conductivity and high heat content per volume. Some bits are plain copper, while others incorporate various additives or have a protective plating applied.

One of the most common problems associated with plain copper bits, is that tin-lead alloys (more specifically the tin in the alloy) will attack the copper, dissolving it away. This makes it necessary to continually file the bits to maintain the required shape, giving these bits a shortened working life. Another concern is the amount of impurity that is imparted to the solder joint when using bare copper bits.

Adding tellurium to the copper improves both wear and oxidation resistance, but does not protect the tip from rapid deterioration. It has been determined that both iron and nickel, despite their low conductivity, are wettable, offer a high level of resistance to erosion and their heat per volume is close to that of copper.

Because of these facts it is possible to maintain good conductivity, while increasing the erosion resistance by plating copper bits with either nickel or iron. These plated bits are generally referred to as nickel-clad, or iron-clad and make up a large majority of the bits in use for modern soldering applications.

Courtesy of American Beauty Tools

Even Solder Beads on Edges

Running an even bead on the edges of copper foiled projects is often difficult. Several things can help.

Hold the panel vertically and ensure the edge you are applying solder to is horizontal. This means that you have to keep moving anything that is not rectangular.

To apply solder and move the piece ideally needs three hands – one for the solder, one for the iron, and one to manipulate the piece. Failing such an evolutionary leap, you can use a small vice to continually alter the angle of the edge, you can get a friend or colleague to manipulate the panel, or you can place the solder so that you can pick up little drops of solder and place them on the edge. With practice, you can pick up some solder and transfer it to the edge before the previous dot of solder has cooled, so leaving a smooth bead by the joining of the dots.

Alternatively, you can place dots of solder near each other around the piece. You then come back and with one hand manipulating the piece the other can use the solderimg iron to heat and join the dots.

You do have to be careful that you do not move the panel before the solder has hardened, or it will run down the newly created slope to the new horizontal edge.

I find that it is much more difficult to run a bead on an edge than it is to “pat” the solder dots. This patting motion allows the solder to join together, but does not heat such a long line that it flows as you turn the piece to keep the edge currently being soldered horizontal.

Even Solder Beads

Getting even solder beads is a lot about where you look while you solder. Unlike drawing or cycling looking at where you are going is not so useful when soldering. You need to see the effects of what you are doing so looking behind the solder bit will help you understand what you are doing. If the bead begins to get small or narrow you either slow down the forward movement of the solder bit or add solder to it more quickly. If the bead begins to get too thick, you do the opposite. You can move the bit faster, or reduce the speed of feeding the solder to the bit.

Another element in getting an even bead is the heat being delivered. If you use a wide soldering bit you are delivering more heat to the joint. You hold the chisel bit so that it runs along the foil. The bigger the bit, the more heat is being held. And the more heat held in the bit, the more heat is applied to the soldering. Small bits are for getting into tight spots and for decorative soldering. Big wide bits are best for running beads.

Plaster Properties - Effect of Plaster-Water Ratio

Plaster-water ratio (by weight) of 100 plaster to 30 water gives:
a setting time of 1.75 mins,
a compression strength of 813 kg/sq cm., and
a density of 1806 kg/cubic metre

Plaster-water ratio (by weight) of 100 plaster to 40 water gives
a setting time of 3.25 mins,
a compression strength of 477 kg/sq cm., and
a density of 1548 kg/cubic metre

Plaster-water ratio (by weight) of 100 plaster to 50 water gives
a setting time of 5.25 mins,
a compression strength of 318 kg/sq cm., and
a density of 1352 kg/cubic metre

Plaster-water ratio (by weight) of 100 plaster to 60 water gives
a setting time of 7.24 mins,
a compression strength of 230kg/sq cm., and
a density of 1207 kg/cubic metre

Plaster-water ratio (by weight) of 100 plaster to 70 water gives
a setting time of 8.75 mins,
a compression strength of 176 kg/sq cm., and
a density of 1083 kg/cubic metre

Plaster-water ratio (by weight) of 100 plaster to 80 water gives
a setting time of 10.5 mins,
a compression strength of 127 kg/sq cm., and
a density of 990 kg/cubic metre

Plaster-water ratio (by weight) of 100 plaster to 90 water gives
a setting time of 12 mins,
a compression strength of 99 kg/sq cm., and
a density of 908 kg/cubic metre

Plaster-water ratio (by weight) of 100 plaster to 100 water gives
a setting time of 13.75 mins,
a compression strength of 70 kg/sq cm., and
a density of 867 kg/cubic metre

Properties of Typical Gypsum Plasters and Cements

No. 1 pottery plaster
Water to be added as % of dry mix by weight - 70%
Setting time - 27-37 mins
Dry density (kg/cubic metre) - 1106
% expansion on setting - 0.21
Compressive strength (kg/sq cm) - 127.26


No. 1 molding plaster
Water to be added as % of dry mix by weight - 70%
Setting time - 27-37 mins
Dry density (kg/cubic metre) - 1106
% expansion on setting - 0.20
Compressive strength (kg/sq cm) - 141

Plaster of Paris
Water to be added as % of dry mix by weight - 70%
Setting time - 27-37 mins
Dry density (kg/cubic metre) - 1106
% expansion on setting - 0.20
Compressive strength (kg/sq cm) - 141

No. 1 Casting plaster
Water to be added as % of dry mix by weight - 65%
Setting time - 27-37 mins
Dry density (kg/cubic metre) - 1162
% expansion on setting - 0.22
Compressive strength (kg/sq cm) - 170

Pottery plaster
Water to be added as % of dry mix by weight - 74%
Setting time - 27-37 mins
Dry density (kg/cubic metre) - 1057
% expansion on setting - 0.19
Compressive strength (kg/sq cm) - 127

Hydrocal cement
Water to be added as % of dry mix by weight - 45%
Setting time - 25-35 mins
Dry density (kg/cubic metre) - 1442
% expansion on setting - 0.39
Compressive strength (kg/sq cm) - 35

Hydroperm cement
Water to be added as % of dry mix by weight - 10%
Setting time - 12-19 mins
Dry density (kg/cubic metre) - <641
% expansion on setting - 0.14
Compressive strength (kg/sq cm) -


Hydro-Stone cement
Water to be added as % of dry mix by weight - 32%
Setting time - 17-20 mins
Dry density (kg/cubic metre) - 1914
% expansion on setting - 0.24
Compressive strength (kg/sq cm) - 707

Ultracal cement (30)
Water to be added as % of dry mix by weight - 38%
Setting time - 25-35 mins
Dry density (kg/cubic metre) - 1588
% expansion on setting - 0.08
Compressive strength (kg/sq cm) - 424

Solarisation

Old glass can show changes in colour as evidenced by the different colour of the glass under the lead came where the light cannot reach the glass.

Drew Anderson has provided the explanation.

This change in color of some glass is known as solarisation.

The main ingredient of most glasses is silica, which is usually introduced as a raw material in the form of sand. Silica itself is colorless in glass form but most sands contain iron as an impurity, and this gives a greenish tint to glass. By adding certain other ingredients to a molten glass, it is possible to change the greenish color and produce colorless glass.

These ingredients are known as decolorizers, and one of the most common is manganese dioxide (MnO2). In chemical terms, the manganese acts as an oxidizing agent and converts the iron from its reduced state - which is a strong greenish blue colorant - to an oxidized state which has a yellowish, but much less intense, color. In the course of the chemical reaction, the manganese goes into a chemically reduced state, which is virtually colorless.

When pieces of decolorized glass containing reduced manganese are exposed to ultraviolet radiation for long periods of time, the manganese may become photo-oxidized. This converts it back into an oxidized form. Even in low concentrations this imparts a pink or purplish color to glass. The ultraviolet rays of the sun can promote this process over a matter of a few years or decades.

Selenium and cerium have also occasionally been used as a decoloriser and can produce solarisation colors, just as manganese does. The colors developed by these two elements are said to range from yellow to amber.

Mesh Sizes from a Typical Manufacturer

Mesh sizes have traditionally been measured by the number of wires per square inch used to sieve the material. This table gives a grit size measurement for the mesh/grit numbers in common use.

Mesh = Mesh opening (mm)
12 =   1.5240
14 =   1.2954
20 =   0.8636
30 =   0.5156
40 =   0.3810
50 =   0.2794
60 =   0.2337
80 =   0.1778
100 = 0.1397
120 = 0.1168
200 = 0.0737
325 = 0.0432
400 = 0.037
625 = 0.020
1200=0.012
2500=0.005

Break-Down Temperature of Common Mould Binders

The temperatures that various binders used in mould making is important to consider, as once they reach the break down point, they lose their strength and therefore ability to hold the mould together. The following table gives some indication of the characteristics of various binders.

Binders and Break-down Temperatures (degrees C)
Gypsum plaster - 704 - 816
Hydrocal cement - 704 - 816
Hydroperm cement - 760 - 927
Colloidal silica - 1260
Colloidal alumina - 1260
Calcium alumina (ciment fondu) - 1538

These of course, are not the only considerations in mould making but do show why combinations of materials is important. The common plasters and cement break down before the casting temperature of glass, typically 850C.

Polishing 3D Glass on a Wet Belt Sander

Polishing three dimensional objects depends on the shape of the glass you are sanding down to the polished surface.

Convex shapes can be done on the wet belt sander with ease.

You can polish slightly concave items on a belt sander if you have an unsupported section of the belt. On machines with a flat platen, you can remove the platen to use the ability of the belt to form into a slightly convex curve.

Removing silicone

To remove silicone before it is cured you use a putty or other straight bladed knife to remove any of the uncured paste. Then wipe the area clean with isopropyl alcohol to remove any leftover residue.


After it is cured you should first you should remove as much of the silicone as you can with either a knife or a razor.

A solvent can them be used to remove any oily residue or any remaining silicone. It may be necessary to soak the silicone in a solvent overnight to break it down.

A list of solvents in the order of aggressiveness in attacking the silicone:
Paint thinner (mineral spirits)
Toluene
Xylene
Acetone
Methylene chloride.

When using solvents, as with any material, proper safety precautions should be observed. Material Safety Data sheets are available upon request from manufacturers. Similar information for solvents and other chemicals can be obtained from manufacturers.

There also are “Silicone Eaters” on the market now. The chemical composition is unknown, but are less messy and more expensive than some of the other solvents. Use according to instructions.

Glass Polishing Machines - Linisher

A wet belt sander, or linisher, is a machine intended to grind the edges of flat pieces of glass. It can do some work on bent, shaped, or slumped work, but its primary function is edging work while it is flat.

Table top model

The machines consist of a vertical or near vertical belt and a water supply to keep the belt and work lubricated and cool. Work generally starts with a low numbered grit belt, perhaps 80 grit, and then proceeds through the higher numbers. For example: 80, 120, 220, 400, 600, cork. Each stage should approximately half the grit of the previous one.

Floor standing model

Even with a cork belt, don’t expect a gloss you would see from a fire-polished piece. For that you need a cerium oxide belt or a felt belt with cerium oxide paste. Trizact is a brand name for fine polishing belts not requiring cerium oxide paste. These may be substituted for the more messy paste methods.

You can buy silicon carbide or diamond belts for a wet belt sander. The diamond belts are very expensive, but much longer lasting with proper care. If your belts are likely to receive rough treatment stick with the cheaper silicon carbide belts.

Cooling Events

This is based on Graham Stone’s work with float glass. The temperatures are applicable to float glass, and so need to be adjusted for a particular glass, but illustrate the principle of how heating temperatures affect the glass. Temperatures in degrees Celsius.


600 Common temperature for crash cooling toward. Glass beginning to "freeze".

555 Annealing temperature of float. Bungs in.

515 Approximate Strain Point of float.

535-400 Critical slow cooling down phase for float that overlaps annealing range.

400-300 Medium cooling down ramp rate.

300-10 Fast cooling down ramp rate. Cracking the kiln open possible.



Based on Firing Schedules for Glass; the Kiln Compainion, by Graham Stone, Melbourne, 2000, ISBN 0-646-39733-8, p24

Casting Temperature Events

This is based on Graham Stone’s work.
Temperatures are in degrees Celsius.

660 Bungs still out for casting.

710 Mould "curing" starts (molecular moisture being expelled).

820 Bas relief complete. Whiting gives off CO2

850 Glass flowing. Viscosity decreasing quickly. Common casting temperature

870 Fine mould/mold detail complete

900 Plaster moulds becoming very brittle

950 Un-reinforced plaster moulds no longer viable.

1100 Glass runny enough for sand casting and other manipulative techniques.


Based on Firing Schedules for Glass; the Kiln Companion, by Graham Stone, Melbourne, 2000, ISBN 0-646-39733-8, p24

Disposal of Used Bullseye Thinfire

The main ingredients of Bullseye’s Thinfire are cellulose, aluminum hydroxide, fiber glass, and organic binders. It is predominately a nuisance dust and irritant.

Use a vacuum sweeper with a high efficiency filter and a bag rated for plaster dust. Also many vacuums with a HEPA filter system will be sufficient. Wrap the disposable bag in another -preferably paper - bag to avoid dispersing the dust when it goes into the rubbish.

Viscosity Changes with Temperature

This is based on Graham Stone’s work with float glass. The temperatures are applicable to float glass, but illustrate the principle of how viscosity changes in a non linear pattern with the increase in temperature. Temperatures are in degrees Celsius.

515 Viscosity 10145 poises (approximate strain point of float)
555 Viscosity 1013 poises
610 Viscosity 1010 poises
730 Viscosity 976 poises
850 Viscosity decreasing faster
900 Viscosity now 105 poises and falling

Based on Firing Schedules for Glass; the Kiln Companion, by Graham Stone, Melbourne, 2000, ISBN 0-646-39733-8, p24.

This shows that viscosity changes rapidly from the lower strain point (the solidification of glass) to annealing.  The change slows from the annealing point to full fusing, but changes rapidly after that.  This is an important factor to control in casting and free drops.

What is viscosity
Graph of the changes

Paint – Temperature Effects

This is based on Graham Stone’s work with float glass. The temperatures are applicable to float glass, and so need to be adjusted for other glasses, usually a bit lower. But these temperatures illustrate the principle of how heating temperatures affect the paints. The temperatures will need to be adjusted when fired on other glasses than float. Temperatures are given in degrees Celsius.

570 Low firing glass enamels fired
650 Silver stain fired.
690 Low fire red enamel burnout.
730 "Paradise" paints fired.
750 Onglazes fired.
800 Lustre burnout begins.

Based on Firing Schedules for Glass; the Kiln Companion, by Graham Stone, Melbourne, 2000, ISBN 0-646-39733-8, p24

Iridised Side of Glass

It can be challenging to determine the iridised side of glass. The coating is very thin and so cannot be seen by looking at the edge. There are several ways of testing for the coated side. Two that I find useful are:

The pencil test – In this you put a pencil point or other point to the glass. You then look for the reflection at an acute angle to the glass. If there is a gap between the point and the apparent surface of the glass, the coating is on the other side. And in reverse, if the point is immediately reflected with no gap, the point is touching the coated side.

Another test is the fingernail test. If you have sensitive nails, you can feel the difference in surfaces by gently dragging your nails at an almost right angle to the glass. The rougher side is the coated one.

There are other tests but these two work for me.

Foil Lifting While Soldering

There are several possible reasons for this.

The main one is that the soldering is too slow. This causes the adhesive on the foil to fail before the solder has a chance to become rigid.

The foil may not have stuck to the glass firmly. Reasons for this are many, but some are:

- Dirty glass. Make sure the glass is washed and polished clean, especially if you have been grinding, when you need to get all the glass dust out of the pits on the edges.
- Oils from your hands. The oils can be natural or from hand creams. If you have oily skin or need to use hand creams consider cotton gloves for use when handling the glass prior to and during foiling.
- Inadequate contact between the foil and the glass. This can be from both the above, but can also be that the foil was not pressed firmly to all the sides and edges of the glass pieces.


The foil adhesive may be inadequate through manufacture or age. If a test piece does not feel tacky to your finger tips, it is not going to stick to the glass very well.

Grinding for Copper Foil

It is often thought that every piece of glass has to be ground to enable the foil to stick well to it. There are conflicting views about this. I am firmly on the side of not grinding. The impact adhesive on the back of the foil is thin and will not fill the depressions caused by grinding. It will adhere to a smooth surface more strongly than a rough one. Remember the purpose of the foil is to provide a surface to carry the solder. It keeps the foil in place until the solder bead is completed on both sides. It is not a permanent adhesive. So some of the discussion about which surface is best is academic.

There are ways of obtaining clean cuts that help avoid the need to grind.

Score with an even pressure. This helps the glass break clean with few shells or chips. If there are any overhangs, you can eliminate them with a quick wipe of the edge of the cut piece on the waste piece.

Ensure you hold your cutter vertically. This will encourage the break to be at right angles to the surface giving a clean smooth cut face.


The only NEED for grinding is to adjust an inaccurate cut. We all make inaccurate cuts from time to time.

Copper Foil Oxidisation

Protection of foiled pieces from oxidisation

If foiled pieces are going to sit a while before soldering, put them in a sealed plastic bag with the air squeezed out. This will prolong the time before the oxidization becomes a problem for the soldering process.

Another possibility is to tin all the pieces before putting them away in the plastic bag. Solder oxidizes more slowly than copper does.

Transparency Sketches

Use matt finish acetate .25 to .12mm thick. This will later be fixed to Perspex for presentation.

You will need rigger brushes in sizes 0, 1, 2, and 4 for doing the lead lines and other areas of graphic delineation. In using these brushes for lead lines, you want to maintain a line that is consistently thick. It is a different feeling from general image making and you may want to try locking your wrist to maintain a greater consistency of pressure.The paint for the lead lines can be a calligraphy ink or a black acrylic paint. The lead lines and all other tracing is applied to the matt side of the acetate.

Once the tracing lines are all completed, start laying the colours on the backside, the smooth side. The brushes to use are bulbous pointed sables in sizes 2, 3, 5 and 6. The application is in a "floated" versus a "stroked" manner of application. Stroking has a tendency to hasten the drying resulting in streaking. You may find this a bit of a trick at first. It is advisable to place colour throughout the design so it has time to set up and dry a bit, as opposed to putting wet against wet.

When the colour has dried, one can emulate matting on the matt side with an ebony pencil. And if you want to take out some lights, that can be accomplished with carefully placed extender. The extender is also used to make the piece transparent and to emulate a variety of textures available in glass from reamy to seedy.

When the colours are dry, mount the sketch on 3mm Perspex to stiffen the presentation, provide weight and give the presentation with some "substance”. You can also add double matt board doors hinged with smooth electrical tape to keep the lacquer colours away from sustained sun. Also when open, they support the sketch during the presentation.

When putting matting boards around the presentation sketch, they should be much wider than a drawing or water colour so that ambient light from behind is modified by a greater expanse of black or dark matting board.

Edited from emails by Richard Millard