Soldering Bit Maintenance - Tinning

Introduction
Proper care and maintenance of your soldering iron bit involves tinning, wiping (and wetting) and also periodic cleaning of the bits shank. These actions are very important and quite simple to perform, but are often neglected. When performed properly they will not only ensure the longest possible working life for your soldering iron bits, but they will also have positive effects on the overall performance of your soldering iron.

TinningTinning may not be necessary if the bit you are using is new and arrives pre-tinned from the manufacturer, or has been used previously and been properly maintained. When a bit does need to be tinned (or re-tinned) it must be clean and free of any surface oxidation before it will accept any solder. Once the bit is properly tinned, care should be taken to prevent bit de-wetting by occasionally cleaning and adding small amounts of fresh solder, especially if the bit is being subjected to long periods of inactivity or idling.

If the bit to be tinned is un-plated copper it should be cleaned and dressed with a single cut, flat file. After filing the bit it should be heated in the iron. When the bit reaches the lowest temperature required to melt solder, a rosin core solder should be fed onto the bit. Do not allow the iron temperature to rise too high before applying the solder, because excess heat will cause the bit surface to re-oxidize and no longer accept the solder.

If the bit is plated it should never be filed, or heavily abraded. Care should be taken to ensure the plating is not damaged or removed, as this will shorten the working life of the bit dramatically. When pre-cleaning is necessary for plated bits, they should be cleaned with a mildly abrasive emery cloth and may require an acid flux to remove the oxides before tinning, or re-tinning.

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

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