Glass Grinder Use

Glass grinders are very handy tools. They mainly consists of a spinning diamond coated cylinder (the bit) extending above a grid surface that can rapidly and accurately grind glass to the desired shape.

Don't purposely cut glass large with the intention of grinding. Ideally no grinding would have to be done. It should be used only for minor adjustments or for grinding tough-to-cut inside curves.

Bits
The diamond bit must be kept wet in order to reduce wear on the diamond and prevent glass dust from developing and being inhaled. There are several grits available. "Fine" grinds slower but leaves fewer chips in the glass. "Coarse" grinds very fast but leaves larger chips. "Standard" is a central compromise.

Water reservoir
Ensure there is water in the reservoir before starting any grinding. Empty the reservoir daily. This keeps the water from producing a smell, and allows you to clear the glass residue from around the grinding bit.

Nails

Horseshoe nails are normally used to temporarily hold glass and lead in place while assembling the panel. The flat side of the nail goes against the lead. If the final lead is in place, try to put nails where there will be a solder joint. This will hide any "dings" in the lead. If no lead is yet in place, use a piece of scrap lead to protect the glass from chipping and to raise the glass to a common level before placing the nail. When pulling a nail, rock it in the narrow, side-to-side direction in order to prevent bending the tip.

An even more convenient nail is the round German nail which is hardened steel and sharply pointed. This nail can be started with one hand which is handy when your other hand is busy holding everything together. Use a twisting motion to pull the nail.

Lead-Free Solder

Most of the advice around lead free solder is to avoid using it. However, lead-free solder is essential for making jewellery (which may have skin contact) or any project that may be in contact with food.

Lead-free solder does require a hotter iron than lead bearing solders, plus it does not flow easily. This is in spite of its relatively low melting point.  It has a pasty state between solid and liquid that is prone to lumps and spikes. If this is not bad enough, it also does not take patina designed for lead bearing solders well.

Those using rheostats with their soldering irons, should get rid of the rheostat (see tips on soldering irons), as they limit the ability of the iron to recover the soldering temperature. The best iron to use with lead free solders is a temperature controlled iron, like the 100 watt Weller, or even a higher powered one like the Weller 200 watt. You can get tips that run at 800F to replace the standard 700F tips. This helps with the higher temperatures needed for the lead free solder. But you should not be vaporizing the solder as that is what could hurt you.

Consider the effects of the flux that you are using. Experimenting with various kinds (see the flux tips) can lead you to one that works better than the others.

As always, good hygiene and good ventilation are required when soldering. Also you should wash your hands well and frequently, and eat in a separate room.

Flux Core Solder

A tube of multicore electronics solder is used for manual soldering in the electronics industry - the flux is contained in five cores within the solder itself.

Solder often comes pre-mixed with, or is used with, flux, a reducing agent designed to help remove impurities (specifically oxidised metals) from the points of contact to improve the electrical connection. For convenience, solder is often manufactured as a hollow tube and filled with flux. Most cold solder is soft enough to be rolled and packaged as a coil, making for a convenient and compact solder/flux package.

The two principal types of flux are acid flux, used for metal mending, and rosin flux, used in electronics, where the corrosiveness of the vapours that arise when acid flux is heated could damage components. Due to concerns over atmospheric pollution and hazardous waste disposal, the electronics industry has been gradually shifting from rosin flux to water-soluble flux, which can be removed with de-ionised water and detergent, instead of hydrocarbon solvents.

Fids or Lathkins

Fids or lathkins are available in hardwood or plastic in a variety of shapes. They are used to open the channel of lead came, press the leaves of the lead tight against the glass, and burnish the copper foil against the glass. They can be purchased or made from hardwood.

Soldering Lead Came

Historically soldering tips were copper, placed in braziers. One tip was used until it became too cool, when it was placed back in the brazier of charcoal and the next tip was used. Later gas irons were used and currently electric soldering irons are most commonly used.

The lead needs to be clean and bright to enable the solder to stick to it. If it's fairly new lead it may be solderable without further preparation. However, if the lead is dull and oxidized, you should scrape the lead in the area to be soldered with the blade of a lead knife.

Then apply the flux.

The iron is held over-handed (as you would a bread knife) in order to get the handle low enough to have the tip flat on the lead. You can allow the weight of the iron to press gently against the joint to transfer the heat into the lead or foil.

The solder is fed to the iron tip so as to melt an approximately five millimetre long piece of blowpipe solder.  Move the solder away as soon as it is melted, so it doesn't become attached. As soon as you see the solder at the joint melt and spread, slowly lift the iron straight up.

This image represents the principle of soldering any metal, not just computer boards

Avoid "painting" or dragging the iron across the joint. The object is to have a shiny, smooth, slightly rounded solder joint. There should be no points sticking up from the solder joint. If a solder joint is not satisfactory you can re-flux and re-solder. Don't apply too much solder. It's easier to add more solder than to remove excess.

The most common concern is whether there is enough solder on the joint. Very little solder is required to stick the joints together. Often a securely soldered joint shows the ends of the cames. For cosmetic reasons it is usual to use enough solder to disguise the ends of the cames. It is not a structural requirement.

Trimming Lead Came on Site

There are a variety of reasons for the panel not fitting the opening easily. These can range from poor measurements through parallelogram, trapezoidal openings or irregular perimeters of the openings.

In the cases of irregular openings, you can trim the edge cames if you have made them 12mm (1/2”) or more wide. The quickest way of trimming cames to fit the opening is to use a rasp or “surform” tool. The open nature of the teeth, allows the lead to fall away. It is much quicker than using a lead knife, and it puts less pressure on the panel.

Filling Gaps Between Glass Pieces

Gaps along the bead line

When you have a gap between pieces of foiled glass, fill the gap with small pieces of lead or copper foil tape that has the adhesive side folded together. These will have to be cut to a width of just less than 3mm to keep them from projecting above the surface of the glass. This material helps to fill the gap and reduce the amount of “melt through”. Put a bit of masking tape on the top surface of the gap and turn the panel over.

Solder the back first. You can do this with 50/50 or 40/60 solder as it does not change from solid to liquid and back so quickly as 60/40. (See melting points of solders.) However the masking tape will keep the solder from dripping through if you apply too much heat. When you have finished soldering the back, apply masking tape to the now filled gap and turn over.

When completing the soldering of the top, you will need to take care to avoid over-heating the solder filling the gap. Over heating will allow the solder to melt through the existing solder and flow along the back. Usually, an application of dots of solder next to each other avoids transmitting as much heat as running a bead will. When you have passed the gap area, you can continue running the bead in the normal way.

Gaps between pieces

When you have gaps between glass that cannot be cut or re-cut, such as globs, fill the gap with a piece of lead or copper foil sheet cut to the size and shape of the gap. This is better than folded up pieces of lead or foil as it carries the solder over the gaps to the foiled pieces of glass. It allows for a smoother surface, and uses less solder.

Note:
Remember to avoid moving the panel for a while, as the large solder bead will require longer to become solid.

Exposed Foil

After soldering, inspect the solder seams for small areas or strips of copper foil edges that aren't covered with solder.

If this exposed foil is where you want the solder bead to be, you need to clean the foil and re-apply solder. Usually scrubbing with “000” steel wool is sufficient. If, after scrubbing and applying flux, the solder still does not stick, you need to wash the piece and after drying, scrub the exposed foil, re-apply flux and solder again.

If the exposed foil is surplus or where you do not want any solder, take a craft knife, and carefully trim off the exposed foil.

Transporting Glass

Store, carry and transport glass as near to vertical as possible.

If you are transporting a number of sheets, place paper between the sheets to avoid scratches and vibration damage or breakage. The glass should be tied tightly together, preferably on a rack.

If you do not have a rack, you can put into the back of your vehicle and put the seat belts around the glass to keep it from flying forward in the event of an emergency stop. Cushion the seat belts from the edges of the glass to avoid cutting the belt with emergency breaking.