Thursday, 18 December 2008

Glass painting tools

The tools needed for glass painting are few and relatively common, although the blender is specialised. The minimum you need are:

Glass palette –
a lightly etched glass sheet on which to grind and mix the paints

Palette knife –
a paint knife with a flexible metal blade used to mix and pile the paint

Tracing brush –
a thin and long-haired brush used to apply paint to glass. Sable is considered superior as it can hold a lot of paint allowing long lines.

Badger blender –
a wide and flat brush made of badger hair used to blend or evenly disperse a layer of paint on the glass, or to stipple a fine layer for a pin-hole effect

Stippler
a round, thick brush used to apply wet paint and create a stippled matte.

Tuesday, 16 December 2008

Enamels

In a discussion of art technology, enamel (or vitreous enamel, or porcelain enamel in American English) is the colourful result of fusion of metals carried in powdered glass to a substrate through the process of firing, usually between 750C and 850C. The powder melts and flows to harden as a smooth, durable vitreous coating on metal, glass or ceramic. It is often applied in a paste form and may be transparent or opaque when fired. Vitreous enamel can be applied to most metals.

Vitreous enamel has many excellent properties: it is smooth, hard, chemically resistant, durable, can take on long-lasting, brilliant colours, and cannot burn. Disadvantages are its tendency to crack or shatter when the substrate is stressed or bent.

Low firing enamels formulated for glass are forms of paint designed to fire between 550C and 600C which avoids the distortion of the glass that would occur with enamels designed for metals.

Monday, 15 December 2008

Breaking Pliers

Description
The breaking pliers is a special stained glass tool that has smooth jaws that meet at the tip of the pliers. This enables the tool to reach over the top and bottom of the glass with only the tip coming into contact with the glass exactly against the score line.

Use
The pliers handles are held at a right angle to the score line. The edge of the glass needs to be close enough (within 20mm) to the score line in order to use this tool, as the tip of the jaw needs to be against the score line. It is used in lieu of your hands when the piece being broken off is too narrow to be comfortably grasped by hand. When bending the glass, the top jaw comes down flat against the surface of the glass (that's why we want the smooth jaw) and as more bending pressure is applied, lateral/pulling pressure is applied. This tool can also be used to groze the glass by carefully nibbling away the edge, but grozing pliers work better.

Sunday, 14 December 2008

Framing Panels with lead

One option for framing, especially where the edges are not rectangular is to use lead. The lead touching the glass or copper foiled edge should be 10mm flat came. This allows you to insert a 5mm mild steel rod shaped to the outside of the panel. This is then covered by a 13mm flat came. The came is smoothed by gentle pressure on the upper and lower flanges with a stopping or lead knife to bring the two flanges together. This gives a pleasant finish to the edge.



by Gene Mallard

Thursday, 11 December 2008

Cartooning for Acute Angles

When you are designing panels, you can prevent some leading difficulties. If you have shapes that join at acute angles, you can alter the design to make the leading simpler.

Say you have two balls touching. You can design the panel so the cut lines intersect or touch each other. This makes for extremely acute angles in the cutting of the cames. Two balls touching in the presentation drawing will not look the same if leaded that way.  So if you make the edges of the balls just a few millimetres separate, the cames will pass each other, just touching, and so have the appearance of the presentation drawing, rather than the appearance of overlapping.

You separate the lines by the thickness of the came you will be using for that area. If you are using 6mm came, the cut lines should be just less than that distance apart. This will allow the cames to go around each shape and the flanges of the came will just overlap. This makes for quick leading and a clean appearance.

Tuesday, 9 December 2008

Handling Large Sheets

PreparationUse proper glass handling gloves.

Wear closed toe shoes, preferably with steel toe caps. This also allows you to set the glass on your toes prior to changing your grip to place the glass in the rack.

Clear the passage ways of all obstructions, whether on the floor or at the walls and door ways before moving any glass.

Lifting from horizontal
The transition between horizontal and vertical is important because the glass sheet can break if it does not have the proper support. However, there is a tried and true method for laying glass down and turning it over.

Rest the glass on the edge of the bench, half on, half sticking off. Support both sides of the sheet. Then pivot it to the horizontal, still resting the middle of the glass on the edge of the bench as your fulcrum. This provides support at the middle during the transition from vertical to the horizontal of the bench top.


CarryingTo carry large sheets of glass safely (for yourself and the glass), you need to support from below as well as the end. One gloved hand goes under the bottom and the other on the side. The glass is then carried vertically, with the edges at an angle. This is done in a manner so that the glass is on the side of your body with both palms are facing outwards. If there is a trip or other accident, the glass will be tipped away from the body. This sounds awkward, but is safe and easy when you get used to it. It also is the glazing industry standard method of carrying glass.

If the glass is too heavy to lift in this way, use suckers and get others to help.

If the glass breaks while carrying it just let it drop. Trying to catch or save it will lead to a hospital visit.

Always set the glass edges down on a cushioning material. This can be wood, linoleum, carpet, etc.

Transporting

Store, carry and transport glass as near to vertical as possible.  You need to be careful when handling glass. In larger sheets it is very weak in a horizontal plane. It is strongest when it is in a vertical plane. (That’s why glass is always supposed to be shipped upright.)


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, perferably on a rack. If you do not have a rack you can put into your vehicle, you can put the seat belts around the glass to keep it from flying forward in the event of an emergency stop.




Monday, 8 December 2008

Outside Curves

Outside curves are usually the easiest curve to break out. You do not have to worry about breaking the piece you wan to keep.  The break, if it goes off the score line, will be away from the piece rather than into it. 



Outside curves often have complimentary inside curves. So, on the principle of making the most difficult break first and the easiest last, the outside curve will be broken out last. Unless, of course, there is a straight line on the other side of the curve when the straight line would be the last, as it is the easiest score to break out.

Thursday, 4 December 2008

Preparing the Glass Paints

Paint
Measure about one tablespoon of black paint powder onto the center of your palette, With the edge of the palette knife, break up any clumps in the pigments. Grind the paint with the flat side of the palette knife until it feels and sounds smooth. Then mound the prepared powdered paint into a pile. Using the blade of the knife, pat the paint flat to about 1/8" thickness.

Gum Arabic
Then using the end of the palette knife, take some powdered gum arabic and, gently tapping the knife, sprinkle the gum over the surface of the paint. Use only enough to give the impression of a faint dusting of snow or sprinkling of salt. This step is crucial to the end result, as too much gum arabic makes removal of the paint from the glass with brushes and sticks difficult. Too much gum arabic can also cause the paint to bubble and splatter at firing temperatures. The correct amount may require some trial and error, but it is better to have less than more gum arabic.

Mixing
Blend the gum and paint together while dry. When thoroughly mixed, push into a mound, and make a valley in the center. Add about 1/2 teaspoon of water and with your palette knife, blend the pigment with the water. Add water and continue to blend until the paint is silky smooth and the consistency of thin yoghurt. Work the paint with a circular motion across the palette, then repeatedly "pile" the paint to the center of the palette.

Wednesday, 3 December 2008

Glass painting Media

Mixing agents
These are the carriers that give "tooth" to the paints and are water-based or oil-based.

Common water-based media are:
  • water & gum arabic,
  • wine,
  • sugar water,
  • vinegar

Common oil-based media are:

  • clove oil,
  • lavender oil,
  • damar varnish

Binders


Gum arabic
This natural gum (also called gum acacia) is a substance that is taken from two sub-Sharan species of the acacia tree, Acacia senegal and Acacua seyal. It is used primarily in the food industry as a stabiliser, but has had more varied uses in the past, including viscosity control in inks. For artists it is the traditional binder used in watercolour paint. It is sold in powder and liquid forms.


Dammar gum
This is obtained from the Dipterocarpaceae family of trees in India and East Asia, principally those of the genera Shorea, Balanocarpus, or Hopea. Most dammar gum is produced by tapping trees, however some is collected in fossilised form from the ground. The gum varies in colour from clear to pale yellow, while the fossilised form is grey-brown. It is used in foods, as a glazing agent, in the making of incense, varnishing and in other processes. Dammar was first introduced as a picture varnish in 1826 and is commonly referred to as Damar varnish

Tuesday, 2 December 2008

Glass Painting Terms

Tracing
to paint a very thin line in one smooth, calligraphic stroke to define the basic shapes in the glass painting

Matting
to apply a very thin coat of paint over the entire surface of the glass (usually
after tracing and firing) for further definition and highlighted details of the glass painting

Stippling
removal of the matting to expose more glass and often used as a shading technique, using a pouncing motion, producing a pinhole effect

Stick-lighting
removal of the matting to expose more glass and often used as a shading effect to create roundness and dimension in the glass painting

Firing
the heating of the glass and paints to fuse the paints with the glass or stain the glass with the silver stains

Monday, 1 December 2008

Laminated Glass

Laminated glass is a type of safety glass that holds together when shatered. In the event of breaking, it is held in place by an interlayer, typically of PVB, between its two or more layers of glass. The interlayer keeps the layers of glass bonded even when broken, and its high strength prevents the glass from breaking up into large sharp pieces. This produces a characteristic "spider web" cracking pattern when the impact is not enough to completely pierce the glass.

Friday, 28 November 2008

The Glassy State

  • Glass is a state of matter.
  • Glasses combine some properties of crystals and some of liquids but are distinctly different from both.
  • Glasses have the mechanical rigidity of crystals, but the random disordered arrangement of molecules that characterises liquids.
  • Glasses are usually formed by melting crystalline materials at very high temperatures. When the melt cools, the atoms are locked into a random (disordered) state before they can form into a perfect crystal arrangement.

The complete description can be seen at the Corning Museum of Glass

Thursday, 27 November 2008

Smooth Solder Beads

Good smooth soldering occurs when the temperature of the iron is correct for the job and the solder being used.

The problem of bunched up solder or peaks as you lift the iron from the solder is caused by the iron being slightly too cool for the job and the solder being used. Looking at the conditions causing the problems may lead to a better solution.

If the problem is caused by the iron being slightly too cool to let the solder flow properly, this can be caused by a number of things.
  • If your iron is too low power, you may start out well and have the problem develop as you solder.
  • If your iron is high enough power and you're using a 'rheostat' or dimmer controller, this has the effect of lowering the iron's power and the problem will occur as above.
  • 50/50 (tin/lead) solder requires a hotter iron than 60/40 (tin/lead) solder to keep the molten metal flowing properly.

The best possible soldering iron controller is a genuine temperature controlled iron, where the iron’s controller maintains the tip temperature by applying full power to the heater when the tip cools slightly, but otherwise just 'idles'. If you can't get (or afford) one of these, possibly the best would be to get a higher power iron or throw away the 'rheostat' or dimmer 'controller'.

If the problem still occurs, then use 60/40 solder – which melts and solidifies in a narrower range than 50/50 - or perhaps do the soldering in shorter 'bursts', letting the iron recover for a couple of minutes before starting again.

In any case you need to match the speed of movement and the speed of feeding the solder to the iron according to the capability of the iron to adequately melt the solder.

Also you have to ensure that the foil has been properly fluxed and tinned.

Wednesday, 26 November 2008

Foil Pulling Away from Edges

If foil is pulling away from the glass on the perimeter of pieces, there are several things to remember.

Clean all the edges and surfaces just before foiling. This ensures there are no oils to interfere with the contact adhesive of the foil.

Avoid hand creams just before foiling as this increases the amount of oils getting onto the glass.

Remember that lots of heat breaks down the adhesive. So do not remain in one place too long. However the adhesive is not the element that keeps the foil attached to the glass in the long term.

Instead, think about whether the bead on the edge is thick enough to provide the rigidity required without relying on the adhesive of the foil.

Finally, think about whether an edging came would provide better support and finish to the piece.

Tuesday, 25 November 2008

Copper Foil Limitations

Unsupported windowsWindows without either rebar or internal support via Strongline or re-strip should not measure any more than 610mm in any dimension.

Flat work
It is not advisable to create anything over 1220mm (4 feet) by 1830mm (six feet) for a window installation even with re-inforcing bars. All such large copper foiled windows need an exterior piece of safety glass flush against the stained glass. Alternatively, split the window into smaller panels supported on “T” bar.

ReinforcementsAnything over 610mm square normally requires internal reinforcements with either Strongline and/or restrip. Inserting long strips of either Strongline (copper plated steel) or restrip (thicker strips of copper) in between the copper foiled glass pieces to create a "spine" and then a "grid" of internal support is necessary when dispensing with rebar (horizontal lines of brass, steel, or other stiff metals attached to the panel for structural support).

Monday, 24 November 2008

Polishing Solder lines

Before polishing, clean the solder (see cleaning tips) and apply the patina, if any.

Use a good quality furniture polish or wax. Shake the bottle well if it is a liquid, then apply liberally to a soft cloth, or good quality paper towel, rubbing all over solder. If you have a glass with a deep texture, try to avoid this all over process, as it can be hard sometimes to remove all of the polish afterwards, and it is noticeable when it dries. Alternatively, mask off the glass from the solder.

Immediately after applying the polish, take a clean, dry soft cloth or new paper towel, and begin to gently rub the solder seams. If you are using paper towels, you will need a lot of them, as they tear up quickly. When both sides have been polished, check for any missed spots, especially along the edges of your solder seams. Also check for polish residue in tight corners and along the edge of the solder. An old toothbrush often works to remove it. If you need stiffer bristles, make sure you keep this new toothbrush separate from all the others in the house.

Friday, 21 November 2008

Lampshade Pattern/Cartoon Tools

Lampshade patterns –tools for custom-made patterns.

The items you need to have for creating your own pattern are not extensive or unusual.
  • Craft knife or razor blade
  • Baby/talcum powder
  • Fine pointed felt tipped pen (Sharpie)
  • Highlighting pen
  • Pencil
  • Eraser
  • Carbon paper
  • Drawing paper
    Masking tape
  • Lampshade form
  • End/vase cap
Further design process information is here and here

Thursday, 20 November 2008

Lampshade Pattern Construction, 3

Cut the finished template into sections (if you are using a 360 degree form)
The masking tape template will need to be cut off the curved form and laid out flat. This is easier to do if you can logically separate the template into smaller sections. To do this you need to find lines running almost vertically from the top to bottom of the template. Mark these separation lines in a different colour. Also label each section.

Remove the template(s) from the form and press it out flat
Take a craft knife or razor blade and trim away excess masking tape from the end cap mark. Do the same for the bottom edge. Carefully remove the excess and throw it away.

Prepare a section of your work surface by sprinkling some talcum powder on it, and onto your hands as well. This will help keep the sticky side of the masking tape from sticking where you don't want it later.

Using the craft knife, slice through the middle of each separation line that you marked in a special colour. Try to stay in the exact middle of the line. Be careful that you do not tear or cause to pull away the underlying masking tape as you cut through the line. Do this with each separation line.

Starting with the top edge, use the craft knife to gently pull the masking tape template off the form. If the masking tape starts to separate, stop and repair it. As each section is taken off the form, put it sticky side down into the talcum powder and press it flat. Do this for each section.

Scan/copy the template(s)
At this stage you can scan each section into Glass Eye or other image software. This allows you to:
  • select and change colour/glass choices very easily
  • print out or email colour proofs to the client
  • keep them in an electronic form for future reference or manipulation

You don't have to scan your pattern, but you do need to make at least two copies of the pattern.

Cut out one copy and reapply it back to the form
One copy is fastened back onto the form so that you know where to put your glass pieces.

Cut out the other copy and paste it onto your glass
The other copy is cut out using pattern shears (the three-bladed scissors) and glued onto the glass for cutting.


Based on work by Christie A. Wood, Art Glass Ensembles

Wednesday, 19 November 2008

Lampshade Pattern Construction, 2

The second stage is to get the design onto the prepared mould and make adjustments to give a balanced and pleasing appearance

Trace the pattern onto the template
Take your design elements and trace them onto the masking tape on the form. The use of carbon paper enables you to put the design element and trace right on top of the taped mould so that the image is transferred onto the tape.

An alternative method is to use a pounce wheel to perforate the design element. The element is placed on the form and dusted along the perforated line with a bag of dark coloured powder such as powdered poster paint. This will leave a temporary trace on the form that can be changed easily, but needs to be pencilled in before too much other work smudges the shape.

Do this tracing with each design element, flipping and rotating them around so that you don't repeat any element exactly. Fill up major sections of the form using this method. Drawing the main feature first and filling with the minor elements helps provide a pleasing composition.

Fill in blank areas
Now that the key design elements are onto the masking tape template, create background pieces by linking your design elements. Use pencil, since you will probably need to do corrections. Remember, avoid creating large horizontal pieces. Larger vertical pieces are usually better. However, try to keep all the pieces of similar size.

Correct any pieces and number them
Once you are satisfied with the design, go over every line with a fine felt tip pen or other ink pen so that each is clear and distinct. Number each piece and mark colour and glass textures as necessary.


Based on work by Christie A. Wood, Art Glass Ensembles

Friday, 14 November 2008

Grinding Tips

Protect your cartoonWhen grinding a lot of pieces, you can place a piece of clear float glass over top of your paper pattern, or encase it in plastic to protect it from becoming wet. Then you won't have to grind, dry, test, and repeat. You can just grind and test, quickly grinding where needed.

Placing your cartoonAlso try to have your pattern where you are test fitting right beside your grinder, to cut down on time spent moving from grinder to pattern.


Grinder resevoir maintenanceRinse out your grinder sponge often (at least daily), and replace when it becomes deformed.


Clean out the ground up glass in the bottom of your grinder regularly with a narrow putty knife. Scrape it out into a small old plastic container with a top, and then throw the container into the garbage when it is full.


Grinder head maintenanceMove your grinder head up or down, as it is wears, to a new section. You should be able to get three or four sections out of a typical grinder head.

Monday, 10 November 2008

Copper Foil vs. Lead

The copper foil technique may or may not have been invented by Tiffany, but he certainly used it extensively in his studio. Thus it is often referred to as the Tiffany method.

It is neither easier nor more difficult than lead. However, it’s significantly cleaner because it does not involve the use of whiting or cement, which is why this technique is most often taught to beginners in North America. In Europe leading is most often taught first.


Some people deduce that copper foil must be stronger than lead because the solder goes all the way around and between each piece, but lead is still the preferred method architecturally, holding up huge weight-bearing windows for hundreds of years.


One thing copper foil can do, though, is allow stained glass panels to curve, as you can see in the multitudes of Tiffany lampshades that are still around today.


There are a few other differences from lead in the construction of copper foil panels. First, copper foil is less forgiving in that there is no channel to hide errors in glass cuts. Precision in cutting becomes especially important.


However, while cutting may be a little more difficult, soldering foiled pieces is a little easier because you can’t burn through copper foil the way you can through lead. If you accidentally apply too much heat, the solder just drips through to other side and forms a ‘mushroom’ that must be cleaned up later. Or it cracks the glass.


Finally, lead panels are usually constructed from the corner out (pieces of wood form an “L” shape and the panel is started in that corner and grows up and out). Copper foil panels are usually started inside a (temporary) wood frame that goes all the way round the panel, like a picture frame. You don’t need to start in one particular spot because the pieces aren’t going to shift within their frame.

Friday, 7 November 2008

Copper Foil Repairs

Repair or not

First consider whether any repairs should be carried out at all. Repairing can sometimes cause more damage, and if it is an older piece, finding an exact match may be impossible. So gluing may be the better approach.

If small shards of glass are missing, daylight is visible through the broken part, or sharp bits are exposed, then it should be repaired, assuming the client is willing to pay.

Starting the repair

Having decided to repair, the first action is to use fine steel wool to remove any patina from the solder around the broken pieces, on both sides.


Removing the broken glass

Next, work out the shards using a fine blade to get between the broken pieces. You should be wearing safety glasses during all the processes of getting the glass out of the piece.


In some cases in may be necessary to score the remaining part of the broken piece with your cutter in a criss-cross pattern, from edge to edge. Also try to go toward the centre of the piece from each corner while making the score lines.

Now start tapping the centre of the broken, scored piece of glass with the ball on the end of your cutter and then work out to the edges. Keep tapping the glass and it should start to fall out. When most of the glass in the middle has fallen out, take out small pliers and gently wiggle the broken shards out, one at a time. Remove all the glass possible, but you might not be able to get the glass in a tight corner.

Removing the solder and foil

Now take your soldering iron and melt off the bulk of the solder seam, slowly going all the way around the hole. Wipe excess solder off on your iron stand sponge. Do the same on the other side. During this process you will be able to remove any remaining small pieces of glass.


Apply the hot iron to the corner joint to expose the piece of copper foil that was wrapped around the broken piece of glass. With a pair of tweezers, grasp and very gently tug out that inner piece of foil while keeping the iron on the solder line to keep the solder molten. Try not to pull the foil off adjoining pieces. If some other foil does come off, then remove that entire length, scrape clean, wash off, dry, and re-apply a piece of the same type of copper foil, cut to size.

Re-flux the exposed foil lines, remove any solder blobs - particularly in any corners - with your iron, wiping excess off on your sponge again.

Replacing the glass

Taking the shape
Take your piece of glass that best matches the broken piece, and position it underneath the hole. Trace the shape of the hole onto the glass. This works best for flat panels. Curved forms usually need to have a paper template made by tracing from the back onto the paper. Cut the shape out of the paper and put it on the piece of new glass. Make sure that the grain of the new glass is in line with the original. Cut the piece out, grind to shape, doing lots of test-fitting in the hole, until it fits.

Foil
Clean any flux off the new piece from your test fittings, and apply the same size and colour backing of copper foil that was used on the piece that you removed.

Soldering
Fit your replacement piece into its place, making sure that it is level with its surrounding pieces. You might want to tape it into place. Check its position, and if you are happy with it, then tack it twice per side.
Proceed to solder it into place. If your fit wasn't perfect, or the piece is a little rough, fill in any gaps with some 50/50 solder. Let it cool, and then finish off with 60/40 solder. Blend your new solder lines with the quality of the solder lines on the rest of the piece.

Cleaning
Wash off the flux, scrub clean, and patina if required. If copper patina was used on the piece, don't worry when you apply the copper patina. It will not match if the panel is not brand new as copper patina ages much more than black patina. Wash the patina and polish it to blend the piece in.

Thursday, 6 November 2008

Cleaning Solder Beads

After soldering, cleaning and drying your piece, use fine (000) or extra fine (0000) steel wool and a brass wire brush to go over all the beads. Use the brush first if you want to use it, and follow with the steel wool, since it will provide fewer scratches. This helps remove any leftover flux that on solder lines.

Omitting this step increases the chances of developing whitish blotches later on the solder lines. However, including this step makes a better base for applying the patina, if you are using any. After using the steel wool, use a soft brush to remove any residues from the steel wool, brush, flux or solder.

Wednesday, 5 November 2008

Choosing Copper Foil Widths

Width of the foil relates to:

Glass thicknessThin glass requires thinner foil to maintain a neat solder line of about 3mm. Thicker glass requires thicker foil to maintain the same width of solder line. So 2mm glass would require 4mm foil, and 3mm glass would need 5mm foil.

Glass textureHeavily textured glass usually needs thicker foil, as the thickest part of the glass is greater than the thickness of average glass. This requires a little experimentation to get the one you like best, but usually is one step up in thickness from your usual. Remember you are looking at only one half of the resulting solder line thickness on each piece of glass.

Desired width of solder lineThe desired width of the solder line will also affect the choice of foil. If you like a thin line of solder, you should choose foil that is only 1 or 2mm wider than the thickness of the glass. This will give a solder line of 1 or 2mm wide. Be careful when choosing a thinner width. You still need enough foil on your glass to maintain the strength of the solder bead. If you like wider lines, a foil that is 3 or 4mm wider than the glass thickness will give a 3 to 4mm wide solder line.


Of course is possible to trim the copper foil to be thinner after foiling.  This can be to even up the line, or to thin it.  Gentle pressure with a sharp craft knife will cut the foil to the width you want. You may want to do this when all the pieces are assembled before soldering.  This gives you the opportunity to see how the width of the resulting solder line will be.  It is also the time when you can see what the line of the solder bead will be and make adjustments before begining the the soldering.

Tuesday, 4 November 2008

Choosing copper foil Thickness

Foil comes in different thicknesses as well as widths. Thinner is easier to form round curves, but tears more easily. Thicker is more robust, but crinkles up more on inside curves and so needs more burnishing. Mostly it is personal choice on what is easiest to work with.