This presentation will cover basic knowledge in regard to using aluminium, glass and sealants in the shopfitting and joinery industry.It addresses key competencies in the Units: CPCCSH2002A: Use Aluminium Sections for Fabrication CPCCSH2003A: Apply and Install Sealant and Sealant Devices LMFGG1001A: Complete a basic glass and glazing project (It may be beneficial to discuss performance criteria and critical aspects to evidence while going through ‘Student Assessment guides’ with all students before moving on with the presentation, or later, depending on the situation).
Refer to the Viridian DVD ‘Modern float glass line’, and watch prior, during or after the presentation
Tinted glass is produced by adding colorant during a clear float production run. Aesthetics, Reduction in Heat entry and glareApart from complimenting modern architectural trends (aesthetics), tinted float glass has its main application to reduce unwanted heat entry and reduce glare which in turn increases comfort levels from the point of view of the occupants and reduces cooling costs.Tinted float also improves privacy during the daytime and reduces fading and sun damage to carpets and soft furnishings.Surface Orientation The manufacturing process associated with float glass results in an 'air' and 'tin' side to glass, this creates a reflective difference which is not noticeable in clear glass. Tinted glass may be more visible. Glazed panels that are installed without regard to surface orientation may result in a 'checkerboard' appearance. This is particularly noticeable with banks of louvres and curtain wall. It is recommended that glass be installed with the 'air surface' to the exterior. Tin side can be identified with a short wave ultraviolet light source.
Like tinted glass, reflective glass reduces solar gain. From outside, it appears to be a mirror, obscuring the view in. But be aware, at night time, it gives the opposite effect when you have the light on inside.
Mirror is manufactured by coating high quality float glass with silver and protective backing coats. These coats protect the silver from abrasions and damage. protective coats can be plastic film, baked enamel paint, and vinyl backing for safety.
PVB stands for Polyvinyl Butyral, and is the most common form of film for laminated safety glass
Benefits of laminated glass (excerpt from Dupont USA literature)Safety Ordinary window glass is brittle, breaking into long sharp pieces which can cause serious and sometimes fatal injuries. The principal feature of laminated safety glass is its performance under impact. DuPont interlayers absorb the energy of the impact, resisting penetration. Although the glass may break, the glass fragments remain firmly bonded to the interlayer, minimizing the risk of injuries. Little wonder that laminated glass is mandatory for automotive windshields in almost every industrialized country in the world and increasingly specified or required in architectural glazing. In glass skylights, sunspaces, sloped glazing installations and curtainwalls, there is always the possibility of glass breakage. Without laminated glass, that could mean a big safety problem caused by falling glass. Unlike all types of monolithic glass, laminated glass remains intact when broken, protecting people from injury. This is why many building codes worldwide require laminated glass for overhead glazing. Security Burglars often break windows to get to door and window handles, and laminated glass can resist their intrusion. Even if it is accidentally broken, the interlayer continues to safeguard the building until the glass is replaced. Reglazing can be done when convenient, rather than during expensive after-hours. Laminated glass can be designed to withstand bullets and bomb blasts by using multiple or thick layers of glass and interlayer. In prisons, laminated security glass can replace traditional bars to create a more humane environment. The rise in urban crime and terrorism has created a need for glazing materials that enable people to carry on normally and be protected from harm. Laminated glass made up of several glass sheets and interlayers can provide protection in medium to high security applications. For extra security, including armoring of vehicles, DuPont offers SentryGlas® Plus interlayers with 100 times the stiffness and 5 times the toughness of traditional interlayers. Sound reduction Noise, just like a burglar, gains easiest entry to homes and buildings through windows. Laminated glass has proven to be an excellent barrier to noise, having a higher sound reduction index than monolithic glass of equal thickness between the frequencies of 125Hz and 4,000Hz. This sound dampening is due to the "viscoelastic" properties of the interlayer material. The coincidence effect experienced with monolithic glass at certain frequencies is also considerably reduced with laminated glass, and the noise reduction performance of IG units can be greatly improved by incorporating at least one layer of laminated glass. Tailored for noise control applications, DuPont™ SentryGlas® Acoustic™ sound reduction interlayers are available. Solar energy control While natural light plays an important role in architectural design, too much sunlight can also mean too much heat. Tinted laminated glass can reduce heat gain from sunlight to lower air conditioning costs, and it can also control glare. Laminated glass also can be used to combine reflective coated glass or low-E glass with heat-absorbing glass tints. In warm climates, these combine the penetration resistance and sound reducing qualities of laminated glass with good shading and energy management. In laminated glass containing coated glass, the metallic coating faces toward the inside of the laminate, where it is protected from harmful dirt or contact. UV control The major cause of deterioration and fading of furnishings and pictures is the chemical reaction caused by short-wavelength UV radiation. UV-absorbing additives in the interlayer in laminated glass can screen out almost all these damaging rays. Protection from weather and natural disasters If broken, laminated glass remains in its frame, preventing interior damage, while reduced flying glass protects people both indoors and outdoors. In developed areas subject to heavy winds and rains such as hurricanes or cyclones, buildings often need extra protection. Flying debris carried by these winds can shatter the glass of windows and doors, injuring people and opening buildings to often devastating further damage. Laminated glass constructions can be properly designed to remain intact under impact and keep the envelope of the home or building sealed. Glass fallout in earthquakes exposes people to dangerous broken shards. Again, laminated glass has been shown to keep the glass intact and in its frame. DurabilityLaminated glass is durable, maintaining its color and strength, and is as easily cleaned as ordinary glass. Installation easeLaminated glass is simple to install. Standard-sized, two-ply glass panels can be cut to size on-site, and can also be drilled or notched. Low visual distortion Laminated building glass is usually glazed in an annealed form, avoiding the distortion caused by "roller waves" in tempered and heat-strengthened glass. Sharp reflected images are possible with curtain walls constructed of laminated annealed glass.
Benefits of Toughened GlassStrengthToughened glass has much greater strength than annealed glass. (typically 4 – 6 times stronger)SafetyIt is also safer, because when toughened glass shatters, it breaks into small pieces rather than splinters or shards, as does annealed glass. DisadvantagesBecause toughened glass cannot be cut, drilled, polished or bevelled, these processes must be completed on the annealed float glass before it is subject to the toughening process.
Encourage students to have a look at the WERS site, even go there on the screen if you like before moving on to the next slide.
Q: Obviously insulated glass units (double glazing) provide a high resistance to heat gain/loss, but why would everyone not use these units?A: Cost!!!Reflective float glass on its own is a slightly cheaper alternative, but IGU’s are still the most cost effective way of reducing energy bills etc. (less solar gain / thermal loss = less bills!!)
Unlike MDF, Whiteboard, Timber, even aluminium, Glass cannot be cut with a wide range of tools.Abrasives are used for grinding and polishing edges, cutting finger pulls etc. To cut to size, we must use the score and break method, wether it be with machine or by hand, still same principal except when talking of Water Jet method.
Q: Anything else to check? - defects/ scratches? - check colour matches between sheets (some vary slightly, so use all off 1 sheet if possible) - enough in-stock? - confirm type and thickness of glass to be used - Cutters in good working order? (oil?) - where will the glass be stored after it is cut? - Q: For those who have cut glass before, What has gone wrong when you have cut glass? And could it have been avoided with proper planning and preparation?
It would be a good idea to hand out some glass cutters to students to have a look at, preferably a couple of different types.Generally I feel there are dry cutters or oil- feed cutters. (if using a dry cutter, dip it in oil or lubricant)I feel that oil is needed to lubricate the wheel of any glass cutter. It keeps the wheel of your glass cutter turning smoothly, and free of tiny glass chips that can lodge between the wheel and the shaft. It is also needed to keep the score clean and cool. It helps to prevent minute chips of glass from flying about. The final reason I use oil is because it preserves the life of the wheel. Did you ever listen to a dry cutter going over glass? It sounds like you're dragging it over sand paper. In my opinion, that shortens the life of the wheel.To fill your glass cutter with oil, unscrew the brass cap on the end of the cutter and remove it. Fill the barrel with oil to about 1/3 to 2/3 full. Replace the brass cap. To regulate the flow of oil, open the brass cap about 1/2 to 1 full turn. Totally unscrewed will make the oil run fairly fast (not a good thing), and full closed will give you very little or no oil at all. Experiment with your cutter. They all seem to flow a bit differently. When your cutter is not in use, tighten the cap so that oil doesn't leak out.
Without abrasive (fine grit sand), a water jet is relatively harmless (although with enough pressure it may crack or break the glass). It is only until the abrasive is added into the mix that cutting is possible.
Glass edgers provide a very quick and consistent way of polishing, arising, and bevelling the edge of the glass.Water or lubricant is very important to assist the diamond grinding wheels while cutting.Some edgers may be single wheel or multiple wheel. In multiple wheel models, the glass passes through the wheels from coarse to fine.
Float GlassFloat Glass, often referred to as ‘standard ‘ or ‘annealed ‘glass, is madeby flowing molten glass, then allowing it to solidify, over a bed of moltentin.The glass is then heat treated, or annealed, to increase its strength andstability.Float glass is available in a range of finishes including clear, tinted,reflective, patterned or opaque forms.
Tinted Glass Aesthetics Reduction in Heat Entry (solar gain) Reduction in Glare Improved privacy
Reflective Glass Reduces solar gain Mirror-effect on outside
Mirror Mirror is manufactured by coating float glass with silver and protective backing coats. These coats protect the silver from abrasions and damage. Separate sheets with butchers paper to protect surfaces
Laminated GlassLaminated glass isessentially two pieces offloat glass bonded togetherwith a vinyl film in between.This film, otherwise knownas a polymeric interlayer,provides added strength. Italso increases thermal andacoustic insulation, andprevents glass penetrationby holding all fragmentstogether when breakageoccurs. http://www.rylock.com/images/anim_laminglass.gif
There are two types of laminated glass:PVB and Resin laminated glass PVB laminated glass is two or more sheets of glass which are bonded together with one or more layers (PVB) under heat and pressure to form a single piece Resin laminated glass is manufactured by pouring liquid resin into the cavity between two sheets of glass which are held together until the resin cures.
Benefits of Laminated Glass Safety Security Sound Reduction Solar Energy Control UV Control Protection from Weather and Natural Disasters Durability Low Visual distortion
Décor Patterned glass This is float glass which has a pattern embossed into the glass during manufacture. This is done by passing the semi molten glass through a set of rollers prior to annealing. One side remains smooth and one is textured. ‘Obscure’ glass and ‘slumped’ glass are all types of patterned glass
Insulating glass units Also known as ‘double-glazed units’ where two or more panels of glass are bonded to a metal or thermoplastic spacer (TPS). Air or argon gas is used in the space between the glass panes. Their primary benefit is insulation (Acoustic and Thermal) and solar control. Most types of glass can be incorporated into an insulating glass unit.
1. Glass2. Air pocket3. Metal spacer section4. Rubber seal5. Desiccant6. Silicone Sealant
Toughened glassToughened or Temperedglass, is float or patternedglass which has beenheated to a hightemperature and thenrapidly cooled using airjets.This creates a glass inwhich the centre is intension, while the surfaceis in compression.
Benefits of Toughened Glass Strength Safety (shatters into small bits or ‘cuboids’)Disadvantage Cannot be cut, drilled or polished once toughened.
Toughened Laminated GlassThis is the optimum in safety glass.Each piece of glass is toughened toprovide superior structural strengthwhen compared to annealed glass.These pieces are then bondedtogether using either PVB or Resinas the interlayer medium, to ensurethat if the glass breaks, the smallpieces are held together by theinterlayer.
Energy Efficiency in GlassAs homes are heavy users of energy, the Building Code of Australia (BCA) now stipulates energy efficiency regulations for all residential buildings so that new homes will need less artificial heating and cooling.The type of Glass used can have a major difference in the amount of energy used in a home.The window energy rating scheme or WERS provides a way of rating certain windows and glass units on a five star scale.Heat gain and heat loss in glass are just some of the considerations used in the rating. To find out more, go to: http://www.wers.net/
Cutting GlassGlass is a material that requires a particular method of cutting, and if not followed correctly can result in damage or injury.Glass can be cut by: Hand - using tools which have specially ground cutting wheels attached to a handle (other types use a small industrial diamond). CNC machine - Computer controlled, using similar cutting tools to that used by hand Water Jet – A mix of water and grit (sand) in a fine, high pressure jet, blasting through the glass.
Before cutting any glass: Check the sizes of the glass to be cut Determine if any off-cuts can be used up first Determine the best method of cutting / breaking Clean off benches and cover with protection Select appropriate P.P.E.
Glass cuttersGood quality glass cutters have hollow handles that contain lubricant(usually oil) for the wheel which is released when pressure is applied.
To cut Glass by hand: To cut glass, lay the glass on a clean, firm and flat surface that is covered for protection (felt, blanket or carpet is satisfactory). Mark the cut size or shape on the face of the glass with a fine point felt marker or white pencil. For best results use a well lubricated cutter to cut the glass. A single score must be made on the surface with out any misses or jumps. If the cut misses or jumps the score line can be joined although there is no guarantee the glass will break successfully along break line, it may run off. Once a cut line has been scored on the surface do not run the cutting wheel over the same line as this can fracture the glass or damage the cutting edge on the tool. Start the scoring at the edge of the glass and apply a firm even pressure and draw the cutter across the face in a single stroke until it runs off the opposite edge. You should be able to hear the tool scoring the line.
To score the glass, hold the glass cutter between thefirst and second finger, gripping the lower end firmly withyour thumb and fingers. ‘Thomas’ Grip cutter Pistol Grip cutter
To make square or straight cuts hold a ‘T’ square or straight edge alongthe set out to help guide the cutter, making allowances for the setback inthe tool, i.e. the distance from the cutter to the edge of the tool.Apply a firm downward pressure on the guide and place the cutteragainst the edge. Start the scoring at the furthest edge of the glass anddraw the cutter back toward you with a smooth even pressure.
Methods of ‘breaking’ glassSmaller sections of the glass can be snapped by hand.With your thumbs over the top and fingers underneath, snap theglass with an upward pressure. Larger sheets can be snapped inthe same manner, by starting at the edge of the sheet and liftingthe sheet slightly, the cut will run along the score line.
Another way to break glass is to gently tap the glass directlybelow the score line with a sharp object (the back edge of theglass cutter is ideal) until a fracture starts. Care must betaken to tap the glass directly below the score, this methodworks best if there are no gaps in the score line.
Running Pliers can also be used.They work by placing the pliers over the edge of theglass with its marker in line with the score and applyingpressure on the handles. This creates a fracture and willopen up or “run” along the line.
Larger sheets can be broken bysnapping the sheet on thecutting table.- Place the scored glass near toand parallel with the tablesedge but not overhanging. Theoverhanging section of thesheet must be supported.- Place both hands evenly onthe edge of the sheet and applyan even downward pressure,the glass will snap along theline.- When cutting thicker glassmore pressure will be required.- Lift the sheet slightly andsuddenly, but smoothly snap thesheet down on the table, thiswill cause the sheet to snap.
Apply an even, downward pressure, and the glass will snap along the line.
You can also break glass by placing a straight edge directly in line withthe score line beneath the glass and applying a gentle firm downwardpressure on either side. The glass will snap along the line.
Narrow slivers can be removed with special glass pliers with relieved jaws, bylevering down and pulling away from the score line. Smaller sections and thejagged edges can be trimmed back to the score line with glass pliers or bynibbling away the waste with the notches on the back of the glass cutter.
Caution: Always be careful around glass, especially when ‘breaking’ the cut, or injuries will occur! Always wear eye protection as glass chips sometimes break off, and cause major damage to your sight!
Speed cutters provide a fast and effective way of cutting glass parallel to one edge. The base plate houses a number of grooved rollers at an angle, allowing them to sit on the edge of the glass and move freely along the edge. The arm is fixed to the base plate at 90° and consists of an adjustable cutter block and a fixed tape measure.
The cutter can be adjusted to the desired measurement along the arm.
Ensure that the wheels of the speed cutter areproperly located on the edge of the glass asshown
When using a speed cutter maintain one hand on the base plate to retain its position on the edge of the glass. The other hand holds the cutter arm and applies a slight pressure as the speed cutter is moved along the face of the glass creating a score line.
Glass cutting machinery Off-site specially designed machines may be used to cut particular shapes or designs from glass of varying thickness and types. CNC machines guide laser, plasma or water jet cutting heads that can cut and shape glass to the finest detail and intricate shapes.
Water-jet cuttingPeriodically clean off the glass
Important points to remember when handling and cutting glass Always wear safety glasses Wear gauntlets and gloves Never leave glass hanging over a bench Before moving around with glass, make others aware of your intentions Keep oil cutters oiled! – ….duhh…. Don’t go back over scored lines Always cut glass on a clean bench Check glass for scratches before cutting