Showing posts with label Safety. Show all posts
Showing posts with label Safety. Show all posts

Wednesday 10 August 2016

Super Glue - Kiln Forming Myths 29

The use of super glue in the kiln causes cyanide gas
This is not true.  But because it is such a persistent belief, a lot of detail is given below.  In short the precautions are: 

  • use the minimum amount, 
  • use an organic gas face mask, 
  • do not wear natural fibres or gloves, 
  • let the glue cure before placing it in the kiln, 
  • have the solvents at hand while using the glue.

Super glue is frequently used as a temporary fixative in assembly of kiln forming projects. There is some concern about safety, as it is known that super glue is made from cyanoacrylate, which it is feared will break down in the kiln into cyanide gas.

Greg Rawls, a certified industrial hygienist says

"I looked at the MSDSs for several forms of super glue. The main component is Ethyl 2-cyanoacrylate, which has a TLV of 0.2 ppm which is relatively toxic. [However,] the thermal decomposition products are carbon monoxide and carbon dioxide. I did not see a reference to cyanide gas. However, as I recall cyanide gas dissociates into elemental carbon and nitrogen at about 800 F. Since you use it in such small quantities, I would not worry about it. In my opinion the worst thing that could happen is you glue your fingers to the glass."

Safety issues

To treat the safety issues seriously and determine if you feel Greg Rawls' view is justified, you need to look at the issues of toxicity, reactions, adhesion of tissue, ventilation, first aid and decomposition products in the whole context.

Toxicity
The fumes from cyanoacrylate are a vaporized form of the cyanoacrylate monomer that irritate sensitive membranes in the eyes, nose, and throat. They are immediately polymerized by the moisture in the membranes and become inert. These risks can be minimized by using cyanoacrylate in well ventilated areas. About 5% of the population can become sensitized to cyanoacrylate fumes after repeated exposure, resulting in flu-like symptoms. It may also act as a skin irritant and may cause an allergic skin reaction. On rare occasions, inhalation may trigger asthma. There is no single measurement of toxicity for all cyanoacrylate adhesives as there is a wide variety of adhesives that contain various cyanoacrylate formulations.

The United States National Toxicology Program and the United Kingdom Health and Safety Executive have concluded that the use of ethyl cyanoacrylate is safe and that additional study is unnecessary. 2-octyl cyanoacrylate degrades much more slowly due to its longer organic backbone that slows the degradation of the adhesive enough to remain below the threshold of tissue toxicity, so the use of 2-octyl cyanoacrylate for sutures is preferred.

Reaction with cotton

Applying cyanoacrylate to some materials made of cotton or wool results in a powerful, rapid exothermic reaction. The heat released may cause serious burns, ignite the cotton product, or release irritating white smoke. Users should not to wear cotton or wool clothing, especially cotton gloves, when applying or handling cyanoacrylates.

Adhesion of the Skin

Various solvents and de-bonders can be used. These include:
·         Acetone, commonly found in nail polish remover, is a widely available solvent capable of softening cured cyanoacrylate
·         Nitromethane
·         Dimethyl sulfoxide
·         Methylene chloride
Commercial de-bonders are also available.

Warnings include:
·         It is a mild irritant to the skin.
·         It is an eye irritant.
·         It bonds skin in seconds.
·         Any skin or eye contact should be copiously flushed with water and medical attention be sought immediately.
·         Do not attempt to separate eye tissues – the bond will separate naturally within a few days.

Precautions
·         Use goggles.
·         Do not wear cotton or wool clothing while using super glue
·         Ventilate the area well. Since cyanoacrylate vapours are heavier than air, place exhaust intake below work area. Activated charcoal filters using an acidic charcoal have been found effective in removing vapours from effluent air so the bench top air filters are suitable for use while using super glue.
·         Avoid use of excess adhesive. Excess adhesive outside of bond area will increase level of vapours.
·         Assemble parts as quickly as possible. Long open times will increase level of vapours.


Evaporation Effects
·         The effects of heating cyanoacrylate are not completely known. The flash point is known to be greater than 85ÂșC. As a precaution do not remain in the area of the kiln after that temperature has been reached.
·         The decomposition products are carbon monoxide and carbon dioxide. There is no reference in the literature to cyanide gas. It is highly unlikely that heat will cause the release of cyanide gas at any time during the heating. To be certain, you should make sure the evaporation of the glue is complete before firing the kiln.

See this tip for the use of super glue in kiln forming. http://glasstips.blogspot.co.uk/2013/12/super-glue.html


Wednesday 13 July 2016

Didymium Lamp Working Glasses - Kiln Forming Myths 27

Lamp working glasses can be used to look into the kiln at high temperatures.

Definitely not! 

Didymium glasses are used by lamp workers to protect eyes against sodium flare – the yellow glow coming off the glass in the torch flame.


In kiln forming, the radiation that our eyes need protection against is infrared.  Welders’ goggles do this, but didymium glasses do not.  Welders goggles and helmets are much cheaper too.

Tuesday 16 June 2015

Diamonds and Water Use

When drilling glass with diamonds, water has three uses.



It cools the glass.  The action of grinding away the glass surface creates heat.  If this is not dissapated, the glass will break from the heat differentials caused by the drilling.

Water helps to lubricate and clear the grinding dust from between the diamonds on the drill bit.

Water keeps the glass dust that would otherwise be circulated in the air contained and easy to clean. Ground glass does not cause silicosis.  This is from a leading industrial safety expert:

"It is important to understand the difference between glass and crystalline silica because exposure outcomes are extremely different!  Glass is a silicate containing various other ingredients which have been melted and upon cooling form an amorphous, or non-crystalline structure.  While silica (SiO2) is a primary ingredient in the manufacturing of glass, when glass is formed under heat, the crystalline structure is changed to an amorphous structure and is no longer considered crystalline.  Ground glass is rarely respirable because the particle is too big.
Always use wet methods when grinding glass! Water captures the dust."

Source: http://www.gregorieglass.com/Health_Safety_Chemical.html

Wednesday 20 August 2014

Fiber Paper Safety


There are often concerns raised about safety relating to the dust from Thinfire, a trade marked product from Bullseye. These concerns also apply to the Spectrum product called Papyros. The main constituents of these are cellulose, aluminium hydroxide, fibre glass and organic binders. It therefore is mainly a nuisance dust and irritant. Greg Rawles, a certified industrial hygenist with a scientific and common sense approach, says that the toxicology of fibre glass is not yet determined. So the best idea is to wear a P95 respirator while dealing with the dust – mainly the cleaning phase of dealing with the shelf. He also recommends keeping the kiln closed during the burn-out phase of the binders, although others recommend venting to avoid anything settling on the glass during the burn-out.

Some people seem to have skin reactions to dust including that from Thinfire and Papyros and tend to wear gloves. If you are wearing rubber or latex gloves for extended periods, it may actually promote a reaction to the gloves rather than a primary reaction to the dusts of the paper. So checking on alergic reactions to the gloves is advisable in addition to the dust. 

If in fact, you are reacting to fibre paper dust, consider using kiln wash instead. If this is not practical or desirable there are several things you should do.
  • Use gloves (for those with sensitive skin),
  • wear long sleeved high necked shirts and pull the gloves over the ends of the sleeves to prevent dust getting to your skin,
  • vacuum the kiln with HEPA filters,
  • dampen the powder with water spray before brushing,
  • take precautions against taking the dust home by changing in the studio and placing clothing in plastic bags to take to the wash.


Wednesday 4 June 2014

Super Glue Safety


Super glue is frequently used as a temporary fixative in assembly of kiln forming projects. There is some concern about safety, as it is known that super glue is made from cyanoacrylate, which it is feared will break down in the kiln into cyanide gas.

Greg Rawls, a certified industrial hygienist says "I looked at the MSDSs for several forms of super glue. The main component is Ethyl 2-cyanoacrylate, which has a TLV of 0.2 ppm which is relatively toxic. [However,] the thermal decomposition products are carbon monoxide and carbon dioxide. I did not see a reference to cyanide gas. However, as I recall cyanide gas dissociates into elemental carbon and nitrogen at about 800 F. Since you use it in such small quantities, I would not worry about it. In my opinion the worst thing that could happen is you glue your fingers to the glass."

Safety issues

To treat the safety issues seriously and determine if you feel Greg Rawls' view is justified, you need to look at the issues of toxicity, reactions, adhesion of tissue, ventilation, first aid and decomposition products in the whole context.

Toxicity
The fumes from cyanoacrylate are a vaporized form of the cyanoacrylate monomer that irritate sensitive membranes in the eyes, nose, and throat. They are immediately polymerized by the moisture in the membranes and become inert. These risks can be minimized by using cyanoacrylate in well ventilated areas. About 5% of the population can become sensitized to cyanoacrylate fumes after repeated exposure, resulting in flu-like symptoms. It may also act as a skin irritant and may cause an allergic skin reaction. On rare occasions, inhalation may trigger asthma. There is no single measurement of toxicity for all cyanoacrylate adhesives as there is a wide variety of adhesives that contain various cyanoacrylate formulations.

The United States National Toxicology Program and the United Kingdom Health and Safety Executive have concluded that the use of ethyl cyanoacrylate is safe and that additional study is unnecessary. 2-octyl cyanoacrylate degrades much more slowly due to its longer organic backbone that slows the degradation of the adhesive enough to remain below the threshold of tissue toxicity, so the use of 2-octyl cyanoacrylate for sutures is preferred.

Reaction with cotton

Applying cyanoacrylate to some materials made of cotton or wool results in a powerful, rapid exothermic reaction. The heat released may cause serious burns, ignite the cotton product, or release irritating white smoke. Users should not to wear cotton or wool clothing, especially cotton gloves, when applying or handling cyanoacrylates.

Adhesion of the Skin

Various solvents and de-bonders can be used. These include:
Acetone commonly found in nail polish remover, is a widely available solvent capable of softening cured cyanoacrylate
Nitromethane
Dimethyl sulfoxide
Methylene chloride
Commercial de-bonders are also available.

Warnings include:
  • It is a mild irritant to the skin.
  • It is an eye irritant.
  • It bonds skin in seconds.
  • Any skin or eye contact should be copiously flushed with water and medical attention be sought immediately.
  • Do not attempt to separate eye tissues – the bond will separate naturally within a few days.

Precautions
  • Use goggles.
  • Do not wear cotton or wool clothing while using super glue
  • Ventilate the area well. Since cyanoacrylate vapours are heavier than air, place exhaust intake below work area. Activated charcoal filters using an acidic charcoal have been found effective in removing vapours from effluent air so the bench top air filters are suitable for use while using super glue.
  • Avoid use of excess adhesive. Excess adhesive outside of bond area will increase level of vapours.
  • Assemble parts as quickly as possible. Long open times will increase level of vapours.


Evaporation Effects
  • The effects of heating cyanoacrylate are not completely known. The flash point is known to be greater than 85ÂșC. As a precaution do not remain in the area of the kiln after that temperature has been reached.
  • The decomposition products are carbon monoxide and carbon dioxide. There is no reference in the literature to cyanide gas. It is highly unlikely that heat will cause the release of cyanide gas at any time during the heating. To be certain, you should make sure the evaporation of the glue is be complete before firing the kiln.

See this tip for the use of super glue in kiln forming.

Wednesday 22 January 2014

Glass Dust


This is from Greg Rawls' website.  He is a glass worker and a certified industrial hygienist. A huge amount of practical information on safety in glass working is available on his web site:


Ground Glass

OSHA classifies glass dust as a “Nuisance Dust”. Ground glass does not cause silicosis. You can wear a respirator if you are concerned about exposure.

Glass is made from sand, which contains silica - a naturally occurring mineral silicon dioxide (SiO2). Crystalline forms of silica, also known as “free” silica, can contribute to the development of silicosis under prolonged exposure conditions.

It is important to understand the difference between glass and crystalline silica because exposure outcomes are extremely different! Glass is a silicate containing various other ingredients which have been melted and upon cooling form an amorphous, or non-crystalline structure. While silica (SiO2) is a primary ingredient in the manufacturing of glass, when glass is formed under heat, the crystalline structure is changed to an amorphous structure and is no longer considered crystalline.

Ground glass is rarely respirable because the particle is too big. Always use wet methods when grinding glass! Water captures the dust. Sometime other chemicals are used to add colour to glass such as arsenic, lead, cadmium. These are usually present in low concentrations and are bound to the glass and not readily available but could present an exposure issue under some circumstances.

Wednesday 4 December 2013

Super Glue


Super Glue
There are multiple cyanoacrylates (superglues) on the market, and they will give very different results. Gel superglue formulations usually have some type of rubber or fumed silica additive to make them thicker, and the additive usually doesn't burn out. That's probably where the "superglue leaves a mark" originates. Usually the cheapest possible superglue is best for temporary glass holds because it'll mostly be additive-free.

The glue will burn out around 700F or so, so it shouldn't be used to position the glass against gravity. I disagree, however, that it should never be used. I buy cheap superglue by the carton and use it in everything from temporary casting assemblages to making glass boxes for frit panels to tack-fusing. It is the best way I know to hold wobbly pieces in place until you can assemble the rest of the glass around it.

Some tips for using superglue:
  • You are more likely to get whitish residues if you let moisture get to the superglue while it's drying, so keep the glass surfaces as dry as possible and don't put a superglue-assembled piece on a wet kiln shelf.

  • Always try to put the glue under opaque or dark glasses, just in case something goes wrong.

  • Use the smallest amount possible. Don't flood an area with glue and lay the glass on top - that will almost always leave too much glue on the glass. Instead, I assemble the glass and put a drop of glue right where the two glasses join. Capillary action sucks just the right amount of glue into the joint.

  • If you wipe excess glue away with acetone, be careful about which acetone you're using. Some types (such as nail polish remover) can have additives that leave residues on the glass and make the problem worse. If the glue is in a readily accessible area, it is usually better to wait for it to dry, then peel it off the glass with a razor blade. Only use acetone where there's texture or something else that makes the glue difficult to remove. And in any case, don't worry much about removing superglue right on the surface--it will burn off.

  • Superglue joints will NOT support the weight of your glass, i.e., never, ever lift your assemblage by a superglued-on piece of glass. Common superglue is actually a lousy glue for glass--which is why it works as a temporary hold.

Wednesday 28 August 2013

Finger protection

Grinding lots of glass pieces often leads to a number of small cuts on the tips of your fingers. There are several things that can be done to reduce these cuts and the tenderness that comes from lots of grinding.

The first thing is to take the sharp edges off the glass. You can do a simple, light grind all the way around the piece. This removes the extra sharp edges that often remain after breaking the glass.


You can go a step further and do a light arris around the piece. This is just lightly holding the glass at about 45degrees to the grinding bit and going all the way around on all sides. This does not take off the shape of the piece, but gives a more rounded feel to the piece.

Illustration of the effect of holding the glass at an angle to the grinding head - not so much needs to be taken away as in the illustration to get the effect

It is not generally recommended that you wear gloves around rotating machinery. There is too much risk of injury, even on a small grinding machine. Some of the alternatives to gloves include plasters (band aids), masking tape, electrical tape.

Other purpose-made things you can buy include rubber finger protectors, finger tip pads, finger caps (as used in counting money).




Other tools are made to hold the glass such as the grinder cookie




and Nick's Grinder's Mate 





Tuesday 25 September 2012

Fibre Board for Kiln Shelves


Some advantages of fibre board:

  • It is light weight making it easy to move.
  • Fibre board has very good cooling characteristics as it doesn't hold the heat the same way a mullite shelf does.
  • The board is fragile, but with care can last years.
  • Fibre board shelves do not thermal shock as ceramic based shelves can.

Considerations for use:
  • If it will be moved it needs hardening.
  • It needs repeated sanding and hardening for a really smooth surface. Alternatively you can smooth on something like batt/kiln wash or alumina hydrate for each firing.
  • It needs to be supported on kiln posts at 100 mm intervals.

You need to use dust masks when ever working with fibre board.

Some disadvantages of fibre board:
  • The board can warp over time even when supported every 100 mm.
  • The board will warp over time if placed on the kiln floor.
  • The board needs to be thick - at least 25mm, thicker for larger kilns.
  • It can't be scraped clean of batt/kiln wash.
  • Ceramic fibre board is possibly not much cheaper than mullite shelves.

Tuesday 15 May 2012

Glass Stains

A lot of people want to use old window glass – for recycling reasons, for the character of the older glass or because it is cheap or free. This glass often has stains or the appearance of corrosion or etching from age or storage conditions. To remove these blemishes you should start from the least aggressive method and work your way through the more aggressive methods until you find one that achieves the cleanliness you desire.


When using these methods appropriate breathing and hand protection are a requirement. 

Surface deposits
The first method is to wash the glass in water with a bit of crĂšme cleaner. Place the glass flat on a work bench and scrub it with a brush containing the water and cleaner. Rinse and dry. This may be all that is needed.

More persistent stains require chemicals. Use rubber gloves for this kind of process. Soak the glass in a dilute (5-10%) solution of lye. This is also known as caustic soda. Chemically it is sodium hydroxide (NaOH). After the soak wipe with a disposable towel and dip it into a dilute solution of hydrochloric acid (5-10% again) or vinegar to neutralise the caustic soda. Wipe the glass with a towel and rinse with plain water and polish dry.

Metallic stains or iridescence and etched surfaces
If the blemishes are more than surface deposits, more aggressive methods are required. The metallic-like stains and iridescence are usually evidence of the corrosion of the surface of the glass. These and any etching require grinding and polishing.

You should start with a polishing process to determine if that will be sufficient to bring clarity back to the glass. The use of an optical polishing material such as cerium oxide paste and a felt polishing head is often enough. Ensure that you do not let the cerium oxide get any drier than a paste to avoid localised heating and therefore breakage of the glass. Rinse the glass in clean water and polish dry.

If this does not remove enough of the surface to provide the desired clarity of the glass you can try either using pumice or jeweller's rouge, or dilute hydrofluoric acid.

Hydrofluoric acid used in a 10% or less solution will remove the surface of the glass, so eliminating the evidence of corrosion. It will even out, but not eliminate, the evidence of any etching. The disadvantage to this method is the risks associated with such a dangerous chemical. There is within this note on acid etching a door panel some advice on safety.

If you decide to avoid the hydrofluoric acid method, you can use mild abrasives such as jeweller's rouge or pumice with water and a felt polishing head. Once you have ground the whole of the surface, you need to wash it very thoroughly in clean water. Then change the felt head and go to cerium oxide to provide the optical finish.

Note:
All the dilutions and solutions suggested here are with water.

This note assumes the glass has had any paint already removed. For a method of removing house paint see this tip.

Wednesday 10 June 2009

Combing Glass

This process is done at relatively high temperatures for fusers – around 925C. It consists of pulling or dragging the surface of the hot glass to produce a marbling effect.

Preparation:
A batt washed ceramic shelf is the best surface. You can use fibre paper on your shelf, but you must be careful to avoid raking deeply enough so that you pick up the fibre and drag it into the glass.

Make a boundary with 10-12mm fibre board on your shelf. You can use strips - for the most efficient use of the board – or cut a shape from a sheet. If you are using strips, fasten them together with wire staples. This will resist the glass flowing at the edges.




Place the glass into the space created by the fibre board. You can place 10mm strips on edge to form very tight lines, you can shingle glass to give broader lines, or you can place the glass in a more random way to give quite different effects.




When shingling or placing glass randomly, it is often best to cut a sheet of iridised clear to lie on the bottom to ensure you have enough depth of glass. Placing the iridised side of glass down toward the shelf provides an additional release, and can give added interest to the back. Anything less than 8-10mm thick leaves the glass pulled away from the edges in the direction of the combing.

Firing:

The initial temperature rise can be fast because the glass is made up of narrow strips. No bubble squeeze is required for the vertical or shingled strips, as there are easy ways for the air to escape. Randomly placed glass should have a bubble squeeze at around 650°-675°C for 30 minutes at least. Otherwise you can fire at about 300°C/hr to 925°C.

You need to programme a soak at that temperature for approximately 120 minutes. This soak allows you to do the combing and have the kiln recover temperature without needing to re-programme. When the combing is finished you cancel the soak after the kiln recovers to 925°C (which allows any peaks generated during the combing to settle down).

Allow or programme the kiln to cool as fast as it can to the annealing temperature and soak for 120 to 180 minutes. Set the annealing cool at 30°C/hour down to 450°C, then 60°C/hour to 370°C and finally at 200°C/hr to 21°C.

Combing:

Safety first. You must do you combing in a kiln that has a safety switch to turn the power off once the lid is opened a short way. If your kiln does not have such a safety device you should reconsider your desire to comb in your kiln. Many say you can overcome this by switching your kiln on and off at the wall socket. However, in doing so you also turn off the controller, making it necessary to re-programme your kiln each of the several times you have to reach into the kiln with your raking tool. This is essentially impractical.

The combing tool is a pointed steel rod, bent at right angles to the shaft - often called a rake. The shaft should be of wood to avoid holding a hot metal rod in your hand. Stainless steel rods are best as mild steel can spall and leave flakes of metal in or on the glass. The rod and wooden handle should be soaked in water while the kiln is heating up. The wet wood will not char so quickly as the dry. This bucket of water should remain beside the kiln so you can cool the metal point, when it begins to stick.




The second bit of safety. You will need to wear gear to protect yourself against the heat. A full face visor is important as the heat will singe you hair. You need to have heat resistant gloves. You need to have heat resistant sleeves to go over your arms. You should wear only natural fibres - cotton and wool are best, as they smoke before bursting into flame, giving you some warning that things are just too hot. An assistant to hold the kiln door/lid open while combing is advisable. And the assistant should have the same heat resistant gear that you have.



You begin to do the combing at 900°C. The glass will be soft enough to be pulled by a gentle stroke across the surface of the glass. Avoid digging into the glass. That will pull or push a gather of glass ahead of point. This leaves a characteristic droplet shaped mark in the glass at the end of the stroke. It may also go deeply enough that the kiln wash or fibre paper that is underneath the glass will be pulled up into the glass. Only light pressure is required to do the combing.



You will only be able to do a few strokes with the rake before the temperature of the glass falls and the glass resists movement. When the glass becomes difficult to move, it is time to close the lid and let the temperature recover. You will have to do this numerous times, until you have the look you want.



Another limitation is the speed that the rake metal heats up. When the metal becomes hot, it sticks to the glass. Whenever the rake is not in use, it should be in the bucket of water cooling off, and re-wetting the wooden handle.

You can comb the glass in any manner you wish. To get the traditional feathered look, you need to alternately pull and push the rake to give chevrons in opposite directions. Experienced people sometimes use two rakes – one to pull and one to push - at the same time. You can also rake diagonally across the sheet and even across the previous rakings. Some experimentation will show which effects you like best.

Wednesday 15 April 2009

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.

Tuesday 14 April 2009

Handling Large Sheets of Glass Safely

Preparation
Use 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.

Carrying

To carry large sheets of glass safely (for yourself and the glass), you need to support it from below as well as the end. One gloved hand goes under the bottom and the other on the side edge. 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 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.

Tuesday 31 March 2009

Refining Edges

You can make the freshly cut glass safer to handle by gently wiping the edges of the cut piece with the waste piece. This removes the sharpest edges without chipping the glass.

After the glass is scored and broken, you can remove small, unwanted chips with grozing pliers. The serrated jaws of these pliers are used to gently nibble away at the jagged edges.

Rough edges can also be smoothed with a carborundum stone. You rub the stone along each edge, upper and lower, to remove any sharp edges. You can remove more glass with the stone if you wish by a little more aggressive grinding action or just a longer light rubbing of the stone against the edges.

A diamond smoothing pad removes glass in much the same way as a carborundum stone, but does it more quickly with the coarser grades. You can use a number of grades to get an almost bright polish to the edges. These pads must be used with water.

A glass grinder is used by many people. Many models of grinders are available. The grinding surface of the bit is covered with fine diamonds, which grind away unwanted glass very quickly without chipping the edges. In addition, they are water-fed which keeps the glass from cracking due to heat, prolonging the life of the diamond bit, and preventing the powdery ground glass form flying around.

A glass grinder is not a substitute for accurate cutting.

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.




Thursday 18 September 2008

Finger Cuts while Grinding Glass

Before serious grinding, first run the whole perimeter of the piece very lightly against the grinder. This removes the worst of the 'scalpel' edges and avoids the micro cuts on your fingers.

Let the grinder do the work. Many people seem to put huge pressure on the piece to grind away the waste more quickly, but this is actually counter-productive. Less pressure means less fatigue, less chipping at the edges, fewer broken pieces, and most importantly, fewer cuts to the finger tips.