Posted by Mike Jackson on March 30, 2003
Rick gave John Jordan a few of his techniques, often hand written and photocopied. John recently transcribed his notes to a text document and forwarded them. He is supposed to be sending photocopies of the rest of the techniques. I have a package at the Post Office right now, and hopefully that's it. I will be going there tomorrow. As I get time an energy, I will create a single page on www.theletterheads.com with this formula and technique.
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Rick Glawson's Glue Chipping Technique
One pound of glue will generally chip between 7 to 10 square feet.
HERE ARE THE BASICS
1. Prepare the glass (clean)
2. Mix the glue
3. Apply the glue
4. Let glue dry
5. Clean with warm water after glue chips
IT'S AS SIMPLE AS THAT
PREPARING GLASS
The surface of the glass required to be chipped must be roughened up to allow the adhesion needed between the glue and the glass. This is usually done by sandblasting the area to be chipped. To do this yourself you will need an air compressor and a sandblasting gun , either siphon or pressure pot. OR check out your local Yellow Pages under "Sandblasting" to find someone to blast the glass for you The material should be at least 90 grit , the higher the better. Your Sandblasting/chipping stencil should be the double filiment sandblasting type.
MIXING THE GLUE.
The type or pattern of desired chip design is dependent on the "Glue to Water Ratio". Generally the dry glue is combined with COLD water in a ratio two to one (2parts water to 1 part glue) This is measured by weight 1 1/2 oz of glue to 3 oz of cold water per square foot of glass. If your glass area is 24"x24" this is 4 square feet, remembering that 144 sqr. ins= 1 sqr. ft., you will need 6 oz of dry glue and 12 oz of water. After mixing, let the mix stand for about an hour enabling the glue to absorb all the water, it could help to stop evaporation if the container is covered.
AVERAGE RECIPE
1 1/2 to 2 ozs of Dry Glue per square foot
3 ounces of Cold water per square foot
Heat this mixture in a DOUBLE BOILER container(DO NOT try to heat the glue container directly on a burner. This will stink tremendously. SLOWLY heat the mixture to 140 to 150f. It is important that you do not boil this mixture and that the temperature remains at 140/150, stir occasionally. HEAT SLOWLY and use a brewers or candy thermometer to measure the temperature of the glue.
APPLYING THE GLUE.
The glass should be clean, making sure all the residue of sand blasting is wiped off, particulaly on the edges of your pattern mask. If there is any dust left from the blasting the glue will not stick to the glass
Place the glass on a level surface, pour the glue onto the blasted area (using a regular tomato sauce dispenser) in an even layer between 1/16 th to 1/8 th thick, if the glass is level the glue will level out to an even thickness, the glass maybe tilted side to side to help glue flow. The glass should be at room temperature....CAUTION if the glue is too hot it could break the glass from shock and WHAT A MESS
DRYING TIME>
The glue will go through the initial drying stage, this is the first hour or two depending on the humidity and temperature of the drying area. Make sure the glass is always level. The preliminary drying stage takes between 12 to 24 hours. This is where the glue will and lose most of its moisture. Circulating air will speed up this process. The glue should be left to dry at its own time, do not hurry, uneven curing may cause a result of poor chip pattern. Then it is time for the secondary drying and chipping stage. This is when the glue actually starts to peel and chip. Th glue shrinks considerably during the total drying process, as it shrinks it grips into the pores caused by the sandblasting and literally tears the face off the glass.
SECONDARY DRYING AND CHIPPING STAGE
This when I use a small space heater to warm the glass to about 125 f. Do not point the heater directly at the glass and keep it at least several feet away from the glass. You do not want to get the glass too hot and crack. This indirect heat cause rapid evaporation of moisture leading to curling of the glue and the chipping of the glass surface. The glass is under EXTREME stress at this time and should, if necessary, be handled with care. On sunny days the glass can be chipped in bright sunlight, this is the easiest way to chip glass, but the chips can fly with some force, take caution, ie. safety glasses. After the glass is chipped there maybe small pieces of glue still left on the glass, soak the face with warm water and scrape off the softened glue.
If you wish a double chip simply repeat the process after the sandblasting.
CAUTION...THE GLUE CHIPS WILL HAVE GLASS SHARDS LEFT ON THEM FROM THE PROCESS AND CAN CREATE A PROBLEM IF NOT CLEAREDAWAY, BECAUSE THE GLUE I S AN ANIMAL PRODUCT DOGS AND CATS LOVE TO EAT THESE CHIPS ...PLEASE PROTECT YOUR PET
VARIABLES EFFECTING THE CHIPPING PATTERN
The chipping pattern is sublect to many variables.The duplication and uniformity of each is dependent on RIGID controls of these variables
Some of the these variables are:
1. Glass -type and surface preparation
2 Room temperature during preliminary drying stage
3 Glue type, concentration, temperature at time of application
4 Weight of DRY glue applied per square foot of glass
5 Dryness of glue film at end of preliminary drying stage
6 Temperature of drying room during chipping process.
DIFFERENT GLUE WEIGHTS
Primary control over the chip design lies in the amount of glue to water per square foot of glass
1 1/2 oz of glue per square foot is the minimum, chip will be spotty or none at all
2 1 1/2 oz of glue per square foot gives the best results, uniform chipping is usually the fernleaf
pattern
3 2 oz is what I normally use, this gives me a larger ICEBERG looking chip
4 3oz of glue is economically wasteful and usually the glue is so thick it will not chip.
Experiment with these various amounts to see what get, If you will need to repeat the pattern keep good notes
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Hope this is of some benefit to all,
Mike
Denver Chapter of the Letterheads