Return to Sitemap
TIL - Things I learned - was a repetitive topic in Hot Glass Bits and these are selected from various issues to put them in one place.
FOAM PEANUT CONTROL - While packing some glass for the Empty Bowls project, I was using foam plastic peanuts and plastic bags from the grocery store, when it dawned on me that if I put the peanuts inside the bags, I could make a flexible firm ball for fitting in between the glass pieces and not have loose peanuts all over, including inside the glass. 2003-02-13
-39
TIL - Things I Learned. In this issue, TIL is used at the start of many short items that represent useful items I learned while traveling.
HOT GLASS BITS 13
TIL BEESWAX - A block of beeswax allows lubrication of jack blades, simply running the warm blades across the block picks up enough wax to reduce chatter and squeaking.
HOT GLASS BITS 13
TIL STRINGER - When pulling stringer, taking the time to loop the end around a tweezer tip gives a more even pull.
HOT GLASS BITS 13
TIL PIPES I - I found I like a lightweight pipe with a tapered stainless mouthpiece and no grip, having previously only used medium size pipes.
HOT GLASS BITS 13
TIL DELICACY - Delicacy of tool use- I was delighted to watch the B Team and others work with the marver and jacks as delicate tools. With the marver, whether shaping a large cone of glass or pushing back the faint curve of a puntle, the concentration was easily visible as a delicate roundedness was worked on. The jacks, more often, seemed to briefly move to produce an unvisible perfection and then, after reheat, cause the perfect flaring of a goblet base or bowl.
HOT GLASS BITS 13
TIL MARVER EDGE - The edge of marver can be used like a jack, especially with large amounts of glass. I have seen various slabs of metal used as marvers, but the sharp square edges of BGSU's tables were used artistically.
HOT GLASS BITS 13
TIL BUTANE LIGHTERS - Never again. I have been told butane (like Bic) lighters are dangerous because they leak, but an accident at the workshop set my mind: Anytime I see a lighter in a glass environment, I will ask that it be gone. In this case we were using lighters on the propane torches and one was laid down on the large marver. While using the torch on glass, the flame washing across the table melted the plastic on the lighter which produced a three foot sphere of flame over the table (and rocketed the lighter off to a corner of the room, where we later found it.) One of the B Team received severe 1st degree (reddened, cooked skin) and some 2nd degree (blisters) burns on his face. I was standing very near and was looking at the flame, but it happened so suddenly, I was disoriented and didn't understand what had happened or that an injury occurred until I saw him being treated at the sink.
HOT GLASS BITS 13
TIL STRIKERS - One reason I have use butane lighters is the repeated failure of spark strikers to work when needed. Since getting my welding rig, I have discovered that there are two grades of strikers: one has a wire handle and the flint mounted on the end of the bent wire, while the other has a flat metal handle, a different mounting for the flint so it is obviously replaceable and a much different appearing striker area under the cap. The latter is much more reliable, giving good sparks with predictable action. I will do what I can to replace the former when I encounter them.
HOT GLASS BITS 13
TIL PIPE SUPPORT - Everyone seems to use a square base with four grooved wheels, like pulleys, running on angle iron tracks, with concrete in or on the base for weight. In some cases, the units were so easy to move that they slid under the weight and slope of the pipe. I would put a projecting shaft type handle at about waist height to allow easy control with the non-pipe hand. [As I mentioned in an older HB, I like and would add a shield for the hand on the stand.] The standard roller ball units are fairly expensive; from my theater experience, I would like to try block teflon, which slides in all directions like the balls, but doesn't corrode.
HOT GLASS BITS 13
TIL MARVER - Andres & Chapman's marver plate was mounted on short wood rails, on the lid of the storage chest, with the threading wheels mounted at the back, a bracket for the color puntle to the right, all easy to take off and carry or store. 5/29/93
HOT GLASS BITS 13
TIL EXTRA GLASS - In designing a piece, in planning the making, an allowance of glass is required at the bottom, to grasp while twisting [and while pulling a goblet bowl to shape.] The extra also receives blobs of color at the end of threading job. 5/29/93
HOT GLASS BITS 13
TIL GLORY HOLE - A&C's glory hole door was angle iron in square form, filled in with diamond shape expanded steel. A center round hole is set in smaller square doors hinged on rods from the outer frame. These doors are set in larger square doors. Ceramic fiber is wired to the expanded steel. One layer of fiber is set within the frames. A second layer is wired inside the large doors, overlapping the center door opening to protect the steel of the small door frame. The best design I've seen so far. 5/29/93
HOT GLASS BITS 13
TIL SPIRAL COLOR - To spiral color in grooves, set stringer in each groove in the optic, using a hot gather to pick up the color, much hotter than common optic grooving. 5/29/93
HOT GLASS BITS 13
TIL BUBBLES - "Some days the glass will not be as bubble free as others. Blowers should have a design line that uses applied color to conceal the bubbles, so blowing can be done every day." Art Allison.
HOT GLASS BITS 13
TIL - Things I Learned. In this issue, TIL is used at the start of some short items that represent useful items I learned.
HOT GLASS BITS 14
TIL BENCH WIDTH - A bench can be too wide. If the arms are too far apart, the hanger ring and the glass will be too close and may bump the arms. (Of course, it can be too narrow, since most people work with their arms to the right of the bench's arms and need space for free movement for the left arm. 6/13/93
HOT GLASS BITS 14
TIL HANGER HEIGHT - A pipe hanger can be too high. It is awkward to place a vertical pipe well above eye level and it can place the hot part of the pipe at too convenient grabbing level. (Of course, it can be too low, preventing hanging a big piece of glass and bumping people's heads. But most people don't hang big pieces. A hanger at 6' for a standard 54" pipe - with the hanger stop about 10" from the tip - leaves 28" clearance.
HOT GLASS BITS 14
TIL MARVER PLACEMENT - I thought was convenient to put my marver plate across the front of my standup work bench ... until I put the water bucket for wood and paper on the shelf behind it and found myself dribbling water across it. Haven't quite decided whether to put the marver on a separate stand or see how it works on the left side of the bench. 6/13/93 [Put it on the side, with an angle brace and it is working rather nicely. 7/17/93]
HOT GLASS BITS 14
TIL CULLET - I have been blowing molten Spruce Pine batch cullet given me by Divas. Last night I got a couple of nice sized (for my 8" glory hole) globes worked. But I also was working some scrap bottles from the annealer and having the softer SP on the punty became a real problem as the piece flopped all over on its softer connection. 7/14/93
HOT GLASS BITS 14
TIL - Matthew says that even a modest lip on the opening of a
glory hole reduces the heat loss a lot, forming a wall of heat
across the opening. The lip may be as little as an inch or so on
a full-sized barrel hole.
Matthew usually blows 4-5 hours a day all year round, doing cold
working during the remainder. His style involves, in many cases,
a medium black thread wrapped around clear with a color core. He
makes perfume bottles, paper weights and "cave weights"
which are bigger, flatter and cut away on one side to show
innards against an opaque background.
HOT GLASS BITS 15
TIL is Things I Learned; FYI/A is For Your Information/Amusement.
HOT GLASS BITS 16
TIL - When chilling the glass at the neck, to break it from the pipe, touching it with jacks or scratching it at two places will start the crack. Filing it a number of times or otherwise overworking it simply confuses the stresses and blocks the cracks with each other. 11/21/93
HOT GLASS BITS 16
TIL - When using a punty, the idea when releasing the glass into the annealer is to hold it at one point and rap it at another so a good clean snap occurs at the joint. With a solid punty, it works to rap the punty either above or below a hand holding it in the middle, but with a hollow puntle, only the rap below the hand seems to work.
HOT GLASS BITS 16
TIL - While blowing, I was abruptly reminded of rule 2.5: if you rap on a pipe or punty to crack off the glass and it doesn't crack off, don't hit it harder in the same place, hit it some place else. I think I was supposed to have learned this two days into my first classes, but we all learn again. 11/12/93
HOT GLASS BITS 16
VENTILATION - Several kinds of ventilation are needed in a glassblowing studio and ideally these should be relatively independent. One requirement is removal of the chemical fumes of fuming and dusting, which is a specialized need with a filter, moving a moderate amount of air. The second need is removing the huge amount of heat generated by the furnace and glory hole. The third need is removing/controlling the heat on the blowing floor. Many studios use (corrugated) sheet metal walls to isolate the furnace wall heat from the blowing area. Often the solution to the last two needs is one fan pulling air from the furnace side with replacement air coming from a window or doorway. The problem shows up when the air being pulled in is cold, as it was in Ohio in May or Houston in April where a rare chill put the temperature at 40;deg;. If at all possible, the fan venting the furnace area should have its own air source, while a separate fan should vent the work area, the former keeping the temperature safe, the latter keeping it comfortable. If the floor is very cold, the glass will work differently as it will if it is windy, losing heat more rapidly. If the floor is too hot, the workers can suffer heat stress and materials and controllers can be damaged. If too much air is moved past the furnaces, heat losses and operating expenses go up. Art Allison and others have a very close vent hood over the furnace, pulling just enough air to remove the heat, while adding ventilation for the floor in other ways.
HOT GLASS BITS 19
VENTILATION - A studio's ventilation system should, if possible, not include free standing fans to shift glass dust around the shop. The exhaust point of the system should be near or above the hottest part of the shop to move both heat and furnace fumes out of the shop. A planned entry point for air should be used and when possible two or more should be provided: one which provide for the best air flow across the work area and another which supplies air during winter to ventilate without chilling the workers. Only one input should normally be used at a time so that air flow velocity is as high as possible for best cooling and removal of dust and fumes. The input should be chosen so that it does not normally pull in dust from passing cars or exhaust from parking cars. If several openings are provided, normally air will flow over the shortest possible route from input to exhaust, including along walls, bypassing the people in the center. A fan blowing into a building normally provides poor ventilation except for the direct air flow within a few feet of the fan; there are many dead pockets where fumes and dust may collect. Heat shields in front of furnaces may also help control the air flow - with enough surface before the furnace area, it may be possible to have two exhaust fans, one primarily for heat and fume control and one for work area air flow. When possible, work with the prevailing wind, setting exhaust fans into the downwind side of the building and intakes on the upwind side. Drawing air from the shadier side or from under a building may result in cooler air for much of the day. 5/30/95
HOT GLASS BITS 25
TIL PLUMBING AIR - Recently, I have been revising the connections on my glory hole and making them for my furnace. In the past, I have connected my blower directly to the burner head and have used PVC pipe. The latter was so rigid that things tended to come apart while I was adjusting the position of the burner. This time around, I am using 3" flexible metal duct, the kind that is used for venting gas water heaters. It is very light and inexpensive and relatively smooth inside. Since most of my air piping connections are 2" PVC, it is nice that a 2" coupling fits with a little slack inside the 3" duct, so that when a large hose clamp is applied, the duct pulls down onto the connection without much distortion. I can then treat it as part of the plumbing, using 2" PVC at the blower and at the burner connection and at any valves and connection boxes I build. 7/28/96
HOT GLASS BITS 35