Contemporary Canadian Glass

Randy Walker demonstrating blocking technique while students Doug, Bruce and Sylvia look on.

Rogue Wave Glassworks in Chemainus, B.C. hosted an intensive workshop with Randy Walker November 12-14, 2010.  The workshop reviewed basic glass blowing skills, covered surface decoration techniques (powder applications and crackling) and also sculpting the hot bubble.  It was a lot of information to cover in three days but at the end of the session on Sunday everyone was feeling satisfied that they had learned some new techniques and broken old bad habits.

If you ever have the opportunity to take a class with Randy Walker, I highly recommend that you take advantage of that chance especially once you have developed some skills and confidence in the hot shop.  Randy teaches intermediate glass blowers and helps them to fine tune their skills.  In this article, I will describe what I learned about setting up basic blown forms, and in subsequent articles I will cover punties, surface decoration and hot sculpting.

The first two days of the workshop were dedicated to understanding how the glass behaves and how to use heat and mass to achieve the wall thickness and form that you are after.  We began at the beginning – gathering and starting the bubble – and worked on basic forms such as cylinders, cones and pulled bottle necks to manifest in tangible terms the effect of mass on heat.  Randy repeatedly pointed out that there is not one way to work with glass, no step-by-step approach; but that understanding the impact of mass on heat is the key to understanding how to control how the glass moves.  Every contact that we make with the glass is a part of its ‘memory’ or history — once it has a history it is no longer neutral; the heat is affected and various throughout the form.

Of course it is possible and often convenient to use torches to heat the glass but for this workshop we learned methods for blowing out our shapes without torches.  We reviewed posture and body movement; moving slowly when the glass is hottest (after gathering and when heating) to maintain the form, how and when to move quickly to preserve heat, keeping the pipe ‘neutral’ (parallel to the floor), how to anchor our bodies when marvering, bringing a hot bit or bracing the pipe for someone who is hot sculpting and how best to hold tools for the most power and for ergonomics.  We learned how to rotate the pipe with our left hand so that we use the whole bench rail smoothly, a method of hand movement that I will have to practice and practice and practice before I am able to perform it effectively.  This hand movement is hard to describe but we called it the crab walking method.   Randy used lecture time and illustrations to explore the concepts with us before heading into the hot shop for demonstrations and practice.

Bearing in mind that there isn’t one right way to blow glass, I will describe the way that we learned to start out most of the shapes that glass blowers use to make their work.  This procedure ensures that the shoulder of the piece is blown out on the pipe and eliminates frustrating and inefficient catch up work later (when your shoulder and neck are too thick and you are unable to penetrate that area with heat and still maintain control of the rest of the piece).  It also protects the bottom of the piece from blowing out too thin and too fast.

It is important to be mindful of the heat and mass while gathering, making sure to gather an even moil and to consider the effect of the pipe’s temperature on the temperature of the fresh gather.  Once the initial gather of glass has been collected head to the bench but be careful to hold the pipe parallel to the ground so that the gather doesn’t lengthen or move back over the moil.  At the bench use the block to cool the outside of the gather, gently shaping the glass so that the centre of mass (the widest point) is just off the end of the pipe and the bottom of the shape is softly pointed to keep it from spinning outward in the glory hole with centrifugal force.  Then head to the glory hole to even out the heat of the gather.  Concentrate on your pipe rotation speed at the glory hole to preserve the tapered bottom and keep it from spinning outward.  Use your palms to turn the pipe.  Back at the bench, block the glass briefly before you blow and cap the pipe.  We practiced blowing and capping using our left hands so that we could be more efficient with our movements, preserving the heat and saving time.  The bubble forms quickly and the shoulder is thin because the centre of mass at the shoulder holds the most heat and draws the bubble to move there first. The walls are even and the bottom is slightly thicker; the taper has protected it from blowing out.

Randy drew attention to the way that we used tools such as the blocks and the newspaper and encouraged us to touch the glass as little and as gently as possible (try not to mash the glass with your block or paper; rather, let the glass fall into it) and to roll the pipe quickly and smoothly using the whole bench rail.  To prepare the bubble for subsequent gathers, pay attention to the centre of mass, making sure that it is just off the end of the pipe (shoulder).  Keep the bottom softly pointed so that you can protect it more easily from becoming thin (keeping the bubble from shooting out the end).  After gathering over the bubble return to the bench to block the fresh glass keeping the most mass at the shoulder and making sure that the glass does not fall to the bottom creating mass there that will collect heat and cause the bottom to become thin.

Keeping your pipe parallel with the floor as you move to the bench after gathering will help eliminate the problem of having too much mass at the bottom.  It is better to avoid this than to have to use a lot of tooling (and cooling) to repair it at the bench.  After blocking the new gather head to the glory hole to even out the heat then back to the bench to block and blow.  This inflation is short and sharp to puff up the shoulder and followed by immediate marvering and blowing.  At the marver, start at the tip of the bubble to protect the bottom from blowing out, make it pointy, rest the pipe off the back of the marver and blow short and sharp to puff up the shoulder.  Then marver the tip again, working your way up the side to the shoulder (the bubble should be cone shaped now) and, again off the back of the marver, blow short and sharp.  Keep the angle of your pipe shallow to prevent the bubble from stretching and the marvering brief, using three or four passes, moving quickly so that you don’t lose heat.  Do not marver the actual shoulder (keep it hot) but rather the sides just below it.

Student Bruce at bench starting to pull out the neck of his piece with helpers student Sarah and student Doug.

Randy stressed that the beauty of the bubble while you are marvering is not very important and spending a lot of time on the metal trying to correct an oval shaped bubble is counter-productive as it will just rob heat from the glass.  Your bubble will be too cold after marvering and blowing two or three times so re-heat it and do more marvering if you need to rather than trying to blow the shoulder all the way with a too-cold bubble.  Marver the tip a lot to cool it before you re-heat in the glory hole; the cold pointy angle of the bottom of the piece will keep the bubble from overheating there and allow you to get a lot of heat in the shoulder.  Plus this shape is easy to handle when you are re-heating.  After this step the bubble is cone shaped with a puffed out shoulder and it is time to set up the form at the bench.

For a cylinder, get an all-over heat in the glory hole, paper the shoulder to the width you desire, then paper the sides and get bench air to puff out the bottom so that the width at the bottom of the bubble is the same as the width at the shoulder.  This should result in an oval-shaped bubble with a thin shoulder and a thicker bottom.  Papering the sides keeps the walls from expanding where you don’t want them to.  Point up the very bottom of the oval to protect it from blowing out too quickly and reheat the bubble from the shoulder so that you can drop out the cylinder shape.  When you retreat from the glory hole, hang the bubble to let the shape fall out as you slowly rotate the pipe.  Start at a shallow angle so that the drop out is not more extreme than you want it to be, you can adjust this angle if you want the bubble to fall faster.  Swinging the glass is fun but risky to the integrity of the form and your control over it.

For a cone shape, take the marvered pointy bubble with the puffed out shoulder to the glory hole and heat it in increments starting at the bottom (which you want to be the hottest) and moving up to the shoulder.  As you leave the glory hole, hang your bubble at a shallow angle (adjust the angle as required) and let the cone form fall out.  You can repeat this step until you have the length you are going for.  If you want the bubble to fall out into a straight sided cone (not convex) gently puff out the sides at the bench before you re-heat, making the bubble more of a bullet shape, and the sides will straighten out again as you drop the shape.  If you heat and drop a straight-sided bubble, the sides will curve inward creating a convex wall profile.

For a pulled bottle neck, set up a bubble as previously, making sure that the bottom is pointed and cold and that the shoulder is puffed out.  Get a lot of heat in the glory hole.  At the bench make a trough in the shoulder to make it easier to start the jack line then use the jacks to squeeze down to the diameter of neck that you want, starting to pull out as well when you have the right diameter.  Stop squeezing the neckline and start pulling your jacks outward (to the right) keeping them straight up and down.  Have your assistant puff gently to blow out the shoulder some more as you are pulling out the neck.  Be careful to keep the bubble below the shoulder on centre; one way to do this is to quickly paper (cool) the cone-shaped bottom before you apply the jacks to the neck.  You have to do it in one pull.  From this point on you are working below the shoulder because trying to heat above the shoulder and maintain control over the form is extremely difficult.  Make a crease for the jack line now.  The neck will hold heat for a surprisingly long time, so you might not need to flash the neck and moil until after your first heat and re-shape of the bubble below the shoulder.

Preheating and waxing your jacks is recommended so that the tool doesn’t rob heat and glides smoothly.  If you are making a piece with an abrupt shoulder, avoid hanging the pipe down as you walk to the bench to thin the shoulder in preparation for jacking.  Instead, create a ‘trough’ for your jack line by angling the top of your jacks outward (to the right) and gently sloping the bubble here.  This will make it easier to make the crease line in a large puffed up shoulder.  Once you have a trough, hold your jacks straight up and down to make the break off crease.  You can always use a torch to make this crease deeper when it is time to break the piece off the pipe so leave a wide enough jack line to have stability and control.

Not enough brain cells?  We drank gin to cope at this stage (the end of day two) and rested up for day three.

I know that a lot of this information is common sense and basic to hot shop practice but I found myself surprised by how many inefficient habits I had formed by not analyzing my process.  I think the most important thing I learned is something I already knew but stubbornly ignored:  the concept of mass=heat.  In some ways, it is counter-intuitive – put the most glass where you want the blown form to be thin.  I have always had difficulty blowing out the shoulder so I am really grateful to have broken the bad habits I had around this concept.  I learned a lot about marvering (something I usually avoid because I am not good at it).  I made friends with the marver.  As for the left hand, I will have to practice my turning technique and build muscle for a long time before I see good results there.

For more information about Rogue Wave Glassworks and to find out about future classes, visit their website at www.roguewaveglassworks.com.

Jill Allan is one of the GAAC Regional Representatives for B.C.  She graduated from the Alberta College of Art + Design in Calgary in 1999.  She currently lives on Vancouver Island, travelling to Chemainus, Vancouver and Victoria to make her work.