Glass Blowing – Sizing the Piece on a Blowing Iron

    Published: 06-16-2009
    Views: 18,421
    Glass blower Todd Hansen demonstrates how to size the piece on a blowing iron when glass blowing.

    Todd Hansen: Hi, I am Todd Hansen. We are at the Art of Fire-Contemporary Glass Blowing Studio. I am showing you how to blow glass today. Next we are going to learn how to size the piece on the blowing iron. I am going to hang it down just slightly, take it back to the bench this time. By keeping the glass pointed slightly towards the floor, I keep the glass moving away from the iron that is where I want it off the iron because that is where it is really usable. We use cherry wood block here soaking in water, just very gently support the glass, roll back and forth across the arms of the bench, sort of like cradling a baby's head. You just want to support it, you dont want to push it, you just want to hold it, make sure it stays stable.

    Now that we have got a nice, cool surface on the glass, we are going to take it to the marver, cool just the bottom portion here by rolling it across that steel plate. Roll across once, twice and we are ready for our second blowing cap. Fingertip over the iron, blow lightly, trap the air and let that bubble expand, keep the iron turning. If you stop turning, the glass it is going to go off center. It is going to make it hard to create a balanced shape. So we have got a nice size to the piece. We are going to take it to the gloryhole now, heat it up, bring it back to the bench and we will start shaping up this with the jacks. After these first couple of reheats, we are going to put the entire piece in the iron. We are going to put the moil, the neck, the entire body of the glass in because we want the whole thing to move and stay hot. There is really no reason now to go any deeper in the gloryhole, because if you do this, all you are going to do is heat the iron up and make it harder to handle. So we are going to stay right behind the doors here just inside the gloryhole, get this glass hot, we will take it back to the bench and start shaping it. One question I am often asked is how hot do I want to get this in the gloryhole? It is a general rule of thumb, I would say get it about as hot as you think you can handle it, just about the point where you lose control, count to five, then bring it back to the bench and start shaping the glass. So let's start to move it a little bit, when I stop turning, you can see it starts to get little bit floppy. If you are in this situation, you see the glass is starting to get little wobbly on you, just take it, turn it, bring that high side up the top and let it fall back, get that wobbly side, bring it to the top, let it fall back on center.

    You can see you can bring it back on center pretty easily and the glass is starting to move pretty good. Let's take it back to the bench. This time we are going to start shaping with just the jacks. Hang it down just slightly, let that neck extend a little bit, have a seat in the bench, keep the glass under control, pick up the jacks, place the blades just on the edge of the bubble there and with a nice, smooth rotation roll the glass back and forth across the bench, apply just a slight amount of pressure with the jacks and start cutting your neckline. It is always important to get the neckline cut straight first and deep second, cut it straight first, deep second. If you get that neck crooked, it is going to be hard to correct. Now we are going to use just a pad of paper on the bottom to cool the base of the piece while I keep that portion thick and that will hang it off the edge of the bench, just very gently blow. Take a look at to see what we have got, you see the neck has expanded back out a little bit, but our bubble has gotten a little bit larger, so we are in good shape. One of the ways to judge how hard you want to blow, it's sort of like if you had a pea inside a soda straw, if you were to blow just enough that pea was fitting really tightly just so you can get that pea to roll slowly down that straw, that is about the pressure you need. It is easy to blow hot glass, but if you are trying to work with cool glass you will never get to move, so hot glass moves, cold glass doesnt. If it is not moving, go back to the gloryhole which is where we are going now. Again, we are going to heat the entire body because we want to move the neck, we want to move the body of the piece and we are going to use that paper to cool the base so it is doesnt move. But for now, let's just get the whole thing hot. Keep it turning, keep it on center, nice, easy rotations are all you need. If you turn too fast you will find that the glass starts to pull to one side, if you turn too slow it is going to start to droop. So just a nice, easy rotation, focus on the glass and keep it on center. Again, get to that point where you feel like you are just about out of control, count to five, three, four and five and here we go, let's go back to the bench again. I am going to hang it down just slightly to let that neck stretch a little bit further, take our jacks, cut the neckline. Now we have got the neckline straight, we can cut it little bit deeper. Lean the jack's head just a little bit, that gives you a little more from the top of the moil here, then we are going to cool the bottom with a pad of paper again. One more time, let's blow it out a little bit further to inflate. So there we go, we have got that nice, softball size shape, we have got an even wall thickness all around, a little bit of thickness in the bottom, we are in pretty good shape. So that is how we size a piece on the blowing iron. Next, we are going to learn how to shape the piece when glass blowing.