I'm currently taking this glass blowing class at San Francisco State University, it's offered as part of their 'extended learning' program (which means you have to pay for it separate from university fees (i.e. they make more money from it), and it also allows you to take classes while not being a member of the student body(which is really cool)).
The most difficult part of learning how to, and actually blowing glass is finding a place to do it. You can look in the yellow pages, search google or try putting your zip code into this search in order to try to find hot shops in your local area. There's usually someone blowing glass in most major cities (and quite a few non-major ones).
When you find a place with the tools, contact them and see how much it would cost to stop by and use their equipment. Several places I've seen only require you take a basic class at their centers in order to come back and rent shop time.
Step 1: Materials
The second most important thing you need is a blowing pipe. You can see punties and blow pipes in one of the images below, punties don't have a hole through the center of the pipe while blow pipes too.
Other tools that will come in handy:
Annealer (an oven to cool off the glass)
Gloryhole (for warming up the glass if it gets cool, you can use the furnace if you don't have one)
Wood Blocks (Not needed, but used for shaping the glass into a spherical design. This can also be accomplished on a marver, with jacks or just by holding the blow pipe correctly while rotating it)
Marver (Not really needed. For our purposes, we placed the Frit on the marver to pick it up.)
Frax (Also called ceramic blanket)(If you'd prefer not to use this, find a similar materical that won't absorb the heat from your piece and also won't catch fire, like Kevlar)
Mold (for support)
Frit (powdered colored glass)
Ornament holder (a stick with a piece of wire sticking off the end of it, for picking up the ornament)
Sunglasses (looking at bright lights hurts the eyes)
All of these tools can help, but depending on what you're doing, and what designs you want to give your ornament, you may not need to use all of them.
Step 2: Preperations...
One is the frax/mold combo. When working with frax, make sure you wash your hands immediately after use. It's very bad for just about everything. On that note, frit is also very bad (it's powdered glass), you don't want to breathe it in or get it on yourself. Make sure your area is well ventilated, and take proper care whenever using hazardous materials. It's good practice to wear a respirator when setting up your frit and frax.
First you want to set a stool, or other higher up object near the annealer for you to work at before you put your piece away. Second, you want to line that mold with the frax so that when you tap your ornament off it rests ever so gently in the frax.
Frax doesn't soak up any heat from the glass, or cool the glass off in any spots, which lets you add some final detail to your ornament, without it breaking from a temperature difference.
Step 3: Get a Pipe. Gather Some Glass!
note: Whenever holding a blowpipe or punty you should always be rotating it in your hand. When you stop rotating the pipe, the glass starts to tip to one side. The only way to keep everything on center and uniform is to rotate your pipe, constantly!
Grab a blow pipe off a pipe warmer. Molten glass doesn't want to stick to cold metal. If you don't have a pipe warmer, let the tip of the pipe sit in the door of the furnace for about a minute (until it starts to glow red). Warm metal + molten glass = what we want at this stage.
Place your blow pipe into the furnace horizontally, so the end of the pipe is about in the middle of the furnace. As you slide the pipe into the furnace, move your hands back to the far opposite end of the pipe. Slowly lower the tip of your pipe toward the molten glass while looking for a reflection on the surface of the glass.
The light is so bright in the furnace it's going to be really difficult to tell where the glass is. By looking directly below your pipe for it's reflection you have a much easier time of figuring out exactly where it is.
As you start to dip the tip of the pipe into the glass, (make sure you're spinning the pipe!), stop lowering it when the glass covers around an inch of the tip of your pipe. Turn your pipe for two full rotations, and the tip your pipe back horizontal (never stop spinning).
Once you're horizontal, you can start backing your pipe back out. Close the door when you've made it out of the furnace, and congratulate yourself on a good gather.
Step 4: Add Color!
When you've got enough frit on your glass, place the glass tip into the glory hole in order to heat the frit up to the same temperature as the molten glass.
Once your frit and your glass are together and the same temperature, it's time to move on!
Step 5: Shape Your Glass in Preperation to Pop a Bubble!
Shape your glass so that the molten blob is even all around the pipe. and the portion that is hanging off the end of the pipe is centered. Like checking pool stick on a pool table for straightness, you can lay your blow pipe on pipe rollers or a marver (with the glass hanging off the end of the table) and roll it, while watching the tip to see if it waves up and down as you spin it. If the tip waves, things aren't on center. (it's a good practice to do this before you start working to ensure the pipe you're working with is straight). If you roll your pipe, and the glass hanging off the end rolls even, everything is lined up properly.
To get the piece in shape here, a wood block was used. Wood blocks remain in water when not in use. Leaving them out of the water causes warping.
Sitting at the work bench, rolling your pipe steadily, take a wood block out of your bucket of water with your right hand (dump out any water in the block - you want it damp, not pooling). Roll pipe with your left hand (if you're left handed you might have to rearrange the glass shop as most are made for right handed people). Place the wood block horizontally next to your piece, lining it up before you make contact.
When you're ready, apply a soft, even pressure with the wood block on the glass. Keep the glass centered on the wood block, and the wood block horizontal, always rolling the pipe. As you roll, move the wood block with the pipe. If done right, you'll have a nice rounded smoothed piece of glass. Don't push to hard your you'll push all your glass back on the pipe, and you don't want that.
If your glass loses too much heat while you're blocking, take it back to the glory hole and heat it back up!
Step 6: Pop That Bubble!
This will take some practice. The easiest way to practice is to clog your pipe first.
To clog your pipe, dip it into glass, and dip your glass into water. The glass will harden on the inside of the pipe and you'll no longer be able to blow through it (this is fixable). With the pipe clogged, you can see if you're blowing correctly.
To practice blowing into the clogged blow pipe, hold pipe with one hand near the opposite end of where the glass will be gathered, in a way that you'll be able to put your thumb over the end to trap air inside when you need to. Place the other hand halfway down the pipe to support it (this hand will be used to rotate the pipe while you're blowing).
Have your thumb ready to cover the only hole that air can escape from on the pipe. Blow into that hole with some force, and cover it up with your thumb fast enough to trap air inside (this is the part that needs practice). It might be easiest to place your thumb in your mouth while blowing, and cover the pipe mid-exhale. To see if you did it correctly, place the end of the pipe with your thumb covering it next to your ear. While it's next to your ear, let off your thumb. You should hear an expelling of air from the pipe. If there's no exhalation of air, you need to keep practicing.
To pop your bubble, follow the same steps as in practice, but this time it's way more important to make sure you're spinning your pipe constantly, or you're bubble is going to be off center and awkward.
While you're thumb is capping the end of the pipe, keep an eye on your gather! You're bubble is going to show up on the other side soon, and if it blows out too much, you're going to have to start over. It's better to do less then more, you can always blow more air in later. When you see the bubble start to form, stop capping the end of the pipe. That is to say, take your thumb off the end of the pipe as soon as you start to see a bubble.
Congrats, you've popped a bubble!
Step 7: Shape Your Ornament
For this project, we opted to keep things simple and to make something round. The best way to do this is to have a second person helping you. Have them sit at the open end of your blow pipe, and blow as you watch your bubble. Use the tools on the bench to shape it how you like.
While you're shaping, make sure you put a jack line into your piece.
I can't really give much direction on this step as it all depends on how you want to shape your piece. So use the tools to their fullest potential. If you're playing with molten glass there should be someone in the near vicinity who can tell you the proper way to use the tools, in case you're unsure of the proper methods.
Step 8: Knock It Off and Add a Bit (Part One)
First you have to knock your ornament off into the prepared mold.
At the same time, someone should be gathering glass to bring you a bit.
(A bit is simple glass gathered on the end of a punty rod, brought straight from the furnace to the person working.) On occasion the person may request shaping it a certain way before you bring it. If you shape it, make sure you reheat it, bits should always be brought very, very hot.
There's two easy ways to knock off your ornament.
1) You can use the diamond sheers. While holding your blow pipe vertically, with the piece facing down over your prepared frax. Place the diamond shears around the jack line on the piece and close until it hits the glass. Open them up a bit, turn the pipe a bit, and close again until it hits the glass. Keep repeating this process until the shears have touched 360 degrees around the jack line. Then take the diamond sheers off, and use the back end of them to smack the rod of the blow pipe. This should knock off your piece.
2) You can also use the tweezers. Gather some water in your tweezers, and put a few drops on your jack line (ensure you don't get any water on your ornament or it will be ruined). Place your blow vertically, so the ornament is directly over your frax. With the back end of your tweezers, tap the blow pipe lightly and the ornament should pop off onto its frax blanket.
The point of what you're doing here is making a temperature difference. The diamond shears are so cold that when you touch your piece with them, it creates a fracture point on that line because it was cooled to fast. By doing this all the way around the jack line, you've created a stress fracture entirely around your piece exactly where you want it to be. The water works on the same principle, but is much more effective, so you should be more cautious when using it (you'll be able to see your piece cracking when pouring water on it).
Step 9: Knock It Off and Add a Bit (Part Two)
If you don't all ready have them in hand, grab whatever tools you're using. I find either a combination of diamond shears and tweezers or shears and tweezers to be the most useful. Work with whatever you're most comfortable with.
Get down eye level with your piece, and have your partner hold the punty vertically over your piece. Grab the punty with the tweezers and pull it down so that the glass coming off the end touches your piece where it broke off the blow pipe (The goal of this is to cover up the sharp corners that were left when you knocked the piece off, and giving you a loop to hang the ornament from the tree).
Let the glass completely cover the jagged part of your ornament and then pull the punty up away from your piece. You might have to hold your piece down with the shears or diamond cutters while pulling the punty away.
With the punty a few inches away from your piece (find the distance that works best for you...not too far, not too close), you want to grab the glass (closer to your ornament then the punty) with the shears or or diamond shears and pull it up and stick it to the glass on the punty. If you touch hot glass to other hot glass it will stick quite well. Since we don't want too fat a loop we need to thin out the amount of glass that is currently attached to our ornament. The way you do this, is to grab the hot glass near the ornament and pull it up and stick it to the glass by the punty. Continue to do this until the glass on your ornament is pretty thin and you think it would make a nice loop.
Use the shears or diamond shears to cut the glass, and have the person with the punty move away. Grab near the end of the glass with the tweezers and loop it around and touch the end of the glass with the hot glass toward the base. This should create a small hoop that you'll be able to tie string to, attach a metal hook to, or use whatever other means you like to attach it to your tree.
Step 10: Put It Away and Bask in Your Glory!
The annealer will cool your piece slowly. If you cool it too quickly (by leaving it sitting too long at room temperature), you'll create stress fractures throughout your piece. While it might stay together if you don't put it in the annealer, it will be far more fragile, and the slightest thing could cause it to explode at a moments notice.
So grab your stick tool and hook the loop on the ornament. Open (or have someone open) the annealer door, and gently place your ornament inside. Once inside, close the door. Once the annealer temperature is sent down, you'll have your very own hand made glass ornament!
There are many videos on youtube and other sites of glass blowing being performed. If it sounds interesting, I suggest checking them out, and searching your local area to see if there are any glass shops you could check out. A lot of places have live demonstrations you can sit in and watch as some amazing things are made (hopefully, they give you ideas of things that you can incorporate into your own work)!