A Good Place to Start
by Stephen E. Kersey

Introduction

This discussion is not so much a tutorial as it is a primer to the aspiring glass carver. I will delve into some of the general aspects of my company, such as the kind of studio I run my business out of, as well as some of the equipment I have realized was necessary to create the artwork that I so enjoy. I guess I should start off by saying that I am a self taught carver. Because of this, I've had to seek a means, and learn through trial and error, always speculating on my observations as to whether my work was art, and if not, how could I make it so.

After twenty years of trial and error, I find myself still learning (I know this sounds cliche but really it is true). Because of this, I know that I cannot impart my experience to you, but perhaps I can help you gain some insights into what has made my studio what it is today. I invite you to Kersey's Glass Works, and hope my tour will give you a different perspective that will help you to better your potential as a glass artist.

My Studio Layout

I work out of a 1250 square foot industrial bay. This is not because I like cement, but because the equipment I use requires industrial electrical hook ups, and a location that won't disturb the neighbors. We have two rather large compressors which generate a lot of noise, and push a lot of dust. As much as we try to contain it within our studio, much of it escapes due to the volume of work we do, and the size of the projects we contend with.

Because of the amount of dust we generate from our sand carving, we have had to engineer a large filtration and dust collection system to help combat "nuisance" dust. You'll notice I said combat and not conquer! I'm amazed to this day how it is that our studio computer has lasted as long as it has. We've only had to replace one "hard" and one "cd-rom" drive in the last year ;) But as my son likes to say... "but I digress"

Our Rather Large Work Horse (and the field he plows)

Because sand-blasting consumes large volumes of air, we have found the need for a rather large work horse. Well, we have two. We currently have a 10 horsepower compressor with a 60 gallon tank which serves as our overflow tank to our 15 horsepower/ 80 gallon compressor. Yes, these compressors not only generate a lot of air pressure, but they also generate a lot of noise. Surprisingly though, our 15hp compressor is much more quiet than our 10hp.

So where do I blast my glass?! My studio space allows me to have two 10' x 8' x 8' walk in sandblast booths. One I designate for #100 silica carbide, which is my primary medium for carving as well as blasting holes. The other blast cabinet is designated for "texturing grits" (grits anywhere from #48 aluminum oxide to #6 garnet). I realized that being able to walk up next to my glass, and touch it as I work, is an essential part of my art work. Only a walk in blasting booth can afford me this luxury.

In order to deal with a blast cabinet, and take full advantage of having one, I suit up and go into the cabinet with the glass, the sand pot, sand pot controls, and"piped in music" (gotta have the music for creativity to seep in!). Being able to stand close to the glass, touch it with my bare hands, and adjust air pressure/grit flow as I work, allows me a freedom to work at a pace that directly affects the quality of my work. The freedom to stand next to my glass is so liberating in fact, I can de tape, re tape, maneuver the glass and change my posture all in one sand blast session.

A Fortunate Venture: The Sand pot makes all the difference

Having a walk in the blast cabinet is only half of the liberation. A good sand pot is perhaps the most essential part of my work. I can't stress this enough, so I say it again in bold print! A good sand pot is perhaps the most essential part of my work!! When I first began sand carving, I did not know one sand pot from another. I really feel fortunate that I naively purchased a Ruemelin pressure pot back when I first began. A good analogy might be this... Imagine driving a car with the throttle under the hood, and you had to climb out of the window, reach into the engine compartment, and dink with the throttle every time you wanted to accelerate or decelerate. It would probably affect how you planned your trip to Disney land. The same is true of blast pots. Having a blast pot that will allow you the luxury of manipulating air and sand flow while IN THE BLAST CABINET is key to achieving any kind of consistency and depth to your artistic ability!

The Ruemelin pot allows me to mix the pallet of grit flow and air pressure as I "drive!" I don't need to use pressure gauges to keep track of air pressure, in the same way that you don't need to look at your speedometer when you drive. The nice part about having the controls with me in the cabinet is that I can drop down from 60lbs of air pressure to 2 1/2 lbs with the flick of the wrist and, I can in the same manner, down mix the flow of sand. This ability to control the flow of both sand and air dramatically affects every aspect of my artwork. And now, dare I venture into a discussion about grit?!

Getting Down to the "Nitty Gritty"

I use silica carbide in my studio. Silica carbide is one of the hardest grits on the market, not to mention one of the most expensive. I contemplated the use of it for a while back when I first began, and soon realized its advantages. I found that it pays for itself insomuch as it is very hard and breaks down far slower than aluminum oxide. It is also faster cutting, so I save time and get crisper edges and imaging.

Carbide has the quality of etching to either side of a hair on glass, leaving the image perfectly clear. It will also etch around any glue left on the glass from your masking tape. I'll talk more about this in my next tutorial. It can cut a clean hole through 3/4 inch glass as fast as drilling and is cleaner than drilling from front diameter to back diameter.

Another attribute is that carbide has a low dust value right up until it's ready to discard. Beware in purchasing though. Only the, experienced in this medium can tell the quality of the grit. I have had the misfortune of getting new grit that was obviously from a factory with poor quality control. Perhaps in actuality, it may have even been recycled grit. Nevertheless, new carbide is almost dust free. If it is unusually dusty to begin with, take it back and find another source. We are traveling an extra thirty miles because our local distributor doesn't know any better, and refuses to acknowledge the low quality.

Aside from silica carbide, I also use aluminum oxide, but mainly for hi-lites and rougher textures. I use various grit sizes of aluminum oxide to achieve these rougher textures than the satin finish of carbide. To obtain some of the rougher textures, I will use a #25 grit to #6 garnet. This requires gloves and extra clothing. #6 garnet is similar to buck shot. It may seem a little odd, but using this grade of grid can be painful if you don't suit up correctly! I have drawn blood from the rebounding pellets penetrating my blast suit! So you should treat the bigger grit sizes with a little respect, and foresight! We find that we have to use extra padding over the walls and cabinet doors in our #2 blast room to help reduce the amount of damage caused by these flinging boulders. We also have to use wire mesh over our lighting system, and tape the edges and backside of the glass we are working on.

If you plan to use some of the courser grit for texturing as we do, understand that course grit requires adjusting the grit flow opening of the pressure pot. This is because two grains of garnet trying to go through a regular size opening side by side, are wide enough to jam up the whole system.

Having two blast cabinets like we do is incredibly helpful and time saving when we have large complicated jobs. It also requires a little extra effort to keep from contaminating our carbide. My main concern when using the rough grit room is to contain the grit to the room. This is like raking leaves in a wind storm! The grit bounces and rolls around like ball bearings, and winds up everywhere, even when I think I've sealed my room well enough!. That means protecting my carbide room flying bandits isn't enough. I have to sift every time I fill the pot or risk having a bandit shoot out of my carbide pot and ping my glass. Not a good thing, especially when frosting tempered glass!

And what kinds of preventative measures do I use? I find that it's best when using multiple grades of grit to use different pots altogether. We have two, one for our carbide work, and one for all other heavier grades. In our rough grit room, if I go from a #6 garnet to a #48 aluminum oxide, emptying the pot is not sufficient to protect from the garnet still being in the system (i.e.. the mixer box). The mixer box must be dismantled to clean out any lingering garnet. At this point, I turn on the pressure with the mixer box open just to make sure the pot is clear.

Also, to make sure none of the bandits are hiding in my carbide room or manage to sneak into my carbide pot, I screen my grit as I pour it into my sand pot, as well as after every use. Multiple grits require different mesh screens to ensure grit size consistency. Wire cloth companies have every size you could possibly need for screening your grit. We have traveled many directions in grit types and uses. Too many in fact for a dissertation. A question and answer format at this point would be much easier, so I leave it to you and glass rumors to take up the rest of this discussion. Your choice in grit is one of those essentials in my opinion, so take the time to investigate your options!

Well with all this hoopla about grit, you must have had a feeling that the next topic would be titled "Avoiding Gray Boogers". And well... you were right.

Avoiding Gray Boogers and silicosis.

Silicosis is a lung disease caused by the inhalation of particles which cling to the walls of your lungs. In its advanced stages it can lead to all sorts of medical complications which I won't go into since you can pick up all sorts of information by doing a http://www.altavista.digital.com search for silicosis.

Since sand blasting is dusty, and breathing dust is obviously bad, I have invested a lot into my filtration and clean air system. I use an OSHA approved clean air supply filtration system for my air fed hood, and I have a squirrel cage evacuation fan which I modified with a sock filter trap to trap much of the airborne particles in my booths. The dust still flies, sometimes thick during intense blast sessions, but it drastically reduces the amount of airborne dust. We have experimented with many filtration systems, and this one seems to work fine for us.

I opted for the air fed helmet because it keeps a positive air pressure buffer between the dust and me. I found that I had to slightly modify my air helmet to suit my needs as a sand carver. The original hood had a clear plastic insert which had a slight arch or bow to it. This bow caused a strain on my eyes, so I replaced it with a piece of 1/4 inch plate glass, and a piece of clear acetate in front of that to keep the glass from getting blasted. It is much easier to replace the plastic, than the glass.

I would like to issue a warning about air fed helmets. Piping in air from your compressor without a clean air filtration system is extremely dangerous. Oil fumes from the compressor can cause serious lung damage, and yes... even death over a long period of exposure. So if you plan to purchase an air fed hood, don't stop there! You also need to pick up an OSHA approved air filtration system to filter out oil vapors from your air source.

In Conclusion

Well I have adequately exhausted myself, and eagerly await your input. In the meanwhile, I will continue my series by going into some of the finer details of sand blasting. My next tutorial I expect will be on masking materials; which ones to choose for which kind of jobs, and why. I think you will find this next in the series very enlightening, as it delves into some issues I have not heard anyone mention yet (in the glass industry, or on the Internet).

Thank you for visiting my site, and I hope to see you in Glass Rumors!