While I don't claim to be an expert, I have drilled a lot of Sea Glass lately.
In that process I have also ruined plenty of gorgeous pieces.
This little tutorial should help you get started in creating some great jewelry from treasures you might find.
Drilling Sea Glass
First take a look at your piece of glass.
Check the thickness and size.
Look for cracks or folds that would put stress on drilling and crack the entire piece.
A good piece to drill is even or generally the same thickness with no cracks.
Next you'll need a small tub of water. You will be drilling in water. I use a clear plastic bin. The clear plastic helps me see the glass better. It also helps me watch the water. You'll see when you start to drill that the water will get cloudy (it's the glass dust). Using a clear plastic bin helps to see the changes in the glass.
I drill also drill into a piece of wood that holds my glass and gives me some adjustable height.
In order to drill glass you must use a diamond drill bit. The size and style are totally preferential. If you are using a Dremel you will also need the right sized collet to fit your drill bit. Check the size of both to make sure they match.
Like I just said..I use a Dremel with a Flex Shaft. It's small enough to hold and easy to maneuver. I have friends that drill glass with a Dremel in a drill press or use a Foredom. I like my set up, but you'll have to use what works for you.
I can tell you from experience attempting to use a regular drill is just bulky and hard.
Put your piece in the water.
Make sure the water covers the piece but just barely covers the top.
Hold the piece with one hand/finger. I have seen some people put the piece in silly putty to hold it steady.
With a steady hand (ha ha) start drilling. The important part is that you apply steady pressure but not too much. Let the drill do the work. It takes a long time..be patient.
You'll notice that the glass dust is starting to surface.
This is good it means it's working. Back your drill out often.
Once you get about 1/2 down turn your piece over and drill the other side.
This take lots of patience and strategy to get it just right.
You could mark both sides, but in time you'll just sort of get the feel for it.
You can always email me if you have questions. If you want examples of my work take a look at my Etsy site..or maybe stop in and see me at the Juneau Artist's Gallery