There are a variety of DIY projects where you can use glass (for example, to create covers for candles or glasses). However, to reuse a bottle or glass object, you need to smooth out any broken and jagged edges. Fortunately, you can easily use sandpaper, a sanding tool and a power tool, or even silicon carbide powder to easily smooth glass edges.
Method 1 of 3: Use Sandpaper
Step 1. Dampen a piece of 80-grit sandpaper and place it on a work surface
Make sure the sandpaper is very wet and the work surface is hard and sturdy. To moisten the sandpaper, soak it in a bowl of clean water. Then pour some extra water over the paper after you spread it out.
You can also use emery cloth if you don't have access to wet sandpaper. You can buy a multi-pack of emery cloth at most home improvement or hardware stores
Step 2. Place the cut edge of the glass on the sandpaper
Hold the glass with your dominant hand and keep the sandpaper stable with your non-dominant hand. Make sure to wear protective gloves and goggles for maximum safety.
- You can usually buy gloves and safety glasses at any home improvement store that also sells sandpaper.
- If the glass has multiple sharp edges, you should hold it so that neither edge cuts your palm. If it is impossible to hold the glass this way, consider smoothing the edges with a different method.
Step 3. Swirl the glass in a circular motion for 5 minutes to smooth the edge
Apply gentle downward pressure to the top of the glass so that you push it slightly toward the sandpaper. Rotate the glass piece every 2-3 circles to maintain a more even sanding.
- If you refrain from turning the glass piece, you may end up sanding one side much more than the others and leaving a noticeably uneven finish.
- Try to do this for around 5 minutes to make sure the edge of the glass is properly smoothed out.
Step 4. Sand the inside and outside corners of the glass trim by hand
After you finish sanding the “front” part of the glass edge, take the sandpaper and dip it back into the water to moisten it. Then, take the sandpaper in your dominant hand and place it over the edge of the glass so that your thumb and middle finger are on the corners of the edge. Lastly, rub the sandpaper back and forth to sand these sharp corners smooth.
You should keep the sandpaper wet while you do this. You may need to submerge it in the water several times to keep it properly moist
Step 5. Repeat this process with increasingly fine sandpaper grits
Sand the edges with 150, 220, 320, and finally 400 grits to make the glass even smoother. Then use 1000 and 2000 grit sandpaper to polish the edge to perfection.
Wipe the edge of the glass with a clean, damp cloth once you've finished sanding to remove any sand or dust residue
Method 2 of 3: Sand with a drill
Step 1. Attach a sanding bit to a Dremel tool or power drill
For best results, you should choose a medium-grit sandpaper finish (60-100 grit) and a relatively large sanding bit. The larger the bit, the more edge you can smooth at one time.
Make sure the sanding bit is the correct size for the piece of glass. For example, if you are smoothing the edges of a wine bottle that you have cut in half, make sure the bit can fit into the hole so that you can sand the inside corners of the glass edge
Step 2. Hold the tool in your dominant hand and the glass in your other hand
You can try putting the piece of glass in a clamp to keep it secure, but this makes the edge much more likely to break. However, you should only hold the glass in your hand if you can hold it safely without it coming into contact with the sanding bit.
- Make sure to wear sturdy work gloves to hold the glass securely.
- If the glass object is too small for you to hold in your hand safely, the best option is to use a clamp to hold it or use an alternative method to smooth the edges.
Warning - Be very careful when handling power tools. Wear gloves, safety glasses, and a respirator mask.
Step 3. Run the sanding bit against the inside edge of the glass
Press the power button to turn on the power tool and hold the side edge of the bit against the inside corner of the glass edge. Avoid applying pressure to the bit, as you could break the glass. Instead, you simply need to hold it against the edge to allow the straightening process to take place.
- You should spend 3-5 minutes doing this to smooth the inside edge of the glass properly.
- Make sure to wear a ventilation mask during this step, as the sanding process will kick up a lot of glass dust into the air.
Step 4. Move the sanding bit to the top and outside corner of the glass edge
You should work towards the center and out on the outside edge to get a rounded edge. Turn the bit slowly until you have gone all the way around the outside edge.
It shouldn't take more than 3-5 minutes to complete this step
Step 5. Repeat this procedure with fine-grit sandpaper to polish the edge
Replace the sandpaper on the bit with a finer grit. Then run the bit back over the edge of the glass to smooth it out even more. Repeat this step as needed with increasingly fine sandpaper grits until the edge of the glass is polished to your liking.
- You can also simply polish the edge of the glass by hand if you don't want to continue using the power tool.
- Once you've finished sanding, use a clean, damp cloth to remove any sand or dust residue.
Method 3 of 3: Smoothing with Silicon Carbide
Step 1. Place a piece of float glass on foam rubber on your work surface
You will be using float glass as the “main” work surface on which you will polish the edges of the glass. The foam rubber will help keep the float glass in place and prevent it from slipping during the polishing process.
If you don't have a dedicated float glass piece, you can also use polished flat glass (for example, a window, mirror, or picture glass)
Step 2. Add water and a coarse grain of powdered silicon carbide to the glass
Pour a small amount of water in the center of the float glass to create a small puddle. Then pour in enough silicon carbide to cover the surface of the puddle. Lastly, use your fingers to gently stir the silicon carbide and water.
To make the process of adding the silicon carbide powder easier, you should first pour it into a small disposable cup before you start adding it to the glass
Step 3. Place the sharp edge of the glass against the polished flat glass
Hold the piece of glass with your dominant hand (or with both hands, if necessary). Make sure to place the edge of the glass directly over where you mixed the silicon carbide with the water.
For safety, wear gloves to avoid cutting your hands on the glass
Step 4. Make circles with your hand and the bottle around the glass for 30 to 60 seconds
Move the glass over and through the silicon carbide making a number eight and applying gentle downward pressure as you do so. Make sure you stay within the surface of the glass and avoid moving past the silicon carbide puddle.
Look at the edge of the glass after about a minute of making the circles. If the glass is no longer shiny or smooth to the touch, then you are done
Step 5. Clean the glass with a towel and use sandpaper to smooth the inside
Use a damp paper towel or a dedicated cloth towel to remove the silicon carbide water from the glass piece. Then use wet sandpaper as needed to smooth the inside corner of the glass edge if necessary.
- For example, if you smooth the bottom of a cut glass bottle, you won't be able to smooth the inside corners of the glass edge with the puddle of silicon carbide.
- You can also use sandpaper to sand down any rough spots that you find the silicon carbide missed.