Can you mold glass

You can use any cooking oil such as olive oil or Pam as a mold release. Paint on the olive oil. Spray on the "Pam".

Fire the mold in a kiln to at least F to ensure they the mold will tolerate thermal shock while being used to fire cast glass. To create a mold using a "ceramic slip cast" technique, begin with the same small box. Coat the object with oil and plant it upside down in the bottom of the box. Pour molten clay over the object until the box is full. The positive is absolutely glistening with silicone mold release. I added four walls around the plaster brick with a wrap of ceramic paper, to contain the molten glass during casting.

A slab of billet glass was simply placed on top of the open mold, and allowed to melt onto it. With lost-resin casting, you have much more freedom in what you create - virtually any shape is possible. Lost-resin is a casting process that involves a plastic burnout stage.

This can only be done with great kiln ventilation, like a big fume hood or by rolling your kiln outside. This can double as your glass fusing kiln, although the mold will need to fully cool before you can load it with glass.

Otherwise, the force of the expanding resin will break the mold as you burn off the positive. PLA plastic , this is less important - but the less infill you can get away with the better. We use string to create thin channels for air to escape — this helps prevent air from getting trapped by the molten glass as it flows through the mold. The moldmaking step is fun: we mix plaster, mesh silica, and water. You can also use a pre-mixed investment powder , just add water.

After burnout, soda-lime glass is placed into the feed cone and the molds are set into the kiln to be cast. Over the next three days, gravity and heat do the rest of the work.

Make sure to place these molds in sand - they can break in casting, and the sand will protect the bottom of the kiln. The result: Glass Stanford bunnies, with some fun textures. More techno-kitsch than art, but I like them anyway. A wonderful aspect of glass is that you can embed visible forms inside other shapes!

This is really easy to do with digital design and kilncasting. Negative-space snake. Or negative space-snake? This should be around degrees C for a long time, or closer to C for a short time but no promises that your glass will be pretty. Let glass cool in crucible. It is also possible to skip this step if you can find a different way to position your glass pieces directly over the opening to your investment.

Ceramic, perhaps? Maybe stainless steel? Our graphite crucibles ended up disintegrating, which made a huge mess. Now you need a furnace big enough to hold your investment in the flask and your glass piece over it.

We simply upended the crucibles full of glass over the mouth of the investment. Close furnace and turn the heat up to C.

Leave it in there for six days. We also put some little ceramic boats with extra glass chunks in the furnace, just so that we'd have some visual feedback. We did C for 12 hours, but our glass didn't turn out very pretty. That's why you should use a different material, I guess When you're casting metal, you can just quench your investment in cold water and it will pop right off, giving you access to your pieces.

However, glass cracks when cooled too quickly, so you'll have to let it slow cool. Turn your furnace off and let it sit until it returns to room temperature. When your investments are cool, remove them from the furnace. Put them somewhere that can get messy.

Wear a dust mask so that you don't breathe too much investment powder in. Scrape at the investment around the edges of the flask. It should be pretty easy to scrape and make a big powdery mess. If you can, try to scrape around all of the investment until it dislodges from the flask.

If not, just dig down into the investment to treasure hunt for your pieces. Be careful- depending on how delicate your pieces are, you could accidentally break them. Once you're out of the flask, put your pieces in a big sink and run water over them while continuing to scrape and clean.

You're trying to remove all of the investment from your glass pieces. Once you're down to just glass pieces and glass sprue, you'll want to take your pieces off of the sprue. I used a tabletop diamond bandsaw. Note to my friends: if you ever want to get me an expensive present, this is it. If you don't have one of those, try scoring and very carefully breaking your pieces off of the sprue, then sanding down the sharp edges. Wash your pieces with soap and water.

Use a brush to get into the crevices. If you're lucky like me, you have access to an ultrasonic cleaner. If that's the case, put soap and water in that, throw your piece in, and let it vibrate for five minutes. Rinse and repeat for all pieces. Then replace your soap and water with a coarse polish, vibrate and repeat.

And one more time with a fine polisher I used an oil-based diamond slurry. That should get your glass looking lovely! For flat sides, you can also try grinding with wet fine-grit sandpaper. Our pieces, as you'll note from the pictures, have a distinct non-glass quality to them.

Specifically, they're opaque. We're not entirely sure what happened to cause this, but since our processing was rather messy, there are a number of possible points where this could have occurred: -Melting could have introduced debris into the material.

Our crucibles weren't perfectly clean, so little bits of dust and graphite got mixed in. We were trying to save time, but we might have introduced defects into our product. Clear materials, such as glass and clear plastic, have amorphous microscopic structures, which means that they have no crystal structure. Sometimes, when glass is cast, it forms a milky, opaque surface, where the glass has crystallized around foreign particles.

The diamond slurry polishing should have removed any surface devitrification, but since the glass was mixed with foreign debris throughout in the melting step, this isn't enough evidence to cross off devitrification as a possible source of opacity.

So I took samples of each type of cast glass to the SEM to look for crystal structure. Two of the pictures above are through the SEM. They show the red glass at 60X and X magnifications. No clear crystal structure emerges, because the surface is too textured. The glass looks porous- there are hollows for many tiny bubbles within the glass. If you made anything, be proud! This is a really difficult and time-intensive process. I'd love to see pictures of other people's homemade cast glass!

I hope I didn't bore you with the science :. I use 'quenching' thermal shock to make smaller chunks of glass out of bigger ones. One interesting feature of glass is that it has high surface tension so if you have a chunk of glass with a lot of fractures in it, you can remove the fractures by heating the chunk up enough without the chunk melting.

Unfortunately, I use a microwave kiln so I do not have temperatures to talk about - only of minutes in kiln. Cooling metal too quickly can generate cracks. But almost always leaves a less-desirable molecular structure. Don't cool it faster than you have to. Reply 9 years ago on Step 6.