How to Make Glow in the Dark Glass?

Glass Blowing with Techno Glow Powder

Glassmaking is not an activity for beginners. It takes years of training and hands-on experience to become an accomplished glassmith. This article specifically discusses how to incorporate Techno Glow powder into your glass projects and is not intended to provide a comprehensive glass working overview. We would recommend you have a good understanding of the glass production process before starting to experiment with our glow-in-the-dark powders. Adding additional elements to a glass project makes it more complicated. Even experienced glassmakers can end up fracturing finished works due to the increased stresses these powders transmit to the glass. With that being said, it is still definitely possible to make glow-in-the-dark glass! Just be prepared for some trial and error, as this is a more intense undertaking than some of our other artistic applications.

The two applications for our glow pigment to glassworks is distinguished by two different glass making technics, glass blowing (free blowing or mold blowing) and lampworking. While similar, how you will add glow-in-the-dark powder to the glass is slightly different. It’s important to note we would only recommend working with our three main colors, natural green, natural aqua, and natural blue since they produce the brightest glow. Micron size is also an important factor to consider when working with illuminating powder into your glass sculptures. A finer micron size, 50 microns or less, is easier to apply because it adheres more quickly to hot glass. It is still possible to use a coarser pigment, 100+ microns, but this will have to be rolled onto a large chunk of molten glass. We would suggest using a finer micron size for lampworking projects because this is the easiest application method. However, it is important to note the amount of powder you add to the glass will affect its viscosity and flexibility. Using a larger micron size, 100+ microns, helps the glass keep more of its original properties, while a finer micron size will cover more surface area and affect how the glass can be shaped. One micron size is not better than the other. It will take some playing around to figure out how much of what micron size will work best for your project and the desired finish.

Method 1: Glass Blowing, Free Blowing, or Mold Blowing

For glassblowing, the best way to add our powder to your project is the same way you would add any other type of frit. There are many ways to apply patterns and colors to blown glass, so this is an area you are welcome to experiment with to achieve different finishes and textures. However, the most common technique is to roll molten glass over the glow-in-the-dark powder. For more precise applications, it’s also possible to sprinkle the glow powder directly onto the area you would like colored. The most complicated obstacle to overcome is the phosphorescent powder effectiveness diminishes when exposed to high heat. It definitely will still glow, but the duration of this glow will be significantly less than if mixed with a room temperature resin, epoxy, paint, or another transparent medium. This limitation applies specifically to glassmaking, primarily when it comes to making glow-in-the-dark glass frit for future use. We wish this were possible, but you cannot mix illuminating powder with silicate, soda-lime, or borosilicate and expect the glass to glow once your project has been completed. The extreme temperatures used to create molten glass will render the glow powder obsolete. Therefore, it can only be used on projects which are completed in a timely manner. The constant reheating and shaping of more complex projects will negatively affect the glow duration and brightness.

However, one way to mitigate this problem is to encase the glow-in-the-dark powder between two glass layers to protect it from extreme fluctuating temperatures. The most common application of this glass skin would be a bead shape with a glowing powder center. Clumping the powder together in the center of a transparent glass sphere will better protect the glow powder from high heat. Some of our more popular projects have utilized this technique because it allows the artist to apply more complex artistic details without worrying about diminishing the glow time caused by constant reheating.

Method 2: Lampworking

Lampworking is distinctive from glassblowing because torches are used instead of a furnace. Molten glass is replaced with different sized tubes that are heated then bent and fused to create an infinite number of shapes, patterns, and finished products. Since there is no molten glass to roll the glow powder onto, glassmiths must either use the encasing method mentioned above or delicately fuse the powder to the inside of the glass tubes. There are a few basic guidelines for this type of work. First, any borosilicate lampworked glass combined with various glow powder applications must be done in an efficiently ventilated area to eliminate any toxic fumes that may be produced at high temperatures. This is a good rule of thumb for any lampworking project but is especially true when working with glow powder. All our glow powders are non-toxic, but we have only tested them at room temperature and not when they are exposed to high heat. (1500+ °F) If you are comfortable making glass beads, we recommend using this technique to encase the glow powder. This solid glass ball will help maintain a bright glow and protect the powder from extreme temperatures. It is easy to make several of these balls at once, then save and apply to future projects down the line. An alternative application is to sprinkle an even coating of powder inside a hollow tube and then heat the outside with the torch as you slowly rotate the glass. The glow powder will stick to the glass once it reaches an optimal temperature, somewhere between 1500-3000 °F. It is crucial not to overheat the glass and cause it to boil. This will reduce the glow effect significantly. If the glow powder gathers in a thick amount when it sticks to the glass, it will likely fracture. This will not be an issue with solid sculptural work (like the glass beads mentioned above), but it could cause catastrophic failure to a hollow structure. As with all glass production, completed pieces need to be properly annealed. Without this process, there is almost a 90% guarantee the glow-in-the-dark glass encasement will fracture.

Making Glow Glass Takes Practice

After reading this article, you might be thinking to yourself, is making glow-in-the-dark glass even worth the risk? Yes, absolutely! Obviously, we are biased with this opinion, but it doesn’t take much convincing after viewing some completed projects below. Our natural green, aqua, and blue colors are white-ish when they are not glowing and blend incredibly well into the glass. Once the lights go off, or a black light is shown, your project will come to life! The application process is complicated and will result in some failed experiments while you test it out. However, if you are an accomplished glassmith and are looking for a new challenge, this is something to try. There are not a lot of people creating glow-in-the-dark glass projects right now. You could be one of the first to capitalize on this new enterprise.

Artist Joey Walker

We want to give a special thanks to Joey Walker, who was instrumental in helping us create this article. Techno Glow randomly came across @joeywalkerglass on Instagram in August 2020 after noticing he was doing some experimentation with our glow powder and his small lampworking business. Joey is an incredibly creative individual, and we were instantly drawn to his passion for glass projects. In addition to his glassmaking, Joey also offers private lessons to share his knowledge and inspire future generations to continue the rich tradition of breathtaking glassworks. Please reach out to him for any custom order requests - Joey does both lampworking with borosilicate and soft glass/furnace work.

Visit Joey's Website: www.joeywalkerglass.com
Joey Instagram Page: @joeywalkerglass

Glow in the Dark Powder

Featured glow powders used in above methods.

Frequently Asked Questions

Q: Can you repeat any of the above steps for multiple layers to obtain a more solid glow?
A: It is possible to repeat the process of encasing the glow-in-the-dark powder between two glass layers, but eventually, there will not be enough UV light that gets through to the original layer, which allows it to glow. There is an increased risk of fracture with constant reheating and cooling of both the glass and the powder. It is not a good idea to attempt to clump an excessive amount of powder together to obtain a brighter glow as this will only increase the chance of glass fractures or breaks when cooling.

Q: How do I charge glow-in-the-dark glass to make it glow?
A: Our pigments are charged by UV light, so any form of sunlight or a UV black light will charge the powder. It does not even have to be direct sunlight. Any ambient light absorbed will be enough to produce a glow once it gets dark.

Q: Will glow-in-the-dark powder work with any type of COE?
A: Yes! You can add our glow-in-the-dark powder to any glass. A Coefficient of Expansion (COE) simply measures the rate that glass will expand and contract when it is heated and cooled. This is only used when figuring out if multiple pieces of glass will be compatible when fusing. COE does not affect the added glow powder.