Saturday, April 9, 2011

An Experiment in Frit Making: Lessons Learned

I mentioned that my goal this year is to use up my scrap glass. For the red, orange and yellow glass, I decided to try making frit as I typically use these colors in tandem and they typically do not fire as well in the higher temperatures used for pot melts.

Frit is basically crushed glass, which comes in a range of sizes from powder to coarser bits. Frit is made by crushing glass either with a hammer or a pre-made metal device called a "frit maker," which is designed to more easily crush the glass. Given that this is my first time and I'm not sure how often I'll be making frit, I decided to go with the hammer method. To make it easier to crush, I first quelch the glass. Quelching involves heating the glass (I heated the glass to 1000 degrees) and quickly cooling it in water. I heard that there would be steam and a little splattering at this point. This didn't happen with me although I could hear some sizzling when it first hit the water. As you can see the ice is still in tact after the glass was dumped in.

The glass is still in tact as well. I thought it might break up into pieces but it did not. However, there are tiny fractures in it. It has the sound of plastic rather than glass, and I can break a piece by bending it with my hands.

To crush the glass, I contained the glass using a stainless steel ring. As you crush the glass, the pieces want to fly somewhere and the ring helps keep them contained. I also placed a plastic baggie on top. The bag keeps the glass from flying but allows me to see through it. In addition, it keeps any metal from the hammer from falling into and contaminating the glass bits. I also placed the glass on a few pieces of re-inforced plastic tarp. The tarp was strong enough to withstand the crushing (although I had to double it towards the end) and didn't leave fragments of plastic in the glass.

After I crush the glass, I pour it into the frit sifter, which contains a grid on the bottom to separate the glass by size. The bigger pieces stay on the top and smaller pieces fall to the bottom. Fortunately, I want coarse pieces of glass, so I am saved from all the pounding required to get the glass to be really tiny :)

Lessons Learned:
Use a stainless steel bowl for heating the glass. This makes it easier to dump the glass into the bowl of water. I also used tongs and welder gloves to protect me from the heat.

Use the side elements to heat the kiln if you have this option. There's much less heat radiating out than if you're using the top elements (forgot about this with the second round).

Quelching, while more time-consuming, is much better than just hammering. The glass is easier to break and less prone to having sharp edges, which is a huge benefit! With all the broken glass, I did not get one cut and could run my hands through the broken glass. I'm positive that had I not quelched the glass, that I would have used my fair share of bandages.

Using the tarp, ring and baggies are great ideas, especially since this is fairly messy. The tarp is sturdy and great for pouring, while the ring and baggies help keep the glass contained. A vacuum cleaner is also a must.

Make the frit, starting with the lighter colored glass and move to the darker colors. While I vacuumed the tarp, ring and frit sifters between crushings, there's still a possibility that tiny bits of glass could have been transferred. Having each glass color be slight darker, minimizes the appearance of any stray fragments should this have happened.

Buy or make a frit sifter. Even if you want large pieces, you will get every size from powder to chunks. A frit sifter helps sort out these sizes and is especially helpful for the smaller sizes (powder, fine, medium).

Thoughts Moving Forward:

For me, frit making was a little more time consuming, labor intensive and messy than I would have liked. If I choose to make more items using frit, especially using smaller pieces of crushed glass, I would purchase pre-made frit rather than make it myself. However, given that this is a great way to use up my reds, oranges and yellows, I'll still continue to make frit. And, I might consider making more frit with excess glasses that I don't have alternative ways of using. For example, I have a lot of excess amber glass. Amber is not a glass that's in my color palette but was something that I used quite a bit for Christmas ornaments. Another consideration is how my fused glass pieces turn out with the frit I've made. I'll write about these projects as they happen down the road. I can tell you that the first one didn't turn out. However, now the challenge is to make it into something usable. Thank goodness for my tile saw! More on this in future posts (once I create something worth sharing)...


  1. Thankyou for this post, it is so helpful!

    1. Thanks for the comment! Glad you found it helpful.

  2. Great tips for making frit. I love working with frit and will definitely try making my own with glass scraps. Thank youvor sharing valuable experience