Q & A Mondays are answers to reader questions submitted via email or social media.  All personal information has been removed for privacy reasons and messages have been edited for clarity.  You may submit your own questions through the About/Contact page.

Q: I am looking to include sand and seashells in a fusing project. I saw the fusing with inclusions information. (Thank you) “Put it in a terra cotta saucer and run it through a firing cycle” – I was wondering what firing cycle you are referring to. I never fail to learn something from your classes, information or demonstrations. Your work and efforts are very appreciated.

A:  I usually use just tuck the saucer in the corner of the kiln when I do a full fuse.  It doesn’t need a special firing, just needs to burn off all the bits of organic material.  I think you will have issues with the seashells however, as they are essentially organic materials themselves.  I would strongly recommend doing a small test tile with a shell in it before doing a whole project.

Q: I  bought a kiln and I have never used it.  I am somewhat intimidated by it.  I wanted to start by slumping a bottle neck (donut) and some glass fusing.  The kiln is a Paragon sc3. I am looking at the fuse schedule you have for the donuts and I don’t
understand it.  Can you explain it to me better.  I get that you take the temp up at a certain rate per hr and hold and then cool down. When I saw the 9999 I got confused.. Sorry I am so new to this.

A: No worries, we were all new at this once, it took me 6 months to work my way up to firing my kiln, I would just go sit by it and then chicken out.
The 9999 is a code that means ‘as fast as possible’. Some kilns use 0000 instead.  Typically it means to cool as fast as possible, as we rarely ramp up asap.  In the cooling case, it just means the kiln turns the elements off during cooling, so the kiln will cool as fast as the ambient air will allow.
This step typically takes place after the top hold, because we want to get down to the annealing temperature without lingering too long in the temperature range that causes devit.
Another note, in your message you say you want to slump donuts and fuse glass.  I just wanted to clarify the terminology quickly to help skip disappointment later.
SLUMPING means heating the glass enough to bend it, but not a full fuse, this typically means bending a flat piece of glass in a mold.  I often see people use this word to mean flattening bottles, which is incorrect, to fully flatten and melt something, you need to
FUSE – heat the glass to a warm honey consistency so multiple pieces join together, and bottles will flatten, and donuts will be round and glossy.
If you are interested, I do have a Basic Bottle Glass Fusing class on video.  You can see more about it here:  https://www.curiousmondo.com/basic-bottle-glass-fusing-course?highlight=WyJqb2RpIiwiam9kaSdzIl0=

Hope that helps!

Q: Thanks so much for responding.  Yes I am just intimidated by it.  Not sure why as I usually am not to scared to try new things. I will try it out and see what happens.  I was just going to try to start with the bottle donuts for a pendant.

A: That’s a great place to start.  Don’t forget to kilnwash your shelf, or use paper so the glass doesn’t stick, and if you need help tweaking the firing schedule after your first try, let me know.  You got this. 🙂

Q: I have 5 very large boxes of Avon bottles that my father collected in the 70-80’s. He used all the cologne and but the bottle back in the original box.

My thought initially was to try and sell them, but then recently wondered about fusing them.

I broke one up today. Question(s): would you lay these flat (bridging pieces) and full fuse and then shape and slump? Or build a piece in a small dish (making sure the pieces had contact to each other) and then use the tack fuse schedule on your website?

What are your thoughts…

I have sooo many bottles some are really beautiful colors.


how fun are those? The first thing I would do is a quick firing test to see what kind of glass we are dealing with.  I do have a tutorial: https://glasswithapast.com/knowledgebase/fusing-with-mystery-glass/

but the gist is, fire a piece of the avon bottle next to (not on)a piece of fusible glass and a piece of float glass and see which one it behaves most like.  This gives us a baseline, if it fuses more like the fusible art glass, then we know to use a similar schedule, if it behaves more like float, then we know it needs to fire hotter.

Once you have an idea for fusing temps, then you can start doing the fusing into a full sheet, or building a shape in a mold, either one will work.  Do the test firing, and let me know how it goes and I can help tweak firing schedules for your projects.

Q: First, thank you for all the excellent info you have posted re: working with float glass. Question: Are there any less expensive ways to add accent colors or patterns to float glass projects other than the frit (like
Armstrong’s)? I have tried working with Glassline paints but they are too viscous to work with a stencil. Thank you!


Sorry for the long response time, I’m way behind on the emails at the moment. Adding color to float pretty much will always take a 3rd party product, depending on what that product is, the prices will vary.
Things I’ve tried (some I like better than others)

Fusible paint (glass line, color for earth, etc.) – These tend to be expensive because the materials to make them are also quite expensive.
I make my own paint, and there is not a significant cost savings, but I
do like my own formula better

Enamels – Thompson enamels makes a good enamel for float glass (also
works on bottles).  I like their sample pack, it comes with 60 colors, a
little bit of each, and isn’t very expensive.  The down side is their
website kinda sucks.  Make sure you get the float glass enamels, they
make many kinds of enamels.  The particle size on these is a bit like
the smallest frit size, great for stencils, not so great for fine
details like writing.

Frits – Armstrong Float fire as you mentioned.  The powder is fine
enough for stencils, and I usually buy the Kilo size bottles, and they
do last a very long time

Mica – You can use craft mica powder (some, you do have to test, many
don’t survive).  I also make mica, I buy mica rocks and cook it at high
temps until it changes color, grind, filter, etc.  The downside is the
mica powder is more of a watercolor kind of wash, and the mica flakes
have to be capped.

Oxides – lots of choices here, and some of them are inexpensive.  Some
also don’t work very well, so again with the testing or taking a class
(I have a video class if you are interested, I can send the info).
Oxides also have to be capped

Inorganic material like dirt and sand – also have to be capped and
prefired to burn out the organics.

Decals – ceramic decals work well on glass, make sure you get the low
fire kind, I haven’t tried the underglaze transfers yet

Hope that helps, 🙂