Fusing Tips

How do you apply kiln wash to a shelf?
Mix up kiln wash according to the manufacturers instructions. Most recipes consist of one part kiln wash to four or five parts water by volume.

Brush the kiln wash onto the kiln shelf using a haik brush; this allows the kiln wash to go on more smoothly. At least four coats of kiln wash should be applied to the shelf, with each coat brushed on in a different direction (side to side, top to bottom, and diagonally in two directions). Also stir up the kiln wash between coats because the kiln wash can settle quickly in the bottom of your container. Once you have applied all of your coats, allow the shelf to air dry for a day. Otherwise, you can speed up the drying process by placing the kiln shelf in your kiln, heating up the kiln to 500 F, and allow the shelf to cool down. Make sure that you use a kiln post to slightly open up the lid of the kiln and allow the moisture to escape as it evaporates from the shelf.

Once the kiln shelf is dry, examine the kiln wash on the surface. If it looks like it needs to be smoothed a little, a piece of panty hose works great to lightly brush over the surface and remove any imperfections.

Do I have to have a Hot Box kiln to make bent glass bracelets?
Yes. The Hot Box kiln is a small table top kiln that heats up and cools down quickly which is ideal for bending bracelets and keeping the shape. If you use a larger kiln, it won't heat up quickly enough to simply soften the glass bracelet without changing the shape.

Also, because the Hot Box kiln has a smaller heating chamber, it's only necessary to wear gloves to protect your hands and forearms from the heat. In a larger kiln, it would be necessary to wear a protective face mask as well as a Kevlar suit to reach into the kiln to prevent being burned.

Can I make beads in a kiln?
Yes. Beads made in a kiln are flat compared to the round beads made in a torch. To make the hole in a bead, you can cut up narrow strips of 1/8" fiber paper or coat a stainless steel mandrel with bead release and place between the layers of glass. To ensure that the glass will wrap and mold both side of the hole, make sure that the glass extends at least 1/4" past the mandrel. Sometimes the stainless steel mandrels roll around a little, so you can use the thicker fiber paper until the ends of the mandrel to hold it in place.

Once you have fused the glass beads, simply pull the stainless steel mandrel out of the hole. With fiber paper, a pipe cleaner to push out the paper.

How do I drill holes in glass?
Drilling holes is very easy to do using a dremel and a diamond coated bit. Inland has a very affordable drill bit assortment (#50115).

Start with a container large enough to hold your glass piece. Place a scrap piece of glass in the bottom of the container, stack the piece of glass that will be drilled on top and then fill the container with enough water to cover the surface of the glass by about an 1/8". Hold your glass piece firmly in one hand, and gently start to drill the glass hole allowing the bit to do the work. Don't push down on the Dremel because it's possible to break the glass. Occasionally pull the bit out of the hole to allow water in and check on your progress.

Can I fire silver jewelry clay in my glass kiln?
Yes. The extra thing you'll want to use is a separate kiln shelf just for jewelry clay. When firing silver in a kiln, the silver leaves a permanent stain on the shelf. If you then fuse glass on the same shelf, the stain might contaminate and leave a mark on your fused glass.

Do I have to use kiln wash on my fiberboard mold?
If you're using the fiberboard that Delphi sells, it isn't necessary. Just like fiber paper, glass can be placed directly onto the surface of the mold. It will leave a very subtly texture on the bottom side of the glass. For a very smooth surface, lightly sand the surface and edges of the mold before firing. Remember that anytime you are working with fiberboard you should wear a respirator. After your project is finished, it may pick up some fiber particles that can be cleaned off with water.

It's possible to make a longer lasting mold by treating the fiberboard with mold hardener. Once this is done, you will need to use kiln wash on the surface of the mold so that glass won't stick to it.

What are the steps to using mold hardener with fiberboard?
To treat fiberboard with mold hardener, first cut out your mold. The mold should be fired at 1200 F in a vented kiln to burn out any binders in the fiber board. Place the mold in a container and saturate it with the mold hardener. Allow the mold to dry for several days and then re-fire to 1200 F to cure the hardener and burn out any remaining moisture. Once cooled, you can lightly sand out any imperfections and coat with kiln wash before covering with glass.

How do I put kiln wash on a stainless steel mold?
Regular kiln wash doesn't stick to a stainless steel mold unless the mold has been preheated first. Heat up the mold in your kiln to about 400 F. Wearing heat protective gloves, remove the mold from the kiln and place it on a heat-resistant surface. Kiln wash can either be brushed or sprayed onto the surface. The mold will cool quickly, and you'll notice that the kiln wash will start to roll off the surface. If the entire surface isn't coated, place the mold back in the kiln and reheat it. Again, remove it from the kiln, and apply more kiln wash. You will want to repeat these steps until the mold is completely coated. Note: Do not spray kiln wash on the mold while it's in the kiln. The kiln wash may coat the kiln elements and burn them out.

There is also a new product available exclusively for stainless steel molds called Mold Armor. A thin coat is either brushed or sprayed onto the mold at room temperature. Then place the mold in a vented kiln and fire to between 1100 F and 1292 F to cure it. Once the mold has cooled, smooth the surface with a very fine steel wool. The manufacturer claims that one application can be used up to 60 times.

I'm ready to buy a kiln. What other supplies do I need to get started?
Selecting a kiln is a big decision. If you are unsure which one is for you, please don't hesitate to call us, and we can help you make an educated decision. Once you have selected a kiln that will fit your needs, here is a recommended list supplies that are necessities when getting started.

  • Kiln Shelf
  • Kiln Posts - three or four to place underneath the kiln shelf, and one or two for venting or other purposes
  • Kiln wash
  • Haik brush for applying kiln wash
  • Heat-resistant protective gloves
  • Safety Glasses
  • Lid Lifter - to safely open the lid on larger floor kilns
  • Assortment of compatible glass

To take the confusion out of what to order for your kiln, Delphi has already put together kiln accessory kits that contain everything you need to outfit your kiln, except for glass.

I'm having trouble programming my kiln controller. Can you help?!
Absolutely! Call us on our toll-free helpline, and one of our helpful associates can walk you through programming right on the phone!



Tuesday, July 6, 2021
1 Post

I'm confused with the anneal 9999. I've read many posts, but don't understand the 9999.


Friday, February 8, 2019
91 Posts

@ When filling a casting mold with frit, some bubbles are likely. The finer the frit, the more tiny bubbles you are likely to entrap - therefore when you want the best clarity possible, it's best to use coarse frit, or even nipped up chunks of glass. If you wish to eliminate as many bubbles as possible, you may want to essentially introduce a "bubble squeeze" in your firing schedule. For castings of this thickness, this may mean you reduce your ramp rate once you've reached 1000 degrees F to a rate of 50 degrees per hour from 1000 degrees until you reach 1200 degrees, then you can return to a faster ramp rate until you reach your process temperature.


Thursday, June 29, 2017
91 Posts

@robinsnest69 Fusing has some additional "rules" that don't exist when creating stained glass and mosaic art. It is important to ensure that all the glass that is used in the project is tested compatible (all 90 COE or all 96 COE). Van Gogh glass is not tested compatible for fusing (the COE is unknown) and the special color coating is not rated for heat work, meaning that it will burn off, and could release harmful fumes when fired in a kiln. The cracks are a result of glass incompatibility which causes stress as the glass expanded and contracted at different rates during heating and cooling - it has essentially pulled itself apart. I hope this explanation helps you to get the results you desire in your next firing.


Thursday, June 15, 2017
1 Post

Hello. I did my first firing the other day. It am definitely hooked. I see some cracks in my piece and am guessing that came from the annealing stage ( coe 90 glass) I used some Van Gogh tiles in my piece, in silver and Purple, but all the color is gone. Did I fire too hot? Please help.


Thursday, January 19, 2017
91 Posts

@ Using pattern bar slices as a design element can create some unique and stunning art. If you wish to create a center motif of pattern slices with a border, there are a few considerations to make. First, how thick are the pattern slices? If they are about 1/4" thick, when full fused they should remain approximately the same dimensions. If they are thicker, the glass will flow outward a bit, or if they are thinner, the glass may pull in a bit. Many artists opt to cut slices a little thin, and position them on a layer of clear fusible glass to help stabilize the size and shape. Additionally, for the border the glass needs to be stacked approximately 1/4" thick, if you use a thin base glass, you can simply add a layer of color border over top to achieve this. If you wish to avoid using a base layer of glass, you will want to stack 2 layers of the border color to help ensure it fuses evenly with the center motif.


Thursday, January 19, 2017
91 Posts

@ Boron Nitride spray works well as a release on stainless steel molds. Make sure you shake it well before use, and keep the can upright while spraying. The first time you treat the mold you will want to apply several coats of release.You do not need to use a kiln shelf in your kiln, however it is often recommended. The kiln shelf will protect the floor of your kiln by ensuring that if glass sticks to a surface, it's the removable and replaceable shelf that is damaged instead of the floor of the kiln. If you wish to fire without a shelf, be sure to use a fiber paper to protect your kiln floor.


Monday, January 18, 2016
91 Posts

@lisagw To use a curved surface draping or slumping mold such as the table lamp mold you mention, you will want to make sure glass is centered and balanced on the mold. It is easiest to do this by placing the kiln washed mold on your prepared kiln shelf, then positioning the glass. If your glass is un-evenly weighted (maybe it has extra decoration only at one side) it may not sit level, but as long as it is correctly placed by measurement it should form nicely. Hope this helps - and happy fusing!


Wednesday, January 13, 2016
1 Post

Hi! I'm confused about where to place the glass when using a table lamp mold (item#80685.) Do I balance it on the top of the mold (won't it fall off?) or do I center it and lean it against the mold (won't it melt funny?) Thanks, Lisa

Jennifer Bonesteel

Thursday, May 21, 2015
Delphi Expert
188 Posts
Top Contributor Gallery Artist

@gatormichals like ovens, kilns vary and sometimes small adjustments need to be made to accomodate the kiln size, where the elements are, etc. Based on the results you got I would shorten the hold time at the highest temperature. Maybe try 30 minutes. We tested a mold like this and we found that we had to watch it as it started dropping to be sure we weren't going to fast. You don't want to open your kiln up much, but it's okay to open it just enough to peek in. Good luck!


Monday, May 11, 2015
4 Posts

I need advise, I made the system 96 Poppy sundae dish; I used COE 96 glass I followed all of the instructions and the firing schedule to the letter, however when I fired the dish the drop section for the bowl dropped way too much and melted down or the foot. The throat / neck portion of the bowl was way to thin and ended up braking, I believe it was because it couldn't support the weight on the top lip of the bowl. What happened, what did I do wrong? Can a Delphi expert or some one with more experience can offer assistance.