Monday, November 16, 2009


Let me start by showing you examples of the good, the bad and the ugly to see if you recognize any of these.  In the meantime, I welcome your questions, comments and suggestions as well as pictures depicting your experiences.  A picture of the problem you are experiencing helps a lot in determining a workable solution.

Please be aware that all microwave kilns, microwave ovens and even fiber papers are not created equal.  In other words you might have a friend that has the same type of oven (stove) as you, you both bake the same type of cake using the same ingredients and baking pan however; yours happen to turn out better.  Something is different, what is it?

Can you tell me what the problem is and what caused it in the samples below?

PROBLEM:  Chips or cracks in graphite lining due to one or more of the following:
- Melted glass, metal clay, etc. stuck to lining and pulled loose.
- Portion of lining chipped off during packing or transporting of kiln.
RESULT:  Missing graphite lining will cause cold spots and result in glass not fusing evenly.
SOLUTION:  The MicroKiln Repair & Recharge kit will remedy this problem. 

PROBLEM:  Kiln base damaged due to one or more of the following:
- Glass or metal clay fired too hot too long.
- Firing glass or metal clay without a fiber shelf & fiber paper.

RESULT:  Glass or metal clay burns hole(s) in kiln base.

SOLUTION:  Always fire with a 1/8" fiber shelf and 1/32" fiber paper. Fuse glass and sinter metal clay at the correct temp and rate based on your microwave oven's wattage.

PROBLEM:  Metal clay design melted.

RESULT:  Metal clay design destroyed resulting from over firing (fired too hot, too long or combination of both).

SOLUTION:   Fire and sinter metal clay at the correct temp and rate based on your microwave oven's wattage.


PROBLEM:   Black based dichroic etched design displays part of clear top fused glass layer on upper left of design.

RESULT:  Glass design not attractive and will need to be cold worked and fire polished to correct.

SOLUTION: Top layer of glass needs to be properly cut and balanced over base glass otherwise the heat will cause the top layer to shift.

Below are a few pictures of designs that were successful created using the MicroKiln:


   Looking forward to hearing from you and seeing pictures of your designs.


  1. How wonderful you are doing this blog, just when I'm getting into using my little Fuseworks kiln. I have a "big" programmable kiln for use with PMC, but bought the microwave one to save on electricity. It seemed a fine way to do a few dichro cabs for my PMC work. Anyway, I've been running into the problem of one layer slipping off/alternately cracking into several pieces. I've been using dichro with a base or top layer of black or clear (same COE). I even tried one single piece of dichro with no top or bottom layer, and it still cracked in half at 4 min. I have an 800 watt microwave with a turntable I bought at a yard sale for $5, and have been running the fuse for 3 to 4 minutes with the turntable disabled as per kiln instructions. Sometimes when I look at 3 min., it's not done, and put it in 30 seconds more per kiln instructions. So, does glass thickness have anything to do with it? Should I use a fuseable glue to hold the pieces together? Is the highest setting too much and should I back off on the highest power? Does the extended time period have anything to do with any of my problems? Some of my pieces have come out fine, but most are not. I'm spending a lot of time in trial and error, and that can add up with dichro. Sorry, lots of questions, but no answers readily found. I enjoy using the kiln, but want more consistent results if possible. Thanks so much.

  2. Happy you found my site, and will be more than happy to help you resolve your problems. First, I must ask if you know that the microwave you purchased is indeed an 800-watt. Unless you were given the manual that came with the microwave or it is indicated on the unit itself it may not be an 800. Higher wattage and depending how much higher this could be part of your problem. However, let say, it is an 800 watt then this is what needs to happen:

    Note: If glass heats up to hot to fast it will crack.

    • Create your design with no less than two layers of glass.
    • Pre-heat your glass for 2 minutes at 70%. This will allow your glass to heat up slowly and evenly; otherwise, it will crack.
    • Next, without opening your microwave door, turn your dial to 4 minutes on High (your microwave oven automatically reverts back to High). Then open and peek briefly at your piece (a rush of too much cold air can cause your piece to crack).
    • From this point start adding in 30 second increments until you get the desired look.
    • Add the total minutes and seconds up to give you the total Fusing Time; this does not include the 2 minutes warm-up.

    1. DO use your turntable. Despite what you and I have both read, you do need the turntable. Glass wants to be evenly heated just like in a regular kiln and the turntable helps to ensure this.

    2. A “cold spot” in your microwave kiln’s top (hood) can also cause your glass to crack. A “cold spot” is where a chip of the black granite is missing thus not allowing the heat to reach that specific area causing not only uneven heat distribution but also the design facing that spot to not fuse properly.

    Yes, glass thickness, the type of glass, the number of layers, etc. in the MK has an affect on how long it will take to completely fuse a design.

    Your glass slippage is generally due to unbalanced layers of glass. Heat pulls or draws glass and if it is unbalanced will draw that unbalanced piece down and away.

    The glue you are using is probably fine but, if it is not completely dry, your piece will crack.

    Follow the instructions I have given you and you should be okay, assuming it is an 800-watt microwave.
    • Warm-up 2 minutes at 70%
    • 4 minutes on High
    • Gradually peek and add in 30 second increments
    • Do not remove the MK from the oven without venting it for at least 10 minutes. This can cause shock to your glass also.

    Looking forward to hearing from you with positive results.


  3. Hi Sam!

    I'm happy to find this site as I just watched a YouTube video about fusing glass in the microwave using a microwave Kiln. I'm going to do some more research before I invest in this though.

    Do you recommend one brand of MK over another?


    Sally Wooten

  4. Hello Sally, so happy you found my site. As a glass fuser and instructor, I always like to test products before I recommend them and in this case, it is the MicroKiln out of Canada. I have worked with this particular MK and others over the course of 2 years and have found the MicroKiln to be the best thus far and have become one of their US distributors. In addition, the step-by-step instructions you receive with your MicroKiln were written by me an end-user. In addition, if you purchase one of my MicroKilns, you would be free to ask me directly any questions regarding its usage in the design of your jewelry.

    You can find information regarding the MicroKiln on my Designs by Sylvanye Glass Studio website at,

  5. Where can I purchase the MicroKiln that you speak about? It sounds like you have done all the testing and can help if we have any problems. Can you give me some information without me having to go out to different websites and search for it. Can I purchase a Microkiln from you and if so what all do I get and what is the cost.


  6. You can purchase the MICROKILN directly from my homepage website at or Cut & Paste this link into your website browser:

    Yes, I have been testing microwave kilns for a while now and know that the MicroKiln can do all as advertised.

    The cost of the MicroKiln from my website is $125 USD (largest microwave kiln sold in the US) and comes with the following:
    - 5 Sheets Fiberpaper
    - 1 Fiber Shelf
    - 1 MultiPen fusing-enamel paint
    - Instructions for firing jewelry using an 800 - 1100 watt microwave oven

    Shipping via USPS and no more than $13.00 if shipped within US
    Payment can be made via PayPal or via any major credit card.

  7. I have a dark discolored spot in the bottom of my kiln, the next piece I fired kind of exploded all over the kiln. Have I ruined it?

    1. No you have not. Just fire your designs using a 1/8" thick fiber shelf and 1/32" fiber sheet and you will be find. In fact, in most cases the bottom of the shelf will turn back white.

  8. Hi there,

    I have just purchased my second Microkiln (this time a medium size) as I thought I had ruined my first one by sanding a few burn marks off the bottom. After that the shelf paper kept burning. However after trying my new kiln today I am having problems with the shelf paper burning still. This happens after warming the kiln on 400 w for about 4 minutes. I thought it might be the microwave so I tried another one but got the same result. The shelf paper I am using is Bullseye thinfire which I used before with really good results. I really cannot understsnd why I am unable to heat the kiln without the shelf paper burning miles before the glass shows any sign of melting. I am absolutely flumaxed and would appreciate any suggestions.

    Thanks very much.


  9. Jannie, not to worry. You are not doing anything wrong and there is nothing wrong with your kiln or fiber paper. Fiber paper contains a sugar binder that must burn away which causes the paper to turn a burnt black and then back to white again. Many times in a large glass kiln and especially if you peek just at the right time you can actually see it catching on fire and even flaming. So everything is okay, you may need to length your fuse time or if you peek sooner like you did just close the door and extend the time in 30 second increments until your glass has fused - don't worry about the fiber paper at all you are using the best kind.

    In the meantime, keep track of the total number of minutes/seconds it took to fuse your piece and use that total number of minutes/seconds the next time you fire a design of the same thickness, size and glass type.

    I hope this helps, please keep me informed.


  10. I seem to have samples of all the Bad, ugly photos above : (. Is there a way to write next to your photos what went wrong by chance? I fear by the time I figure this out on my own I'll be old, broke and in need of a new microwave and kiln. LOL


  11. Marti, sorry it has taken me so long to respond and I hope the explanations of the photos above prove beneficial.

    Thank you for your comments and suggestions.


  12. Can you use a silver plated or silver finding in a microwave kiln? I was thinking of putting a bail sandwiched between the glass so it fused into the piece (better than glue?) but was unsure if you can put metal in the kiln as you cant in a microwave

    1. If you want to fire a metal finding between the glass you need to choose fine silver, copper or high fire temp wire. I do not recommend firing sterling because it will turn black and create a lot of firescale.

  13. Hello there. YES you can fire metal in the microwave kiln, in fact I fire and sinter PMC, Art Clay Silver, fine silver and copper wire between my glass all the time; however I don't recommend firing sterling because it will form firescale and unless you don't mine cleaning up fire scale.

    If you do fuse using sterling or copper, just make sure your top pieces of glass is not transparent so the black firescale will not mare the look of your design. This also goes true for copper but not as bad.

    If you want to fire metal bails between glass, I recommend using fine silver strip, cutting it to length and using a pair of round nose jewelry pliers to turn the bail end - it works great and looks very professional.

    I hope this helps. "Sam"

  14. Hi
    I just had a piece of glass fall off the paper in my fuse works microwave kiln. It has melted onto the exposed part of the kiln base. If I can get it off is there a way to salvage the kiln base? Or do I need to buy a new kiln base?

    1. Yes you can salvage it by scrapping off the damaged portion and either using a durable fiber shelf to cover and fire with or purchase the MicroKiln Repair & Recharge kit which will repair both the top and bottom portions of the kiln. I sell the product on my homepage @

  15. Hi,
    Is the MK capable of firing terracotta clay? or does it not get hot enough.


    1. Jon, I fire high fire ceramic clay and it works great for that. Not sure of if Terracotta fires hotter. If not, it should work.

  16. all the kiln does is turn my paper brown and does not melt the glass

    1. You are not leaving your glass it in the kiln long enough. The binder burns out of the fiber paper thus causing it to turn brown and then it turns back white again.

      I hope this helps otherwise, please contact me again.

  17. There is a sugar binder in the fiber paper that keeps it together as a solid sheet until fired. The brown you see is the binder burning away and once it is completely gone the fiber paper will turn back white and the fusing of the glass generally begins - in other words you are not letting the glass fire long enough. If you have any other concerns, please feel free to contact me via my email address @

  18. Also Sam I forgot, is it important to use the fibre kiln shelf, am I right in saying that is the thicker felt stuff that goes under the fibre paper?

    1. You are right but it is only 1/8" thick and can be used several times before having to throw it away.

  19. Is there a product for just repairing the base of a mcrowave kiln?

    1. Yes, Jennifer their is and it is called, Microwave Kiln Repair & Recharge kit which repairs the top and bottom of the kilns. However, there are two other options. 1) You can take some sandpaper and stand down and level the hole with the platform base or like I do 2) Fill the hole in with some ⅛" fiber paper then use a piece of the same as a shelf and afterward lay your fiber paper on top of this. Hope this helps --- Sorry I am just seeing the info request for the first time on my system; don't know what happened.

  20. Hi here. My first try at fusing glass was a disaster. I am using the large Fuseworks kiln. I must have fired it too long because it caught fire and disintegrated. Now the interior is coated with a white film. Am I a kiln killer? What can I do to save the kiln? Can I repaint the interior with graphite? HELP!

    1. Joan, all is not lost but I am a little confused by your statements and clarification would really help me certain the best method for helping you repair your kiln.

      "it caught fire" - what caught fire; the glass, fiber paper, etc.?????????
      "disintegrated" - the glass, fiber paper, etc.????????
      What were you firing?
      What wattage is your microwave?
      What speed or temp were you using?
      Is the white base of your kiln in tact?
      Please send me a pic of the inside of your kiln to: and I will respond once I receive your answers and pic.

      Not to worry, you did not kill your kiln........ "Sam"

  21. I am trying to use small slumping molds in the microwave kiln but the glass always cracks. Any suggestions?

    1. What type of mold are you using, ceramic or stainless steel? What the of release are you using? When does it crack - while still in the mold or after it comes out.

  22. Hi there! Very interesting stuff, and I love your designs! I saw the comments about firing with metals, and I was curious if gold and silver leaf/powder are safe to use in the microwave kiln? I figured I would ask someone with some beautiful accomplishments and quite a bit more expensive than me. Thanks in advance for any help you can give me, and keep up the great work! :-)

    1. Yes it is. You can fire it just like you would in a conventional glass kiln and as far as that goes you can also fire metal like copper between glass to create a bail as well as metal clays.

      Hope the information provided helps. Checkout and join the Facebook Group, Microwave Kiln Glass Fanatics and there you will find additional information regarding microwave kilns, metals, molds, etc. that are used and much more; just do a search. Also LIKE my Facebook page, Designs by Sylvanye Glass Teaching Studio and their I talk about the MWK and also offer giveaways.

  23. I suppose the glass got too hot because my kiln started making popping noises after I took it out of the microwave and when I looked it had turned into a big brown blob and part of it got onto the kiln base. I tried using a knife to scrape off the glass and it got most but not all. Also, now the base is just slightly bumpy. Will glass residue and a slightly bumpy base affect future projects?

    1. First, don't take your MWK out of the microwave until it has cool down. You can crack the microwave door open to speed up the cooling. The popping is coming from the inside of the kiln getting too cool to fast and can even cause the side walls to crack - this even happens with conventional glass and ceramic kilns.

      Not sure what turned into a brown blob - was it the fiber paper and glass or just the glass. You can still use your base by either filling in the cracks with my repair and recharge kit for MWKs or use sanding paper to level out the hole with the base and starting again or as I do; fill in the cleanup hole with some ⅛" fiber paper then use same as a shelf over the hole followed by your regular 1/32" fiber paper. Please let me know if this info helps you.


  24. A dichro piece blew up in my kiln and there is glass melted to the side wall. How can I get it off without destroying the kiln? Thank you. - Phyllis

  25. Hello Phyllis, unfortunately you have to use the graphite & binder repair & recharge kit to repair the damage. If it were the bottom/base of the kiln I could help you correcting the problem without having to purchase the repair & recharge formulated white paste for it.

    In the meantime, you will need to gently pluck the glass off and fill in the gaps with the graphite/binder kit. My company is the only one I know of that offers this kit which can be found on my website @

    Although it is not shown separately, I am now offering the repair & recharge kit for repairing cracks and holes in the hood without having to purchase the base for only $40 plus $8.75 if you reside in the US otherwise I will have to quote you a corrected shipping charge.

    Since it is not listed as yet on my website you can either purchase it using your credit card directly rather than through Paypal or send payment to my Paypal account @ If purchased I will send you a confirmation along with a copy of the invoice and instructions on use. The kit would be mailed out via USPS Priority Mail the very next day.

    If you would like to discuss further, you can call us at 615-397-6406 and ask for Sylvanye nickname "Sam"

  26. Love your informative site. Are you saying there should be 2 pieces of micro paper beneath the glass? I have been putting down just one single sheet of kiln paper. It leaves more of a pattern on back side of piece than I expected.I'm new to this but very excited about the whole process! Your blog has given me the most information. Thank you Sam for taking the time to help us 'newbies' out!!

    1. Hello there. First I recommend that you purchase a piece of ⅛" thick fiber paper to use as a shelf; then atop that place your regular fiber paper. Your MWK base needs to be protected just like in a conventional glass kiln. It protects your base from any mishaps. Let me know if I can be of further help.

      Have a great holiday and bring the New Year in with a BANG!

  27. Can I put mirror glass in my microwave kiln?