- January 2, 2011 at 3:15 am #9532Hypnotoad88Participant
I am trying to figure out why the small projects i have fired in my new microwave kiln all have rough and edges to them.Is this usual? I purchased fused glass earrings at a Heritage Festival back in august,and they had beautifully rounded edges and sides.,Id ike to try to acheive the same thing.The pieces Ive fused have thinner,flatter rought edges .Also,what would you recommend to smooth the rough edges? since I have a small kiln and am very new i just fired 2 sets of smaller earrings and a small pendant.the kiln and glass i am using came with the Fuseworks begginers kit. the class says its COE 90, the earrings are made of 3 layers of glass the bottom layer is 3mm thick the top two are 1.4 mm i beleive. the kiln was in the microwave w.microwave on full power for 3 min then the glass was allowed to cool in the kiln for 50 minutes.
thanks,January 4, 2011 at 9:10 am #11820Stephen RichardParticipant
There are a number of reasons for the spikes on the edges of kiln formed glass. Without a picture it is difficult to help because so many assumptions have to be made.
If the edges are spiked the classic reasons for that are: a make up of less than 6mm, firing too hot, firing on fibre paper or batt wash rather than thinfire, glass touching something during the firing.
If the edges are rough -as opposed to spiked – the classic reasons are: ground edges without proper cleaning, thinfire curling in and leaving a deposit.
There are, of course, other reasons, but these seem to be the most common.
I have assumed you are using fusing compatible glass. If not, then there are a whole range of other factors that can give difficulty.
Othere have more experience than I do with microwave kilns, but I think you probably are too hot in your firing.
Stephen RichardJanuary 6, 2011 at 6:25 am #11821Hypnotoad88Participant
I use the Kiln paper that came with the begginner kit,i do not know if the kiln paper that came with the kit is “fiber paper” (doesnt say on the box) after firing the paper has a cotton like texture.
I haven’t used any kiln cleaner im not sure if the microwave kiln needs to be cleaned i looked up batt wash online ive never used it
The glass is fusing compatible its all COE 90 and the projects are composed of a few layers of glass definetly thicker than 6mm.
I may try to reduce the power on the microwave and exend the time to see if maybe heating the glass more slowly helps.I cant think of any way,really,to control the temperaure in the microwave kiln aside from reducing the microwave power…I will also try to wash the glass before using to see if that will make a difference.
Can i use a dremmel tool or some kind of buffer tool to smooth the edges ,something i can pick up @ home depot or is there a special tool I’d be better off getting?
your input on this problem is definetly appreciated!!! I will try to get my computer camera working to add a pic of the rough edges which keep occuring.
****….im writing this about 3 hours later than the post above… Success! I started our 1100 watt microwave out @ full power for 2 min,then set it @ half power and microwaved the kiln in increments of 30 sec until the glass seemed like it was fused to the extent i wanted. the edges of the project i tried this with came out smooth and beautiful.This seems like the most successful approach yet to work w/this kiln. Thanks again for the advice about the temperature!******January 6, 2011 at 9:21 pm #11822Stephen RichardParticipant
It shound likethe kiln paper you used is not the smoothest available- it is Bulllseye Thinfire. It looks and feels like cartridge paper.
vacuum on low suction should be enough to clean the kiln. Do not damage the interior of the kiln by knocking it or sucking at the insulation.
Yes you can use the sanding and buffing attachments for the dremmel. Be sure to keep everything damp, for your health and the health of the glass – heat buildup will break the glass. The buffer should have something like jewellers rouge or cerium oxide as a paste to polish the edges. It is messy.
Glad you have found a way to begin controlling the heat.
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