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Wall elements

Posted: Sat Nov 15, 2014 12:31 am
by Aglassygirl303
I am curious to know what the difference is between using the side elements or the lid. My Olympic Kiln is equipped with both. Although I always use the lid. This is a 186GFELTC and the largest kiln that uses 120, so this kiln can not use both at the same time. Either lid or wall. Is there any reason to use the wall elements? If I use the wall will there be an issue. Reason for asking is that my lid is having issues that we have not yet fixed and I want to continue to produce. Any help is appreciated. Thank you

Re: Wall elements

Posted: Sat Nov 15, 2014 9:41 am
by Bob W

We have the same Kiln, and we started using the side elements after advice from the guy we bought it from, but then changed to the top elements after advice from a glass fusing friend with a lot of experience.

To be honest there did not appear to be a lot of difference in the finished product

From a theoretical point the only difference I can see would be at lower temperatures when the top elements may heat the glass more directly giving a quicker rate of heating while the elements are energized and therefore a marginally (but not worth worrying about) higher chance of thermal shock ..... once the kiln approaches anything like forming temperatures it will be glowing all over the interior and therefore the radiant heat will be much more even. I suggest using a test piece just to put your mind to rest, and fire on the same schedule as normal.


Bob W

Re: Wall elements

Posted: Sun Nov 16, 2014 5:32 am
by Stephen Richard
On the contrary, heating from the top provides a more even heat to the glass.
Heat from the sides heats the edge of the glass first.
Because glass is such a poor transmitter of heat, this difference is important.
Side heat will get the edges of the glass hotter than the center, sometimes enough to cause breaks. Therefore, a slower rate of advance is needed on side fired kilns.
Because the heat transmission is so poor, the edges of a multiple layer piece will seal before the air has escaped from the centre. So, baffles are often required.
Side fired kilns have advantages in casting, and some thick forming.

Re: Wall elements

Posted: Thu Nov 20, 2014 12:44 am
by Aglassygirl303
Thank you. I will have my new lid in a couple of days, whew! In the mean time I attempted to fuse a small 9" plate with a poinsettia in the center...I went with an adjusted schedule, a full fuse, but ramped slowly, 175dph. I still got little bubbles. They when I formed it I got thermal shock. Oh so sad. This was with the side elements. So since then I decided to wait until I have my new lid. I have successfully been fusing small pieces like ornaments for Christmas and pieces for wind chimes. Got caught up on pebbles too, lol

Can't wait to get back to normal production