Making glass?

[Z/MAN]

I have noticed that the firebricks in my evaporator are turning green and getting very shiny and glossy. Especially the middle ones right under the pan. They actually appear to be turning into glass. My rig runs extremely hot from running all cut off 2x4s and 2x6s. I have stack temps over 1,800 degrees. I know I know that is too hot but that is what works for this rig. I have a 2x3 that gets 13 GPH so I just keep feeding it all it wants. Is it possible that the brick is really turning to glass or is there another explanation?

[mike z]

Doesn't seem possible, but if they start turning into gold, P.M. me and we can forget about all this syrup making nonsense. I've never been to Daleville.

[Woodsrover]

....I have stack temps over 1,800 degrees....

:o

Yikes!

Keep a hose and fire extinguisher close by!

[ecolbeck]

Some cursory research shows that there is significant silica content in firebrick. Silica is the main component of glass. There may also be some trace compounds causing the color (iron oxides maybe?). It seems like temperatures of around 3000 F are needed to make glass unless there are borates present (sometimes used as a lumber preservative but different than pressure treated) which lower the needed temperature significantly.

Sounds like you need a longer arch if you’ve got that much heat on hand!

[Z/MAN]

Some cursory research shows that there is significant silica content in firebrick. Silica is the main component of glass. There may also be some trace compounds causing the color (iron oxides maybe?). It seems like temperatures of around 3000 F are needed to make glass unless there are borates present (sometimes used as a lumber preservative but different than pressure treated) which lower the needed temperature significantly.

Sounds like you need a longer arch if you’ve got that much heat on hand!

I built a 2x5 arch and run it with a 2x3 pan. I did that so that I can expand in the future. I am at that point now and plan to get a bigger pan shortly. Yes, I believe more pan will eat up a lot of that wasted heat.

[ecolbeck]

I'd say that anybody who's arch turns firebrick to glass is pretty bad a$$.

[Sugarmaker]

Yes I second that!
Regards,
Chris