j_sum1 - 23-4-2016 at 02:10
I was a bit divided on where to post this -- bad days in the lab, short questions... Decided on a new thread.
I had a nice little boil over distilling some nitric acid today and spilled hot saturated KHSO4 solution all over my mantle. It shorted to earth and
flipped the circuit-breaker.
Pulling it apart the glass wool insulation was quite damp and seemed to be what was causing the shorting. I could dry and re-use it but there are
couple of reasons for not doing that.
Firstly the glass fibres seem very short and brittle and not well interlocking -- the material is quite powdery and a pain to work with.
Secondly, I really should wash it thoroughly to remove any potassium bisulfate present. Otherwise I am going to get a melt when the element gets over
200C.
So I am looking for a suitable glass wool or felt to repack the mantle. I have not had a whole lot of success in finding pottery / kiln suppliers
locally and have also had no success in the pizza oven area. I am assuming that standard house insulation is way below the grade needed. I had
wondered about packing the space with fire-blanket material.
Can someone give me suggestions on a readily-available suitable insulation material?
NedsHead - 23-4-2016 at 02:37
Furnace builders use a ceramic wool called Kaowool, I've heard it is available in Aus but I don't know where from or how much it will cost, maybe
rockwool can do the job? it's cheap and easily found at hydroponic shops
Orenousername - 23-4-2016 at 04:48
I am unfamiliar with how the wiring in mantles is done, but if it thin, interlocking wires then i would suggest a carbon-clay mixture. A bit messy
after a while but will hold up decently (does for my crucibles and shat together hot plate anyways)
XeonTheMGPony - 23-4-2016 at 04:56
rock wool I've usedon custom ovens befor and it seemed to do the job well.
NedsHead - 23-4-2016 at 05:15
with a heat resistance of 700-850c I think it'll do just fine https://en.wikipedia.org/wiki/Mineral_wool