What is Mica? - "Mica" is a plexiglass like mineral mined in a handful of locations around the world.
What is Isinglass ? - Another name for Mica.
Why is Mica used for stove windows? - Mica is tranparent and withstands high temperatures to around 600 oC. Also Mica is flexible and can be used for curved windows.
most frequent question......
My stove has a large window made up of several panes, is this one single sheet of Mica? - very unlikely, most antique & vintage stove windows are made up of a number of individual panes, each pane will have it's own individual piece of Mica .
But my stove has one large single window pane, is this mica ? - probably not. Over large areas of about 125 x 125mm or larger, Mica doesn't have the strength to withstand the normal working conditions of a stove. In most cases large areas are heat proofed glass.
Do you cut the Mica to size for me or can I do that myself ? - It is very simple to cut Mica, just mark out the shape and cut with a good pair of household scissors.
What holds the Mica in place? - The door window has an inner window frame which is held in place with screws or nuts & bolts. The Mica is either laid or tacked in place, then the inner window frame is screwed onto the back of the door, firmly clamping the Mica.
Do you recommend a Mica fixative? - Without a doubt, as often the clamping frame does not clamp all of the individual panes firmly, so a Mica fixative will solve the problem in these cases. We use Mica fixative every time we replace Mica as it allows us to know that the clamp seal is 100%, plus it is excellent in helping to stop the Mica sheet from sliding when making the final assembly. The 17ml Thermocoll tube has an extended fine nozzle, which is perfect for running a precise bead of fixative exactly where you need it on small panes of mica.
Can I replace the Mica with heat resistant glass? - In the main no, you have to stay with Mica. Often the inner and outer frame are built to clamp the standard thin (0.12 - 0.15mm) Mica sheet in place and for thicker glass it is not possible to clamp. Plus...many of the classic and antique stoves have curved windows, Mica can accomodate the curves easily, glass has to be specially cast to suit each pane.
Why are the larger sizes of Mica sheet proportionately more expensive? - The larger blocks of Mica are much harder to mine and to peel the large sheets from, so they command a premium price.
How long does Mica last? - In the main Mica doesn't deteriorate with age and often we remove pieces that were fitted maybe 30 or 40 years ago from a well cared for stove. In some cases where a stoves has seen little use we have probably removed the original Mica panels fitted maybe 70 or more years before on first assembly! Mica will wear with intense use, having sharp objets pushed into it etc, but normally if a stove is little used it should last for decades.
Does it matter if there is a hole in a part of the mica window? - Yes. This will allow air into the fire box that is not controlled and in a position that may not be suitable for correct combustion.
How do you keep mica windows clean? - Sometimes this is difficult but try not to clean too often if possible. We use Marseilles soap for all our stove cleaning jobs including the mica windows as this is a gentle fairly pure traditional soap that was used for generations in France, and it still appears to work. If you can't find this we always have a few blocks around for sale. The best method of keeping windows clean is burning quality fuel at a medium burn for about 30 minutes in every 12 hours or so as this creates a form of self cleaning action. If you are using non seasoned wood or a non premium coal/coke it will be harder to keep windows clear.
If you have any other Mica questions, please ask and we'll try to give you answers ~ firstname.lastname@example.org