Muffle stove with your own hands - is it possible?

This article will be interesting to those readers who like to do something with their own hands. For example, people who sculpt different figures from clay and do not know how to dry them. They just need a muffle furnace for baking ceramics. This article will tell you how to make this device yourself.

For working at home, the electric version of the muffle furnace is more suitable. You can buy a ready-made unit for laboratories in a specialized store, but a muffle furnace made by your own hands is the best option. Factory furnaces usually have small dimensions, and on your own you can make a device of any necessary dimensions.

The variant, which will be given below, also has a not very large interior space. But this scheme is given for a fundamental understanding of the design. According to this description, a muffle furnace can be made by the hand of any desired size.

The main part of this device is the working chamber. It needs to be made of refractory clay. Homemade muffle furnace, more precisely, its working chamber, should have a wall thickness of at least 10 mm. Its internal dimensions are 210 × 105 × 75 mm. In order to fashion a muffle, it is necessary first to make a mold from cardboard.

Instead of the form, you can use a box of suitable dimensions. Preliminarily it is impregnated with stearin or paraffin. After that, you must apply clay from the inside. If you decide to coat the form from the outside, then when drying in the walls of the muffle, cracks may appear - in fact during it the clay gives some shrinkage.

Of the same material, you need to fashion the ceramic part of the door. These details must first be dried in the open air, and then - at +100 degrees. After that, they are burned, bringing the temperature to a mark of +900 degrees. The firing can be performed in the furnace of a home oven. It is necessary to get the parts only after they have cooled down, so that the clay does not crack because of the sharp cooling.

Ready-made doors and muffles should be fitted to each other. For this, the parts are neatly filed with a file and sanded with sandpaper. Then a winding of nichrome wire is wound on the working chamber. Its thickness should be 0.75 mm, and the length will be approximately 18 m. Naturally, if the muffle is large, wires will also be needed more.

When winding it, it is necessary to maintain an equal interval between turns and to cover these spaces with clay. When the first layer dries, you need to smear the second time with the same material, adding asbestos crumb to it - so that the thickness of the coating is about 10 mm. In addition, it is necessary to short the first and the last turns, so that the winding does not spin during operation.

When the heating element is fully ready, it must be placed in a housing made of millimeter steel sheet. For this working chamber, the outer dimensions of the body are 270 × 180 × 180 mm. To make it easier to assemble the body, it is better to make the front and back covers removable and fix them with screws. Then the door is fixed - so that it will recline in the horizontal plane.

The nichrome wire is drawn to the back cover of the case, its ends should be insulated with ceramic insulators ("beads") and attached to the connectors of the pin shape. These elements can not be bought, but taken from unnecessary electrical appliances. In this case, the muffle furnace, made by hand, will be cheaper. To connect the electrical network to the connectors, you need to connect a standard cord equipped with a plug.

The space that remains between the body and the heating element should be filled with asbestos crumb. Also it is necessary to provide the grounding of the case. To muffle furnace, made by hand, was more convenient, in the door make a window through which you can watch the ceramics. This hole is closed with a metal latch.