Heat treatment of steel parts annealing, quenching and tempering is possible only if the bugle or muffle furnace. Last is the best allows thermally treated any metal parts, as well as to produce a tool items to homemade designs, etc.
Basis of a small muffle furnace is from the usual round ceramic hotplate. Furnace equipped with a spiral made of wire or brand OH27YU5A OH23YU5A. The length of a spiral wire of 16 m wire diameter of 0.75 mm. At the same muffle furnace will have a capacity of about 1.2 kVt.Esche can do much prosche.Naprimer taking regular household electric oven and make kolpak.Bolee details read the full news.
Products from raw clay will be durable if they burn. This requires an oven at 950 ° C. Today we`ll show you how out of household electrical tiles make a muffle furnace. By the way, it can be used not only for ceramics, but also for the heat treatment of steel products, tools, smelting of many metals and alloys.
Look at the picture. Bottomed on the tile up a cylindrical cap. He also has set up a working camera. The hood is shown in cross-section, however clearly visible layers of which it is composed. The inner layer forms a deep cup of refractory clay grog. Clay you can get in small boiler, where it is used to wash boilers. The cup is made in the form of cardboard soaked in paraffin or stearin inside to form from sticking. Clay layer thickness up to 10 mm.
When the clay is dry, she easily fall behind the walls of the mold. Ready cup should firmly stand on the hotplate. That there were no gaps, bottom edge treat a file or a knife, and then sandpaper.
The outer layer forms a protective cap cover. Cylindrical shell and cover cut from sheet steel 0.5-0.8 mm. At the bottom of the cylinder should provide tabs - their cup will rely on the tile. The cover is attached to the cylinder with three screws and nuts. The cover is necessary to drill a few small holes for the moisture. For greater reliability of fastening set for T - shaped spacer plate. Lower ends, it rests in a ceramic cup and horizontal shelf - in the housing cover. All remaining space between the cup and cover tightly should fill asbestos tailings. For convenience in the oven should have a peephole with a shutter closing. Hole forms a tube of refractory clay diameter of 15-20 mm. Remains to be done on the case of two handles wire diameters of 5-6 mm.
To give the necessary cup thermal stability, it must be burned. Establish a cap on the hotplate.
Attention! All further work enabled tiles require compliance with safety regulations. Tiles must stand on a thick Asbestos-cement based tile or more. If you find the base of this, an electric hot plate set on a steel sheet that can draw on the table ceramic rollers. The gap between the table and the sheet must be at least 20 mm. Now you are ready for baking cups. For a short time to spiral heating turn tiles into the network, and then turn off. Repeat this operation for two hours. Turn tile for a longer time about three hours. During roasting dish can warp a little, and then formed gap. During firing slits reload asbestos cord. When the inner surface fireclay cup warmed to 950 ° C, then there will be a bright orange color control is maintained through a peephole, the firing is completed. Turn off the tile. Once cool cover identified gap should be removed with a file. Asher is ready.
And now briefly describe how you are made pottery. Clay, which you brought from the quarry, wipe with a fine metal mesh. Then add water and mix thoroughly. Solution, leave to stand for several days. This procedure is necessary to ensure that all solids settled to the bottom. Only if the composition of the clay is smooth. Drain the water and clay should carefully stretch hands on the plywood to obtain a homogeneous viscosity coma. Clay to long maintained their original quality, it is kept in a plastic bag.
But you fashioned from clay products. Wet clay, it should be a bit dry. For a few days deliver goods to the bottom of the pan and cover it with a sheet of paper. This technique will prevent the product from the appearance of microcracks that after firing will increase significantly.
After drying, the surface of products gets trimmed scraper and sandpaper.
An interesting method of obtaining hollow clay products - cast in a plaster mold. Molded from clay model of the original products of the future. The model is set in a box and poured half plaster. Get the first mold part. After hardening plaster model is removed. The same operation is carried out from the second floor form. Clay is removed therefrom and both mold parts are joined. In the resulting cavity is filled with liquid mud. Gypsum intensively absorb water. A layer of clay is deposited onto the inner surface of the mold and exactly copies the shape. However, the model for a simple casting should be done, otherwise it will not come out of plaster form and it will break.
Finished clay figures put on the hotplate and cover cap. Within three hours, should conduct a preliminary final drying, the tiles have turned on and as soon as the spiral is heated, turns off. And only after that products are fired at a temperature of 900-950 ° C.
When roasting in a muffle furnace is advisable to lay pieces of charcoal - emit carbon dioxide will prevent the spiral from oxidation and increase its life.
After firing, the product can be coated with the glaze. Suitable ground glass and silicate office glue. To prepare the glass powder fabricate special stupa of solid steel bar cylindrical shape. Along the axis, drill a blind hole with a diameter of 30-35 mm and a depth of 70-100 mm. In a mortar laid a few pieces of broken glass and a hammer on a steel pestle glass breaks into powder. Each piece is pre-coated with a thin layer of silicate glue, and then collapses in a glass powder. Glazes can be given a blue or green, if glass powder add gouache "Cobalt" or "chromium oxide". Last operation: product again fired at a temperature of 950 ° C.