Station: [22] The Tank Enamelling Furnace


Once a container has been welded, the interior has to be coated with a layer of enamel. Take a look at our model to see a demonstration. A milk tank is to be enamelled in the enormous furnace. First, you need to apply the enamel powder to the inside of the tank.

There’s an opening on the left-hand side of the milk tank – the "manhole". Even these days, a worker, wearing a respirator and equipped with spray gun, has to climb into the tank through this opening, in order to apply the enamel coating. Once the job’s done, he climbs back out of the tank, and the initial firing process begins.

The container is moved into the furnace and set down. Then the furnace is closed and heated. The enamel is fired at between 800 and 840 degrees Celsius. Depending on the size of the container and the thickness of the sheet metal, the firing operation takes between six and eight hours. Then the container is removed and cooled over a period of several hours. After that, the second pass begins: a worker climbs back into the tank through the manhole, applies the next enamel layer, climbs back out, the tank is moved back into the furnace, fired, then cooled...

At least five such passes are required before the coating is thick enough and sufficiently resistant. It’s a time-consuming job, but in the end, you have a high-performance product that meets the needs of industry.

All depictions: © Hüttenmuseum Thale