How to fix a thermos?

Repairing a thermos makes sense only if it is a rather expensive, exclusive stainless steel model designed to last for many years. These thermoses often come with a lifetime warranty, and an authorized dealer with a service center to repair their products would help.

There are two types of caps: with and without a button. The cover with a button can be either collapsible - with replaceable parts, for example, with a removable spring, or with a completely molded or glued structure. The former are easy to disassemble and clean, while the latter are cleaned with powerful reagents that soften food deposits and preserve plastic, metals and rubber. The push-button covers are equipped with a valve.

To remove and disassemble the threaded cover completely, proceed as follows:

• unscrew the ring with the button;
• remove the valve;
• remove the pressure washer and spring;
• remove the oil seal - intermediate ring.

Wash all parts from deposits. What is petrified, stuck tightly, is cleaned with a plastic brush and any detergent, such as abrasive powders for cleaning sinks. Then wash the parts with dishwashing detergent to remove the ammoniacal reagents, reassemble the lid in the reverse order.

Some Chinese thermoses are disassembled as follows:

• using force, pull the valve;
• insert a self-tapping screw into the gap for its top;
• pull out the push-button fixture;
• remove the gaskets, washers and spring;
• rinse the parts and reinstall everything.

If the thermos has stopped keeping warm, then something is wrong with the vacuum between the inner and outer containers. Glass flasks that are cracked in at least one place cannot be repaired. The fact is that a crack is a defect that begins to let air through. Its width is much larger than the atoms and molecules of air that make up the atmosphere. They freely pass even through microcracks, filling the vacuum to normal atmospheric pressure in a maximum of several hours. The thermos is heated from the outside to a warm state, since air, unlike a vacuum, conducts heat.

If you are repairing a steel thermos with your own hands that has lost its vacuum due to a hole, then do the following:

• Drill a hole in the bottom and solder a metal capillary tube into the hole. It is advisable to take copper, such are produced for the repair of refrigerators and air conditioners. Steel is brazed using zinc chloride or other soldering flux - the solder spreads over it evenly, not to mention brazing copper.

• Pump air with a car or refrigeration compressor. Do not exceed 2 atmospheres pressure.

• Find and solder any defects in the case. If the inner flask is damaged, then it is difficult to repair the narrow-necked thermos - it is extremely inconvenient to use a soldering iron in a narrow space. It is impossible to pour sour and salty drinks into a thermos sealed from the inside, as well as store, for example, canned food in an opened can: tin and lead react with acids, turning into salts poisonous for humans. This thermos is only suitable for water. If the defect is outside, and the flask is intact, then use a thermos, as before the breakdown.

• Pump out the air. Check on the pressure gauge whether the pressure in the inter-wall space does not increase after the compressor stops. If so, the hole is not properly sealed. If not, leave the compressor and thermos under vacuum for a few hours.

• If there is no vacuum leakage, the air is not sucked in, it means that the gap is filled with high quality... Bend the tube, squeeze it, for example, with a pair of wire cutters, going over an area a centimeter or more in length. Bite off the excess end, leaving a kink. Air will begin to be sucked in through the micropores of the bend. Until the vacuum is seriously broken, solder the bend and cut of the tube. You need to act quickly - use a flux so that the solder instantly spreads over the cut end and reliably clogs the bend and cut of the tube until the air has completely displaced all the vacuum.

• Bend the tube closer to the bottom. From above, solder an opened tin can without a lid of a similar diameter to the body. This will protect the suction tube from damage, allowing the vacuum to be maintained.

The thermos is restored, you can continue to use it.

In thermoses, a button, valve, stopper and other parts that do not affect the inter-wall vacuum often break. To make a new cork to replace the old one that has no threads, you need a piece of wood. From it, in the image and likeness of the old plug on a lathe (or with the help of a milling cutter), a new one is turned. A rubber gasket is cut from rubber of a similar diameter and inserted into a technological recess (groove). It prevents liquid from spilling out if the thermos is accidentally tilted or turned over.

To fix a button at home, do the following:

• if the button and valve are collapsible, then disassemble the cover - according to the previous instructions;
• if the button is broken so much that it is impossible to glue its parts, then carve a new button from a piece of plastic on the machine;
• put it in place of the broken one and collect the thermos.

The spring changes only to a similar one, with a similar stiffness and diameter.Spare parts can be found by ad or in the economic row of the local market, where they sell all kinds of spare parts from old equipment. Dents in the external vessel are straightened with a hammer from the inside, with the flask removed, and only if the thermos was vacuum-free.

Detailed instructions on how to repair a thermos can be found in the following video.