Camping, fishing, hunting, trips to not too civilized places require appropriate equipment. And not the last thing in such cases will be a thermos.
What is a thermos for
Hot tea in the winter forest, a cup of steaming coffee on a foggy autumn morning – what could be better? Thermos and home useful. It is best to insist herbal teas.
And the thermos is a universal gift. You can give it to anyone. You can choose in appearance and at the price of exactly what you need.
Thermos is not difficult to buy. Their selection is very large. But it is not always possible to buy a quality product. The main requirement – how long the thermos can keep warm. It is also important how reliable the cork is, whether it will leak (and the ability to retain heat also depends on this). And the price also plays a role.
All thermoses for purpose can be divided into two types: for drinks and for food. For drinks – tea, coffee – a thermos should have a narrow mouth, less heat will come out through a narrow mouth. Wide mouth at thermoses for food. In such thermos warmly keeps less.
The volume of the thermos also determines how long it will keep warm.There are some differences for the types of thermoses. For drinks: the larger the volume of the flask, the longer the contents will be hot, subject to full filling. For food it is better to take just such a volume, how much food you will put there. You can not take a large thermos and fill it partially – the food will cool down due to the presence of air. The entire volume of the thermos needs to be filled with food (and preferably liquid or dense), then the food will be hot longer.
What does the quality of the thermos
All thermoses are arranged in the same way: a durable outer shell (metal or plastic), inside of which a glass or metal flask is placed, the shell and flask do not directly contact each other, since connected in the neck area with a special heat-insulating gasket. The inner flask is hot, but between it and the outer shell, good thermoses draw air out to reduce heat transfer.
Cork (often screwed) is also made from a material that does not conduct heat well.
Which thermos is better: with a metal flask or glass?
Glass flasks have one significant disadvantage, which often outweighs all their advantages – they are easy to beat. Glass washes better, a thermos with a glass flask does not acquire an unpleasant smell, it is these thermos flasks that hold the heat better.
Modern high-quality metal flasks are no worse than glass ones for temperature retention. They survive the fall (although it is better not to throw the thermos). But to wash them harder and should not be kept tightly closed – there may be a “musty” smell.
How to choose a thermos when buying
Check thermos when buying impossible. You can only focus on the brand, look at the price, not forgetting that cheap goods are very often not of very high quality.
When buying a thermos need to carefully inspect. If you choose an inexpensive thermos, pay attention to how tight the cork or cap fits to the flask, shake it – is something knocking inside, is the flask moving away?
Inspect the cork for a thermos, it happens to the valve and without it. If the cork is without a valve, it is necessary to completely unscrew the cork in order to pour something from the thermos. Heat loss with a little more. But the valve can become clogged (by welding, for example). The mechanism of its opening is the simplest, but sometimes it is unnecessary problems, as a drink can leak through the spoiled valve.
Check the smell inside. If the smell is sharp and unpleasant – then the thermos is made of low-grade materials, it is doubtful that it will last for a long time.
Finally, you can be sure of the quality of the purchase only at home. To do this, pour boiling water into it. If the thermos is heated in ten minutes, then the insulation of the inner flask is bad, it does not keep warm.