What does tar water do?

It makes the water more viscous, increasing the surface tension on the water. The more viscous the water becomes, the less likely it is to flow smoothly. The more viscous the water, the more you risk splashing, so it’s best to use higher quality, long-lasting products that use natural ingredients.
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But it can do more. It can help remove dust and dirt, making the water less susceptible to bacteria, fungus, algae and other unpleasant stuff. It also helps prevent freezing and thawing because it helps cool your water to what it is before the freeze/thaw action.

Why does tar water work?

Tar water is often used when some of the other products don’t work.

How does tar water break down?

When it’s boiled, tar water doesn’t turn to a thick, dark solution. The dissolved solids in the water, called solids to liquids ratio, changes. These solids will dissolve into the surrounding fluid, making the water thicker. What makes this worse, is that water often contains dissolved solids, such as potassium thiosulfate. Potassium is a natural antifreeze, which helps lower ice point temperatures in your water. It is found naturally in the food that we eat – salt is sodium chloride. So it’s natural to expect people to be exposed to potassium while consuming water containing potassium. This occurs naturally. It is also one of the factors leading to water freezing and thawing in the first place. The same thing with soap: The solids in soap dissolve, forming a solution. So when that solution freezes, it causes the soap particles to crystallize around them, making the soap a thick, gooey gel. However, once that solids are separated from the soap, it will dissolve when combined with water. Some people have the perception of the water being thicker when using tar water, but that’s actually because they’re only using a tiny bit of the dissolved solids, and so it seems they have more ice cold water in their system – but it’s just a slight increase in liquid volume.

I think we get the idea that tar water has more antifreeze benefit, but what does that mean?

It’s similar to using vinegar to keep the ice cold. If the vinegar dries over time, you’re left with a thick, gooey gel that has a high concentration of solids and so you can’t easily remove or wash it in water