1906 Rover

Why using a corrosion inhibitor in your cooling system is a good idea.

The usefulness of a corrosion inhibitor

I often feel that I am banging my head against a brick wall when I try to persuade people to use a good corrosion inhibitor/antifreeze.  To illustrate the importance of doing so I set up a little demonstration.

Ten years ago I took a handful of nails (not brand new, they already had some specs of rust) and put some in a jar of plain tap water and the rest in a jar containing water from the radiator of my car, which contained a corrosion inhibitor.  The picture shows that those in plain water continued to rust (while there was still free oxygen in the jar) but in ten years the others have not changed.

In early cars that have gland packing small, sharp particles of rust in suspension work their way into the packing, causing shaft wear and, eventually, leaks.  I have also found that the hard scale that had built up in my cars’ system  before I bought it softened and flushed away when the system was drained.  You cannot reverse any corrosion that has already taken place but you can prolong the useful life of the cylinder block.