Visual Effects of Corrosion Prevention

QED regularly tests the chemicals used in the manufacture of Margel corrosion inhibitors, we also have testing from independent laboratories demonstrating how effective Margel is in protecting steel.

We are often asked how to demonstrate this and have found that a very simple demonstration can prove the fact that Margel will protect steel in air without any direct inhibitor contact with the surface of the steel - proving the vapour phase nature of Margel and also the dispersal of the vapour within water.

A test in the pictures below visually shows the chemical working as a highly effective steel corrosion inhibitor;

In this test 2 glass jars were taken with a small amount of water in the bottom, steel nails were suspended from the lids. The jar on the left has a small qty of Margel in the air space, clearly not touching the surface of the steel, the jar on the right side has no corrosion inhibitor.

This picture clearly shows that after 9 months, the nail without any protection (LHS) is corroding significantly whilst the nail protected by Margel (RHS) has no corrosion.


The same test using an expiremental expanding foam containing 5% Margel; photo shown after 1 year of testing.


25th March 2008 - after 1 month of testing (the same sample as above is shown)


34 years on and Margel is still providing protection to the steel surface!!!

Some original nail tests were carried out as a simple example to prove how Margel 580 works, these were sealed in test tubes in 1983, these pictures were taken in 2010 - 27 years after being sealed. The cork has since dried up and the Margel from the top test tube has long since evaporated. But, the protection can be clearly seen, as the nail in the top tube still has a shiny surface area of metal showing and shows no signs of delamination. The nail in the 2nd tube was sealed without any corrosion inhibitor, this corroded significantly and has expanded to almost 300% of its original volume with no structural integrity left. Whilst this is not re-inforcement bar in concrete, it proves a very simple demonstration of the long term protection given by Margel corrosion inhibitor. Imagine if the nail was a rebar in a concrete structure or was the exterior surface of an oil pipeline - with Margel the structural integrity would remain intact - without - structural failure would be inevitable. 

Nail 03-09-95 vpi small

Above picture - this nail was sealed with a small qty of Margel in 1983

Below - this nail was sealed with no corrosion inhibitor in 1983

Nail 03-09-95 no vpi small

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