Additive F2M is a flash rust inhibitor (FRI) which is offering several advantages compared to other common competitors:

-Free of nitrites, secondary amines or borates.
-Better tox profile & labelling.
-No negative effect on long term corrosion protection.
-Very compatible, thus high dosages are possible.

Additionally, other products offering some or all of the advantages mentioned above have on big disadvantage in common:

Lacking effectivity!


In this test we compared Additive F2M with three commercially available FRI´s, applied in an aqueous acrylic clear coat.
All products were blended in different dosages into the clear coat and they were applied with 120 μm thickness onto a QD panel.
On top we also put a watch glass to slow the drying, thus making flash rust worse.

The other inhibitors roughly contain the following chemicals:
-Inhibitor N: Sodium nitrite, secondary amines (morpholine), zinc salts
-Inhibitor E: Sodium nitrite, secondary amines (DEA)
-Inhibitor L: Alkanoleamine, borates

Final results:

In the end it was proven that Additive F2M shows superior flash rust protection compared to all other inhibitors. Already 0.75 % was enough while other inhibitors needed at least 1.0 %. In addition they caused negative effects on the coatings film plus the fact that all other inhibitors, except Additive F2M, would have caused worse long term corrosion protection. The dosages of all FRI´s were higher compared to pigmented coatings.

    • Dosages of common FRI´s vs. Additive F2M:

      Only in a very small, narrow range common FRI´s might potentially offer an advantage over Additive F2M in term of efficacy. Never the less it is doubtful that at these dosages sufficient flash rust protection is provided!