To obtain a high-quality and durable coating, the surface must be prepared before applying the material:

wash and clean from dirt;
remove a layer of old paint;
remove oil stains and rust;
apply a layer of primer with an anti-corrosion component.
Only then is it time to start staining. Acrylic guts.pk/shop/category/art-supplies/acrylics/ compound can be used to paint a fence made of corrugated board, galvanized metal, cast iron, non-ferrous metals. Any tools are suitable for work: brushes, rollers or a spray gun.

The material is practically odorless and has no toxic constituents, so only splash protection is required. The composition is easily washed off from hands with water.

Rubber paint - unexpected but possible
Acrylic emulsion based on water dispersion with synthetic acrylate latex. Aluminum, galvanized and ordinary steel, corrugated board and other types of surfaces - all this can be coated with rubber paint fitnessthrough.over-blog.com/tips-for-working-with-oil-paints.html, providing the surface with a decorative coating of increased strength and wear resistance. Properties:

environmental friendliness and fire resistance;
highest elasticity;
hydrophobicity;
resistance to any external influences, including chemical;
protection against the appearance of mold.
It will be possible to paint a metal fence with rubber paint and get a long-term effect only if:

completely clean the product from rust, oil stains, old paint and other contaminants;
sand to dullness (refers to glossy surfaces);
degrease;
cover with an anti-corrosion compound and an insulating primer.
Painting is done with a brush, foam roller or spray gun. It is recommended to apply the material in at least two to three thin layers, letting each of them dry for 2-4 hours.