Application / Process
PRE-TREATMENT OF THE SUBSTRATE
VeroMetal® offers composite metals which bond with the substrate in a very elastic way. The strength of the bond and therefore the quality of the final piece depend on the correct pre-treatment of the surface of the work piece.
Target of the pre-treatment is to achieve a smooth, dry and residue-free surface. Processes like degreasing, grinding, tumbling and blasting can help to remove surface impurities like dust, humidity, oil or solvents.
In case of porous substrates like wood or gypsum cavities or holes can be treated with fillers in order to reach a better surface quality. Borders and edges should be ground in order to allow a better polishing of these areas later which will improve the desired decoration effect.
SPRAYING OR CASTING OF THE COMPOSITE METAL
The composite metal consists of three different ingredients: metal powder, binder and hardener.
The mixture of the ingredients is casted or sprayed on the substrate at room temperature. The desired effect and the necessary final treatment define the thickness of the layer, which normally varies between 80 and 150 micron.
After the spraying process the work piece should rest for approximately 60 minutes. Then the work piece is dried for 6 - 12 hours at a temperature of 20-60°C. Afterwards the surface is ready for the next treatment steps.
The dry substrate has a mat surface which shows eventually some uneven parts and an oxide layer, which is due to the chemical reaction during the hardening process. Blasting or grinding will remove the reactive layer as well as uneven surface areas. The function of the mat metal surface is now perfect.
The composite metal can be treated with various processes: additional blasting, grinding, polishing (high gloss or mat), semi-bright brushing, oil grinding, machine treatment or engraving result in surfaces of a different smoothness, brightness and structure.
An acid treatment with different solutions causes a chemical change of the metal surface within a few hours. The following effects are possible:
■ Blackening of bronze, brass and copper
■ Corrosion of bronze, brass, copper, nickel-silver and iron
■ Corrosion (Rust) of iron