To protect the product from corrosion and other negative destructive factors reliably, it is necessary to apply a coating on it. But even coating will not be reliable without the main stage of its application – preparing the surface for powder painting.
We decided to devote this article to the most common mistakes in surface preparation.
Wet surface
It is very important to dry the product completely before painting. If moisture remains on the surface, adhesion will deteriorate. Besides, moisture can cause rust under the coating.
The protective properties and service time of such a product are minimal.
Wet products painted with powder have an awful appearance.
Product can be wet not only if it has been washed with water, but also due to condensation. Therefore, it is forbidden to paint products at high humidity, at a temperature of about +5 ˚С and during warming in winter. Also, be sure to dry the product after cleaning and degreasing.
Bad roughness
A non-rough surface means poor adhesion. Poor adhesion is a short-lived coating. The product can be smooth if rust and other contaminants were removed improperly. Weld seams of metal structures may not be rough. For the coating lays evenly and lasts longer the product preparation to painting should be taken into account.
Dirty surface
Products always have surface contamination. Even if they are stored in a cleanest place. Particles of dust, shavings, oil, scale, rust and cutting lubricants may remain on the product.
And even a small amount of dirt can have a negative effect on adhesion and the final coating. Poor cleaning can cause paint to peel off.
After cleaning, the product must be painted immediately or no later than 16 hours later. If this time has elapsed the surface must be cleaned again.
Rust on the surface
No way painting items with rust! Otherwise, say “bye” to any durability and strength of the coating. Under a layer of paint, corrosion will destroy the metal even more and it will definitely ruin the new coating.
Of course, if you cannot fully clean the product and completely remove the rust, then you can apply a coating. You must understand that it will be short-lived and rust will quickly appear on it.
How to prepare the surface for painting properly
Metal cleaning before powder painting can be done in several ways. And now we will analyze each of them in detail.
For large volumes of work, it is best to equip the paint shop with a whole automated system for preliminary metal preparation. This will speed up the process and guarantee the highest quality cleaning that no other method can provide.