How scale and roll can be effectively removed?
Scale on a large surface can be effectively removed by sandblasting or flame firing. Washing with acid stains is also effective. Small surfaces can be cleaned with rotary grinders. Sandblasting with sandpaper and cleaning with a steel brush is usually ineffective.

New, the untreated surface of the steel sheet was protected against corrosion by grease. How to remove the fat layer before applying a new protective coating?
The steel surface can be cleaned of grease:
1) organic solvents, for example. with a nitro solvent with the addition of hydrocarbon chlorides (such relationships, jak trichloro- i perchloroetylen, For the sake of health and environmental protection should be avoided);
2) alkaline agents, then rinse with clean water;
3) cold cleaners, then rinse with clean water;
4) hot water or high pressure steam with fat dissolving additives.

A description of the technological design of the painting protecting the steel bridge is being prepared. What parameters must be given, so that the tenderer can obtain certain information about the current condition of the bridge?
The preliminary description of the bridge painting technological project should include:
1) characteristics of the old coating, depending on the type of its binder;
2) the thickness of the layer of the old coating;
3) age and condition of the old shell;
4) the degree of adhesion of the old coating;
5) the degree of corrosion;
6) degree of blistering;
7) type and degree of soiling.

Steel sheet frames are to be varnished with gloss. Mechanical damage was found on the surface. Please list the steps that make up the protective coating one by one
These steps are as follows::
1) sanding the undercoat layer, grinding mechanical damage, rough grinding of corroded places, cleaning the substrate;
2) priming with alkyd paints places treated with an anti-corrosive agent;
3) filling the damaged areas with an alkide resin mass (putty);
4) painting with alkyd varnish,
5) top coat with glossy alkyd varnish.