On the smoothly blurred facade of the building, covered with plaster made of PIIa mortar, cracks of a dynamic nature and mesh cracks appeared on a large surface.
The old paint coating from dispersion paint shows no damage and sticks …
Cast
Cast
How does plaster bind?
Gypsum is chemically bonded by attaching water. The water lost during firing combines with the gypsum again during its setting after adding mixing water.
Please explain, why gypsum is not suitable for external use…
Thickness of the thermal insulation layer made of expanded polystyrene
Please calculate the thickness of the thermal insulation layer made of expanded polystyrene, so that the partition analyzed above would reach the value of the k-factor below 0,40 W/(m2K). The influence of the adhesive layer and the protective coating on the thermal insulation layer can be neglected here. Thermal conductivity for polystyrene is 0,04 …
Coatings on aluminum
What is the recommended pretreatment of an aluminum substrate?
The aluminum substrate can be pretreated by:
1) manual cleaning with nitro thinner, and then wiping with an abrasive fleece;
2) manual cleaning with a cold preparation, then rinsing with hot water and wiping with an abrasive fleece;
3) manual cleaning …
Painting the roof made of galvanized steel sheet
Large areas of paint peeling off the hot-dip galvanized steel sheet roofing. It is necessary to paint the roof. Please list the necessary steps for painting the roofing. These steps are as follows:
1) complete removal of the old coating by scraping it off;…
Painting galvanized steel gutters
What materials are recommended for coatings on a zinc substrate?
Dispersion paints are suitable for making coatings on a zinc substrate, dispersion varnishes, alkyd varnishes, PVC varnishes, made of chlorine sulphonated polyethylene, polyurethane and epoxy, asphalt, tar-epoxy and special paints with high …
Coatings on zinc and galvanized steel
Please list the causes of problems with the adhesion of coatings to zinc and galvanized steel substrates.:
1. The new zinc surfaces are smooth, oily or greasy, …
Wooden cube in the room
Wooden paving stone is a versatile floor covering. It consists of rectangular or round blocks, which, juxtaposed with each other, create a floor surface with extraordinary load capacity (high abrasion resistance). The faces of the blocks are pointing up.
The use of a wooden cube is possible in …
Spring-operated "separate function" control mechanism, used in fire ventilation cut-off dampers – current impulse control
Spring-operated "separate function" control mechanism, used in fire ventilation cut-off dampers – current impulse control
In this type of mechanisms, the transition to the safety position is initiated by an electromagnetic release that releases the bolt of the spring drive of the damper., while moving to an item …
Control of fire shut-off dampers and fire ventilation shut-off dampers
During normal operation of ventilation and air conditioning systems, fire dampers remain open, Fire ventilation cut-off dampers, however, remain closed. During the normal operation of the facility, both cut-off fire dampers and fire ventilation cut-off dampers, so they remain in a waiting position. …