MAINTANANCE: SURFACE PREPARATION OF ALREADY COATED SURFACES IMMERSED IN WATER OR IN THE TIDAL ZONE

Steel surfaces
Since steel surfaces are usually covered by fouling, remove it by means of chiselssscrapers and hammers. With the help of chisels and hammers try to remove the degraded coating. Blastclean as foreseen for new surfaces.

Concrete surfaces
Since concrete surfaces are usually covered by fouling, remove it by means of chisels, scrapers and hammers. With help of chisels and hammers try to remove the degraded coating. Blastclean the surfaces to obtain a superficial roughness for a good adhesion of the coating. An accurate inspection to the surfaces must follow in order to verify that there is no uncovered or damaged part of the structure which requires special treatment.

Recommended thickness and forecasted consumption

Recommended thickness for a long-lasting protection is 3 mm. Since application is carried out by hands, it is hard to obtain a homogeneous thickness: usually an average thickness of 5 mm is recommended so that in no spots thickness will be lower than 3 mm. Theoretical consumption is stated in each technical sheet. Said quantity increased by a 10% for possible wastage grants a min. thickness of 3 mm.

Curing time
Underwater: touch dry in 10-12 hrs/ complete curing in 7-10 days.
In the air: touch dry 4-6 hrs / complete curing in 7 days approx. at 2S°C.

How to check the dry film thickness of the applied coating
To check the dry film thickness of the applied coating use a magnetic thickness gauge such as Microtest. For the coating applied underwater check the dry film thickness as follows: engrave the coating in order to have a square pattern of 3cm x 3cm. Remove the small block and check the thickness with a gauge. Seal uncovered steel with ZAMSUB FOR SPREADING.