Preparation of Structures

For maximum result in hot dip galvanizing with minimum cost, we advise to read these recommendations regarding preparing surfaces for galvanizing.

A precondition for good results in galvanizing is clean steel surfaces, thus prior to the galvanizing process the articles are cleaned in an acid solution. Usually iron and steel articles are covered by rust and rolling scum.

Usually iron and steel articles are covered by rust and rolling scum. These can be removed in the acid during pickling process. 
Yet in some cases articles are covered with other coatings or scum, for instance, paint, lacquer, oils, and welding slag. Those not always can be removed by pickling. 
Therefore clients shall clean surfaces of such articles by themselves, unless an agreement is reached that it is performed by Baltic Zinc Technics as a separate service.


Paint and Lacquer

Upon receiving an article consisting of several parts, galvanizer assumes that such an article shall be galvanized as a whole. Therefore it is not desirable to attach varnished or painted structure parts to unpainted parts. One of the best cleaning methods is by shot blasting, while small size structures may be cleaned mechanically.  

For cleaning small size articles different paint dissolvents can be used, but they are not efficient for all paint types.


Paint should not be used for marking steel structures.

The best marking is stamping or using ofsmall size steel plates. Natural chalk can be used, yet crayons shall be avoided.

Oil and Fat

Layers of oil and fat, depending on the volume, may be removed with a dissolvent, fat removers or hot water.

Smaller areas are cleaned with cloth saturated with cleaning detergent. Big size structures are cleaned by pickling them into the respective substance. For cleaning oil and fat it is advisable to use burning furnaces or natrium hydroxide.


Welds should be compact, free of pores, to avoid formation of acid traps.

In case welding electrodes are used, slag deposit should be removed from the weld. It is not possible to remove welding slag through pickling, and thus slag-coated places will not be covered by zinc coating.