Technical advice on Galvanizing
We know all sorts of tips and tricks to get the best results for your galvanizing . We can give you advice to help you design your work to get the best finish, the least build up of zinc in critical areas and minimal distortion.
Design for galvanizing
Consistently good galvanized steel products will be produced when the design and fabrication take into account the way galvanizing is done. If we can give advice to the design engineer, materials engineer, specifier and fabricator it will ensure high quality galvanized products, minimum cost and faster delivery.
Steel items to be processed must fit into the pre-treatment tanks and galvanizing bath. However, this is not limited to the physical dimensions of the bath, because we can use multiple dipping techniques to galvanize products larger than the bath.
Protection against corrosion begins on the drawing board. No matter what corrosion protection system is used, it must be factored into the design of the product. Once the decision has been made to use hot dip galvanizing the design engineer should ensure that the pieces can be suitably fabricated for high quality galvanizing . Adopting the following design practices will ensure the safety of galvanizing personnel, reduce coating cost, and produce optimum quality galvanizing .
Galvanizing very large items
If your work is too big to fit into the galvanizing bath in one dip then it may be possible to galvanize with double-end or double-depth dipping. This procedure involves lowering the item into the bath so that half or more of its length or depth is dipped in the zinc bath. Once the zinc coating is applied to the first “half” of the item, it is raised from the bath and turned so the remaining ungalvanized part can be dipped in the bath. Please note that in this procedure an overlap of zinc coating will occur and may cause a visible “join line”.
Have questions about whether your work can be galvanized by double-end dipping?
If you have product that is over 12.5 metres in length or 3.2 metres in height, contact our Customer Service team for advice.
Safety for Galvanizing
During galvanizing, improperly designed structures can explode and cause serious injuries to galvanizing personnel. Explosions are caused by moisture trapped inside pockets turning to super heated steam as it enters the molten zinc galvanizing bath.
For the safety of galvanizing personnel and the quality of your job, vessels or hollow structures which incorporate enclosed sections must have provision for adequate venting and draining for galvanizing .
Correct venting ensures that the entire internal surface of work is properly galvanized and fully protected. This also ensures that lighter items will not float in the zinc bath due to trapped air pockets. Closed vessels which are not to be galvanized inside, such as certain types of heat exchanger, must be provided with snorkel-type vent pipes long enough to project above the level of pickling, fluxing and galvanizing baths when the work is fully immersed. Contact our customer service staff for more information on the venting requirements.