Text Box: Roften Galvanizing Limited
Registered Office & Contact Address: North Road Industrial Estate, Ellesmere Port, Cheshire. CH65 1AB Registration No. 1290735

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Text Box: FAQ’s / Common Problems -Page 1


Drainage holes should always be placed at the high and low points of tube sections in a fabrication as it is suspended for galvanizing.  In figure 1 the position of the drainage hole on the side of the tube has allowed zinc to become trapped in tube A. 

Some of this trapped zinc has run out of the hole onto the surface of the connecting tube resulting in an uneven ridge of zinc.

If the hole had been placed on a vertical plane the fabrication could have been hung to allow the zinc to drain completely and smoothly from the tube.   

Position of hole in Tube A   






The picture opposite shows a 5500mm x 2500mm frame made with 100mm x 100mm box section.  The fabricator has positioned the holes in the correct location but the hole is only 10mm diameter.  If the correct hole diameter of 20mm had been used the fabrication would have drained 4 times faster. 

The increased time that the fabrication spent in the bath caused a thicker uneven coating increasing the finished weight of the frame and the cost to the customer.        


Posts under 1800mm are suspended vertically (see picture opposite).  Posts normally have fixing cleats or gate hanging brackets which the galvanizer utilizes as suspension points.  On bollards or posts with no brackets, holes must be provided to allow for suspension.    

To contact us call: 0151-355 5757   Email: sales @roften.com


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