Venting & Drainage Issues to be Considered before Galvanizing

When designing fabrication for galvanizing, it is essential that the work is vented correctly for drainage. Any part of the fabrication which creates a trap requires holes of an adequate size to allow the zinc to drain freely.

Extenal stiffeners, welded gussets and webs on columns and beams, and gussets in channel sections should have their corners cropped.
Cropping the corners of these brackets will aid access and drainage of molten zinc and a cleaner coating will be obtained.
Angle bracings should, if possible, be stopped short of the main boom flange. This will allow the free flow of molten zinc across the surface of the flange, enhancing drainage from the structure. This will assist the development of a smoother galvanized coating, reduce the potential for retention of ash on the surface of the flange and help to avoid air traps within the structure, which could lead to uncoated areas.
On structural hollow sections, provision must be made for venting and draining. With vertical members, drilled holes or V notches should be provided diagonally opposite each other at top and bottom.
Every sealed section of a fabrication must be vented for reasons of safety and to allow access and drainage of molten zinc. Holes diagonally opposite each other should be as close as possible to the sealed end.

Advice on this or any other issue is available by contacting us on 01952 412777.