Can a fabrication with contacting surfaces be galvanized?

Yes, providing that the edges of the contacting surfaces are not totally sealed by welding.  If gaps in the weld are not left then you must drill ventilation holes through the contacting surfaces.  These holes need to be a minimum 10mm or the thickness of both contacting surfaces combined (whichever is the larger).  If neither is done, the air trapped between the surfaces heats and expands during the galvanizing process and can explode causing damage to your fabrication and can be very dangerous for our operatives.

Linear contacting surfaces.  For example, where an angle is seam welded down the length of the flange of a beam: a vent hole must be drilled every linear metre or part metre. So, if the contacting angle is 6.5 metres long then there should be seven vent holes drilled through it.

Non linear contacting surfaces.  For example, where a large bracket is welded to a beam: a vent hole must be drilled when the contacting surface area is greater than 200 x 200mm.

For unusual contacting surface shapes or if you are in any doubt, please contact us for our advice.  We can only galvanize steelwork we deem to be safe and so will consult with you if we have concerns over steelwork we receive.