Avoid narrow gaps between plates, overlapping surfaces and back-to-back angles and channels. When small overlaps are unavoidable, seal the edges by welding. When left unsealed, small overlapping areas may trap pickle acid that can later escape to colour or damage the galvanized coating.
If contacting surfaces cannot be avoided, a hole, 6mm in diameter for every 100cm. of overlap area should be placed in one of the members and the perimeter of the contacting area should be continuously welded. The vent hole in one member will ensure the safety of galvanizing personnel and prevent damage to the article. If in doubt, contact your local Perry Metal Protection representative.