Anti-Spatter Sprays Suitable for HDG
What welding sprays are suitable for galvanizing?
When welded items are hot-dip galvanized, the cleanliness of the weld area before galvanizing plays an important role in overall coating quality and appearance. Welding slag and spatter must be fully removed prior to galvanizing to prevent bare spots in the coating, but the use of some welding sprays or spray-release agents can be problematic as well.
Welding anti-spatter sprays generally contain silicone, but some are water based or solvent based. Sprays containing silicone are often not effectively cleaned by the hot-dip galvanizing pre-treatment process. These products leave a film on the surface that must be removed by the fabricator prior to galvanizing or else bare areas will result near the weld where the spray was applied. Water-soluble welding sprays are recommended because they are likely to be fully removed in the galvanizing pre-treatment process without any effort from the fabricator. Some fabricators and galvanizers have success with solvent-based sprays (e.g. Weld-Aid Weld Kleen HD). However, the variety of available products in the marketplace have not been tested.
When in doubt? Ask your galvanizer to run a test sample.
For more information on how to improve the appearance of hot-dip galvanized coatings near the weld area: Welding Appearance After HDG
© 2021 American Galvanizers Association. The material provided herein has been developed to provide accurate and authoritative information about after-fabrication hot-dip galvanized steel. This material provides general information only and is not intended as a substitute for competent professional examination and verification as to suitability and applicability. The information provided herein is not intended as a representation or warranty on the part of the AGA. Anyone making use of this information assumes all liability arising from such use.