A rule of thumb is a maximum of 5 ml hydrogen per 100 g weld metal. However, this is in practice not possible to measure. The hydrogen content in solid wires for MAG welding is typically around 1.5-2 ml hydrogen per 100 g weld metal, while cored wires can pick up moisture in the flux which might increase to higher values per 100 g weld metal. Keep all consumables dry and warm, in particular flux-covered and flux-core ones. Packages should be opened shortly before use.