Been using another technique for Thor arms portion of the costume. I had a base "Power rangers" costume undersuit that Istuffed, then built up muscle areas with foam. Then I taped off all portions of the arms with silver craft duct tape, cut out foamie squares and started gluing the squares down in a pattern. I had to cut some of the squares to fit off-square areas caused by muscle definition ridges and dips.
Very time consuming and I can only stand doing a little at a time. Arms will be sealed then painted silver. They should flex enough without any scale armor popping off. Even if any squares do pop off, there is silver tape beneath so should only look like a little "battle damage". I plan on adding some battle damage to some of the off-shaped squares on the front of the bicep to cover up their non-square shape too.