I have a project in mind to build a cabinet, around 5' long, 2' deep and 3' high. The basic outline of the project will be a SHS frame with sheet metal sides and doors. Plan to add the doors at a later stage. I'd like to have the frame galvanised and powder coated; costs depending, so with that in mind I'm thinking of building the frame first and having it treated and then affixing the sheet metal side panels to the frame with rivnuts rather than welding. Is this a sensible way to go about this? and is there anything I need to be aware at the design/purchasing stage with respect to galvanising and powder coating, never done either before? Leeds Galvanising and Powder Coat are local to me, so plan on using them. Thanks in advance.