Actually Matteo's car was our introduction into this process, so we do things in a different order nowadays...!
When we're approaching a big build like this from the onset (project creep doesn't always allow for the correct sequence, mind you), we'll first totally disassemble the car to the unibody - and I mean totally. All that is left is factory undercoating, glue, and paintwork. Everything gets filed and binned by car and put on shelves here at the shop.
Then the car gets shipped to our bakeoff contractor, who puts the car in a large oven which turns all that good german goop into ash. They then pressure wash the entire unibody, every nook and cranny, with a zinc phosphate solution which acts as a temporary rust-inhibitor (like for several months to a year indoors, if necessary.)
Upon receiving the car at our facility in phosphate coat, the fabrication begins. By doing the bakeoff first, we save TONS of prep time over Matteo's project, where we had to do material removal in every area we were working. Additionally, there are no hidden suprises in the body in this method, as you are staring at bare metal - no fillers, no lead, nothing to conceal damage or rust.
The smaller parts - doors, fenders, hinges, hood, decklid, etc. go to a local e-coat facility to receive the industry-standard for corrosion protection, as the major car manufacturers utilize today. This is the black e-coat finish you see on panels in some of our threads.
Upon completion of the fabrication, pre-galvanized unibodies (like 1976 and prior, for instance) are now going to be shipped to a massive contractor that has the capacity to e-coat the entire unibody. Galvanized cars will have this option also, at customer's request, for additional corrosion protection. We are adding this step to the process so as not to have to rely entirely on the paintshop to be meticulous with the OEM-style waxy-goopy stuff that they spray into enclosed channels and whatnot to ward off corrosion. Although that process worked fairly well for the original cars, the years take their toll (even on the galvanized chassis, like my own) and we'd like to see more longevity and have better control over the product (as opposed to trusting the client's preferred paintshop to correctly protect the car against corrosion)
(As a side note, we are looking at keeping a small inventory of titled, repaired, stripped and e-coated unibodies available to individuals and shops to purchase for project-starters and restorations in the future.)
So, now you have a zuffenhaus-modified, stripped and e-coated unibody that can go straight to paint! Or powdercoat.
For additional weight savings (over using sound-deadening and undercoat on the underside) and better wear and tear in the trunk, cabin, and engine compartment areas, we offer the option of having the unibody powder coated. As Matteo mentioned, exact color match isn't always possible, and the powder coat has a different surface sheen than paint, but the color is uniform and the wear qualities exceed that of paint (although nothing is indestructable). the car we've done leave us looking like a big piece of colored-candy - everything coated uniformly with the powder coat.
The powder coat is not applied to the exterior panels, however - these receive traditional paint refinishing that we are all accustomed to. Powder-coat is not spot-repairable and is not an acceptable exterior finish.
As Matteo pointed out, further work can and does happen on the powder-coated areas - as he illustrated with the rear suspension pickup work on his car - the powder coat is ground away, then feathered, and paint is applied over the top for protection.
Did I leave anything out?
