Bodyshell rust protection for an MGBV8 rebuild

What is electrophoretic coating?
The fundamental principle that makes electrophoretic coating work is that opposite charges attract each other. In the electrophoretic coating process a direct current rectifier is used to create a voltage potential between a conductive part and an oppositely charged electrode that is immersed in the electro coat paint tank. The electro coat paint particles are also capable of being electrically charged and are deposited out of a water suspension to coat the conductive part when the rectifier is turned on. The industrial process of electrophoretic deposition consists of several sub-processes: first preparation of the part to be treated which usually consists of some kind of cleaning process. Then the coating process usually involves submerging the part into a container or vessel which holds the coating bath or solution and applying direct current electricity through the bath using electrodes. The part to be coated is one of the electrodes, and a set of "counter-electrodes" are used to complete the circuit. After deposition of the coating, the object is normally rinsed followed by a baking or curing process.

Posted: 170307
One of the features of an RV8 bodyshell which is the envy of enthusiasts with an original Factory MGBGTV8 is the electrophoretic coating which provides very good rust protection. The RV8 bodyshells were produced by the BMH at their Faringdon factory in Oxfordshire with the industrial electrophoretic process carried out at the MG Rover facilities at Longbridge. This continued until MG Rover stopped dipping BMH bodyshells in late 2007 by which time BMH had relocated to its current plant at Witney. Seeking an alternative provider, BMH approached many companies with electrophoretic facilities providing good quality bodyshell cleaning and coating service which could get into the closed sections like the cills. As finding facilities for relatively small runs of bodyshells was a difficulty, BMH decided in 2008 to move over to giving their bodyshells a very good coating with etch primer all over and then two coats of high build primer. However we hear the various BMH replacement bolt on panels - wings, doors and tailgate or boot lid - continue to have an electrophoretic coating.
Is electrophoretic coating still available when restoring an MGB or V8 bodyshell?
Specialist companies like Surface Processing in Dudley offer chemical immersion cleaning for the bodyshell and then an electrophoretic coating service for the shell. They can also provide that service for the tailgate, bonnet and doors and wings if they are off the car. Indicative prices in February 2017 were £895 for chemically cleaning the parts and then for an electrophoretic coating, £350 (for doors, bonnet and tailgate), £70 each for the wings if they are off the shell and £1,450 for the bodyshell. So a total of £2,435 or just under £3,000 including VAT. You can get further details from their website.

For anyone planning a rebuild with an existing shell, their useful online guide to restoring your bodyshell is well worth reading. They note that whilst their "process will not affect brazing it will invariably remove lead loading and customers must ensure that all aluminium and zinc items are removed from the shell and other parts prior to the process as they will be dissolved if left on the shell". They offer a separate service for cleaning aluminium and zinc parts and panels. They note "preparation makes a successful restoration". Useful guide

Soda blasting a shell

In the Rebuild reports contributed by Mike Macartney he described how his MGBV8 bodyshell was sent to Soda Blast Limited where it was soda blasted to remove the paint and a limited amount of grit blasting on rusted areas. They then they etch primed the shell, two doors, both front wings, bonnet and boot lid, and then painted the shell in 2-pack high build primer. See his report. More and the SBL website.