Black factory body coating

[Dr.Mabo]

Does anybody know more about the black body coating on the bare metal?

I found it under the first layer of filler. Its the second MK1 body I recognized it on (I haven't done more until now). The body on the photos was sand blasted arround the edges, so I just found the coating on the side panels after removing the old paint wiht a heat gun. On my previous full body restoration I sanded down the old paint by hand and although found the black coating arround the lower part of all body panels, including doors and bootlid. So the bare but assembled body must have been dipped into the coating before the factory painting process began. Its not perfectly leveled but runs arround all the panels up to appr. 20-25 cm above the sill seams.

so long
the Doc

[Tim]

It looks like a 'slipper dip', where the lower part of the body has been dipped into the coating. Why it wouldn't have had the full rotodip coating, I can't explain. Both Longbridge and Cowley had rotodip plants during the Mk1 period.

Tim

[Pete]

What era shell is it? I didn't think rotodip was black?

[Tim]

The rotodip primer was a very dark brown, it often looks black.

Tim

[Dr.Mabo]

What era shell is it? I didn't think rotodip was black?

The shell you see on the photos is a 66' shell. The shell of my previous restoration was May 65.

What is a "rotodip"? Is it some kind of corrosion prevention?

I never heard or red something about any kind of dip in the history books.

so long
the Doc

[Tim]

Rotodip was a method for cleaning the newly built body shells and applying the primer, before they finishing coats were sprayed. The bodyshells (usually with the hinged panels already hung) were skewered with a large pole, through the large hole behind the speedo and the matching one in the rear seat back. The poles were suspended on a system that rotated the bodies and dipped them through a series of rust preventative and degreasing washes, dried them, then immersed them in the primer. Because the bodies were rotated, they were able to be completely coated, even inside partially enclosed sections.

This illustrates the process


There were rotodip plants at all of the major UK factories. Cowley,Longbridge and Fisher and Ludlow at Castle Bromwich had two each, Nuffield Metal Products had one, and the Austin J40 pedal car factory at Pengam in Wales had a miniature one. There was also one at the Australian factory in Sydney.

Here's a mini being spitted at the Australian plant.


The Pengam factory had the first one, around 1948 and the last one was built at Castle Bromwich in 1964. I think they stopped being used between 1970 and 1974 to cut costs. After the Australian one was decommissioned the bodies received some kind of a dip, but but I don't know much about it.

Tim