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#1 Paint for Differential
Posted: Wed Mar 04, 2015 3:12 pm
by Steve Marshall
Can anybody point me in the right direction to get dull pumpkin (matte?) paint for a differential?
Seem that concours judges are not permitted to inspect the suspension or transmission, in the US anyway (who knew?) - so this is ignored in every document I have found after hours of research. Not that I am going concours, but might as well get it right.
SNGB stopped supplying it last year.
Thanks, Steve
#2
Posted: Wed Mar 04, 2015 5:00 pm
by Heuer
The paint is Red Glyptal which is used both internally and externally to seal the casting. It is still available. Early cars had the diff over painted in black but Jaguar stopped doing it once Mr Arthur Whittaker (Jaguar Chief Buyer) found out about the 'waste'. The black paint was also not a good match for the Glyptal so it literally washed off hence the arguments over colour. Order seems to have been early cars painted with black Glyptal which was superseded by the red version for some reason. As the Factory already had a large stock of black painted steel diff covers they elected to over paint the red with black because that was the way things were supposed to be. They then gave up on the idea and left the diff's red. No idea of the changeover dates and last time I tried there was so much "well mine is xxxxx colour and it was built in xxxx" I abandoned the project. Not helped by owners looking under the car and seeing red paint and sometimes failing to spot the remnants of black. I have a photo somewhere to prove the point. S2's should be red.
#3
Posted: Thu Mar 05, 2015 9:51 am
by Steve Marshall
Hope I am not being impertinent questioning my elders and betters - but ... why are they so frequently photographed as being sort of matte russett colour? Eg Google images 'E-Type differential' throws up a gratifying number. Maybe there was another shade of Glyptal available at the time. You would expect any over-restorers to go redder and glossier, not go in the other direction. And I am worried about a terrible colour clash with the red springs :(.
#4
Posted: Sat Mar 07, 2015 2:22 pm
by Moeregaard
From I understand, Glyptal was originally developed by Thomas Edison/General Electric as a coating for electrical windings. No. 1201 is the original red/maroon shade I think most of us are familiar with and, as David indicated, is still available.[/url]
#5
Posted: Tue Mar 10, 2015 10:13 am
by Steve Marshall
Thanks Moe
In my early career as a mining electrical engineer, I do remember open armatures on the big GEC/Parsons/AE motors and fans being coated in a a sort of waxy/glossy red. I think you might still see such things on display at the Science Museum. I never knew why they were so, I still don't think its insulation properties could have been that significant at 11kV. I also can't entirely see the advantage of coating the inside of a diff casing to make it slippery to oil, or to protect it from corrosion. Or a crankcase for that matter. Perhaps in an automotive context it was really a precaution to seal any minor porosities in the castings with a coating which was resistant to hot oil. Still doesn't explain why nearly all the photos show diffs being dull russett/pumpkin shade. Maybe they are all Series 1. When I get my hands on the 1969 diff I will examine it forensically and report back to the forum for posterity.
Anyhoo, I always accept advice from those who know better than me, and Glyptal red it shall be.
#6
Posted: Wed Mar 11, 2015 11:43 am
by Steve Marshall
Epilogue
I told the restorers to use red Glyptal 1201. I called to follow up, and they said that it had to be imported from the US, so they simply had someone mix some orange paint to match the original paint! Might have checked with me ... Like everybody else, I think that my diff has been untouched by human hand since it left the factory. Admittedly a few chimpanzees seem to have taken it upon themselves to hand paint the outside of the car at some point, but it don't think their hearts were really in it. Seems to be a remote possibility that the diff was ever removed, and that it is highly probable it lest the factory in Feb '69 orange, or orange with a black paint overcoat which subsequently just fell off. If the latter were true, one should expect to find black paint remains under the washers.
#7
Posted: Wed Mar 11, 2015 1:03 pm
by jagman1970
#8
Posted: Wed Mar 11, 2015 3:02 pm
by Heuer
This is the diff from a 1961 car; red Glyptal over painted black:

#9
Posted: Thu Mar 12, 2015 1:27 pm
by Steve Marshall
Well the man on the Clapham omnibus would say that is definitely orange, overpainted with black, in 1961 - as the legend says.
On the other hand, I reckon my 1969 diff is orange which has
never been overpainted ever with black - when I get the chance to clean the grime off I will get a better idea. (It temporarily has an XJS ribbed cover).
So is Glyptal red 1201 in reality orange (or near-orange)? The orange on the 1961 and 1969 diffs are remarkable similar, especially considering the limitations of colour photography.
I know that the Glyptal actually IS available, just they seem to want to repair my car instead of restoring it. Having finally got things moving after 15 months I don't want to put the brakes on ...
[img]
[img]http://i36.photobucket.com/albums/e5/st ... xuga57.jpg[/img][/img]
#10
Posted: Thu Mar 12, 2015 2:19 pm
by Heuer
Glyptal 1201 enamel is "red" or "orange" depending on your perception of colour.
"Bake or air dry. Meets MIL-E22118; used for coils, armatures and other electrical apparatus. Also used as a primer, sealer for screws, pipes, vacuum systems and hydraulic fluid chambers."
Glyptal 1209 is the same type of enamel in gloss black. They also make it in white, green, blue, light grey, medium grey and dark grey All 4.2's should have a red differential.