Im just getting started on my 3.8. I’ve noticed there’s undercoating….everywhere! Do owners leave it on or remove it in areas like the engine compartment? If they do remove it, which I intend to. Would it be best to leave it primer red or paint to match the body color?

 

Factory original it's supposed to be body colour over stone chip or Schutz. (German for "protection" ~ 3M Corp use it as a Brand for their under-body, rust preventive coating).

 

Subject to correction I think on Mk2's that included the scuttle face. S Types not.

 

One of my pet hates to to go to a classic car show to see these beautiful cars but they all have their bonnets closed. When you ask if you can view the engine bay you are presented with a dirty unkept engine where the engine bay has been painted black. This happens even more so when the car has had a colour change and rather than pull the engine to paint the engine bay the same new colour they paint it black. My S Type was resprayed top and bottom so the bottom of the car although treated with an underseal, I used Tetrosyl White Stone Chip, was then over painted the same colour as the top of the car. This included inside the wheel arches. The new products you have on the market now allow this but in the 1960s and 1970s underseal was like a black bitumen product that was sprayed on the underside of the car, could not be over painted and in time became brittle and cracked. The cracking allowed water to seep under the undercoat and you would then get rust which you could not see.
If you are going to do it do it properly.

 

 

See under-body & wheel arches being painted car colour after sealing compound. Today we would use anti corrosive stone chip/Shutz etc. after dipping or spraying. As I had no dipping capability we used BASF/Glasurit Porsche self healing primer & spayed every nook & cranny as first coat for everything top & bottom. All double skinning of the monocoque, inside doors etc.

Pity their Phosphating & initial primer dipping did not work a little better.

 

The original paint on the external surfaces of my car go: red lead, pale greeny cream primer, opalescent dark green top coat. The original paint is quite tough, much more resistant to a hot air gun and scraper than subsequent coats of cellulose applied by body shops.

Under the bonnet, it goes: red lead, black body schutz, green top coat. The absence of the cream primer makes the top coat look much darker, almost black. The inner wings and bulkhead all have the same treatment.

The result of seeing a dark top coat over black schutz has probably fooled many into refinishing the under bonnet in black.

 

Very possible Peter. On an Old English White car everything was Old English White. Under-body, wheel-arches, under bonnet & engine compartment.

 

The engine bay colour was always the same as the external body colour. It was just a standard manufacturing process keeping costs down.
The MK1 and Mk2 were "cheap cars" compared to their larger Mk7 to 420G vehicles.
The Mk7 had specially colour coded painted wheel hub caps and were painted internally with red lead primer.
The MK1 had no paint at all on the hub caps and only on the jaguar central emblem.

 

OK, wow! That’s the way to go! That’s beautiful looking.

I hate the look of this stuff. Originally then they sprayed the undercoat directly on the primed underbody, wheel wells and through the the engine compartment. I’m disassembling the engine compartment now. Lucky for me this stuff is soft as butter thanks to a lifetime of oil and coolant leaks.

Thanks for the great photos.

 

Thank you.
They used to say that all Jaguars had oil leaks built in to them on the assembly line as an rust protection. lol.
Even though my engine, gearbox ad power steering have all been rebuilt I still have a drip or two but I just can't work out where it is coming from. Not enough to leave a mark on the floor but just a dampness on the sump which I have to wipe off every time I go under the car. Not red so I don't think it is gearbox or PAS. I think it is coming from the cam cover behind the carbs. I will try and sort this in the spring when I normally take the cam covers off to polish them before the show season starts.

 

My only oil leak was the O ring on the speedo drive. (83)
Easy fix.

 

Check the camshaft oil feed pipes and connections to the head.
I have chased down this leakage a few times.

 

 

My leak is from the front just above the distributor under the carbs area. Very minor and easily cleaned off but frustrating on an otherwise dry engine. I will find it but have to wait until drier and warmer weather in the UK to get the incentive to go look for it.

 

I’ve been scraping soft gooey undercoating off with a plastic scraper. Easy but tedious, I’m a patient person and a cigar helps pass the time. The problem is I’m running out of the easy stuff. Is there an efficient method of removing the “hard stuff”?

 

Possibly a hot air gun to soften up the harder bits. The stuff is really hard to remove even when you have a chassis grit blasted as the grit just bounces off it. It will come off in an acid bath but that means everything comes off after stripping the car back to nothing. Not even sure a paint stripper will work but you would have to be very careful about getting the paint stripper on places you don't want stripped.

 

Many use a gas torch & scraper.

 

The methylene chloride in that jelled paint stripper probably would take it off, but what a mess !
If you can even find the stuff anymore.

Cass's hot air gun would be my choice, but it will smoke a lot.

 

Oops ~ Cass & I crossed one another but I endorse Cass' method. A friend from Dallas owns a 50% share in a restoration shop in Poland and they do it the gas torch/hot air gun method. Works a treat. You need a couple of different shape scrapers.