Vanity Project - Detailing Exterior of the Engine and Engine Bay

[Pengue]

 I am thinking of having my engine pulled and doing a full exterior cosmetic face lift, having the engine bay repainted along with the underside of the hood.  A couple of years ago I had the fuel lines and throttle connecting rods re-plated (opted for phosphate wash not cadmium) and they came out great.   Just trying to get the rest of the engine compartment to look as good as the day it left the factory.  I've attached a few pictures of the current status.

Any thoughts or experience with this type of project and approximate cost?  Any and all input would be greatly appreciated.

[John Betsch - "SADIE"]

I am sure you will receive many replies, but here is a quick one: underside of the hood did not have pristine paint from the factory but obvious paint runs down the center, as it was not expected to be a looked at area


jb

[Pengue]

Noted and thanks!

Dan

[lreppond]

Hi Dan

Before I’d go through the hassle and expense of pulling the engine, harness, et. al. to repaint the engine bay, I’d hire a hot shot detailing person and see what he/she can do.  You won’t have any down time and I’ve seen amazing results.

Over the last few months, I’ve been detailing my engine bay.  Areas that I thought were irredeemable were just covered in grime and once removed it looks great.  I’ve had the power steering reservoir powder coated  and overflow tank repainted.  I’m not going for a new look but rather a scrupulously maintained engine.  I’m almost there.

The photo you attached shows very little so hard to assess just what shape  yours in but even if you have to replace the firewall pad, almost all other parts can clean up pretty well. 

[rwmastel]

... Just trying to get the rest of the engine compartment to look as good as the day it left the factory ...

To what end?  Personal satisfaction?  Winning major national car show awards?  Increasing resale value?  Each may warrant a different approach.

[49er]

 Here's my hood and as you can see no care was taken to avoid runs when painted. Touch up paint was brushed on in many places in the engine compartment and sloppy welds were evident particularly on the rear hood bumper brackets (on my car at least). As John B. said Mercedes felt most owners of their cars would never open the hood. I guess I was in the minority

John

[John Betsch - "SADIE"]

I should note that while I posted about the paint drips, that information is courtesy of Peter Lesler, then Chairman MBCA Sub Committee Committee in his article "Some Points on 230/250/280SL Authenticity" published  in 1993

jb

[Pengue]

Looks like on my original post some of the pictures did not get uploaded.  All fixed.  There should be 4 photos.

[lreppond]

After seeing all your pix I’m more convinced than ever that all that is required is a good detailing, replacement of all those cheese graters clamps with proper Norma brand ones and print out or purchase a new set of decals.  Honestly, I see no need to go through all that work, downtime and expense.

[Pengue]

Not to show my ignorance but what is a cheese grater clamp?  I've rebuilt a handful of engines in my time and I always called them "hose clamps" or "airplane clamps"

[Vander]

Not to show my ignorance but what is a cheese grater clamp?  I've rebuilt a handful of engines in my time and I always called them "hose clamps" or "airplane clamps"

I believe he means the hose clamps are the incorrect style and look like a cheese grater. A Norma style hose clamp would be more correct.

[rwmastel]

Not to show my ignorance but what is a cheese grater clamp?

The tightening screw goes through open slots in the band.  This can damage (grate) the hose.  Google "Norma clamp".  There are ridges for the tightening screw to grab. Then, there is the t-bolt clamp style.

[tockuly]

I love the look of your fuel line and linkage. Can you point me in the right direction for this phosphate wash you mentioned. I would love to do the same in my under hood restoration project.

[mdsalemi]

 “Phosphate wash” is not plating. It isn’t a substitute for cadmium or zinc or any other plating. It is more properly called a conversion coating but that’s not too important.

The phosphate conversion coating is generally done over freshly plated parts. The “wash” as it were imparts additional protection to the underlying plating.

In the case of engine bay parts on our Pagodas, I believe that when new, most or all the steel engine bay parts were cadmium plated because that was common. As time went on the toxicity of cadmium became problematic for the automotive industry and zinc became more common. Both zinc and cadmium plating are naturally silver. Cadmium is a bright silver, zinc more grayish silver.

BOTH platings can have a phosphate conversion done. That’s what gives the parts the distinct yellowish color. It adds a bit more corrosion resistance than plating alone. Unplated steel can also have a phosphate conversion; black fasteners often are often created that way, so is the finish on many guns.

Yellow is not the only color imparted by a phosphate wash or conversion.

Cadmium plating is much longer lasting than zinc. My cadmium plated parts look new, even after many years. The zinc ones have faded.

[dirkbalter]

Adding to the “phosphate wash”.
 My body (shell) after dipping (chemically removing all the paint Bondo …) was in addition dipped in a phosphate solution, temporarily protecting the bare metal from rust or better, surface rust. I liked it a lot and didn’t see any rust appearing till it was ready for primer, approx 1 year later.

[mdsalemi]

…didn’t see any rust appearing till it was ready for primer, approx 1 year later.

Wow, with such a time difference between bare metal and primer, that was a smart thing to do.

Some powder coaters do the same—a phosphate conversion prior to coating.

[Pengue]

I had all the top side parts removed and took them up to Jim Cosgrove at Old Timer Restoration up in Harvard, MA.  Jim is a total pro and he aggregated my parts with others and sent out to his plating contractor.  He would not disclose who he uses.

Cadmium is the original plating material but is now considered a toxic metal.  Jim highly recommended that we go the more environmentally friendly route.  In rare cases he has gone the cadmium route but only in the most discreminating restorations. 

[mdsalemi]

...sent out to his plating contractor.  He would not disclose who he uses...
...Cadmium is the original plating material but is now considered a toxic metal...more environmentally friendly route...

Zinc plating with or without the phosphate wash, is typically done in a barrel. There's little hand work involved, and whether you are doing 10 pieces or 100 pieces, as long as they fit in the batch it's not a big deal. Why he wouldn't tell you his vendor is a little silly; it's not done in secret and the firms that do this are plentiful.

There are some newer plating processes using zinc (zinc nickel, for example) that provide a longer lasting plating than just zinc alone. As zinc is a very soft easily sacrificed plating anything to improve it is worth looking into.

Zinc is also toxic but in a different way and to a different level. At my local Mercedes club function some years ago, a vendor was going to demonstrate a restoration technique using some kind of zinc spatter process, but decided that it's too toxic to use in a demo and couldn't supply the proper safety gear for everyone.

While technically "more correct", beyond that, the advantage is that cadmium is more robust and much longer lasting than zinc. I can assume that the surviving cadmium plating firms in the USA are adhering to the EPA and local rules, and their workers are properly protected. My zinc plating from 20 years ago has long since faded, indicating that it has indeed "done its job" and as a sacrificial coating, is wearing out. Next time, cadmium for me.

Next to a stellar paint job, and shiny exterior chrome, the next best thing (arguably even more impressive) is a detailed engine bay. You may call it a vanity project but there is nothing that will bring out the oohs and ahhhs and smiles when car folks see a detailed engine bay, with "all the right plating"!

[Pengue]

Thanks Michael.  You clearly have a much better grasp of the plating options than I do.  Sounds like I should have pushed for the cadmium route!  Back to my under the hood stuff,; I just had the inside of the hood repainted (looks fantastic) and next up is ceramic coating the exhaust manifold and cleaning up the intake manifold and valve cover.  My winter projects.  After that - I'm done.

[mdsalemi]

Thanks Michael.  You clearly have a much better grasp of the plating options than I do.  Sounds like I should have pushed for the cadmium route!  Back to my under the hood stuff,; I just had the inside of the hood repainted (looks fantastic) and next up is ceramic coating the exhaust manifold and cleaning up the intake manifold and valve cover.  My winter projects.  After that - I'm done.

Oh you jest. Trust me—you’re never done! 😉

Please post some before and after photos of the ceramic coating for the manifold.

When freshly done both zinc and cadmium with the proper phosphate wash will present nearly identical. Its just the cadmium should last longer.

I have some true cadmium plating and it looks spectacular even nearly 15 years later. Everything else that was zinc is mostly faded. Oh well.

[rwmastel]

Just trying to get the rest of the engine compartment to look as good as the day it left the factory.

I just had the inside of the hood repainted (looks fantastic) and next up is ceramic coating the exhaust manifold and cleaning up the intake manifold and valve cover.

You say, "as good as the day it left the factory".  Are you trying to replicate factory looks, coatings, finishes, etc.?  Or, are you trying to make it look the way you want it to look?  For example, at the factory they left the paint runs under the hood.  They didn't ceramic coat exhaust manifolds.  I don't know what your plans are for "cleaning up" the intake manifold and valve cover, but several discussion threads can be found regarding the outcome of various techniques used on these parts.

[Pengue]

Can you point me to the threads regarding coating the intake manifold and valve cover?  You are correct in that I am not looking to replicate factory delivery.  When delivered the exhaust manifold was cast iron with no coating.  Ceramic coating will be more pleasing to MY EYE and the rationale is totally cosmetic.  Same with the intake and valve cover.  Totally cosmetic.

Thanks for the input!

[rwmastel]

Can you point me to the threads regarding coating the intake manifold and valve cover? 

No, but I can "teach you to fish", as they say.  I searched for "valve cover polish" and there were 24 threads in the results.  You could also search for "valve cover coating" or "valve cover sand blast" or "valve cover sandblast" or any other words you think would be appropriate.

[mdsalemi]

Not specific to any past threads, but...

1. Valve Cover Finish. That's raw aluminum. When it was fresh from the mold, or fresh from professional cleaning it would have looked like the photo attached here. That was how Metric Motors prepared it. What did it look like BEFORE? That's the second photo. Kind of nasty.

You achieve that look only with a chemical cleaning. Any mechanical cleaning will damage the surface texture of the aluminum. Do a search for "aluminum cleaning" and you'll find products that work. Simple, over the counter products include wheel cleaners (Meguiars Hot Rims comes to mind), but you need to look for the ones with the most warning labels on them. Why? Because it's the nasty acids that do the dirty work. On Amazon, they sell a number of products under the aluminum brightener search, such as Aluma Bright, Purple Power, BooYah, Aluminator and more. Typically these more industrial products use either hydrofluoric acid or ammonium biflouride combined with either phosphoric, hydrochloric or sulfuric acids. Yeah, all nasty stuff--don't even think of doing this indoors or without significant eye, breathing and skin protection. But I'm here to tell you those products work like nobody's business.

Important note of caution: the hydrofluoric acid and derivatives, pass through the skin and will start to work on bones. You won't feel it. That's one reason why it's often mixed with the other acids...because those you will feel! "Because of the ability of hydrofluoric acid to penetrate tissue, poisoning can occur readily through exposure of skin or eyes, or when inhaled or swallowed. Symptoms of exposure to hydrofluoric acid may not be immediately evident, and this can provide false reassurance to victims, causing them to delay medical treatment." So take proper precautions but man the stuff works.. There are plenty of YouTube videos of people using various aluminum cleaners and brighteners with before, during and after results...

Once you've got the valve cover clean and bright, now the trick is to keep it that way. I think there are matte finish clear powder coats, but I have no idea if they yellow over time.

But speaking of powder coats, you may find a well equipped and highly experienced powder coater that could formulate a sort of mottled bright silver matte finish...you don't know until you find them and ask.

2. Exhaust Manifold. As pointed out, the exhaust manifold is raw cast iron. When "fresh out of the mold" raw cast iron is a medium dark gray--usually--with just a little bit of shine to it. The problem is, it begins to tarnish and rust nearly immediately. These high temperature ceramic coats come in many colors--including gray. CeraKote is one manufacturer but there are others out there. You really need to find a local finisher and visit them to chat them up about what you are trying to achieve. Once coated in the color you want it will probably stay that way for a very long time.

Hoping this keeps your winter projects going!