W123 Engine bay paint advice req'd - PeachParts Mercedes-Benz Forum

Stretch · #1 10-11-2010, 02:16 PM

G'day Folks,

I'd like to paint up my engine bay as is has been somewhat abused by judicious spraying of waxoyl which now looks like crusty old custard and in a few places it has been patched up and then painted over with what seemed to be underseal.

I've started the job - I'm cleaning, de-greasing, POR15ing, POR15 tie primer-ing and soon I'll be sanding, undercoating and top coating.

Take a look at the attached photographs

Question 1

If the body base coat required a clear gloss top coat did Mercedes apply this in the engine bay? I don't think they did on mine as it all looks a bit dull... but I wanted to check. I've got Manganese Brown metallic (480)

Question 2

If I do apply a clear gloss top coat on the body work in a W123 engine bay is this likely to look bloody terrible? For example there is a whole lot of factory brushed on seam sealant in my engine bay that I guess won't help with my intended beautification exercise.

Question 3

Has anyone out there done this before / got any tips / got any do's and don'ts?

Mike D · #2 10-11-2010, 04:23 PM

On my W115's with clear coated bodies D-B didn't clear coat the engine compartment. I touched them up while repairing some rust areas with the factory color and then, using a rattle can, sprayed a coat of aftermarket clear. It's not very glossy but it looks good. You don't want the finish to be shiny but you do want to protect the paint.

Stretch · #3 10-12-2010, 04:38 AM

Quote:

Originally Posted by Mike D

On my W115's with clear coated bodies D-B didn't clear coat the engine compartment. I touched them up while repairing some rust areas with the factory color and then, using a rattle can, sprayed a coat of aftermarket clear. It's not very glossy but it looks good. You don't want the finish to be shiny but you do want to protect the paint.

Thanks for the input - I was kind of thinking perhaps I could find a satin finish clear coat - like you say some sort of protection would be nice.

jmk · #4 10-13-2010, 06:58 PM

Auto manufacturers generally do not clearcoat inside the engine bays or inside the trunk. It was a cheaper coating that was matched to approximate the body color. No aluminum or mica flake was used. It was a monocoat.

Frankly, a clearcoat will not add durability inside the engine bay. Clearcoat's primary purpose is to protect the basecoat from weathering and ultraviolet radiation. There is no UV under the hood. It actually may cause problems because of chemical resistence issues.

Frankly, I cannot remember what those coatings were called. It was something like blending primer. The coating was called a primer eventhough it was a topcoat. I know blending isn't the right word, but it was a word to show that you were approximating the topcoat's color and eliminating the grey of the primer surfacer or e-coat.

Mike D · #5 10-13-2010, 09:21 PM

There's your answer! JMK's the man when it comes to paint questions.

Stretch · #6 10-14-2010, 04:25 AM

Hmm - OK then. What should I do then?

Normal base coat and a satin top coat?

Ferdman · #7 10-14-2010, 06:42 AM

Army, suggest talking to your local MB dealer or a high end bodyshop for advice on what paint they use under the hood. A high end bodyshop makes every effort to make their repair work look "original".

Stretch · #8 10-14-2010, 08:00 AM

Quote:

Originally Posted by Ferdman

Army, suggest talking to your local MB dealer or a high end bodyshop for advice on what paint they use under the hood. A high end bodyshop makes every effort to make their repair work look "original".

Thanks for the tip - I'm not aware of any high end body shops where I live or even close to where I live. I'll have a chat with the dealer they've got an old school mechanic there who has given me advice before (poor chap)...

jmk · #9 10-19-2010, 06:43 PM

That is the way to go. They'll have a refinish product. Actually, if you go to any good paint supply store, they should be able to help you. Since you seem to be doing a restoration job, I'd ask anyone in your area for a reconmendation.

Just to let you know:the paint bought at the dealer isn't really anything different that what comes from a top level supplier. Years ago, the paint would have been manufactured by Herberts or BASF. Herberts was bought out by DuPont a long time ago, and PPG became a major player in Germany since then. BASF is still supplying paint to the dealers. It will probably be one of those three manufacturers in the can, and they are all good.

Stretch · #10 01-09-2011, 02:23 PM

I've had trouble getting the real stuff so I've had to go for normal paint and a satin clear top coat. Here are some pictures of the progress so far which has been hindered by a bloody cold November, December and January.

This is the first layer of the colour coat - I'm going to rub it down again and do another before I start on the satin top coat.

jmk · #11 01-10-2011, 09:04 PM

You've gotten the desired apprearance. It looks pretty good. Consistent but not too perfect. I really wish I could remeber what these coatings were called. I even formulated a couple of them for Toyota's Canadian plant.

We'll just see if the paint you used will hold up to engine heat, grease and dirt.

Stretch · #12 04-03-2011, 02:25 PM

Honest opinions wanted:-

What do you think?

gschira · #13 04-07-2011, 09:10 PM

I have a 1988 300SE. Maybe they are a bit different. Mine, in the engine bay is just as glossy and shiny as the exterior (black). Waxes up really nice. I'll try to post pics sometime.
The "slickness" sure does make an easy job of cleaning under that "bonnet".........

gschira · #14 04-07-2011, 09:11 PM

Oh, I forgot. Very nice job, Army!!!...........

Stretch · #15 04-08-2011, 02:25 PM

Quote:

Originally Posted by gschira

I have a 1988 300SE. Maybe they are a bit different. Mine, in the engine bay is just as glossy and shiny as the exterior (black). Waxes up really nice. I'll try to post pics sometime.
The "slickness" sure does make an easy job of cleaning under that "bonnet".........

Er yeah sorry the odd English term creeps in once in a while I'll try and say "hood"!

I'd be interested to see some pictures if you get the chance - particularly in places where there are seams or joints in the metal. My car has loads of seam sealant all over it - which was why I went for the mat look. I thought that a high gloss finish over such an uneven surface would look worse than some of the sealant jobs I've seen around baths and shower trays... I'd be interested to see how it is done on your car or even if you have the stuff there at all - it could have been a Swiss after thought in 1981 when the car was born...