Must rocker panel plastic be removed for rustproof?
 

On this model year, the rocker panel is hidden by plastic trim.

I plan to spray Waxoyl (aerosol spray can) on rocker panel. Should I remove the plasic on the rocker panel? Or is it enough to open the protective cap from the jack support tube opening to have the mist of rustproof sprayed across the rocker panel?

To remove the rocker panel plastic should I remove all the plastic trim above it?



Should I apply Waxol 120-4 Aerosol or Hardwax Aerosol?


Oops. Should I remove the threshold too? This area is usually inside and does not get the salt directly.

threshold picture

I'm not familiar with the detail of the plastic trim on your rocker panels, but if the picture in the thumbnail in your post is showing it, level with the jack hole cap, then I'd remove it to get the Waxoyl in between the plastic and the outer surface of the steel rocker panel. Just removing the caps probably won't get you access to the middle part of the panels, and spraying into the jack hole will only coat the inside of the tube. If you want to get this stuff into the inside of the rockers, which is what will give you the best protection, get some caps that the undercoating/rustproofing guys use and drill access holes, spray inside, then insert the caps into the holes.
I'd pop the thresholds off too and spray the painted surface. Salty water gets into there from feet dragging the slush in. Winter sucks! My benz goes into hibernaton late Nov - April.

If it can be sprayed on rocker without removing any trim, it will save time and I do not need to prepare clips - some old clips may be loose -.

As in this picture, Waxoyl spray is like a fog. So perhaps it can be sprayed on the whole rocker panel just by opening the jack hole cap. The inner end of jack hole is open - there is a gap between the inner end of the hole (cylinder) and the inner vertical wall -.

http://www.rustbusters.co.uk/main/door.gif

By the way, John Robison at Robison Service replied "We can remove the rockers if you want". He did not say "it has to be removed." But it was in his quick email reply, and he did not see my car.
But there is a chance that it can be sprayed without removing the plastic trim.

By the way, according to MB service CD, all the lower plastic trims above the rocker must be removed before removing the trim on rocker. Not a five minutes job.

Prophylactic Waxoyl ?
 

Wow, I like the looks of the FOG. What is waxoyl? If it is some kind of rust inhibitor, should I treat my car before it rusts? Of course I will do some searching to learn more about waxoyl, but it would great if you guys would just give me quick education.

I don't want to buy a new car for 20 years or more.
http://forums.mbnz.org/gallery/pics/W124_57782.jpg

An experienced Waxoyl applicator in the UK told me in his email reply that the MB factory wax based rustproof is of very high quality and the mineral spririt in Waxoyl may pan cake off the MB factory rustproof - there might be some incompatibility -. In addition, MB owner's manual is against aftermarket rustproof.

Inspite of that, I am still interested in it because I see some rust around some holes underside of hood, roker, etc.

As you can see on several UK web pages and a US web page, professional application is expensive.

I am thinking of applying it myself with a starter kit, but masking things (belt, pulley, exhaust sytem, brake pads and rotors, interior vinyl and carpet areas, etc.) from the Waxoyl fog will be time consuming for a novice like me.

First, get rid of the rust and then treat the affected area.

Rustproofing a car that has been exposed to the elements for years is not a good idea. Things rust from moisture trapped inside the metal and applying some sort of rustproof coating over metal that has moisture in it only accelarates the rusting process. Now if you were putting on a new hood or a new fender that would be fine. If you have rust spots under your hood you may want to apply a product like "Rust Mort" which stops rust from progressing.

That is a good point.

If the rust is between metal and bubbled paint, and Waxoyl is applied on the bubbled paint, Waxoyl may accelerate rust by keeping moisture below the bubbled paint. When the paint flakes off, the area may be too large for Waxoyl to self heal.

But if the rust is already exposed, it will be OK even if it is moist.

For expample, Eureka Fluid Film says their wool wax can be applied on moist surface.

A machind translation of a Russian Waxoyl web page says it can be applied on moist surface due to moist repellent additives.

According to some web pages, the hand pump supplied in Waxoyl kit is not so good.
http://www.google.co.uk/search?q=cache:MAj3uiP--0UJ:www.british-cars.org.uk/kimber/MGF/mgfaq2.htm+waxoyl+hand+pump&hl=en&ie=UTF-8
http://www.fizzindi.demon.co.uk/rustproof.htm

Anyone has experience with the kit?

An independent test in Germany.
http://www.autobild.de/suche/artikel.php?artikel_id=1193&artikel_seite=2

Just click:

Den kompletten Vergleichstest mit allen Daten erhalten Sie über unseren Leserservice. Einfach hier anklicken und absenden.

And send email. You do not need to write anything. You will receive pdf file.

I might not need to remove the plastic threshold.
I am not sure whether it is the same on my W124, but the picture shows no hole to insert rustproof spray.
http://www.poundhost.com/mbclub-file/Merc/sills2.jpg
http://www.poundhost.com/mbclub-file/Merc/sills3.jpg