So i live in New England. This time of year the roads are very salty. Yet i can't go without driving the SDL for more then a week or so. I do my best to clean her off every trip out but it sucks then the hose is frozen, and the dirt road i live in makes it hard to go to a car wash and come home with her clean.

I want to just use some ind of rust prevention type paint on her. My plan is to just cover as much as i can of the undercarriage, do the insides of all the wheel wells, and use POR 15 when doing so. A guy who used to own 1950's Benz back 20 or so years ago told me he used to just spray the under with kerosene. He also said he used to make his own under coating.

Now from what i have heard POR 15 is the best to use. But how do i go about cleaning off my car's underside? I read on the POR 15 web site they say to use this marine clean stuff, but i know that unless they mix magic in that stuff its not going to get all the grime off my car. Someone also told me to go under with a wire brush and clean everything down to metal, but it says POR 15 sticks best to rusty surfaces. I'm lost here as to what do?

If anyone has done a DIY rust prevention job please your feedback would be great.

when i replaced my floor pan on my 240D i coated the entire underbody, inside of floor, wheel wells, & engine bay w/ a Dupont roll on bed liner.

I got a gallon for like $25 bucks or so... took me a couple hours to do... need to jack up car to be able to reach it... make sure its well vented, or you just don't go near it for a day... lol... i was feelin pretty good by the end of the night... i seriously shook can, grabbed an old towel wadded up & applied.

its got this nice rubberish texture... yet debris doesn't stick...
no chipping/scratching/peeling yet almost a year and a half later... also much quieter inside now

who needs zeibart anywho

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Matthew McIvor

2016 E350 4Matic Black/Black
2007 GL450 4Matic with Off-Road Pkg Silver/Black
1995 E300 Diesel White/Gray
1994 S600 Euro Black/ Black Velour
1986 560SL Blue/Blue/Gray
1986 190E Blue/Blue 93k

how do you get the car clean? I am considering just putting a wire brush fitting on a hand held drill and just going to town.

YUp, and a wire brush. The Marine clean is for bare unrusty metal, if I;'m not mistaken. The POR will bond to rusty metal. Clean all the loose stuff off and DEGREASE before painting. laquer thinner would be good. Don't get the stuff on your hands, it will not come off.

Heated garage only, it has to be above 50.

I was thinking about the Carwell oil treatment as my Benz has never seen salt. But since its down again, it isnt an issue.

Marine Clean is a degreaser cleaner. can be diluted up 10 to 1 with water. pour some out of the bottle on asphalt, and it will start disolving the tar/oils out of it.

Metal Ready is for bare metal and rusty metal. will disolve the rust given enough time. depends how much rust. also etches the metal to give the POR paint a tooth to bite into. the surface has to be clean for the paint to stick.

The paint is moisture activated. the higher the humidity, the faster it cures. do not shake the can, bubbles get into the paint. directions say to stir. pour out the amount you want to use, place seran wrap on top of can then place the lid. if not when the paint cures, you will think the lid is welded on. also keeps air/moisture out of paint. the paint will cure in the can. I know ,I have several cured cans, they swell up as they chemically cure.

There is also POR Paste. POR Paint in a paste form for a seam sealer. I use an acid brush to work it in.

I have used Herculiner for a under coat. a black rubberized stuff used for paint on truck bed liner. Used it on the rear wheel arches area, and back under where the rear wheels throw rocks and crap under the trunk area back to the rear bumper. some tough stuff.

Be careful with Marine Clean, it is a great engine cleaner. but will remove the gold coloring off the various parts. and will also discolor aluminium. but doesn`t seem to hurt paint. I spray it on let it work and hose it off. keeps the engine clean. do it over concrete not asphalt.
Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

Be careful with Laquer thinner. it can bubble up paint and is expensive as well as flamable.

there is a product I use that is a wax grease remover the body shops use before painting. flamable also. they wipe the car down with it before sanding/paint etc...
Paint supply stores should have it. also it doesn`t hurt paint enamel or laquer based paints.

Don`t have any open flames in the garage when using flamable products

Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

The underside is already coated. Just get under the car and repair breaks in the undercoating where you can see rust poking through. Other than that wash the undersides with a lot of fresh water as often as you can.


Thats about all you can do. If you keep hunting for little bits of rust poking up and fixing them you can hold it off for a very long time.

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Don't use the junk that comes in a spray can. I did and it was a mistake. Stick with bedliner products.

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

Thats about the best advice there is. Unless the underside is 50% rusted already why would you wire brush the whole thing? It would be simpler and faster to do the parts that need it and then blend into the factory sealed areas with the bedliner/undercoating.

There is a British product called Waxoyl that I have used before with some success. It is hard to find and must be reapplied at least every other year. Its part wax, part oil, etc. The benefit is it "creeps" into cracks and crevices and displaces moisture and supposedly seals existing rust to slow it down. Its not particularly good for areas like wheelwells that are under a constant barrage of water, grit and grime, as it will wear off. It does work very nicely on frames, undercarriages, suspension parts, etc. The other part I really like is there is no real prepwork other than rinsing and drying the area to be applied. Just put it up on jackstands, ramps, etc. and spray it on. Its a messy, smelly process but its not difficult. The Brit car nuts love it.

RT

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When all else fails, vote from the rooftops!
84' Mercedes Benz 300D Anthracite/black, 171K
03' Volkswagen Jetta TDI blue/black, 93K
93' Chevrolet C2500HD ExCab 6.5TD, Two-tone blue, 252K

The waxoyl system looks like the best thing i have seen yet. i may give it a try. My grandfather said back in his day they used to just spray the underside real good with kerosine every winter season after a rinse with the hose. sure this isn't eco-friendly, but does it work?

I agree. If you coat the whole bottom of the car now, you are just going to seal in all the salt that is on the car now. Unless you are going to clean it and get all the salt spray off of every last nook and cranny.

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1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

i had done my 240 w/ bedliner before it even hit the ground after the floor pan change... so i had ZERO exposure...

almost two years later and ZERO problems

__________________
Matthew McIvor

2016 E350 4Matic Black/Black
2007 GL450 4Matic with Off-Road Pkg Silver/Black
1995 E300 Diesel White/Gray
1994 S600 Euro Black/ Black Velour
1986 560SL Blue/Blue/Gray
1986 190E Blue/Blue 93k

I was raised as a hick in the backwoods of CT. Used to know a guy that did the "Vermont rustproofing" to his pickup a couple of times every year. This consisted of spraying the underside of the truck with used motor oil and then taking a spin on a dry dirt road. The dust would "set" the oil, or that was the theory, and keep the oil there. I will say the truck was an extremely nice example of a 77 Ford F350, no rot to speak of in the early 90's. Daily driven in NE winters. Draw your own conclusions. This method is obviously NOT environmentally friendly. Waxoyl is similar in application. RT

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When all else fails, vote from the rooftops!
84' Mercedes Benz 300D Anthracite/black, 171K
03' Volkswagen Jetta TDI blue/black, 93K
93' Chevrolet C2500HD ExCab 6.5TD, Two-tone blue, 252K

Ah, yep that's been common practice in VT since I can remember. According to my dad, it's still being done. I'm surprised it hasn't been shut down, but I know this last fall they were still doing it. It is best done before the salt is used and the roads are still dusty. I hate to think of the environmental damage it causes.

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1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

If there is any existing rust underneath and you live in the northeast. About the best you can do is mix oil and grease in a shultz gun. The type of gun used to spay rocker panel coatings on.

Heat the guns container in a pot of really hot water to aid sprayability and spray away. The grease component will tend to improve adhesion. This is the only thing we ever found that actually slowed the oxidation longer term.

Anything else we tried tended to develop moisture between it and the rusted surface and the oxidation accelerated under it. Other methods are basically effective where no prior rust exists. We have been over this area several times with corrosion engineers years ago.