Hi All,
As fall approaches I'm wondering what the best remedy for rust prevention here in MA for the winter, since they salt the heck out of the road. I've never done anything for rust prevention in the past and as a result I've had to put some money into fixing up areas of the rockers that took a hit (under the front driver and passenger side doors).

Is there a quality product for a DIY remedy for undercoating or a good shop procedure? EPA laws probably won't let me do any thing in MA shops but I could sneak up to VT or NH to get something done.

I'm driving an 88 245 wagon with 127K on it. Still young and would like to keep it going for a while longer (hopefully rust free).

Thanks!

Last year at about this time, I put on the coveralls and went to work spraying on this stuff:

http://www.roversnorth.com/waxoyl/products_corrosion.html

Messy and difficult to work with in ideal conditions, I procrastinated making it harder then it should have been. It's a wax based system that needs to be at proper temp and viscosity to apply. It forms a thin but tough skin and overall held up really well. There are a few small areas that will need to be redone because I didn't get all the rust off prior to applying. Overall I'm very happy with the results and will continue to use as needed.

What has protecting your car have to do with the EPA. Sounds like too much government in MA.
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David Hunter

It is all about air quality, storm water run-off, etc, etc. A lot of paints, coatings, cleaners/detergents that were once available to all are being restricted.

I was THRILLED to find real TSP still available in Indiana. Nothing strips 45 years of chain-smoking grandma's tar off the plaster walls of an old house, like real TSP.

Many states have oulawed its use do to the environmental damage that allowing it into lakes and stream untreated can cause. Of course, allowing that to happen on regular basis is bad, but outlawing the stuff means even worse environmental unfriendly methods must be used to encapsulate the offending tar.

Onkel Udo

I don't like the rubberized undercoatings because I found they can trap water under them, making the rust problem worse. I get mine sprayed at a shop with a "soybean oil based" rust coating, that never really dries, every year. Without a hoist and an air sprayer I don't think you can get at all the areas a 240 rusts.

From what I have seen the rockers and unibody frame members rust from the inside out, so you have to coat the inside. Ditto with the doors and fenders. The bottoms rust out from the inside.

I am also pretty sure the floor tubs rust out from the inside. The foam soundproofing holds a ton of water (probably salty) and is in close contact with the floor. For my last 3 cars I have oiled the floors on the inside, and put plastic sheet over the oil to isolate the floor from the wet soundproofing. The floor tubs on my last 240 stayed almost perfect. Unfortunately I did not figure out how to stop the rear wheel tubs from rusting out on my last 240 and there is no good way to fix them.

The rear wheel tubs are the hardest to protect because water from the tires washes off any rust proofing and mud accumulates under the lip. My latest attempt to stop rust here is 740 plastic rear wheel tubs with lots of rust proofing under them. The 740 tubs will fit a 240 with a little modification. The tubs are almost identical. The main difference is that the top part of the lip on the 740 is flat. I just cut the flat part of the lip off the tubs and they fit right in. This will only be the 2nd winter with the tubs so I don't know if they will stop rust long term.

3M underarmor rubberizing undercoating. you can find it in the likes of walmart.

Ditto, I really like 3M product and used to buy it Walmart. Last week I went there and they had switched to a Rustoleum undercoating so I deceided to go to AZ and get a can. It was 9.99 a can but I really like the stuff and don't feel like switching to another type. I found cheaper prices on certain paints at AZ and Lowe's than Walmart. One item had 25% free from the manufacturer and they had up'd the price by 25%. I was under the impression that was a bonus from the manf. to consumer. I guess always the low price doesn't imply anymore.

If anyone knows a good place to get the 3M stuff let me know.

Any product which is tar like and flows will work fine. I touch up with rubberized roof mastic from home depot. It is oily and slightly thick but can be easily applied with a coarse brush and dries completely in 5-6 days.
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DD-1990 240 DL SW M47II FI 3.1 234 K miles

Good Year makes an excellent undercoat spray that will also give some slight sound dampening. Wear Gloves and a shirt you do not care about when you get ready to apply it. There is also a temp range if memory serves, so you need to apply before the chill sets in. Put something on the drive or garage floor to catch the overspray. Keep your face away from the area being sprayed and wear your safety glasses. And you need to cover your hair also. Sort of messy but good stuff and it even stuck on areas that there slightly oil covered. You will want to degrease and clean the area being coated.

It has a black almost like asphalt base to it and you shake it up and spray on. I used this after doing floor board repair last year with Por 15.

It will coat almost any metal part with a single spray and after a year of running down the road still firmly coating every thing. Have not seen an single place where it came loose. I ended up using it on the gas tank where the old coating had come off and applied it from front to back. Took four or five cans to do everything. Wrapped paper around the transmission, drive shaft, and any other place that needed protection and coated all the exposed surfaces.

You can find it at Auto Zone and a couple of the other Auto Chains in the paint section. McMaster Carr has if under Rubberized Sealant and Undercoating— Black near the bottom of page 2092 for less than $6 a can.

Good Stuff and it will last.

Regards,

Paul

Eastwood markets some stuff that sounds just like the Goodyear product, but for about 80% more. (!)

I've touched up early rust spots with wire brush first, then rust kill spray, then over that used 3M rubberrized coating compound out of a spray can. It stuck well. A bit small coverage per can so the money could add up if you are covering the entire car belly.

One thing I noticed after a salty winter was how the salt stuck onto the aft-most muffler in one thick crusty layer that didn't get washed off in regular car washes - only when I reached down there with the hose did it rinse off. Watch that spot.

I don't live in the NE, but I prefer the slow-oil-leak method of rust prevention. Make sure your car blows a little oil at highway speeds, that way it coats the entire underside of your car every time you drive. Actually, I thought Volvo built this into the 240, since I've never owned one that was bone dry on the underside.

More seriously, why not go to NAPA, grab a gallon pail of undercoating and go to town with a brush? I've undercoated my entire gas tank and other parts with the stuff, it works great.

I've been driving these roads in Ma, NH and Vermont all my life. All I have ever done is use the hose and flush underneath everywhere on any warm winter day. I do that right up til May when the salt is off the road. Then I do my best to keep the underside dry. No rust problems ... lately I've been changing my own oil and I use PB blaster on parts that will need replacing and give potential rust areas a blast also ... couldn't hurt.