Cleaning old caked on mud (1 Viewer)

[therestevethedog]

So I’m finally in shape with the important stuff and now it’s time to start on the more cosmetic side of things. When I bought this truck it had years of caked, dried on mud on the whole underbelly. Used an oscillating sprinkler and let it run for a good long stretch. It got all of the really loose stuff so now it’s time to attack the gunk that has turned to stone

Any thoughts on how I can do this more easily? I can’t spend the next six weekends under the truck scrubbing with an abrasive.

 

[bkfj40]

A just use the truck Offroad. It will take that schit right off.

 

[therestevethedog]

If only

 

[CharlieS]

Dry ice cleaning? Looks effective, but probably expensive.

I'd probably let the sprinker do it's job, and then use a pressure washer with the attachment on rollers that shoots water up (I got one cheap on amazon).

 

[mudgudgeon]

Probably not the most environmentally friendly . . .

spray biodiesel on it, let it soak, saturate again, pressure wash off (with hot water if possible)

 

[Malleus]

If that's truly mud, it's very likely clay. Since it's very alkaline, it's chemically bonded to the metal. You have two choices: chemically remove it or remove it mechanically. Using a mechanical method, like a needle scaler or wire brush, will work, and it will also remove the paint.

Try a mild acidic solution, like vinegar. Put some 50/50 with water, in a spray bottle on a Saturday and spray the fuel tank under cover every hour for as much of the day as you can. Then pressure wash it, with hot water if its available. This will let you know if the process is going to work, and how long it'll take. You can vary the strength of the solution as you work through the process.

Regardless of how you remove it, you're going to remove at least some of the paint, too. You need to be prepared to remove whatever is on the metal surface after you clean it and apply some surface treatment, like a base primer or phosphoric acid solution (my preference; I use Ospho), as soon as possible, or you'll have a rust problem to deal with.

 

[AussieHJCruza]

See if you can get access to a hot water high pressure washer, coupled with a good degreaser (go to a truck cleaning products supplier for something that actually works) and put on a raincoat

 

[therestevethedog]

That photo gives me hope! Now I just have to find somewhere to do it too. Not my driveway lol

 

[AussieHJCruza]

That photo gives me hope! Now I just have to find somewhere to do it too. Not my driveway lol

Around here, a few detailers, especially truck detailers will do an undercarriage clean for a couple of hundred dollars, I'd say it would be money well spent if you can find something similar and haven't got a means to do it yourself

 

[robnicko]

try and find some of this stuff.
used to be sold in Shell servo's and worked unbelievably good on dirtbikes

 

[Kernal]

All the above.

It appears some of those areas are a mix of clay with the old thick waxy protective spray so any process that removes all the clay will likely remove
any remaining protective wax (hot water/steam/pressure).

FWIW all my 80's still have much of that original protective wax which I don't disturb unless it required to service something. Once that wax is removed the corrosion will start so it might be worthwhile to reapply some sort of protection. But then, next time you run through clay it will look like it does now all over again.

 

[77mustard40]

CLR and a scotch bright works great but it’s a PITA. Helps to put a sprinkler under there first.