Cleaning the underbody [Archive]

Damn True

11-25-2008, 10:38 AM

My car was run for a while with a spun pan plug so the bottom is covered with oil. There is also the usual dirt, what's left of the OE undercoating, and the results of some very "enthusiastic" greasing of the rear U-joint.

Anyone have a clever way of cleaning the bottom of a car w/o dragging it somewhere to put it on a lift and pressure wash it?

Right now it's on jackstands in the garage with no front suspension.

hotrdblder

11-25-2008, 10:41 AM

propane torch and a putty knife in a few different sizes, makes short work of old under coat etc, then wire brush/da sand etc
before sandblasting on the rotisserie i always use propane torch and heat and scrape undercoating off, then blast it perfect clean.

Damn True

11-25-2008, 10:55 AM

That part is pretty simple. It's the grease/oil that I'm confounded by. Other than a lot of soap/water (messy while sitting in my garage, and I don't relish the idea of sending that down the driveway and into the gutters and storm drains) what else would work. Is there a quality spray/wipe product that will do a good job?

Simple Green and elbow grease I suppose huh? But I'm worried that the simple green might leave behind detergents that might screw up the bonding of any future undercoating.

parsonsj

11-25-2008, 11:05 AM

I can't recommend my solution: I cut all mine out and sent it to Nova heaven.

Seriously, I'd use brake parts cleaner. I don't know what to tell you about putting some hydro-carbons into the storm sewers. I think you'll just have to find a way to live with yourself afterward. :)

As far as bonding of new under-coating, just be sure you wipe it all off with pre-paint cleaner. It's lousy work, especially while on your back.

jp

jp

hotrdblder

11-25-2008, 11:06 AM

clean it with simple green, then go to autobody place and get some wax and grease remover, and wash thoroughly, it has alcohol in it so it drys very quickly. after that you should be good for epoxy, etc

mhotel1

11-28-2008, 06:00 AM

I used a gallon of water based degreaser and pump sprayer...that stuff works pretty dang good. Got it at autozone and it comes in purple jug cant remember the name.

Chad-1stGen

11-28-2008, 01:25 PM

You can make a catch mat with a tarp or something to catch all the nastiness and then at least send it to the dump rather than storm drains...

Here is some inspiration lol...

https://static1.pt-content.com/images/noimg.gif

comp-spec

11-28-2008, 03:30 PM

clean it with simple green, then go to autobody place and get some wax and grease remover, and wash thoroughly, it has alcohol in it so it drys very quickly. After that you should be good for epoxy, etc

simple green and elbow grease

beep4beep

11-28-2008, 03:56 PM

go get you a cheap drop cloth and two or three cans of easy off oven cleaner best degreaser in the world cuts dirt grease and oil off every thing. then take a torch to the undercoating. good luck with the scraping.....

Damn True

11-29-2008, 02:56 PM

Tom Welch

11-29-2008, 04:04 PM

Just dive in and get filthy, maybe Mike Rowe can lend a hand. Accept the dirt as payment for a clean under side, probably a lot easier to clean with a lot of oil on it anyway.

Chad-1stGen

11-29-2008, 09:28 PM

Jeezus!

Do we have a Darwin awards thread here?

Nah. Not only is that a stripped shell which is pretty light but it's supported by the boards which are bolted to the unibody and it's supported by chain to the garage rafters. It's a good alternative to a full blown rotisserie IMO.

dhutton

11-30-2008, 08:12 AM

I use cheap hardware store paint thinner to cut the grease. You can spray it on or brush it on with a large paint brush. Let it sit for a minute or two then scrape with a plastic putty knife (or a metal one if needed). I then follow up with a wax and grease remover to get the last of the film left behind. SPI sells a good solvent based wax and grease remover that doesn't cost an arm and a leg.

Wear a respirator.

Don

zman1969

01-14-2009, 03:01 PM

D/true- try some Easy Off oven cleaner spray it on and let it soak it will take alot off - messy and nasty wear a clean suit/goggles

fantasygoat

01-15-2009, 11:59 AM

I used lacquer thinner, rags and a wire brush to go from this:

https://static1.pt-content.com/images/noimg.gif

To this:

https://static1.pt-content.com/images/noimg.gif

Well, that and rattle can paint. Technically I used "Gun Wash" which is a cheaper (recycled?) type of thinner.

shep

01-17-2009, 02:46 PM

If it was drivable take it to one of the touch less automatic car washes and get the under carriage wash. That will get the big chunks off.

vanzuuk1

01-18-2009, 05:34 AM

When I degrease something I use the heavy stuff first and then rinse it with some kind of hot soapy blend and use paint brushes to whisk it away.The degreaser or easy off gets the heavy stuff and then the soap and hot water wash all the ugliness away.

Or make a parts washer out of an old above ground pool and a tanker truck of gasoline...maybe not.