Removing rust and protecting the underbody

[tommyg29]

Heres a picture of the rear frame rail which is typical of the rust underneath...mostly surface type stuff, but for some reason the right side is a little worse, and so are the frame rails around where the front of the leaf springs connect. Without spending thousands having the bottom "restored" at a shop, I'd like to do it myself, one section at a time.
This would mean no media blasting, and no grinding....maybe a hand sander...and using the best primer/rust inhibitor I can find immediately after removing all traces of rust. I would probably take months to do most of the reachable areas under the car before removing the exhaust, driveshaft, brake and fuel lines, fuel tank, etc and flatbedding it to a shop and having it finished up, and also having torque boxes welded in at all 4 corners (it's a clone with a 440-6 and a dana rear), so I think the torques boxes would be a good idea.

Any suggestions as to whether this is feasible. Any advice?
What type spray on primer and especially rust inhibitor is recommended?
Anything to make my job easier. Sitting on a creeper for hours on end with crap falling in my face is something I want to minimize. Besides, my arms are 52 years old and dont think I can handle more than an hour or two per week!
I live in a tropical area, and want to drive it, so I want the underbody protected well. No painted surfaces for me.
Thanks

[tommyg29]

And heres a picture of probably the worst area under the car.

[IMNCARN82]

chassis saver.  all over everything. Bedliner in the wheelwells. First Scrape off the under body coating with a heat gun and scraper. Then brake cleaner and scotchbrite and wipe.  Then chassis saver.  Get some comfy carpet. My shoulders still hurt. Pics in my resto thread. There are many resto's here.Lot's of great info.  Rob.

[ted]

chassis saver?

[ted]

similar to por 15?

[Topcat]

This is goinna sound crazy but I hear it works great. I am tempted to do this myself.

If you took plywood and framed it all under the car mimicking the grade slope like that on the floor of a shower stall. Basically, so all water flows into one concentrated area.
Visqueen plastic sheeting goes over that. Make sure no holes doing a water test done once completed. With the car on jacks right over the whole construction you made. 

Now you go over to harbor freight and pick up a bilge pump or West Marine if you have those where you live. Then over to the hardware store and pick up some plastic tubing and a couple of sprinkler heads and hose clamps. Put the whole shebang together so that the bilge pump is in the dropped area picking up fluid and sending it to sprinkler head to desired rust areas.

The fluid you're going to use is...http://www.evapo-rust.com/

I figure 3-4 gallons outta do it. I've heard this was done like this before with excellent results. The PSI to sprinkler is my only concern coming from the bilge pump.

[tommyg29]

So...after reading some more, I think either chassis saver, or zero rust, which also comes in a spray can. From what I can tell they both seem very good. The "minimal prep" part sounds too good to be true though. Rust is one of the most relentless aggravations known to man.

Any more advice about either?

Also, what colors go where underneath and in the wheel wells? I like gray, but not sure what will look more "original", though since I've got a clone, I'm really more concerned with what works and looks best.

[tommyg29]

I'm not sure of the exact process with rust, but from my experience it seems like the only way to stop it is to COMPLETELY remove it, and then IMMEDIATELY seal the steel.
Something about the rust process leads me to believe that it only needs the slightest fuel, such as two minutes exposure to moisture in the air, and even if you seal it immediately, you can unseal the area a year later and find that that little bit allowed the rust to not only start, but somehow continue and grow in a self contained fashion.
I hate it.

[Topcat]

If you plan to go the Zero Rust type paint route without removing rust first then I would suggest getting the Preval spray kit to apply it in confined tight areas.

http://cgi.ebay.com/ebaymotors/PREVAL-SPRAY-POWER-UNIT-AUTO-DETAIL-HOBBY-SHOP_W0QQcmdZViewItemQQ_trkparmsZ65Q3a1Q7c39Q3a1Q7c240Q3a1318QQ_trksidZp4506Q2ec0Q2em245QQhashZitem19b3ef4690QQitemZ110392985232QQptZMotorsQ5fAutomotiveQ5fToolsQQsalenotsupported


Reduce it a little first and spray in confined areas should work out pretty good. Either that or brush it on. Doesn't come out looking as nice brushed on.

I prefer Rust Bullet myself. It's sandable then you can paint over it.

[Topcat]

here's a good thread going on right now comparing.

http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=5315623&an=0&page=0&vc=1

[Chlngrcrzy]

I have used both Por  15 and Rust Bullet in places, and i definently prefer the Rust Bullet stuff.

[dodj]

The fluid you're going to use is...http://www.evapo-rust.com/

Can this stuff be brushed on the underbody to remove rust?  I want to do some welding after the rust removal so paints like POR15 and Rustbullet are out, at least prior to welding. 

[brads70]

Hey Tommy I think your car is just to far gone, I'll come and take it off your hands for ya!  
Mine could use the same treatment! Mine is just VERY light surface rust in places. I have seen and used POR15 but have never used rust bullet? Interesting!

[Topcat]

Can this stuff be brushed on the underbody to remove rust?  I want to do some welding after the rust removal so paints like POR15 and Rustbullet are out, at least prior to welding. 

Yes it can.

Look at this testimony. BTW, This is a Mopar.
http://www.evaporust.com/chassis.html

[dodj]

Thanks Topcat. I bought some today, I'll try that method and I'll see what kind of results I get.