Undercarriage Rust Removal

[SeanC]

Hey guys,

I've noticed that the undercarriage on my '96 Trans Am is starting to get pretty rusty. Its not bad enough where its eating completely through, but i'm worried that if I let it go much longer, it will. First, what is the best way to remove this rust? Second, what can I spray it with to prevent it from getting worse or rusting again?

I'm sure a bunch of people have had this problem in NJ...

Thanks for the help!

Sean

[HardcoreZ28]

You can remove it with some sort of media blasting or a wire wheel.....or you can prep it properly and paint right over it with POR to lock out any future moisture and rust.

[79T/A]

Also, if it's surface rust that isn't running too deep, a 4 1/2" angle grinder with a flap disk on it might do the trick. A little deeper than surface, a regular grinding wheel. Deeper than that, it may be POR 15 time, unless you're up to replacing sheet metal.

[SeanC]

Definitly not up for replacing sheet metal haha. It seems like its only surface rust (hasnt eaten through). I honestly don't know anything about POR.

Wouldnt it be best to grind the rust off and then spray it with a rust proof coating? Do you actually just spray the POR 15 over the rust?

[WildBillyT]

Originally Posted by SeanC

Do you actually just spray the POR 15 over the rust?

Restomotive says to do it this way. You can, but a lot of people wire wheel or clean off the rust first. Make sure that the surface is rough and has "tooth" for the POR to stick to.

[BonzoHansen]

use a foam brush for por15 for what you are trying to do. por15 is bad stuff through a spray, you really need an air supplied respirator.

[maroman88]

if its just a light coating of surface rust, ive always just scrapped off wat i could and sprayed some rubberized undercoating on

[usp55]

Originally Posted by maroman88

if its just a light coating of surface rust, ive always just scrapped off wat i could and sprayed some rubberized undercoating on

I hope you used some sort of rust convertor/inhibitor (por15/stop-rust/etc) before that rubber undercoat. Most people will tell you that that rubber undercoat does a nice job of trapping moisture and causing rust itself. Not to mention that **** is a PITA to get off! I’ve spent 15+ hours so far on my back under my firebird removing it. Hands down the dirtiest job Ive ever done.

[transamws686]

Originally Posted by usp55

I hope you used some sort of rust convertor/inhibitor (por15/stop-rust/etc) before that rubber undercoat. Most people will tell you that that rubber undercoat does a nice job of trapping moisture and causing rust itself. Not to mention that **** is a PITA to get off! I’ve spent 15+ hours so far on my back under my firebird removing it. Hands down the dirtiest job Ive ever done.

I hate that ruberized under coating but it does work, my 81 had the original dealership coating on and it lasted 30 years and I removed it. I will tell you it is HELL wore brushing off but halfway through I realized brake cleaner will dissolve it or get the Eastwood rubber undercoating remover.

For rust treatment, find the area and use a converter that will change the Iron oxide into iron phosphate then spray with a encapsulater or other primer then hit it with paint of your choice.

Depending on where you are I would be happy to help or atleast show you when it is warmer.

-Eric

[WildBillyT]

Originally Posted by transamws686

I hate that ruberized under coating but it does work, my 81 had the original dealership coating on and it lasted 30 years and I removed it. I will tell you it is HELL wore brushing off but halfway through I realized brake cleaner will dissolve it or get the Eastwood rubber undercoating remover.

For rust treatment, find the area and use a converter that will change the Iron oxide into iron phosphate then spray with a encapsulater or other primer then hit it with paint of your choice.

Depending on where you are I would be happy to help or atleast show you when it is warmer.

-Eric

Heat gun and a putty knife, followed by a Brakleen wipe down.

[SRC]

As others mentioned your preparation will be dependent on how bad the rust is. For surface rust the POR is the most popular choice. We have used other brands that have a different viscosity and finish when dry. I've tried to reduce POR 15 but without creating a real mess spraying it becomes a hassle.

I would stay away from a rubberized coating, in my opinion these are for detailing already finished surfaces. If possible before you apply the top coat you can also apply a product like Eastwoods rust neutralizer and/or POR metal ready. Both have multiple steps and should be followed closely before your top coat. Since you probably have the entire suspension in the car it will be best to brush on whatever product you decide to use. I agree with the foam brush but you will find that a variety of sizes will be helpful too.

We recently did this service on a Cougar with all its suspension etc in place, its a bit time consuming if you cover and protect all areas that you want to prevent the POR or other rust inhibitor from getting on, but the results are good.

As with any older car you can be sure that you need to put rust prevention on your annual maintenance schedule.

Be sure to protect yourself, the car and the garage floor.

[CHRIS67]

I've done the POR 15 to cars and trucks in the past and it works really great. It is all in the prep and you can't cut corners. I would wire wheel any surface rust (you don't have to remove all of it), use the Marine Clean, followed by Prep and Ready, and then finally the POR 15 paint. Be sure to wear gloves and a long shirt, that stuff is super hard to get off of things!!!

http://www.por15.com/

Their home page shows 'new' spray on chassis coat aerosol cans. Ooooo.

[3.4 grape of wrath]

Cheap, safe and it works. Just brush it on. You might have to do it more than once depending how bad the rust is.

http://www.harborfreight.com/1-quart...ver-96433.html