[ObsidianWRX]

So right now I'm upgrading my sway bars and taking off the subframe on my 2005 wrx. The subframe has become very oxidized and rusted, so I plan on sanding that down and using some rust converter. My question is, what should I spray on it to protect it from salt and stuff? I have some plastidip laying around but I'm not sure if that will last underneath the car. Any suggestions? thanks

 

[Sasquatch]

I doubt plastidip would be a good long term solution. If you are going to the trouble of sanding / prepping, paint would do better.

 

[zax]

Keep in mind that parts under the car are designed to rust gracefully, and some surface rust is both normal and expected.

If the subframe is not structurally compromised, I would not be so concerned, particularly given the age of the vehicle and your apparent location.

 

[Sasquatch]

Keep in mind that parts under the car are designed to rust gracefully, and some surface rust is both normal and expected.

If the subframe is not structurally compromised, I would not be so concerned, particularly given the age of the vehicle and your apparent location.

Agreed.

 

[ObsidianWRX]

Thanks for the advice guys

 

[Obeisance]

When I was repairing my car after crashing it in 2013, I used chassis saver paint. It is a thick polyurethane with zinc powder in it. For the most part, it has been okay.

I did not perform proper preparation on much of the underbody that I applied it to (just a quick wash and brief wire brush scrub) and I missed a lot of spots (hard to reach places like up in the transmission tunnel and near the outer edge under the rear fenders), so I have re-applied it in 2016. On the places where I properly prepped (such as the parts I was replacing after the accident, like the U-shaped subframe up front), the paint has performed well.

It seems like Subaru's in salty areas will rust. I'm watching the characteristic spots on my car, such as the body panel stress/crease where the gas cap joins the fender (how's that for great corrosion engineering) and the joint between the rear bumper cover and wheel well. At least my subframe is not rusty like they can get.

 

[rqjoe]

If you can get zinc in contact with the car steel, it will help. Otherwise, removing the salt frequently would provide the biggest results.

 

[ObsidianWRX]

When I was repairing my car after crashing it in 2013, I used chassis saver paint. It is a thick polyurethane with zinc powder in it. For the most part, it has been okay.

I did not perform proper preparation on much of the underbody that I applied it to (just a quick wash and brief wire brush scrub) and I missed a lot of spots (hard to reach places like up in the transmission tunnel and near the outer edge under the rear fenders), so I have re-applied it in 2016. On the places where I properly prepped (such as the parts I was replacing after the accident, like the U-shaped subframe up front), the paint has performed well.

It seems like Subaru's in salty areas will rust. I'm watching the characteristic spots on my car, such as the body panel stress/crease where the gas cap joins the fender (how's that for great corrosion engineering) and the joint between the rear bumper cover and wheel well. At least my subframe is not rusty like they can get.

Yea, those spots are good to watch for. I recently just repaired the rust on mine and got it resprayed, and hopefully I won't have to deal with rust for a long while haha. I'll certainly check out that paint, thanks for the info

 

[OIIIIIIO]

I have not done anything to my WRX yet, but in the past I have used POR 15 on 8 of my Jeep frames. If it is clean steel you will want to get their etcher, if the surface is slightly rusted this is perfect. If the steel is scaled, then you will want to knock the scale off and go from there.

You put it on with a brush, and it will make a mess. It is hands down the best stuff I have ever seen. You will only need the base coat as it will not be in direct contact with UV rays. On the Jeep frames I done the base, then the primer, then the top coat. You can do that as well, as the top coat is designed to deal with UV rays, the base coat will break down by direct sunlight.

Hope this helps.

 

[NYSWRX]

I am from NY and have always battled the salt. My dad has used RustCop for many years on his 1999 Suburban and he is now pushing 250+k. If you have the time to go through everything and sand / convert the rust you can do what I am doing on my Excursion. I am converting the rust with Ospho, priming it with ZincIt, and then painting it with Dullicolor truck bed liner. I have used it before and had very good luck but you have to make sure to convert all the rust or you will only make it worse.

If the rust isn't too bad / after you paint I would still treat the car. I just treated my car with a product called Fluid Film (you can watch the videos on you tube). It is a lanolin based, solvent free (it won't dry), oil like application that will stop the rust from getting worse (you still have to re-apply it over time). It is cheap and pretty easy to use, best of all there is no real prep work as you can spray it over rust.

In high traffic areas other products are longer lasting but this really creeps in everywhere and does a good job. You can get a gallon of it for $41 from Napa, Oreilly's will match Napa's price. You can also order it online if you want to pay for shipping. I bought a professional rust proofing gun to get inside the frame rails, control arms, rocker panels, etc. View attachment 281833 View attachment 281841 View attachment 281841

 

[Dongatoni]

+2 on the POR15. I paint cars for a living and thats what I use for frames. I wouldn't use anything else.