Underbody rust/undercoating/rust prevention

[Kyle_T]

So I'd like to take car of the rust on my underbody before the car is on the road. As it looks now, the car will be driven in the winter. Id like to "rustproof" it as much as possible.

The car came from the south and was driven in 1 wisconsin winter by previous owner. The under body seems fairly clean, but there is still quite a but of rust that id like to be gone. And Id like to prevent anymore rust from forming. I read that to do a proper undecoating job all rust and moisture has to be completely gone otherwise the rubberized undercoating will trap the moisture and it will rust the underbody even faster.

Heres some picture I took of the underbody today.

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Worst 2 spots:

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My plan was to:
1. Grind off all major rust spots, and get rid of all "loose" rust
2. Brush on rust converter on all the rust that is left.
3. Clean/Prep rest of underbody
4. Spray rubberized undercoating.

So let me know what you guys think. Any input is great.

 

[604CruisinCroat]

Wow...that doesn't look too great. Get that thing on a rotisserie and start wire wheeling everything. Or you could just do it from underneath. You're going to have to remove everything from underneath to do a proper job. Then POR15 it.

 

[Kyle_T]

Wow...that doesn't look too great. Get that thing on a rotisserie and start wire wheeling everything. Or you could just do it from underneath. You're going to have to remove everything from underneath to do a proper job. Then POR15 it.

Im not sure if I want to go the por-15 route. Its expensive and requires alot of prep work. And you have to completely remove the rust. And im really not worried about the rust on the gas tank shield and exhaust heat shield that much.

 

[Detective Coating]

Search around here for what best suits your needs. They have great products and have reviews about almost every product. Rust Paint - Rust Proofing Products - Rust Protection - Corrosion Control - Eastwood

 

[Kyle_T]

Search around here for what best suits your needs. They have great products and have reviews about almost every product. Rust Paint - Rust Proofing Products - Rust Protection - Corrosion Control - Eastwood

Yea Ive been looking on there and Im most likely going to use the rust converter or rust encapulator from eastwood.

 

[boostinout]

Search around here for what best suits your needs. They have great products and have reviews about almost every product. Rust Paint - Rust Proofing Products - Rust Protection - Corrosion Control - Eastwood

I paint cars at home have paint booth and all. Have to say por 15 is the easy way to go. Ive used the rust mort also and its gonna take about 4 or 5 treatments of rustmort to fix your floorboard. The por 15 you can just hit it with a wire and then just brush it on. cost you maybe 60 bucks for cleaner and product. The rustmort you have to brush on then hose off. Then you have to wait for it to dry before next treatment then you still have to put something on after your done with that. por 15 just brush it on and its a done deal.

 

[Kyle_T]

I paint cars at home have paint booth and all. Have to say por 15 is the easy way to go. Ive used the rust mort also and its gonna take about 4 or 5 treatments of rustmort to fix your floorboard. The por 15 you can just hit it with a wire and then just brush it on. cost you maybe 60 bucks for cleaner and product. The rustmort you have to brush on then hose off. Then you have to wait for it to dry before next treatment then you still have to put something on after your done with that. por 15 just brush it on and its a done deal.

The only thing is the car is sitting in the garage on jack stands and i have no way to hose it off in the garage.

 

[boostinout]

The only thing is the car is sitting in the garage on jack stands and i have no way to hose it off in the garage.

Just hit all the spots you wanna fix with wire wheel. Blow all that off with air hose and just wipe it down with the prep cleaner por 15 offers. Then just brush on the por 15 and it dries with no brush marks. Then just scuff and paint with what ever you want.

 

[Kyle_T]

I thought for por-15 you need bare metal

 

[boostinout]

I thought for por-15 you need bare metal

It;ll be fine

 

[trunks]

My Por 15 product instructions say that it actually works better on rusted metal than on bare metal. It's designed to go right onto oxidized metal from what I understand.

 

[Kyle_T]

Should I grind off the major rust spots first? And wont por15 trap the moisture and rust out even more if the rust isnt completely gone? And would I be able to spray a rubberized undercoating over it? Or do you think the por15 will deaden sound enough?

 

[boostinout]

Should I grind off the major rust spots first? And wont por15 trap the moisture and rust out even more if the rust isnt completely gone? And would I be able to spray a rubberized undercoating over it? Or do you think the por15 will deaden sound enough?

You can paint the por 15 over plain rust. it dont really matter just make sure it clean of oils. I talk to my paint rep about this product. This guy knows what hes talkin about. Ive known him for three years and he is the sales and demo rep for sherwin, sems, martrin senor, and por15.

 

[BLINKY619]

put the wheels back on and push it a couple of feet out

 

[red_devil]

The good thing about por15 is that you dont have to get the rust off first it helps stop the rust from getting any worse. I like to use a wire brush, then coat it with some muriatic acid, clean off then apply por15 for the best result.

 

[pj91gsx]

Ive used rust remover 1st, then rust converter afterward, and painted over that with 96 cent walmart black paint on a rear bumper and the bumper still is holding up without any rust coming back after 4 years!!! Ive also used it on inside the doors of my bmw where there was really bad rust. I ground the majority off and used rust converter and never come back. Really good stuff, just make sure you get the loose stuff off. you could probably pressure wash and wire brush then add the converter, primer, paint and undercoat, good luck.

 

[Kyle_T]

Going to start getting rid of all the rust tomorrow. Ill see how it goes...

 

[Kyle_T]

Whats the easiest way to remove the rubberized undercoating?

 

[cfeyhris]

the easiest way to remove it is a heat gun and a scraper. ive used rust preventer from walmart after grinding everything down, then rubber over that

 

[TiradoCC]

It looks like you have a good plan, don't see any problems with what you have outlined.
I would try to remove as much as possible with the wire wheel/grinder.

Follow the instructions on whatever product your using for the rust and you'll be good to go.
If you need anymore help feel free to pm me.

 

[daren_p]

Check out a company called Rust Bullet, same idea as por15 but I believe independent testing shows its an even better product. I used it on a bunch of parts when I did my awd swap. My parts were clean, rust free & its a summer only driven car but I wanted it to stay like new. So obviously I haven't had any rust issues (2 summers) but I can say the product is super tuff & won't chip or scratch like some other products which would let oxygen & the elements in, preventing the coating from working. Its can but put on already rusted metal as well, just clean up the loose stuff.

Actually my rear diff was very rusty, I sandblasted it clean but left unprotected, it would start rusting again in a day or two. Rust bullet is only a silver colour but can top coat in any colour you like. With the rust bullet & then their gloss black industrial coating on my diff, it looks better then factory new still.

 

[Kyle_T]

What do you guys think about using a brush/spray on truck bed liner instead of the rubberized undercoating? It seems to be much tougher.

 

[pj91gsx]

What do you guys think about using a brush/spray on truck bed liner instead of the rubberized undercoating? It seems to be much tougher.

The only bad part about undercoating the car is that sometimes you go over speed bumps and rub it off, i think the bedliner would help there, so i think you should apply it to the frame rails. I undercoated my car and it works great the only problem is hitting speed bumps, but my car is lowered.

 

[Kyle_T]

I think im going to go with por-15. But im still not sold. Will it need a top coat over the por-15? I hear its tough, but some people said that it chips off.

 

[red_devil]

Its pretty tough stuff but i would use a rubberized spray paint to cover it.