need advice on rust spots

[lunap]

I have some rust spots on my 1980 FJ-40 where the paint bubbled. What is the best way to temporarily treat this?
I am not concerned about cosmetics for now, just want to sand the bad spots and cover with something. Primer? Bondo?
There are no holes, just rust starting to spread.
I would appreciate some advice - I have no experience with paint although I am handy with tools and figuring it out.

 

[Trevor]

Lightly sand, coat with Ospho, then primer. I did this to my rear fenders three years ago and they're still fine.

 

[Jim]

Ospho

What is OSPHO??

 

[Sir_Titus]

OSPHO is an acid whrn mixed with rust it has a chemical reaction and turns it in to iron. It is used heavely by the coast guard and other marine aplications I think the key ingrediant is osphiric acid

 

[mallred]

ospho

I am suprised that I have not seen Ospho here before, we use it in AK on the boats and it stops the rust right now. you just need to get the flaking rust removed and it stops the damage if coated with a exopy paint after it cures.(this is with salt water exposure)

 

[lunap]

West marine sells a similar product - RustGone metal Prep. It's basically an acid that changes the rust into a metal compound.
But shouldnt I just sand out all the rust and cover with a body primer?

 

[Steve C]

Sanding can't get to all the little nooks and crannies as well as the chemical. PPG recomends metal cleaner and metal conditioner before epoxy if the area has rust.

 

[PabloCruise]

If you have bubbling paint, you have rust coming through from behind.

To get at it you need to cut, or blast from behind, or dis-assemble...

 

[Chase77]

Rust Bullet

Go to rustbullet.com and order yourself a pint to cover up your spots in order to stop the decay. Not affiliated in any way but am very very impressed with their product. To treat the spots all you would have to do is sand down the areas to expose the rust and a little of the surrounding clean metal and then roughen up a little of the surrounding paint and lay on 2 coats. THe product sticks to surrounding paint and will seal the rust. Good luck.

 

[Romer]

I would dremel grind first the infected area to remove the bubbling area and get down a layer of metal. Then treat the metal with the chems above. If there is a hole after this, you might want to cut it out and then arc weld a piece of steel (Easy) from the backside, then bondo to smooth over the steel. If there is no hole, then bondo to smooth, sand, prime and paint. Thats what I would do! You do not want Bondo covering and empty hole, you should use it more as a finishing product.

 

[lunap]

There are no holes, just rust spots. Sounds like I am going to sand away the rust to bare metal, bondo, prime and paint. I think Rust Bullet will just cover the rust so no oxygen gets to it.
BTW - I am talking about spots here and there. Short of a full paint job - which I will do eventually - where can I get Rustic Green (OEM color) spray paint???

 

[tucker74]

Short of a full paint job - which I will do eventually - where can I get Rustic Green (OEM color) spray paint???

A good paint shop can match your paint and put it in a spray can for you -



Tucker

 

[largenfirm]

You may think there are no holes, but a through rust removal will likely prove you wrong.

Don't do a half-assed job, as you'll then get to do it again, later, with a much bigger problem.

Kirk

 

[SNLC]

hence the reason a frame off is key on a rusty truck. You simply can not get in all the nooks and tight areas without a body off a frame. No other way to get it all nubbed out for good, IMHO.

 

[lunap]

I understand about the eventual frame off restoration. I am talking about a temp measure for now where I can grind out the bad spots and cover with a primer to slow it down.

 

[Romer]

Before you bondo, treat the area were the rust was. There are all sorts of chemicals and opinions, but treat it first or the rust will be back.