What is the best rust converter for frame/body?

[SOHCman]

The midwest winters have been hard on our older vehicles, and I am looking for a good rust eater/converter to start treating the rusting body and frame before the body work and new undercoating are applied.

Does something that can be sprayed all over the underside of fenders and on frames exist that will actually eat the rust and prevent it with a rubberized undercoating over it?

 

[doitmyself]

I have spent some time researching rust converters on the web and if you dig deep, you will find a lot of controversy questioning if they even work. One system that gets a lot of discussion is POR-15, but you need to follow their instructions closely.

In my opinion, the problem with any rubberized type of coating is that if/and when you get the tiniest breach (crack) in the coating, salt water will migrate underneath the coating.

Also my opinion, but I think the products like what are used by Krown or Rust Check are probably best, but they require annual applications.

Good luck.

 

[SOHCman]

Is Krown something that can be bought and applied at home?

 

[FXjohn]

the best you can hope to do is smother the rust and keep it from getting any worse. use old motor oil, rust encapsulator/por 15 or better krown and rust check.

 

[salesmantony]

Originally Posted By: SOHCman
The midwest winters have been hard on our older vehicles, and I am looking for a good rust eater/converter to start treating the rusting body and frame before the body work and new undercoating are applied.

Does something that can be sprayed all over the underside of fenders and on frames exist that will actually eat the rust and prevent it with a rubberized undercoating over it?


Google "Salvage II rust". Made by Partsmaster, this stuff is absolutely the best.

 

[mechtech2]

Eating the rust and coating it are going to need two different products.
No one miracle product can do this.
An option is to use old fashioned Naval Jelly [phosphoric acid] that is applied, let soak, then water rinse off. It eats rust down to base metal. But then you have to coat it with whatever other product you choose.
Do this piece by piece, one section/area at a time.

 

[Bamaro]

Originally Posted By: doitmyself
I have spent some time researching rust converters on the web and if you dig deep, you will find a lot of controversy questioning if they even work. One system that gets a lot of discussion is POR-15, but you need to follow their instructions closely.

In my opinion, the problem with any rubberized type of coating is that if/and when you get the tiniest breach (crack) in the coating, salt water will migrate underneath the coating.
Also my opinion, but I think the products like what are used by Krown or Rust Check are probably best, but they require annual applications.

Good luck.

I wouldn't really consider products like POR-15 as pure rust 'converters'. They are better characterized as rust encapsulators. Products containing phosphoric acid are rust converters.

 

[cchase]

This has come up on the boards in the past.

In my experience, nothing truly "converts" rust to a stable enough compound that it can be considered "gone".