Rust Inhibitors
Thread Starter
Le Mans Master
Joined: Jul 1999
Posts: 9,206
Likes: 17
From: Sewell NJ
Rust Inhibitors
I started the winter projects on the 74 and while I was disconnecting things I saw that there was a lot of rust in the coolant. Last year I drained the coolant, flushed the system and refilled with a 30/70 mix of anti freeze and water. I don't have any cooling problems but the rust bothers me and makes a mess of the overflow tank. Has anyone used a rust inhibitor and if so did it work well. Also, what type of system flush have you used that worked well. Thanks in advance.
Le Mans Master
Joined: Aug 2000
Posts: 9,662
Likes: 7
From: Semper ubi, sub ubi
Cruise-In VI Veteran
Cruise-In VII Veteran
Re: Rust Inhibitors (vettfixr)
There is usually a whole lot of rust inside an old block. I think the only way to get rid of it is to have the block boiled out. I know that phosphoric acid in the presence of oxygen will convert rust (iron oxide) to iron phosphate. I don't know of any coolant system treatment that will completely remove all the rust.
Last year I used a store bought coolant flush, it did a fair job on the radiator, but when I pulled the heads last month, there was 32 years of scale and rust inside the block.
Last year I used a store bought coolant flush, it did a fair job on the radiator, but when I pulled the heads last month, there was 32 years of scale and rust inside the block.
Racer
Joined: Apr 2000
Posts: 499
Likes: 0
From: Kristiansand
Re: Rust Inhibitors (vettfixr)
I used a rust remover based on phosphor acid. These attacks only corrosion, not bare metal.
After a couple of days all rust was gone and I flushed the system and filled antifreeze. Since then (1/2 a year ago) the antifreeze has stayed clean.
The overflow tank also got completely clean inside.
Dishwashing detergent can also be used, but this in my experience doesn't remove the rust.
After a couple of days all rust was gone and I flushed the system and filled antifreeze. Since then (1/2 a year ago) the antifreeze has stayed clean.
The overflow tank also got completely clean inside.
Dishwashing detergent can also be used, but this in my experience doesn't remove the rust.
Thread Starter
Le Mans Master
Joined: Jul 1999
Posts: 9,206
Likes: 17
From: Sewell NJ
Re: Rust Inhibitors (Ingar, Norway)
Thanks for the replies everyone. For flushing the system I found a radiator cap with a hose connection at the local auto store a few years ago. All you do is put it on the radiator, connect a hose to it and leave the radiator petcock open. It seemed to do a good job when I flushed it last year. I think what I did wrong is that I used a flush agent but didn't run it in the engine very long. If I remember correctly the bottle said to run it for a few hundred miles but I drained it out much sooner. This year I'll give it more time and see if it makes a difference. I hate to put in my new overflow tank and have it looking like crap in a week. Again, thanks for the replies.
