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Rust treatment and removal

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Sargardani

Electrical
Dec 4, 2003
64
I have a 5 years old car and I find that some of the parts like door hinges and bolts etc are starting to get rusted.... is there a product available that would clean and protect these parts?

Sarg
 
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Rustoleum used to make something called rust reformer. It was a brush on product that converted the rust into a stable oxide. Obviously for flaky rust you cant get good adhesion but on surface rust it would prevent rusting under the paint.
 
You should be able to buy it at any auto spares shop, many companies make similar products.
 
It's called "Extend" and it works well.

Timelord
 
The rust converters are mostly phosphor based acids that react with rust to make a strong coating. The brand names may vary from region to region.

Regards

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Thanks pat, its always nice to know why. Of course any answer deserves a new question.

Would there be any benefit to applying these products to clean carbon steel before priming?
 
No

They react with rust, not iron.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
 
I use POR 15 on restoring my 66 Mustang, it dries to a nice satin black but is not photo tolerant (it will deteriorate in UV). It can be painted over however. Its awesome. I have also used a product called "Silver Bullet" which dries to a satin aluminum looking finish, looks ok in some areas, not in others.
Both are great and well recognized in the car restoration crowd.

Franz

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Some of these products utilize chelation chemistry to form a complex ion with an organic component. Thus, you get a very strong bond of the organic rust extender material to the iron oxide (rust) on the steel.
 
You need to go back to one of the oldest of the bunch "Naval Jelly".
It is H3PO4 based product and does a marvelous job with the greatest of ease. The H3PO4 products are excellent wash primers for some paints especially oil based, lacquers, and some epoxies. It made by nearly everyone Duro, Permatex, and Loctite to name a few.

The rust converters as mentioned above work mainly with reacting tannic acid or a salt with the iron oxide. They seem to work best with lite rust. I've had very poor luck with thicker rust scales. I've found that if you can knock off the loose stuff, treat it with Naval Jelly and let it age a day or so then apply the converter it work quite well with oil based paints.

Most H3PO4 products are a good wash primer for new steel. They work as stated above with most water based paints being excluded.
 
Sarg,
If the corrosion you see is on the stamped edge of a hinge or the formed edge of hardware it is most likely "edge" corrosion. Root cause is usually ineffective adhesion of the surface coatings to the comparatively rough edges seen in these parts. It is not an uncommon concern in automotive even in mildly corrosive environments. It is usually cosmetic in its early stages and can be treated using a phosphorous based solution sparingly. Too much for too long may stain. A brush touch up after removing the residue may fix it.
If it is coming from under a bolt on hinge you may find the unibody is not painted at the interface. Use the same process above.
 
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