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Discussion Starter · #1 ·
I have this pair of Hooker headers, originally BBC headers, modified to fit an LS in my '70 Impala (when I did my swap, no headers were available for this swap). The full exhaust was then built from these headers.
Now, 10+ years later, the car has been driven very little, the headers are mostly covered with surface rust. They were never treated in any way, just the Hooker black paint. They are very solid, when you hit them, they sound just like new, no metal has rusted away. The inside is mostly black soot, with a bit of surface rust at the bottom of the collector, which pretty much comes off with a sponge.
What can I do to clean them and
to protect them? Maybe even make therm look better?
What can I do inside, especially in the collectors, when condensation pools?

Musical instrument Wood Sculpture Metal Pipe



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Musical instrument Wood Sculpture Metal Pipe


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Generally, even with new headers, or with any I'm restoring, the procedure is sandblast (I send that out to a guy who does that for me), clean with acetone inside and out (I tie a rag to a string or wire to pull the rag through the primary pipes), then coat the inside with the Eastwood ceramic coating, and paint the outside with multiple layers of VHT "Flame Proof" exhaust paint. Finally, a few hours in the (spare, in the shop) gas oven to bake the paint/coatings on.

he VHT paint is available at most FLAPS. The Eastwood stuff, I get the kit directly from Eastwood , sometimes with an extra can of the coating.


I also prefer to coat inside the pipes and paint outside the pipes at least back to behind the front seat back line to keep heat from the floorpan.
 

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If you want something with long term durability, send them out for ceramic thermal barrier coating.

Nothing you can do at home will look as good nor last anywhere close to as long.

Jet -Hot is the premier company for this...if fact, if you had sent them to Jet-Hot when they were new and not yet used, they would guarantee their coating for life.
they won't put that guarantee on a used header, but they will clean, blast and prep them the same way.
Coated inside and out.
 

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Discussion Starter · #5 · (Edited)
Jet Hot is way out of budget, even if it is the best...
Looking at the headers, I wonder how sand blasting can actually clean (de-rust) in the narrow areas, between the pipes, especially just before the collectors?...
Is there a "chemical" way to de-rust, soaking them in... something?
 

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When I order them online and the budget allows for Jet Hot coating, I just have the seller ship directly to Jet Hot. Saves on shipping that way. Talk to Jet Hot first to find out what markings they want on the "Attention:" line in the shipping address to them so they don't get lost.

Looking at the headers, I wonder how sand blasting can actually clean (de-rust) in the narrow areas, between the pipes, especially just before the collectors?...
Is there a "chemical" way to de-rust, soaking them in... something?
My sandblasting guy always gets them really clean, even in the deep crevices. YMMV.

Chemical treatments for rust (that actually work) fall into two categories. One is phosphoric acid (in solution in water, or in a "rust removing jelly" often called "naval jelly"). That chemically changes the rust to a water soluble powdery substance that can be rinsed away. It's important to neutralize the acid after treatment (a baking soda/water solution is good follow up) and then rinse the byproducts of the reactions completely away with lots of water. Also, that stuff is very toxic. Wear gloves and a good filter mask when working with the stuff. You don't want to get it on your skin, and you don't want to breathe the fumes.

The other chemical treatment is tanins (AKA tannic acid). That converts the rust into a hard substance called iron tannite, which is a hard black or dark brown substance that is sandable, paintable and usable as a "primer" layer for painting. The advantage to the stuff is that it's non-toxic (it's a naturally occurring anti-oxidant substance found in tea and red wines), so you don't need any protection when working with it. The disadvantage to using it on exhaust is that it's often paired with other primer/coating substances that aren't as heat resistant as the final iron tannite from the reaction. It's also difficult to find out the concentration of this substance in various commercial "rust converter" products because it's non-toxic and therefore doesn't have to be listed (and usually isn't listed) on the SDS for the product.
 

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Discussion Starter · #7 ·
Thanks for these info, racer-X-, I had never heard of tannic acid, which pretty ideal! I will look into that, as it seems easier to use than acid (you mention phosphoric, I had heard about muriatic...).
How many cans of VHT do I need to paint my long tube headers? Is the VHT primer really needed?
 

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I've never used VHT primer on bare steel. I always use VHT primer on aluminzed steel exhaust pipes. I'm not sure it's necessary.

The big thing with VHT is that it's better to do several thin coats and build it up slowly. They say 1 can does a pair of long tube headers. I used 1 entire can and another half can on a pair of "shorty" headers for a 6 cylinder, and they're wearing well. I did about 6 thin coats on those.

The tannic acid stuff is often sold as "rust converter" or "rust converter primer."

And other than that and phosphoric acid solutions, most other acids will definitely eat away the rust, and most will eat away (etch) the base metal as well. Many of the other acids (muriatic/hydrocloric especially) will leave the base metal in a form where it's much more likely to rust again.
 

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Ceramic coating is out of the budget so to make 'em clean, look good and have a coating that lasts for awhile.......blast 'em them shoot 'em with VHT primer followed by several thin coats of VHT hi-temp color. Their long tubes so you'll need 2 cans of primer and 3 cans of color. If they'll fit, slide 'em in the oven and bake for an hour. Make sure to open all the windows and send the wife shopping! That's what I did on my shorties and several sets of headers throughout the years. When you install them, do it carefully and have clean hands. They'll last for a good long time.

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Ceramic coating is out of the budget so to make 'em clean, look good and have a coating that lasts for awhile.......blast 'em them shoot 'em with VHT primer followed by several thin coats of VHT hi-temp color. Their long tubes so you'll need 2 cans of primer and 3 cans of color. If they'll fit, slide 'em in the oven and bake for an hour. Make sure to open all the windows and send the wife shopping! That's what I did on my shorties and several sets of headers throughout the years. When you install them, do it carefully and have clean hands. They'll last for a good long time.

View attachment 626329
Wow that looks beautiful. Belongs in a museum.
 

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I have this pair of Hooker headers, originally BBC headers, modified to fit an LS in my '70 Impala (when I did my swap, no headers were available for this swap). The full exhaust was then built from these headers.
Now, 10+ years later, the car has been driven very little, the headers are mostly covered with surface rust. They were never treated in any way, just the Hooker black paint. They are very solid, when you hit them, they sound just like new, no metal has rusted away. The inside is mostly black soot, with a bit of surface rust at the bottom of the collector, which pretty much comes off with a sponge.
What can I do to clean them and
to protect them? Maybe even make therm look better?
What can I do inside, especially in the collectors, when condensation pools?

View attachment 626182


View attachment 626183

View attachment 626182

View attachment 626183
Problem with headers is they rust from the inside out. From the condensation and chemical reactions. Even a set that looks great after a (Few) years start to get real thin. They never rot from the outside. Jet hot coating is too expensive for a used pair. When new that's the only way to go. Gives you the most bang for your buck. You can make them look good on the outside and preserve them somewhat. But it's what is going on on the inside you have little to no control over. The only thing you can do for collector condensation is cut a gap in the collector gasket at the bottom to get rid of some. The hole will scale up but easy to keep open. Worst enemy for a header is short distance driving and a lot of sitting which is what most of the toys do.
 

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Discussion Starter · #15 · (Edited)
The more I read about acid cleaning, the more confusing it gets!
Phosphoric acid is expensive and hard to get in my parts, so it is a no-go.
I like the idea of the tannic acid, being easier to wotk with, but I am always a bit sceptical about "organic", "natural" products... You know, that silly old idea that a product has to be nasty to work... Does it really work, if I dip my headers in that? How long of a dip?
Then there is the dip in muriatic acid , followed by a baking soda clean and the VHT quickly after. Seems to be the sure bet, but harder to work with...
What dilution do you use for the muriatic acid?
 

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Muriatic acid leaves a hydrogen atom behind in the conversion, which can lead to cracking at a later date (Hydrogen embrittlement). Makes it very hard to completely neutralize.

I've got a plastic tub/tote of Citric Acid I use for de-rusting, found the idea in a long thread over at the HAMB forum. Biodegradable, so it isn't nasty to get rid of.
It is easy to get in powdered form, as it is used as a food preservative. 5lb bag usually less than $25
It's the fancier, cleaner way of the old school method of using molasses to neutralize rust.

Technical - Tech: Simple rust removal with citric acid | The H.A.M.B. (jalopyjournal.com)
 

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Get an old battery charger, a plastic tub and some "washing soda" and use electrolysis? Its very gentle on the parts.
Very important to coat the inside if possible with your header coating of choice.
 
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