Fire! Actually, it looks a...
Fire! Actually, it looks a lot worse than it really is. Sometimes the combination of heat and ATF fluid makes for some interesting photos, but the process works well for preventing rust on mild-steel exhaust headers.
In dirt racing, cleaning your car can sometimes be as damaging as anything you can do to it on the track. If you aren't careful, water can invade the hubs and ruin your wheel bearings, cause electrical problems, and even contaminate the fuel system. But washing your car is a weekly chore that's as routine for most dirt racers as loading up to go to the racetrack.
Besides the other problems listed above, preventing rust is also a constant battle. Rust kills the strength and durability of steel, besides galling bolts and looking just plain ugly. The best way to prevent rust is good, old-fashioned paint. And that works in most areas. But when it comes to mild steel headers, paint just won't cut it. Even high-temp paint doesn't last more than a couple races on a high-horsepower Dirt Late Model. And with the constant washing, it won't take long before any area where the paint has been burned off to start rusting.
A common solution to battle the rust problem with exhaust headers is to have some sort of coating applied. Modern coatings do an excellent job of both holding heat inside the headers and holding rust at bay. Most look great and are durable, but they can also add quite a bit to the expense of a new set of headers. Plus, if the headers are ruined in a wreck, so is the coating. You can also use stainless steel headers, but the expense there is often even worse.
If you can afford it, coating your race headers is certainly the way to go. But if the cost is prohibitive, there is another rustproofing method to consider. We recently stopped by the Dirt Late Model shop of Eddie and Chris Hargett while they were making final preparations on their car for the start of the season. The father-and-son team uses a method that basically "pickles" the steel in the headers using heat and automatic transmission fluid. The idea is that the heat (from a torch) opens up the pores in the metal so that the ATF fluid can get good penetration, and then the oil cuts off the oxidation process. The process is a little bit messy, but Chris Hargett says they treated their headers to this process at the start of last season and didn't touch them afterward. The headers were still rust-free at the end of the season.
In fact, the headers we photographed were the same ones Chris Hargett used the previous year. He recommends purchasing a new set and specifying that they arrive unpainted (a set from Schoenfeld are used here) so that you will not have to remove the paint. Sandblasting a painted set or an old set of headers isn't recommended because the sandblasting process will close the pores in the metal. But with a new set of unpainted headers all that's required is to disassemble all the pieces (if applicable), wipe them clean, hang them up, and get started.
The first step is to break...
The first step is to break down your headers if they come in separate sections such as these Tri-Y's. With new or undamaged headers, all that's usually required is a few light taps with a rubber mallet.
Use a good steel wire that...
Use a good steel wire that can withstand a sustained flame. Tri-Y headers usually have several tabs that make hanging easy, but you can also run the wire through the tubes themselves.
The actual process of heating...
The actual process of heating the headers and coating them with ATF fluid can get messy-not to mention the chance of fire-so it is best done outside. Prepare a place where the header components can be hung. Team member Randy Turner set up two ladders and a piece of square tubing outside the shop for hanging the components.
The easiest way to heat the...
The easiest way to heat the header tubes is with a torch. Chris Hargett uses a rosebud tip to put a gentle flame to the metal.
The trick is getting the headers...
The trick is getting the headers to the right temp. They should be heated until they are beginning to turn blue, but not orange or glowing. Just enough to open up the pores.
Eddie hargett applies ATF...
Eddie hargett applies ATF fluid to the heated headers. If the metal is hot enough the fluid should smoke quite dramatically, as you see here. The fluid is applied by dipping a clean shop rag into a bucket of ATF and wiping it onto the headers liberally. Because the headers and the fluid get quite hot, protective equipment, including heavyweight welder's gloves and welder's jacket, should be considered a must.
Be aware that sometimes the...
Be aware that sometimes the ATF fluid can also flame up. The flames don't last long, but this is why a good pair of heavy gloves is mandatory.
Chris Hargett recommends two...
Chris Hargett recommends two applications back-to-back. This means that after the first coat of ATF has been applied, he immediately hits the section of header with the torch again. This helps re-heat and "burn in" the ATF before the second coat. After the second application of ATF, there is no need for the torch a third time. Just let it drip dry until cool and then wipe it clean.
After the components have...
After the components have cooled enough that they can be comfortably touched, Turner wipes them clean with a rag and reassembles with new fastener hardware.
Although most of the header...
Although most of the header components were a year old, Hargett did have two new sections. On the left is a section of header tubing that has gone though the rust-proofing process. On the right is a section of still-virgin metal. You can see the bluing of the treated section from the heat and the application of the ATF fluid.
A newly rustproofed set of...
A newly rustproofed set of header tubes ready for installation on the car. These should be good for an entire season of racing.