Right is right and factory is factory. Natural paint on fender bolts and washers, fasteners, and hood hinges may look close to factory original, but the factory finish was a coating of phosphate and lubricant for rust protection. Paint is easier to chip. The phosphate coating is more durable and resistant to corrosion, plus it's correct for concours restorations.
Today, the Mustang Club of America is coming to terms with natural finishes. In the Concours Trailered classes, their plan is to "come up with requirements for owners to prepare their cars during the 2011 season with enforcement by 2012."
In other words, paint on metal parts in place of "proper" finishes will be a deduction. MCA Authenticity Head Judge Bob Perkins from Perkins Restoration in Wisconsin has played a major role in the preparation phase. Long a proponent of factory finishes, Bob showed us how to phosphate parts. The process is certainly much more complex than simple spray painting. However, just about anybody with a stove, a thermometer, and a stainless steel pan can phosphate these iron-based parts.
More than being concours correct, phosphate and oil finishes last indefinitely. A painted part, like a hood hinge, will eventually need to be removed and painted again due to metal-to-metal contact. Plus, the cost of phosphate and oil is, in Bob's words, "less than buying two rattle cans."
At Perkins Restoration, Tim...
At Perkins Restoration, Tim Laehr heated water to between 190 and 200 degrees in a stainless steel pot, then added the Manganese Phosphating Concentrate. Steam began to rise off the green mixture. (Note: Do not mix first and then heat.)
Perkins Restoration buys Manganese...
Perkins Restoration buys Manganese Phospating Concentrate in five gallon buckets from Palmetto Enterprises (
www.palmettoenterprises.net). Palmetto also offers quart and pint sizes for individual use. Mixing in a ratio of 14 ounces concentrate to 128 ounces (one gallon) water activates the phosphating chemical reaction. Zinc Phosphate is also available but, according to Bob Perkins, Manganese seems to work a little better to get the correct darker gray appearance.
These hood hinge parts are...
These hood hinge parts are clean and ready for phosphating. Grease and oil interfere with the phosphating process. Palmetto's directions recommend removing grease and oils with an alkaline cleaner, which includes Easy-Off Oven Cleaner. However, they say this step is not required unless there is a heavy build-up of grease and oil on the part. They also mention glass beading or bead blasting on parts with a heavy grease build-up. Etching the metal allows the phosphate to chemically bond. Don't touch the parts with bare hands or use cleaners after sandblasting as this will leave a residue and create a spotty or streaky finish.
This hood hinge spring is...
This hood hinge spring is glass beaded and ready for phosphating to restore the original look and rust protection. Our manganese phosphating process will turn this hood hinge a factory correct medium to dark gray finish.
Submerge each part in the...
Submerge each part in the mixture. Tim used rubber gloves. Palmetto also recommends using stainless steel or rubber-coated tongs.
A rubber-coated magnet can...
A rubber-coated magnet can be used for submerging and retrieving smaller parts.
Once submerged, bubbles begin...
Once submerged, bubbles begin to form on the metal and rise in the mixture, similar to dropping an Alka-Seltzer tablet into a glass of water. This fizzing action is phosphating the metal. Palmetto recommends rotating the parts every few minutes to get an even coating.
Leave the parts in the bath...
Leave the parts in the bath for 8 to 10 minutes total, even though the fizzing has stopped. This promotes a slightly darker finish. As you can see, the part is noticeably darker now.
Next, Tim doused the part...
Next, Tim doused the part in water, then dried it right away with compressed air.
Palmetto recommends WD40 application...
Palmetto recommends WD40 application immediately after the phosphate bath. Wipe dry and repeat this step three times to ensure all mineral salts are removed. Notice how much darker this hood hinge spring appears after phosphating.
To restore the original red...
To restore the original red color on bolts and other metal fasteners, Tim opened this bottle of Dykem Staining, available from machine shop supply outlets. Starting in the 1968 model year and continuing through 1973, Ford used red stained dye after phosphating to identify various hardware, including bolts, fasteners, idler arms, and more. According to Perkins, this machinist dye is "identical to NOS and absolutely right on."
Tim poured some of the red...
Tim poured some of the red dye into the bottle cap, then dipped a Q-tip into the dye.
With the Q-tip, Tim daubed...
With the Q-tip, Tim daubed the dye onto the phosphated natural finish bolt for the factory look.
Continue dying the threads...
Continue dying the threads of the bolt, then dry with compressed air.
Installed, the phosphated...
Installed, the phosphated bolts with red dye are concours correct, as seen here on a unit body inside the wheelwell.