Natural Cast iron finish

[Jordan S.]

I am in the process of restoring the front suspension on my 1970. I plan to drive the car on nice sunny dry days and hope one day to have it judged. Many of the suspension parts are supposed to be finished "natural cast iron". I know the most correct finish is bare metal with a preservative applied regularly. This is not feasible for me.

My question is, Is there any difference in the point deduction for clear coat on bare metal versus primed and painted cast iron color parts? Does anyone have personal experience with the durability of clear coated raw cast iron? Will it show rust in a few years or does it hold up well?

[Chuck S.]

Re: Natural Cast iron finish

In your position, I would probably "dust" on satin clear...done properly, it will have no gloss and will be harder to detect. Painted is painted, but I can't help but believe judges will have more sympathy with clear coated natural cast iron versus primed and painted. NCRS standards are to judge according to appearance; while cleared parts are incorrect, the appearance would be closer than primed and painted. As for longevity, you can't expect a lot if you are trying to hide the clear coating, but it should be several years before you get chips and evidence of rust.

On 70s, some chassis components are found in both natural iron/steel and black paint. If you don't care about perfect authentic originality, I suppose it would perfectly reasonable to opt for black if you don't want to deal with originality that rusts. If I remember correctly, these components are the front control arm shafts and the front sway bar. In the case of the control arm shafts, black painted will mean other prerequisites for the control bushings and retainers. If judges were omniscient regarding how the different VIN numbers were built, they would know which should be natural and which should be black, but I don't know that anyone has that information.

[Chuck S.]

Re: Natural Cast iron finish

In your position, I would probably "dust" on satin clear...done properly, it will have no gloss and will be harder to detect. Painted is painted, but I can't help but believe judges will have more sympathy with clear coated natural cast iron versus primed and painted. NCRS standards are to judge according to appearance; while cleared parts are incorrect, the appearance would be closer than primed and painted. As for longevity, you can't expect a lot if you are trying to hide the clear coating, but it should be several years before you get chips and evidence of rust.

On 70s, some chassis components are found in both natural iron/steel and black paint. If you don't care about perfect authentic originality, I suppose it would perfectly reasonable to opt for black if you don't want to deal with originality that rusts. If I remember correctly, these components are the front control arm shafts and the front sway bar. In the case of the control arm shafts, black painted will mean other prerequisites for the control bushings and retainers. If judges were omniscient regarding how the different VIN numbers were built, they would know which should be natural and which should be black, but I don't know that anyone has that information.

[Jeff S.]

Re: Natural Cast iron finish

Jordan

Although I can't think of any front suspension parts that are "cast iron" -- natural or otherwise -- there is a product that will give the proper look with decent protection on gray iron castings.

A coating of a high-temperature graphite lubricant (rattle-can aerosol) imparts a cast gray iron look to properly prepared cast iron, and works especially well on exhaust manifolds. The graphite flakes in cast iron give it that characteristic hue, and the graphite lube is a suspension of these same particles. The casting must be cleaned by glass beading, thoroughly remove any dust from beading, wash with MEK or lacquer thinner for fast evaporation.

Apply the aerosol in a thin even coat. The carrier evaporates in ~10-15 seconds. Apply second coat. I like to roll up a page of newsprint into a ball, and buff the part lightly to knock the sand casting pock marks a bit. It will then look like a fresh cast gray iron. It won't hold up real well with road debris or water, but works fine on manifolds, steering box, etc. Have to buy product at industrial supply house or online someplace; not FLAPS or Wally's. "Sprayon 00204" works well.

http://www.superkleendirect.com/index.asp?PageAction=VIEWPROD&ProdID=3217

[Jeff S.]

Re: Natural Cast iron finish

Jordan

Although I can't think of any front suspension parts that are "cast iron" -- natural or otherwise -- there is a product that will give the proper look with decent protection on gray iron castings.

A coating of a high-temperature graphite lubricant (rattle-can aerosol) imparts a cast gray iron look to properly prepared cast iron, and works especially well on exhaust manifolds. The graphite flakes in cast iron give it that characteristic hue, and the graphite lube is a suspension of these same particles. The casting must be cleaned by glass beading, thoroughly remove any dust from beading, wash with MEK or lacquer thinner for fast evaporation.

Apply the aerosol in a thin even coat. The carrier evaporates in ~10-15 seconds. Apply second coat. I like to roll up a page of newsprint into a ball, and buff the part lightly to knock the sand casting pock marks a bit. It will then look like a fresh cast gray iron. It won't hold up real well with road debris or water, but works fine on manifolds, steering box, etc. Have to buy product at industrial supply house or online someplace; not FLAPS or Wally's. "Sprayon 00204" works well.

http://www.superkleendirect.com/index.asp?PageAction=VIEWPROD&ProdID=3217

[Brett H.]

Re: Natural Cast iron finish

I normally powder caot with a cast blast finish. Deductions are not a biig deal if the rest of the car is in tip top shape.

The finish lasts longer than we will also.

[Keith R.]

Re: Natural Cast iron finish

Where does one obtain a cast blast finish Brett?

[Nick M.]

Re: Natural Cast iron finish

I recently had a long time NCRS member and owner of several Top Flight cars reccomend to me that I use WD40 as a protective coating on natural finish metal parts or any others that are succeptable to rust. He suggests that during long periods of car storage, this will aid in preventing rust on these type of parts. Just curious what experience the masses have had with either WD40 or some other rust inhibitor for the unfinished type parts on the underside of the car.

[Chuck S.]

Re: Natural Cast iron finish

I recently had a long time NCRS member and owner of several Top Flight cars reccomend to me that I use WD40 as a protective coating on natural finish metal parts or any others that are succeptable to rust. He suggests that during long periods of car storage, this will aid in preventing rust on these type of parts. Just curious what experience the masses have had with either WD40 or some other rust inhibitor for the unfinished type parts on the underside of the car.

Quanta Products sells a product called PreLube 6 that is a superior rust preventative for raw steel and cast iron. As with WD40, you will have to continually reapply for rust prevention.

WD40 is not an ideal product for rust prevention...In fact, many will scoff, but I have about decided WD40 has only one really good use, and that is to flush out stiff, oxidized lock cylinders.

[Chuck S.]

Re: Natural Cast iron finish

Where does one obtain a cast blast finish Brett?

If I'm not mistaken, Cast Blast is a paint manufacturer's product name for a gray, metallic paint that has some resemblance natural cast iron. Several vendors have paint products intended to provide a natural cast iron appearance...I know of no "cast iron" paint that will fool NCRS judges.

I assume Brett meant he picked a powder coat color close in appearance to the paint manufacturer's Cast Blast color.