Topic: 1966 coil spring...Black paint or raw steel

[Maksim27]

Guys I'm still having decision issues on weather to paint my coil spring or leave it bare dark steel.  I found traces of black paint on the upper side of the spring after de-rusting with a rust solution,.. The rest of the spring looked bare.  Before de-rusting most of the spring was covered with Factory undercoating and rust as I remember. 

I'm not sure if the Factory had a specific reason to only apply black paint to the top portion before installing the isolators on top.  Both my springs have remnants of black paint on the top portion. 

My question is were most the coil springs painted black or were some coil springs bare dark metal. 

The 1st picture shows the top satin paint remnants.
The 2nd picture is the spring that I refinished with Super-Blue.  But yet undecided to paint the spring or keep it as is.

Jan-66 C4 200 San Jose

[Bossbill]

It was never raw steel and the connotations that brings to mind.
You have to think more of processes -- how was the part made?

Springs are heat tempered. Watch the show "Forged in Fire" and you get some idea of how metal is quenched.
You bring it up to some hot temperature (how hot I don't know with regard to a spring) and quench it in oil.
Drip dry.
If your spring was first in a new batch of oil it will be light. If your spring was dunked in oil toward the end of the bath's life, then much darker. Ask 10 people and you will get various opinions on how dark or light. Maybe due to  the oil used.
Forged parts also have an oil finish as they were hot enough to be malleable/stamped out and oil was used to cool them off and temper them.

I use Brownell's Oxpho-Blue Cream Formula after trying may other different brands. It goes on nicely with 0 or 00 steel wool and will get darker if left on longer. After you wipe it off you can lighten it a bit with a new pad of  steel wool. T-9 afterwards. I do leaf springs with it too. It took 8 oz to do all the heat treat metal on my car.

[Maksim27]

Bill I was thinking of using RPM on the coil springs as a final rust prevention coat.   

If my car was manufactured in Jan 1966 how dark would the springs need to look... Is my 2nd picture dark enough or should it be lighter or darker.  I seen most other coil springs look painted to me by other Mustang owners.  Don't know if that is the darkening process or satin paint.

[J_Speegle]

Bill I was thinking of using RPM on the coil springs as a final rust prevention coat.   

If my car was manufactured in Jan 1966 how dark would the springs need to look... Is my 2nd picture dark enough or should it be lighter or darker.  I seen most other coil springs look painted to me by other Mustang owners.  Don't know if that is the darkening process or satin paint.

You will find examples of what I and others have done but using pictures on the internet rarely reflect what they look like in person. Since these were heat quenched in oil and often very dirty and used oil the coloring will be a very very dark gray - almost black. If you used gun repair fluid or one of the other cold blackening products, strip, clean and prep then color by dipping pour and brush it on in an effort to get a consistent finish them dry, heat if you choose and finally apply a protective wax, oil or coating of your choice

Often we find coils that have been painted by owners and Service/NOS parts were painted black for storage purposes but all of the originals I have found were not painted other than the paint ID markings.  The quenching oils over applied a hard surface that appears to be paint for some but stripper does not affect this and in turn provides that those were not painted

Some of the process above are covered in threads or articles in the Library associated with words such as restoring natural finishes and suspension restoration

[Maksim27]

"If you used gun repair fluid or one of the other cold blackening products, strip, clean and prep then color by dipping pour and brush it on in an effort to get a consistent finish them dry, heat if you choose and finally apply a protective wax, oil or coating of your choice"

So I strip off the super-blue in the 2nd picture of mine and which type of dipping do I pour.  Does the coil spring needs to be bare again to pour something on it and use a brush. 

In the library of natural finishes section it only says to use different types of perma-blue from liquid to paste.  Does mention other other ways but not concretely.

My spring does look fairly dark with super-blue but probably should be darker like black in appearance.

[J_Speegle]

"If you used gun repair fluid or one of the other cold blackening products, strip, clean and prep then color by dipping pour and brush it on in an effort to get a consistent finish them dry, heat if you choose and finally apply a protective wax, oil or coating of your choice"

So I strip off the super-blue in the 2nd picture of mine and which type of dipping do I pour.  Does the coil spring needs to be bare again to pour something on it and use a brush. 

In the library of natural finishes section it only says to use different types of perma-blue from liquid to paste.  Does mention other other ways but not concretely.

My spring does look fairly dark with super-blue but probably should be darker like black in appearance.

The metal will only get so dark with what ever product you use if your dipping or brushing wet and it stays wet for a minute or so. Color change takes place quickly with most of the liquid produces I've used over the years.  Never used the paste since it wasn't for sale here locally and I've been using the regular Perma Blue since the early 90's.  Haven't use the Super and have had a few that have had issues getting same results with it as the regular Perma Blue. Don't believe that "Super" is suppose to make finishes darker but it may have other characteristic that I'm uninterested in for my intended use.

I've also used just a wet rag to apply it also and you want to work it in well and get dark so that the finish is consistent along the long length of the coil.. When I get splotches, unevenness or the finish flashes brown on some projects I restrip to bare metal, clean it and start again

Just sharing what has worked or not worked for me

[Bossbill]

Bill I was thinking of using RPM on the coil springs as a final rust prevention coat.   

I've tried RPM. Twice. It's hard to work with since it's a paste and having to heat the metal to apply it is yet another step I don't need.
Boeshield T9 is much easier to use.
As you can tell from my build thread it has taken years since I had to develop a lot of processes (even with help here) and the property is always demanding attention. All the T9 coated parts are still in good shape.

[Maksim27]

Can heating up the coil spring ruin the spring.  As I use 150-200 degrees of heat with a micro towel to apply RPM to other suspension parts.

[Bob Gaines]

Can heating up the coil spring ruin the spring.  As I use 150-200 degrees of heat with a micro towel to apply RPM to other suspension parts.

Heating up the coil spring can ruin the spring but not typically with that much cooler heat range.

[J_Speegle]

Can heating up the coil spring ruin the spring.  As I use 150-200 degrees of heat with a micro towel to apply RPM to other suspension parts.

As Bob wrote above heat for tempered parts can ruin them. Always a concern if your having a plating shop doing the work as they need to be reminded and you have to trust they will listen to you. Low heat such as you mention should not affect but try to keep it on the low side and just enough to create the conditions your looking for. As mentioned in other threads I often will heat the parts after coloring them to get the moisture out of the metal and prepare the metal to accept the protective product I've choose to apply. Works for me

PS also remember to apply any paint markings your going to do BEFORE you add any protective layer or application

[Maksim27]

I definitely try to apply some heat to the part after getting it clean.  Then perma-blue,  then water soaked towel, and finally heat the part to remove water.  After 24hrs either RPM or T9 the part.

[Maksim27]

Here is my finished coil spring...

I tried to match the stripe color to 90% of the original color shade.  The original stripes were half an inch and I copied that process. 

I finished the spring with RPM which took almost an hour to apply with a brush and finished with a microfiber towel.  Does look more darker after applying the RPM.

Now I'm restoring the second spring that is on the second picture.

Thank You guys for your Help.

[RoyceP]

The metal color looks OK but the stripes are not applied in a way that is realistic. They put the color on with a brush in a big hurry. The idea was to mark it well enough to ID it but to not spend a lot of time doing it. See Jeff's example.

[jwc66k]

The metal color looks OK but the stripes are not applied in a way that is realistic. They put the color on with a brush in a big hurry. The idea was to mark it well enough to ID it but to not spend a lot of time doing it. See Jeff's example.

Exactly. It was a production line.
As to the spring itself, it is hot rolled steel and as such will have a rough look.
Jim

[Maksim27]

I just copied the paint marks as they initially were.  Probably that worker was careful.  Took me one minute to do the stripes.  1/2 inch stripes as I measured them.  Mine are almost 3/4.