72 front suspension coil springs finish

[Tony 38901]

My coil springs are currently black. I'd like to get them the correct color. I don't have my tech guide in front of me, but I think the finish is supposed to be natural? Should I blast the springs and leave it at that or should I paint them (and what color)?

Thanks,
Tony

[Greg L.]

Re: 72 front suspension coil springs finish

Tony,

If they have the same finish as in 69 then you are correct in that they are natural. However...natural in this case means that they should have a blueish-gray appearance with some scale as what forms on hot worked steel. This is very difficult to reproduce.

Once you have them cleaned to the base metal you might try brushing on some Quick Black at full strength untill they turn dark and then rinse them off with water. I brushed some nuts today like this and they seemed to take on a bit of a blueish/black tint and the color was not uniform either. The first thing that came to my mind was that the finish looked like a piece of fresh angle iron which is also hot worked steel.

I cant say for sure that this will work but it might be worth a try seeing as there is no paint that I know of to replicate the original finish.

Greg

[Tony 38901]

Re: 72 front suspension coil springs finish

What if I would take a blow torch to them?

[lyndon sharpton]

Re: 72 front suspension coil springs finish

make sure you have them out of the car!

[Michael H.]

Re: 72 front suspension coil springs finish

Tony,

Glass beading the spring isn't exactly the surface look that they had when new but if you do bead these, you can probably come a bit closer to correct if you use a scuff pad or steel wool to kill the dull grey look from the blasting process. The spring wire wasn't at all polished but it wasn't dull either. When new, they almost looked as if they were in one of those tumblers that slightly brightens the metal.

Before shipment, the springs were lightly coated with some rust preventative that kept them looking new during production but this protection probably didn't last very long, especially if the car was delivered to a northern state in the winter.

[Kent K.]

Re: 72 front suspension coil springs finish

Tony----

Heating springs with a blow torch, if temperatures exceed certain levels, may upset the designed strength and memory of the metal. I'm no metalurgist but, IMHO, be very carefull with heat application to coil springs. Perhaps someone more knowledeable will ammend and/or correct my statement.

On my '67 SB roadster, I bead blasted the springs and applied a coating of wax-like material from a puff can (sorry, I can't remember the product name). It gave them a natrual appearance and prevents exposure to rust forming atmospheres. They still look great after about 12 years.

Good luck. Kent #6201

[Harmon C.]

Re: 72 front suspension coil springs finish

Tony
If you paint and then wipe most of it off using black and cast blast in small areas you may come up with a finish not original but appears some what like the original finish. It won't fool a good judge but won't rust much either.

Lyle

[Michael H.]

Re: 72 front suspension coil springs finish

Unless I'm not understanding the method properly, I would think these methods of making the spring darker would only apply to later service springs, not original production parts. The original color/finish wasn't black like the last of the available GM springs from the last decade of there availability. The raw metal silver color was used right to the end of production at the St Louis plant. Difficult to describe but it's somewhere between the look of bead blasted and polished. Originals had a light coating of something to prevent rust. CRC has a product called SP-350 that will duplicate the coating exactly but last for much longer.

I have no idea what coating was on the later replacement springs.

[Harmon C.]

Re: 72 front suspension coil springs finish

I wipe off 95% of the paint just filling some of the rougher spots if you leave some of the scale on the metal. I agree that the hot rolled finish can't be brought back after the springs have 30 years plus rust on them and the rust is taken off by any method.

Lyle
.

[Michael H.]

Re: 72 front suspension coil springs finish

Ok, I think I understand what you mean now. If 95% of the black is removed, that may help eliminate that "glass beaded" look. The actual color and reflectivity of a new spring certainly is difficult to describe. It doesn't have the variety of different shades like a leaf spring or front sway bar but it definitely does have a look that's not easy to duplicate. I still like the vibrating/tumbling barrell though. Think I'll try a spring in one of those one day soon.

Pic below is a brand new C3 spring being installed at the Mill. Nice clean control arm and spring, filthy dirty frame.

[Patrick H.]

Re: 72 front suspension coil springs finish

Mike,

Any chance of making that picture larger?

Patrick

[Michael H.]

Re: 72 front suspension coil springs finish

Hi Patrick,

I'll have to dig out the original pic and rescan. I enlarged the one I posted a little but, as you can see, the quality was started to decline. I'll scan at high res. I'll try to do this tonight if possible.

[Michael H.]

Larger/Better Quality Scan

This pic should show that these springs were not even close to the look/color of a front sway bar or rear leaf spring.

[Patrick H.]

Re: Larger/Better Quality Scan

Thanks Michael!

[Harmon C.]

Re: Larger/Better Quality Scan

Michael

I worked in the auto industry 35 years and your picture is like the look I was trying for. I agree that front springs and other suspension parts are almost impossible to make look factory original. One must come as close as he can within his budget and hope the judge has some doubt or likes the finish and takes little or no point deduction.

Lyle