Author Topic: leaf Spring Finishing  (Read 5765 times)

Offline ddonzella

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leaf Spring Finishing
« on: August 05, 2015, 11:09:55 PM »
I have researched finishing of rear  leaf springs and shock plates.  I have a June 12, 69 Shelby. I've read both Insta black use and Gun Bluing use for rear shock plates and springs. (Not interested in the Phosphate/Charcoal process). BTW, I saw one post for bare metal rear shock plate and one post for gun blue process???

Insta black is sold by EPI at 105.00 a gallon Gun bluing is dirt cheap and sold everywhere. Is there a noticeable difference in the finish, quality and color? If so, which is truer? If it ends up being insta black do I need a gallon and  where can I find insta black at a more reasonable price? Google only showed me EPI.com

Thank, you!






Offline Bob Gaines

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Re: leaf Spring Finishing
« Reply #1 on: August 06, 2015, 03:15:23 AM »
I have researched finishing of rear  leaf springs and shock plates.  I have a June 12, 69 Shelby. I've read both Insta black use and Gun Bluing use for rear shock plates and springs. (Not interested in the Phosphate/Charcoal process). BTW, I saw one post for bare metal rear shock plate and one post for gun blue process???

Insta black is sold by EPI at 105.00 a gallon Gun bluing is dirt cheap and sold everywhere. Is there a noticeable difference in the finish, quality and color? If so, which is truer? If it ends up being insta black do I need a gallon and  where can I find insta black at a more reasonable price? Google only showed me EPI.com

Thank, you!
Ether product will work on the leaf springs . The lower spring/shock plates should be bare steel. The gun blueing will make them look too dark.
Bob Gaines,Shelby enthusiast, Shelby collector , Shelby concours judge SAAC,MCA,Mid America Shelby

Offline ddonzella

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Re: leaf Spring Finishing
« Reply #2 on: August 06, 2015, 11:36:37 AM »
Thank you. Any vendors for insta  blak?

Offline CharlesTurner

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Re: leaf Spring Finishing
« Reply #3 on: August 06, 2015, 12:03:22 PM »
Thank you. Any vendors for insta  blak?

I've bought it online before.
Charles Turner - MCA/SAAC Judge
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Offline J_Speegle

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Re: leaf Spring Finishing
« Reply #4 on: August 06, 2015, 01:42:42 PM »
I have researched finishing of rear  leaf springs and shock plates.  I have a June 12, 69 Shelby. I've read both Insta black use and Gun Bluing use for rear shock plates and springs. (Not interested in the Phosphate/Charcoal process). BTW, I saw one post for bare metal rear shock plate and one post for gun blue process???

I've used gun bluing for bare steel for many years. You just use it to take down the freshly finished mono tone look that you can often produce in the clearing process. You don't apply or work it like you were reproducing a hardened steel or P & O finish. Its a fairly flexible product but its about the product and the technique in combination. Have posted examples of both finishes many times and they are very different in their final look.

I've not used Insta-Black for other than the dark look so don't know how it reacts to working or applying it with steel wool

These have been gun blued - the reflection makes them look shinier than they are in person

Jeff Speegle

Anything worth doing is worth doing concours ;)

Offline ddonzella

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Re: leaf Spring Finishing
« Reply #5 on: August 06, 2015, 04:30:26 PM »
Thanks Jeff. What is interesting to me is that I have gun blued things before and the solution typically and very quickly changed the finish to a very dark "gun barrel" color. Your example basically looks natural with no darkening color?? Process? A quick dip and immediate wipe? The leaf springs would set in the solution for an extended period to get a more pronounced finish.

Offline J_Speegle

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Re: leaf Spring Finishing
« Reply #6 on: August 06, 2015, 08:46:42 PM »
Thanks Jeff. What is interesting to me is that I have gun blued things before and the solution typically and very quickly changed the finish to a very dark "gun barrel" color. Your example basically looks natural with no darkening color?? Process? ............

I rarely dip anything in the gun bluing - only if its a large part and then I've had issues getting a consistent look everything.

On things like spindles I'll use a acid brush to work from one end to the other getting the finish dark like heat treated. On large pieces that have been recently stripped or even blasted and or wire brushed I return those to new metal look using steel wool daubed in gun bluing and rubbed (starting from one end) it into the surface to slightly darken (working the bends a little more to brighten them) from one end to the other. If I get a spot that gets to dark (using too much liquid on the steel wool) I can wire brush that area and try again until I'm happy

Used the same technique on the main section of drive line (before the the heat stripe)

In the picture you can see the slightly darkened area (I'm working bottom to top on the lower A arm) in front of the steel wool.


Yes I see the pitting on the arm :) Se we do have rust  ::)



Now a couple of things I found. Pour a little gun bluing into a small container and refill as needed. Once the fluid comes in contact with the steel wool DON'T pour in back in with the unused liquid - its done. It is a subtle but noticeable change. 

Some how, chemically, the fluid reacts with the steel wool, darkening it first, and this reduces the fluids ability to darken the piece your working on as it normally does if dipped, applied with a brush or a rag.

If I'm need to darken a couple of screws or a small piece I drop an oz of the liquid in a small paint cup, Dixie cup or similar cup and slosh the fluid around with the part for about 10 seconds - once the fluid has cover the surface of the piece completely. Remove it, flush and wipe it then treat it with heat and oil for a 2 minute plating process

Without having to dip front or rear springs I'm normally able to do everything I need on a car using only two of the small bottles of the repair fluid. I didn't buy from another company a 32 oz bottle last time since locally its difficult to buy the stuff any more- once the meth heads figured out how to use the stuff in their cooking recipes


Just what has worked for me.
« Last Edit: August 06, 2015, 08:53:51 PM by J_Speegle »
Jeff Speegle

Anything worth doing is worth doing concours ;)

Offline WT8095

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Re: leaf Spring Finishing
« Reply #7 on: August 08, 2015, 12:50:54 AM »
Some how, chemically, the fluid reacts with the steel wool, darkening it first, and this reduces the fluids ability to darken the piece your working on as it normally does if dipped, applied with a brush or a rag.

The fluid reacts exactly the same way with the steel wool as with the workpiece because they're both steel. The steel wool has a lot of surface area in a small volume, so much of the chemical reaction is happening on it instead of the part you're working on. Because only a portion of the fluid hasn't reacted, the effect on the workpiece is slowed. Which could be helpful in letting you gradually achieve the effect you're going for.
Dave Z.

'68 fastback, S-code + C6. Special Paint (Rainbow promotion), DSO 710784. Actual build date 2/7/1968, San Jose.
'69 Cougar convertible, 351W-2V + FMX, Meadowlark Yellow.

Offline ddonzella

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Re: leaf Spring Finishing
« Reply #8 on: August 13, 2015, 09:07:40 AM »
Thank You!

Offline Bossman963

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Re: leaf Spring Finishing
« Reply #9 on: August 29, 2015, 01:10:27 PM »
OK a question and after using perma blue- do u coat it with oil or anything to preserve the finish for a long period of time ?
2-69 B302 -twins, 1-1970 Cougar Eliminator B302- matching numbers, 70 B302 in progress, 68 Charger, 74 Pantera GTS, 2 fox body Mustangs 1 conv

Offline J_Speegle

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Re: leaf Spring Finishing
« Reply #10 on: August 29, 2015, 01:40:05 PM »
OK a question and after using perma blue- do u coat it with oil or anything to preserve the finish for a long period of time ?

Yes you need to protect them somehow as they will rust again. Length of how long depends on what you use and how the car is used or stored. Its just part of the maintenance. Most currently use Boe-shield

I haven't had the luck of getting the small bottles of gun bluing to work on the long leaf springs - since you can't apply it all at once I often get an uneven darkened finish. Some are using a product I believe is called Insta Black making a container that will hold the longest spring and dipping them
Jeff Speegle

Anything worth doing is worth doing concours ;)