Painting or Plating rear Trailing Arms

[Kool-aid-82]

When I purchased this 1981 SC back in 1983 I seem to remember these were plated. Zinc/Gold color But this is long gone and now they look like bare aluminum.

I am now looking are rebuilding them and was wondering who has tried what?
Most appear to just leave them bare – Is there a reason for this?

I do not believe painting would hold up so I am looking at plating.
Anyone had success with this?
Worth the cost?

[Jesse16]

I've always thought they were just bare aluminum and of course always filthy (if the car gets driven) because they are under the car. I guess you could plate them but can't imagine why it would improve the aluminum finish. Not familiar with these being surface coated to make them "better", only cosmetic reasons like with brake calipers.

[Elombard]

Trailing arms or spring plates?

[gtc]

Not sure if you're confusing spring plates and trailing arms.
The spring plates were cad plated. The aluminum trailing arms probably had cosmoline or some such protective undercoating that made them look yellowish.
You can't cad plate aluminum.

[Tea Tray]

You may consider a chromate conversion ( corrosion resistant) process trade named Alodine or Iridite. I used it years ago and though our process was technically "clear", it had a yellow tinge to it. By increasing the soak time in the actual Iridite tank, we could get a real neat yellow. The parts MUST be squeaky clean or the operator/plater will curse your children for fouling the process baths. Check local plating houses...

[Kool-aid-82]

Well memory is 30+ years old maybe they have always been bare...
Spring plates still have some plating left on them.

[Bob Kontak]

Originally Posted by Kool-aid-82

Well memory is 30+ years old maybe they have always been bare...
Spring plates still have some plating left on them.

Trailing arms are and were bare. You would see remnants of the plating.

Just clean them up. They look spiffy, as is, without road grime.

Yellow zinc I believe is what you can use on the spring plates and torsion bar covers (hardware, etc). Cadmium plating is not done by many given EPA interference. (assuming original is cadmium)

If you do tear down the rear, spend a few bucks more and have someone like Shaun @ Tru6 plate the parts. At an industrial plating place you can probably have all parts done for under $100. They will say we can boil off rust but we can't boil off paint. The prep is up to you. Shaun removes all doubt as to the quality question.

[Steve@Rennsport]

Any plated suspension part must be baked due to prevent hydrogen embrittlement and thus cracking.

[Kool-aid-82]

Originally Posted by Steve@Rennsport

Any plated suspension part must be baked due to prevent hydrogen embrittlement and thus cracking.

Well that is one reason to leave them bare... I did not know that .
Thanks

[Kool-aid-82]

Thanks Bob I will look into Shaun @ Tru6.
Where is he located?

[ClickClickBoom]

Originally Posted by Steve@Rennsport

Any plated suspension part must be baked due to prevent hydrogen embrittlement and thus cracking.

Plating is also additive, t-bars might get tighter on the splines, mine are airtight, any tighter would be troublesome. I sprayed my entire rear suspension with Boeshield T-9, and went driving to collect a protective layer of dirt. I did spray the inside of my torque tub with ACF50 to stop the corrosion spots.

[78-911SC]

Billy Shaun@Tru6 is right here on the site. Just do a search on him. Excellent work and reviews. PM him for info or you might find his number in some of the posts.

[chris_seven]

I wouldn't consider plating a torsion bar - even baking can be a bit hit and miss as the plating conditions may not be well controlled on simple rack plating systems and so baking can also be a little variable in its effect.

The spring plates shouldn't be so bad as they aren't overly strong.

We are just going to make some RSR spring plates using Hardox steel.

[Kool-aid-82]

Originally Posted by 78-911SC

Billy Shaun@Tru6 is right here on the site. Just do a search on him. Excellent work and reviews. PM him for info or you might find his number in some of the posts.

I did find him, PM'ed & waiting on a reply and finding a large box it ship the parts in...

Thanks for the input, I am not doing anything to T Bars if I remember they are red already - But as you have already seen my memory is questionable...

[78-911SC]

Great I think you'll be happy. Don't forget before and after pics.

[Bob Kontak]

Originally Posted by Kool-aid-82

I did find him, PM'ed & waiting on a reply and finding a large box it ship the parts in...

Thanks for the input, I am not doing anything to T Bars if I remember they are red already - But as you have already seen my memory is questionable...

+1.

Every little stinky steel part you can find. Get it in that box.

The place I took my parts to near Asheville, NC airport was a throw back to the 30's. Old 55 gallon drums, poor lighting, vapors of all sorts. Looked them up on Google and they were on an EPA watch list with something like a "gross infraction" status. Dumping stuff in the creek sort of no no.

The parts were decent and cheap. I know he was grinding all of his three teeth into that job.

Imagine the same job with someone who has a reputation and who cares.

[seafeye]

I took a bunch of stuff here:

High Quality Zinc Plating Services - Gastonia, North Carolina



Cost about $350 for a bucket of nuts n bolts and a bunch of black powder coating.

They don't clean up your parts for powder coating. So clean them really good or they won't come out nice.


Yes the calipers were taken apart prior to zinc coating.

[seafeye]

Trailing arms came out nice. I decided to do my fan as well... doubt it will last but for the first 100 miles it will be cool.

[Bob Kontak]

Originally Posted by seafeye

Trailing arms came out nice. I decided to do my fan as well... doubt it will last but for the first 100 miles it will be cool.

If it's powder coated it will be fine. I REALLY like the black on black.

Blades get dirty as everything goes in there fast. It looks matte/satin vs gloss. It's still smooth to allow cleaning. Biggest risk will be fan rubbing on inside of shroud.

Nice. That's a boat load of goodies.

My old man lives in Gastonia.

[Fixer]

Plating looks great but good paint [not rattle can] will last longer.