Should I re-plate my hardware?

[Michael L.]

guys,

I am finally getting around to re-assembling my 69 after a long delay. Several years ago I tumbled all the hardware that I was going to send out for zinc plating to get it ready. To my amazement the bolts came out astoundingly good from that process. After several years of sitting in my garage they still look great. My question is, should I leave well enough alone and just use them as is or should I still send them out and re-plate them? They can't possibly look any better, I'm not sure how durable the shine is although it has held up for several years. This car won't see much rain of course so not sure I need to worry all that much about corrosion. I just don't want to send them out and have them look worse than they do now, which I realize is of course a real possibility. I'm also aware that the re-plating process can weaken the bolts if not done correctly. What do you guys think? This car will be an occasional driver and rarely shown car.

Mike

[Duke W.]

Re: Should I re-plate my hardware?

Without photos, who knows. You should post some examples.

A lot of the OE hardware was not cad of zinc plated. Many were uncoated or just a black phosphate coating, which caused surface rust to form fairly quickly - often by the time the car hit the dealer, especially if built during the winter months.

If you do have the hardware plated, the entire lot should go through a baking process after plating to avoid a problem called "hydrogen embrittlement". The plater should be able to explain.

Duke

[Eric J.]

Re: Should I re-plate my hardware?

I often just use a wire wheel to clean hardware. Then treat with a product like:

http://www.sharkhide.com/mpinfo.html

or

http://www.rustoleum.com/en/product-catalog/consumer-brands/stops-rust/rust-inhibitor

I have used both. The sharkhide works best on hardware/bare metals exposed to the elements and the inhibitor on underhood/interior hardware

[Michael L.]

Re: Should I re-plate my hardware?

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[Michael L.]

Re: Should I re-plate my hardware?

Here are some quick photos of some of the bolts I tumbled. Not sure it sounds logical, but the bolts I would have expected to be plated came out looking like it was freshly plated after the tumbling but bolts that were likely black phos or natural did not. I wasn't sure if it was possible that some of the zinc was left intact from the factory and that was what I was buffing.

[Duke W.]

Re: Should I re-plate my hardware?

...looks to me, especially the first photo, like clean steel, which would be the result of an unplated bolt with surface rust after tumbling. It also looks like there is some pitting on the washers, which would indicate an unplated or only phosphate plated part.

You could test a few pieces by putting them in salt water for a day or two. If unplated they should have an obvious thin coat of surface rust. If there is any plating left - probably no rust will form.

I know that unplated steel will pick up some specs of surface rust even if left out overnight when the temperature drops below the dew point and moisture condenses on the bare steel.

Plating all the hardware can be considered "overrestoration" and take a points hit. In my case, I hate surface rust, so I had everything plated and baked out. There was a minimum lot charge based on pounds, so the whole job was not that expensive.

Duke

[Alan S.]

Re: Should I re-plate my hardware?

Hi Michael,
I'd think a car that gets driven would require some type of protection on the fasteners to keep rust formation at bay.
Is there Flight Judging in you car's future?
If so, the judges will be looking for various finishes on the fasteners beyond natural steel.
While some fasteners were left natural, many had various plated/coated finishes applied to them including cadmium, zinc, manganese phosphate and black oxide.
Just what the finish or lack of finish was depends on just where the fastener was used.
So if you think you might like to have your car Flight Judged at some point, now is the time to do something about the fasteners.
Regards,
Alan

[Phil D.]

Re: Should I re-plate my hardware?

What I found researching and restoring a 72 was that somewhere around 80-90% of the nuts and bolts on the chassis were originally a black finish, either oxide or phosphate and many washers were unplated raw steel. There were a few more zinc finishes in the engine bay but still predominantly black and many were painted over.

Black oxide is incredibly easy and cheap to do at home with chemicals from Caswell or Eastwood. Dip for a few seconds, watch them turn black, rinse, dry, then dip in your favorite rust preventative or sealer. Zinc plating is a little more challenging and requires some investment in equipment, but still also doable at home with a kit. The only downside to taking your bolts to a plater is that they'll take them out of your little ziplock bags and you'll get them back all in one big batch that you'd have to sort. So I'd say do the black oxide yourself and only take the zinc bolts to be plated since its a much smaller quantity and you can first catalog the sizes and headmarks that go back in each bag.

[Chris S.]

Re: Should I re-plate my hardware?

I send all my hardware to Greg Gregori - http://www.detailplating.com/
I try Caswell and Eastwood
Cant beat professional plating

[Michael J.]

Re: Should I re-plate my hardware?

I just love the zinc dichromate type parts plating, looks like jewelry when done. It never hurts to spray some Boeshield on it either, good for humid climate where condensation from a cold night tends to tarnish and pit over time.