vintage cars and preserviing yellow dichromate

[GrumpyOldGuy]

The engine detailing forum does not appear to have much activity. I thought I would post here. If that is an error, I apologize.

I have some 60's era parts that were first coated with zinc and then went through the yellow dichromate bath. They are a bit dull but still the proper yellow, no corrosion. Putting the car back together. Part of me is inclined just to put it together and do nothing but I keep looking at my boxes of metal polishing, quick detailing, wax type products and thinking that there must be a way to preserve that finish.

I don't want to do anything that would cut it.

Has anyone come up with a way to skin this cat?

Thanks

[theamcguy]

Re: vintage cars and preserviing yellow dichromate

I've had some luck with WD-40. Spray it on let it soak in then wipe off. This is not a permanent fix and may take reapplications every few months.

[GrumpyOldGuy]

Re: vintage cars and preserviing yellow dichromate

I've had some luck with WD-40. Spray it on let it soak in then wipe off. This is not a permanent fix and may take reapplications every few months.

Thanks, That leads me down a different train of thought. I was about to try a paste wax but was unsure of what that would do overtime in a hot engine compartment.

WD-40 could be a good solution but I've found the reapplications can form a gummy mess overtime. There is a less common product called Boeshield T-9 that I used for a non automotive use that may be another option. I recall it was originally developed to prevent spools of cable from rusting while providing some lubrication. Use has expanded over time. A buddy uses it on his boat. I may see if I can borrow a little bit to try in an inconspicuous place.

It does do a little rust conversion, need to confirm it does not wash off the dichromate tint.

Thanks again. I will update the thread when I come to a conclusion.

https://boeshield.com/why-boeshield-2/

[Jonesey]

Re: vintage cars and preserviing yellow dichromate

I've been using the Boeshield for over ten years on customers outboard engines to reduce corrosion under the cowling. There are only a few fasteners that have what looks like dichromate coating, and I've not seen any colour change. The main thing I am using it for is to protect unfinished aluminum from salt water corrosion, and to try to keep the dissimilar metal corrosion at bay, and it does a great job at that. I have not seen it do any rust conversion, only prevention. Mercury Marine sells a product called Corrosion Guard, which sprays on like a thin wax film, which is great for preventing corrosion, but over time leaves a dull finish, which it sounds like you are trying to avoid. The T-9 leaves a shinier finish.

[Jonesey]

Re: vintage cars and preserviing yellow dichromate

Update- just found a spare axle nut from my 9-5 which looks like yellow dichromate coating. Gave it a spray with the T-9 and a quick wipedown. It cleaned off the dirt and left it looking new. No signs of the coating being removed or colour changing.

[GrumpyOldGuy]

Re: vintage cars and preserviing yellow dichromate

Thanks for the replies. The parts I was most concerned with were the headlight and wiper door vacuum actuators on a c3 corvette. I decided to go the conservative route and just wiped them down with a little collenite 845 that I forgot I even had. I suspect that will be fine. Thanks again.