Your preferred finish on various suspension parts?

[82DMC12]

Looking for your experience with various paints / coatings / treatments on the different parts in the suspension system. I'm going to be doing a 100% overhaul of everything connected to the frame and only want to do this once! I know there are preferred ways to deal with different parts, so I'd love to hear what you think I should do for part groups such as:

Hardware (nuts, bolts, washers) - leaning towards sending out to get cadmium plated. I understand cad isn't super durable, but I like the gold color. What else should I consider?

Brake parts - calipers and parking brake mechanism in particular - not too picky on color but leaning towards silver. Should I just get these blasted and then hand-paint with caliper paint, or should I powder coat them? I did a car where I had all this stuff cadmium plated and it looked awesome but I don't know how durable that is with the heat long-term

Large suspension parts - upper A-arm, lower control arm, steering knuckle, roll bar, upper and lower links in the rear suspension, trailing arm, hub carrier - not sure what to do here but probably powder coat?

If you have photos of what you did and how it turned out I'd love to see it.

Making big plans!

Andy

[Josh]

I powder coat everything black.

[84Impulse]

As long as you keep it looking like a space ship. Can you use gold foil perhaps?

[Drive Stainless]

Lotus plated most of their stuff where steel was used. I also like the look.

Maybe plated with a clear powder coat to keep it looking nice would be my ideal?


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[82DMC12]

Thanks guys. Is it often an issue where something gets powder coated but it affects geometry or tolerance? Thinking about the front suspension, is OK to powdercoat the front hub? I would think you don't want to coat where the bearing goes, yeah? What about the steering knuckle?

[Josh]

Thanks guys. Is it often an issue where something gets powder coated but it affects geometry or tolerance? Thinking about the front suspension, is OK to powdercoat the front hub? I would think you don't want to coat where the bearing goes, yeah? What about the steering knuckle?

Do not powdercoat in bearing bores, threaded holes, etc. It will cause issues. The same goes for any sort of coating other than Zinc plating as it is very thin. This is why it wears off and looks bad if you drive your car with any sort of regularity.

[Mark D]

+1 for powder coating.

Mask off the inside of the rear hubs where the bearings install, and taper lock holes on the front knuckles, any threaded holes, etc. as Josh has mentioned.

You'll also need to remove any bushings or rubber/plastic parts prior to powder coat since they be destroyed by the heat. I powder coated my steering rack tube and masked off the ends, removed the pinion bushing, and reinstalled the cover plates so those would get powder coated as well.

Here's the stuff I had powder coated:


For the steering rack I masked off the inner tie-rod end joints, and actually just left the threads on the outer tie rods to be coated and just ran a tap over them to clean up after the fact. Just to clarify, the rack was completely disassembled and I only sent in the tube and the two arms for powder coating. This photo shows the parts during reassembly.





EDIT:
Here you can see the other end where the inner part was masked off



I also had the sway bar blasted and powder coated, though that's not pictured. The rest was zinc plated: (A few new parts shown in here too)

[82DMC12]

Thanks Mark, that looks great! The box with all the nuts/bolts in it - did you get those zinc plated too but without the gold finish? How long ago did you do this and how do you feel everything has held up?

Also - for stuff with threads like the spindles, you had no issue getting bearings into them, or problems with the threaded studs after plating? I'm trying to figure out how much instruction I would need to give a local plater to make sure they don't make my life hard after the job is done while I try to reassemble.

[Mark D]

Thanks Mark, that looks great! The box with all the nuts/bolts in it - did you get those zinc plated too but without the gold finish? How long ago did you do this and how do you feel everything has held up?

Also - for stuff with threads like the spindles, you had no issue getting bearings into them, or problems with the threaded studs after plating? I'm trying to figure out how much instruction I would need to give a local plater to make sure they don't make my life hard after the job is done while I try to reassemble.

Yeah the big box was all the original hardware re-plated in clear zinc instead of yellow. There is a conversion coating that is applied over the zinc plating and the yellow coating is usually thicker and can build up in threads, so the thinner clear zinc is more commonly used on hardware.

The parts were done around 9 or 10 years ago now, but I've only probably put 5000 miles on since then. The powder coated parts still looks like new underneath the slight layer of dust and grime that has built up over time. The zinc plated hardware and other parts have also held up very well, as have the brake calipers and other large parts. Heat degrades the coating slightly faster, so my exhaust brackets and calipers have faded a little and aren't quite as yellow, and have some chalky "white rust" on them which is the zinc starting to oxidize a little. No actual red rust though from the underlying steel.

No issues with the plated parts during reassembly like pressing bearings into the hubs as the coating is very thin. The stock front hubs were originally a black phosphate type coating which has poor corrosion resistance, so that's why I opted for yellow zinc on those even though it's not factory correct.

Your local plating specialist should be able to handle re-plating used parts. I didn't do anything with the hardware like sand blasting or using a chemical dip. All that was handled by the platers.

For the large parts like the calipers and brackets that had significant rust I did blast everything clean myself, but most plating places will have the capability to do that as well. Although, they usually will charge extra if the parts require a lot of prep. I bought a cheap harbor freight bench top blasting cabinet and a couple large bags of aluminum oxide blasting media.

I went through DMC Midwest for all the plating... they have a local vendor they use that is familiar with DMC parts so I felt comfortable that nothing would be lost or screwed up. I had enough parts to do my own special run of plating, but if you've only got a few parts yours can be batched with another group of parts to keep costs down. I liked that all of my parts were in their own batch so there was little chance anything would be lost. The cost was reasonable as well, although I'm sure the rates have changed in 10 years. All my zinc plated parts fit in two USPS large flat rate boxes so shipping wasn't too expensive.





Here's a "before" picture when I was stripping and blasting parts.



There are a lot more pics here in my saved albums which are sorted pretty well into groups.
http://dmctalk.org/album.php?u=269

[CyberBill]

Very similar to Mark - in fact, he was one of the posters I copied for my DeLorean.

You can see it starting here in my build thread: http://dmctalk.org/showthread.php?18...toration/page3

This was done just last year, and I have pricing and other info in the thread about the process.