When people refresh the suspension on a Lotus they normally powder coat, use POR or something similar. Why does nobody hot zinc galvanise? It’s very robust, lighter 
and much less hassle.
Seloc folklore is that it changes the material properties but I can see no evidence that is true from papers etc. Is it just cosmetic and people prefer gloss colours to Matt silver?
No intention of doing mine, just thought about it as I was checking mine and topping up the wax protection.
That’s interesting. What would be the cost of that process on a set of wishbones do you think?
Another question, how robust would it be compared to other options?
I’ve nickel plated the Elan’s wishbones
Sean, I think the finish would be super cheap as it is used for lamp posts, crash barriers and the like. I also expect it’s very durable. If it’s done well it lasts. It’s done on trailers and often looks very tired quickly but I suspect that’s cold galvanising. Audi and a few others used to galvanise body panels and then paint over them.
I can’t see a problem, I must be missing something…Found what I have missed, it does not like salty or acid water.
Keith
The zinc coating bath is quite hot (about 450°C) and the wishbones are welded together. The hot bath could release some tension and the parts would be distorted. And all closed cavitation needs to be opened by some holes so the liquid is able to enter and leave.
The coating itself is very durable even in salty conditions. The rear subframe of the Exige is hot zinc coated.
Klaus,
Do the wishbone tubes have open ends so the zinc can get in and out? You are right, galvanising is done at 450C but I think that’s only a problem on some very high grades of steel, which I doubt lotus use.
There must be a good reason why it’s not done, it’s cheap and effective.
Keith
Keith,
I’m not sure about the ends of the wishbones, I think they are closed. But you could drill some holes into it to open them. That shouldn’t harm the strength too much.
The heat is a problem for mild steel constructions too. When they are welded together a lot of tension gets trapped in the construction. It stays there with no harm but if you heat the part the tension is released and the part may ended up distorted.
It is only a guess and I’m not 100% sure if that’s the reason.
Klaus
I have asked a plater…no reply yet.
Keith
Going to start on my wishbones this year, one query about powdercoating etc. Do they mask off the internal surfaces for the UJ and bushes? or do those get blasted and coated as well? Don’t think I would be brave enough to drill holes in a wishbone though!
Just done mine. Plus uprights, steering arms etc.
Shot blasted with glass to only remove corrosion, zinc coated and then powder coated black.
Wishbone inner surfaces masked before blasting and remaining contact surfaces masked before coating.
Shotblasting - (not sand as it eats to much into the metal) is essential for good adhesion.
Interesting. Did you powder coat for the look as zinc looks horrid or another reason. I suppose the additional cost is minor on newly zinc coated wishbones.
Keith
It’s Zinc Primer Powder Coating, not hot dip.
Some more info here
http://www.qualitypowdercoatings.com/resource_2.htm
My local zinc galvanisers said the following are the reasons they would not use it in suspension wishbones.
However they recommended a product call Zinga to brush on abs waxoyl injected into the tubes. Zinga looks interesting, anyone used it?
Keith
Yes true.
The zinc galvanizing process you refer to is basically to dip the component in molten zinc.
It doesn’t look very nice and the temperature is about 450°C and may not be suitable for Lotus wishbones. It does however offer excellent corrosion protection.
The zinc coating my components got was part of the powder coating process. Simplified they put on a layer of 1. Zinc powder followed by a layer of 2. Paint powder, and then finally 3. Oven baked it.
So obviously not near the protection of hot dip, but a 100 times better than no zinc - and it looks good.
My suggestion would be to just get the wishbones galvanic zinc coated as they were before. If you need some extra protection or if the surface is badly pitted/corroded you may paint them afterwards like I did on the rear of my car. As I’m sure your car won’t be used on salty roads anymore so the galvanic coating does give sufficient protection.
What do they mask them off with??
Mine were masked with 3M 8992.
