Wishbone protection

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winthattt
Posts: 783
Joined: Fri Feb 12, 2010 4:45 pm
Location: Sunny Derbyshire

Wishbone protection

Post by winthattt » Fri Mar 15, 2019 2:01 pm

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 :D 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.

SeanB
Posts: 6767
Joined: Tue Jan 04, 2005 9:24 pm

Re: Wishbone protection

Post by SeanB » Mon Mar 18, 2019 7:50 pm

That's interesting. What would be the cost of that process on a set of wishbones do you think?

SeanB
Posts: 6767
Joined: Tue Jan 04, 2005 9:24 pm

Re: Wishbone protection

Post by SeanB » Mon Mar 18, 2019 7:51 pm

Another question, how robust would it be compared to other options?

661
Posts: 1400
Joined: Fri Sep 11, 2009 4:36 pm
Location: East Sussex

Re: Wishbone protection

Post by 661 » Tue Mar 19, 2019 10:23 pm

I've nickel plated the Elan's wishbones
Graeme

winthattt
Posts: 783
Joined: Fri Feb 12, 2010 4:45 pm
Location: Sunny Derbyshire

Re: Wishbone protection

Post by winthattt » Thu Mar 21, 2019 8:43 pm

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

trackrod
Posts: 293
Joined: Sun Aug 21, 2016 10:43 am
Location: Germany

Re: Wishbone protection

Post by trackrod » Fri Mar 22, 2019 7:00 am

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.

winthattt
Posts: 783
Joined: Fri Feb 12, 2010 4:45 pm
Location: Sunny Derbyshire

Re: Wishbone protection

Post by winthattt » Fri Mar 22, 2019 9:05 am

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

trackrod
Posts: 293
Joined: Sun Aug 21, 2016 10:43 am
Location: Germany

Re: Wishbone protection

Post by trackrod » Fri Mar 22, 2019 4:04 pm

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

winthattt
Posts: 783
Joined: Fri Feb 12, 2010 4:45 pm
Location: Sunny Derbyshire

Re: Wishbone protection

Post by winthattt » Fri Mar 22, 2019 4:21 pm

I have asked a plater....no reply yet.

Keith

gripster
Posts: 4
Joined: Sun Oct 28, 2018 7:44 pm

Re: Wishbone protection

Post by gripster » Wed Mar 27, 2019 8:16 pm

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!

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