Flaky Galvanised bits

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Tengu

Full Member
Jan 10, 2006
12,798
1,532
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Wiltshire
Galvanised steel is fine until it goes.

And then it goes and rusts.

is there any way of restoring it? Apart from complete re galvanising?

I was wondering if filing off the rust, fluxing and re tinning would help
 

Janne

Sent off - Not allowed to play
Feb 10, 2016
12,330
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Grand Cayman, Norway, Sweden
Depends on what it is for an object.

Cold galvanized? Hot galvanized?
Removing the rust manually, then chemically, then using Hammerite has done the job for me many times, and it lasts well too.
 

Tomteifi

Nomad
Jan 22, 2016
294
16
Carmarthenshire, South Wales
Tengu, I trust you know about the dangers of galvanised coatings- If heated giving off extremely toxic as in carcinogenic fumes? It may help if you are able to tell us what the component in question is. In any case at all, I would in no way be heating the piece to either remove, replace or add to its condition in a DIY way. Depending on what it is and its intended use, there is a cold galvanising paint type material available but which is nowhere near as good as hot dipped original. Jannes suggestion is valid and indeed the cold galv paint is an easy fix but tell us more to get the best knowledge.
 

Janne

Sent off - Not allowed to play
Feb 10, 2016
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Grand Cayman, Norway, Sweden
Hot galvanization is not toxic at all.
The item is dipped in melted Zink.

The process of electro galv. did use some toxic chemicals, but I think those processes are banned these days?
Today they use other chemical processes, but the result is not as good.
Some countries still use the old, toxic but quality, process.

The spray-on so called galvanization is imo quite useless in most applications where the surface is exposed.

Hammerite is better, better wear characteristics..
Imo.
 
Last edited:

Broch

Life Member
Jan 18, 2009
8,067
7,857
Mid Wales
www.mont-hmg.co.uk
If it's a restoration project (such as capping on a Series Land Rover) there's no real alternative to taking it off and having it re-galvanized but it isn't actually that expensive. On my series I've actually applied a clear coating on top of the galvanising and surface rust to keep the patina :)

Alternatively, if you want it to remain looking galvanized you need to clean it, etch prime it, then add galvo paint as Tomteifi suggests. If you don't care about the finish, clean, etch prime then coat in a top coat of your choice suitable for the environment.

However, despite man landing on the moon and other such conquests, rust is a foe we have never managed to beat :)
 

Robson Valley

Full Member
Nov 24, 2014
9,959
2,665
McBride, BC
Galvanic corrosion. Check out the electromotive series for metals. That's the tendency to give up electrons or pick up electrons.
Vehicles (and boats) are great piles of different metals. Add an e- conducting salty water = battery!
One electrode corrodes at the expense of the other

One "cure?" is a sacrificial anode such as on boat hulls.
They are designed to be the first thing to rot/corrode.
Ironically, the best metal for that is zinc.
The boat's electrical system is supposed to be "above ground" (potential?)
I never learned if they rot faster when the boat is underway or not.
 

Janne

Sent off - Not allowed to play
Feb 10, 2016
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Grand Cayman, Norway, Sweden
Hence zinc is used to galvanize!

i wonder what kind of thing the OP is needing to protect?

Land Rover designers missed the corrosion lecture while studying.

The Defender is awful in that aspect.
Even Bristol Car got it right. As early as in the 1940's.
 

Janne

Sent off - Not allowed to play
Feb 10, 2016
12,330
2,294
Grand Cayman, Norway, Sweden
Needs to be hot galvanized for a long life. painting with whatever stuff will not last.

I wonder if your old rowlocks were hot dipped, as this does not flake off if done properly.


Sometimes it is cheaper to buy new. I would check out that.
 

Broch

Life Member
Jan 18, 2009
8,067
7,857
Mid Wales
www.mont-hmg.co.uk
Its my rowlocks.

But, a company near here does do regalvanising, I could ask them how much it costs

In which case painting won't do really; it's a wearing component (rubbing) and will need either replacing as Janne suggests, re-galvanising, or just rubbing down and greased as frequent use will keep the rust at bay :)
 

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