Rusty galvanised bits?

[dbartle9]

Just unpacked my 'new to me' galvanised tub cappings and some sections appear to have a coating of surface rust. I must admit I've not really dabbled in galvanised stuff before, but I was under the impression that it was suppose to stop the steel corroding?

If I take the surface rust off with wire wool etc. is it going to come back? I was planning on keeping it all bare, but now thinking I may have to paint them.

They're still a whole lot better than the Swiss cheese ones I've taken off though...

Dave

[Aragorn]

Properly galved steel shouldnt rust, or at least not very quickly. Think farm gates and railings...

That said, i saw a landrover fuel tank that had been galved last week that was rusty in places. I can only imagine it was a poor job?

[miketomcat]

If the galv is thin or worn you will get rust. Galv is rust prevention not a cure think paint that only needs doing once and lasts for 20 odd years. Your options are galvafroid (cold galvanizing) and leave it, prime and paint it or you could try rubbing something like wd40 into it with a rag this will get the worst off and if you do it regularly will keep the rust at bay. Wire wool will damage the galv more and speed the rust up mind it will probable still take 10years.

Mike

[CwazyWabbit]

Stick a picture up of the rust please

[dbartle9]

Pictures as requested. This is probably the worst bit out of all of them.

Surprised I didn't have galv cappings already - is on a 1985 Ninety with original galvanised bumper and roof rails.

Dave

[Team Idris]

Ooh er misses, the zinc has left for good ! That's a shot-blast and metal prime, or a re-galvanising job? Personally I'd go for galvanising.

The zinc only seems to work because it is more reactive than steel. If it's exposed, it's sacrificing itself.

[CwazyWabbit]

I'd be getting those regalvanised before fitting them.

[studmuffin]

They look horrible buddy. My guess would be bad galving or they may have been stored wet and covered so there was no air around them. This causes white rust, possibly still evident on the top edges? When dry, this powders and basically drops off leaving bare metal to rust. Hot dipped galv is a sacrificial coating, and providing it is open to air movement I think that the normal lifespan depends on the Sulphur Dioxide levels present.

This is my version of the techy bit ---

The adhesion in the hot zinc bath depends on possible surface pre-treatment and a correct constant temperature. Failure results in lumpy galv spelter being deposited which de-laminates and flakes off like it was never there!

As everyone says strip and re-galv is the best way to go.

The only possible fly in the ointment is if the metal used has a high silicon chemistry from the melt in the blast furnace. This is fairly unusual these days but if so will not re-galv properly irrespective.

I spent lots of years looking at bad galvanising.

Go for it

[Litch]

You say "new to me" so do you have any idea how old they actually are?

Just have them re-galvanised, if you have ALL the capping done it won't cost more than £20 and then they will last the lifetime of the vehicle.

[dbartle9]

Thanks for all the replies...

They came off a 1986 ninety that was being broken up so they've had their fair share of exposure to the elements!

Think I'll go for the re-galvanising route - anyone know of a reputable place in the West Midlands?

Dave

[Lewis]

There's a place in Wolverhampton that get good feedback

From recent thread on bulkhead galving:

Hi I had mine galved at a firm in Wolverhampton IIRC ,It didnt need bracing , there was no distortion , I had pre blasted it and removed all the seam sealant manually , as you dont need it as the galve will build and seal it permanently . They dipped it twice , and did a load of brackets , and fuel filler at same time .

http://www.wedge-galv.co.uk/Edward-Howell_Galvanizers.aspx .

usual disclaimers , just a satisfied customer .

[Litch]

Personally I use East Anglian Galvanising in Sawtry but you will have to decide which is the closest or most conveniant to use. Remember you don't have to go there, if it is cheaper to do so just package them up and send them.

I like EAG because there is no minimum charge and they usually do an excellent job for me. Ok, thay have just twisted my Defender bulkhead but that was physical damage and not heat distortion. At the moment they are looking to go follow through with the repairs so I don't have a real issue (apart from the delay it is causing me) and have no hesitation in recomending them.

[studmuffin]

I think B.E.Wedge Ltd are still going but the link is not coming up. There is another Galvanizer in Ettingshall/Bilston area called Joseph Ash Ltd. They are part of a biggish group so may not be interested, but if you ring their Sales Dept tomorrow, then they will almost certainly advise who could handle small batch stuff locally within the West Mids. They must get asked the question loads of times.

I am not in that side of the trade now but if you get stuck PM me and I will ask some old friends who still get stuff galvd.

Dont worry - there is somebody local who can do it.

Also brush off the loose rust but dont try to get to bare metal because from memory a bit of light rust helps the molten zinc to key in to the metal surface/substrate.

Cheers

Barry