Galvanising the Shell

[Shackleton]

Hi guys, been away living on a boat and in the meantime my RR has taken a serious beating. Pretty upset about the state of it but I can see that if I don't do something now, I won't be able to save it.

The plan is a full rebuild.

It needs to be able to deal with perpetual sea salt so I want to galvanise the shell as well as the chassis. Have read this thread by Snagger [ http://forums.lr4x4.com/index.php?showtopic=81236&hl=galvanising#entry696792 ] and in general on the net there's lots of talk of horror stories about warping, but Snagger mentions this guy Phil Hinsley who has done it without problem.

Is it a myth? Does anyone here know what the precautions that I should take are, if any?

Also has anyone a clever CHEAP way of stopping a bare shell from rusting between being blasted (can't afford dipping) and being galv'd?

I really want to go this route so unless someone can categorically say that no matter what I do the shell will warp, this is the direction I'm going. A master fabricator friend of mine came to look and the way I understood it from him, warping usually happens when two (connected) but different guage pieces of steel are dipped. I figure that means that where steel is thick because of a joint, it will warp. Is that right?

Maybe I can take the shell to it's component parts and galv separately, but I'd rather not if I can get away with it.

Any advice would be fantastic.

Thanks! George

PS, Snagger, give us the link to your blog if you're tracking your build on there!

[Aragorn]

I've recently had my defender bulkhead galvanised, and yes some warping does happen.

Flat sections of panel gain slightl ripples and some spots have pretty big buckles in them.

Not really a problem for a bulkhead, but i'd imagine quite unsightly for a whole bodyshell if you get the rippling on the outer panels?

What about looking into an e-coat style treatment, like folk often do when restoring classics:

http://www.surfaceprocessing.co.uk/e-coat-paint-process.html

[Shackleton]

Ouch. So it's unavoidable?

I only want to galvanise the inner body, the outer panels are all alloy so no need. But I'm worried about the body not actually fitting back on the chassis, or something like panel gaps being affected or window not going back in right or something.

I'd love to do an alternative coating, but they're not as long lived, which is irrelevant cause I don't have the money for that sort of thing.

[bill van snorkle]

Ouch. So it's unavoidable?

I only want to galvanise the inner body, the outer panels are all alloy so no need. But I'm worried about the body not actually fitting back on the chassis, or something like panel gaps being affected or window not going back in right or something.

I'd love to do an alternative coating, but they're not as long lived, which is irrelevant cause I don't have the money for that sort of thing.

I don't think sand blasting will do for preparation as salt would already have got inside the box sections of the sills, floor stiffeners, bulkhead and side frames.

[landroversforever]

I've certainly seen pictures of a galvanised Range Rover body. Its just the inner body so all the panels can be realigned after I would have thought.

Warping of things happen when the different thickness' expand/contract in the heat of the process at different rates. I would have thought that letting it cool naturally rather than dipping in water straight after the the zinc would help enormously.

[greenstream]

Hi

I have no personal experiance with this.

But around here (Denmark) there are several Citroën 2CV and Renault 4's on the roads thats been galvanized - entire shells and doors etc. and they havent warped. These cars are as you know of much thinner "steel",

If they can make it work, then I cant see why it couldnt be done on a RRC - probaply a matter of applying the right method ?

How about calling around to some of the people close to you who work with galvanizing for a living an d hear what they are saying ?

Good luck.

Morten

[FridgeFreezer]

I can't image warping due to galving would present problems with the usual Land Rover engineering tolerances - if you're worried, build a jig to bolt the body to for galving so it doesn't move around too much. You could also stiffen panels / add supports. I'm sure there's ways of minimising it too, like pre-heating and controlled cooling. I can imagine many galv places would not bother with it when some LR owner wants to pay them £50 to dip a cruddy old bulkhead, but if you engage their professional side (and pay extra for their troubles) I'm sure the better ones would rise to the challenge. Far bigger stuff than bodyshells goes past on the back of Wedge Galvanising trucks round here.

There is a company in the classic car mags that does "dip" paint stripping & protective coating, not as good as galv but could be a lot friendlier.

Also, as said above, shot blasting will not get the salt out.

[heath robinson]

I saw the freshly galv'd body shell of a classic car on the back of an artic at an engineering works near me, along with a massive amount of industrial stuff on it's way back from the galvanisers. It looked pristine, and as fridge suggests, it had a big box frame underneath to hold it straight while being dipped/cooled etc. It seemed to link just about every mounting point.

On the flip side, some relatively simple things have come back from dipping recently with lumps on, scabby patches and spikes all over. I think you should go and size up your prospective dippers, have a good poke about in their recently dipped pile, and make sure their up to the challenge.

[Shackleton]

Great advice guys, thanks. Great to hear about the 2CV's Morten, the RRC pics LFR, and the big stuff on trucks FF.

Realise that the thing to do is talk to the galv experts and gauge their appetite for something like this. Funny, you always focus on something as the stumbling block and by the time you're done it's something completely different. How the F am I going to prep the shell and free it of salt. I haven't seen any car dipping outfit that charges less than Stg£1200. That'sover €1400. I could live on that for a couple of months!

[Bowie69]

As above, outer panels are ali, so not an issue, however you will have to separate them on refitting to stop galvanic corrosion eating the ali, makes a real mess in little time

[Team Idris]

I thought it wasn't like that, and the zink was better with the ally than steel?

Not that keeping ally away from anything isn't a bad idea

[Bowie69]

Same as stainless, not quite as bad as mild steel:

http://www.galvanizeit.org/about-hot-dip-galvanizing/how-long-does-hdg-last/in-contact-with-other-metals

[Shackleton]

Ah now this is something I do know about. From my time at sea refitting a luxury yacht. ALL aluminium was either physically separated from it's steel fastenings with thin strips of flat plastic sheet - the kind of stuff you get in craft shops - or where steel bolts were running through lets say the alu frames of solar panels, you rub a specialised paste on the threads of the bolt. One of the accepted brands is Tef-gel. Here: http://www.tefgel.com/contain.php?param=tefgel_infor

This stuff really works, but it's a bugger cause it's one of those that gets everywhere if you're not careful, it's persistent in terms of trying to casually rub it off your hands/tools and keep working, and its not the cheapest thing in the world.

This is real interesting, and gives an insight as to why boat people are meticulous about dissimilar metal corrosion prevention.

[landroversforever]

Duralac is a similar thing used by the lotus guys on the elise for all the steel bits bolted to the aluminium chassis. Its also being used by the Bluebird Project guys on Donald Cambell's K7 they are rebuilding.

[tacr2man]

Warping is mainly caused by the method/process , if done concientiously , there should not be a problem , I had none with my latest bulkhead galvanising job , done at wolverhampton , and have not had problems in past (long time ago) . HTSH

[Shackleton]

I've just called the best known Irish galvanisers and worryingly they tend to seer away from even chassis' as they 'tend to warp'. I really don't want to get into the situation where I have to bring everything to England to get sorted.

Any Irish on here who could recommend a galvanising outfit?

[spcollins]

Hi Shackleton,

steer clear of Galco. They're as rough as hell. I used Sprint in Blanchardstown http://www.sprintcoatings.com. They send trailer loads up to the north to get galved every week. They did a very neat job and they are nice to deal with. My chassis was fine but my bulkhead was warped quite a bit. A jig is definitely the way to go. I hope this helps.