Anyone galvanized an entire base unit?

P

PeterZRH

Well-Known Member
Just curious whether anyone ever attempted this and whether it was successful. Obviously the unit would need to be acid cleaned.

Would hot-dip (480 degrees) be too hot and distort but I guess not having the thin exterior panels would help compared to other vehicles.

Or would Sherardising (vapour deposition) or electroplating methods be possible on this scale?
 
I took all of Sparky's panels to a company in Birmingham.

They dipped them in a caustic solution which dissolved all of the paint, underseal, aluminium (rivets etc), then they were rinsed off and dumped into a mild inhibited hydrochloric acid which took the rust out at a microscopic lever (well it was supposed to), then it was rinsed and dried and dropped into a vat of paint and electrically charged to bond the paint into the metal.

I did find some rust in behind the front wing supports so it didn't do everything it should have done, but was certainly very good. They would have dropped the whole base unit into the system, so very possible to electropherically coat the whole thing, not sure about galvanising it though.

Richard
 
A lot more restoration companies are starting to look towards soda blasting. There are more and more cases popping up where cars having been dipped are starting to show signs of dipping acids appearing through paint years after.
 
richj said:
A lot more restoration companies are starting to look towards soda blasting. There are more and more cases popping up where cars having been dipped are starting to show signs of dipping acids appearing through paint years after.
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Soda blasting comes with it own group of hassles, biggest one being it is great at removing paint, not so good at removing rust. Solution creeping out from pinch seams is a problem, but really it's down to the company that dipped the part not doing a proper job neutralizing and rinsing.

Yours
Vern
 
redrover said:
http://www.prostrip.co.uk/car-auto

These are the go-to people for this sort of thing in the classic car industry. With the sort of clientelle and calibre of cars they deal with, I wouldn't bother going anywhere else if I were going down that route.
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They're just down the road from me. They stripped my V8 manifold and rocker covers for me and did a nice job too. There's always some sort of bodyshell in the yard or just being driven away on a trailer. If you're going to cut most of the rusty seams out and weld in fresh steel then I think it would be nice to work on a completely clean bodyshell and there shouldn't be a problem with acid seeping out over time either.
 
Repairs to the base unit would be the biggest problem - the repairs will likely cause things to buckle and warp when dipped. I have obviously never actually done one so cannot say with 100% confidence, but in the landrover world I have heard of the same problems happening when people get repaired bulkheads galvanised.

It was for this reason that my Dad got hold of a mint Td5 bulkhead and got that galvanised, rather than repairing the (knackered) original from his 1988 110.
 
I'd think that the various thicknesses of metal and the configuration of panels/welds etc in a base unit would make
hot dipping it an exercise fraught with problems from buckling. Then, you need to consider all the small nooks and
crannies filling up with zinc and adding to weight or blocking drain paths.

I'd look at electro-galvanising as an alternative, but it would need a big oven to cook it in after to sort out any possible
hydrogen embrittlement issues. It also wouldn't have good covering inside the structure, so the expense may not prove
worthwhile for what you would reasonably expect to achieve.

http://www.youtube.com/watch?v=KZCFcxf5IBw&feature=share&list=FL6C4Teuk5BkOffwkJOx3vGQ&index=2
http://www.youtube.com/watch?v=8-gBAjEga1s&list=FL6C4Teuk5BkOffwkJOx3vGQ&feature=share&index=3
 
Good points. I guess you'd need to open up the sills and enclosed sections.

If you could avoid distortion issues I'd actually wonder if it would improve the car in other ways. When (then) BL experimented with a metro body shell which was glued along the seems they found the torsional rigidity massively improved. I wonder whether galvanisation would effectively achieve the same thing and thus improve handling?
 
One problem that looks insurmountable to me is getting the insides of boxed sections clean enough to accept the zinc coating. I've had a Land Rover bulkhead blasted and galvanised (luckily with no buckling) and the only problem areas were the odd nook and cranny where the blasting medium hadn't been cleaned off thoroughly enough. That's on a panel which can be accessed from each side with few double skinned or boxed areas. I can see the sills of a P6 base unit being a much more major problem - how could you avoid leaving crud inside? And they're exactly the areas that you want protected. The only answer I can see, is to put in several inspection holes large enough for pressure washing - but how would you do that safely without affecting the structural integrity?
 
Hi, from what I understand there mustn't be any closed boxes because they could rupture
from the heat. All box sections must have vent holes of at least 10mm. There must be
holes at the top to vent air upon immersion and holes at the bottom for drainage. I was
told you are charged by the amount of weight of zinc used, so you don't want zinc not
going into box sections because of no protection, equally you don't want to pay for a box
section full of zinc.

Colin
 
cant help but think that hot dip galvanising will dimensionally change the car shell significantly as the coating wont flow in as consistent a manner over the entire shell and having seen many other iron structures hot dipped the finished article is some what rough with dags and such. I would have thought that electroplating would yield better results with consistent coverage right into hard to access areas and would not significantly dimensionally change the shell with a plus of not needing to clean up rough hot dip you could immediately paint with no prep.

Graeme
 
Hi, correct me if I am wrong, the trouble with electroplating is it needs 'line of sight' to work
so it would need electrodes inside the box sections. Or is it referring to electrically charging
the shell?

Colin
 
There are many different ways electroplating can be done and as such there will be ways more appropriate for dealing with box sections and occluded areas.

Graeme
 
ghce said:
and having seen many other iron structures hot dipped the finished article is some what rough with dags and such.
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Absolutely. I made the mistake of forgetting my gloves once when collecting a batch of stuff I'd had galvanised and lost quite a bit of blood as a result.
Most of the dags (good word!) are where it's dripped or where supporting wires have been removed, so in theory should be limited mostly to the underside of a car, but I can still see a lot of tidying work needed.
With a galvanised Land Rover chassis, we're advised not to route electrical cabling through the inside of the rails as original because the rough surface would wear away the insulation over time, which says a lot about the finish.
 
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