Corrosion!!!!

[Stuart Wallace]

Help!!

 

I have found some corrosion at the very bottom of the side skins below the windscreen mounting points where the ali skin wraps round the lower chassis rail on my 91 HPC. I seem to remember an article in L.F. some time ago, which covered this problem and suggested raking out any muck in the area between the outer skin and the footwell. I can't see a way of getting behind the side skin to do this, can anybody help? Also what are my options for a cure, is it a re-skin job at Arch?, or is there any other way to sort it? The car is painted by the way.

 

Stuart.

 

[ISmall]

I've got this problem too, but mine is a 1996 K Series. It started last year and I took it to TSK in Dartford who do most of the factory paint jobs. Although they did a nice matching job, the corrosion bubbled through again within a matter of weeks. I've looked at a number of cars in Caterham showroom and at the Festival this summer and it appears to be more common than I would like, particularly on newish cars like mine. Apparently there was a redesign of the frame inside the skin and moisture gathers behind the skin from cr@p thrown up into the engine compartment.

The solution, which I have yet to get around to, is to remove the skin, seal it with some sort of resin, and get the skin resprayed. It's a really annoying aspect about my car. It doesn't seem to bother Caterham Cars too much because I've seen cars in there being sold with corrosion on them (mine had none when I bought it however). Have a look around a Caterham the next time you see one, and you might be surprised!

[Stuart Wallace]

ISmall

 

Thanks for your reply.

 

Remove the skin? Do you mean release the pop-rivets that hold the side skin to the chassis rail and then try to get behind it that way? To remove the side skin entirely seems a big job to me and one I would leave to Arch

[ISmall]

In order to get at the frame inside you have to remove the inner surface of the driver's floorwell, then treat the area where moisture has gathered. It's definitely not a job I would personally undertake, and I'll be giving mine to TSK in Dartford (Tony is a good bloke) to have another go at solving the problem. I think that drastic action is the only way around it. What is Arch?

[Stuart Wallace]

ISmal

 

Arch Motor & MNFG Co Ltd. They manufacturer all the Caterham Seven chassis and bodies. I had a look at getting behind the footwell panel last night, it looks feasible to release some of the pop-rivet to have a look it there and perhaps coat with Waxsol without removing the whole panel and then treating and repainting the outer skin

 

[rynicolson]

My 94 K series has exactly the same problem... I hoover the cr@p out from inside the engine bay but intend to try silicon... after I've repaired the damage...A low pressure hose perforated the skin so it now looks a mess... can you "cut" out the damage and alloy weld back in a plate?

 

Tell me how you get on... I am 450 miles from the likes of Arch so have to find someone local who is competent.

 

 

[AndreK]

I haven't a Caterham...yet, nor seen the problem you describe. If you wish to correct it yourself then suggest panel removal, followed by 'prep and local chassis repaint first. You may need something further though to prevent steel to aluminium contact which won't help (dissimilar metals?). After panel re-fixing seal joint with body/panel sealant and apply waxoyl (spraying it is best using the waxoyl supplied pressure can sprayer). Hope this helps!

[Stuart Wallace]

I drove over to Paul Harvey's at Shoreham to get his advise on Friday. It was a bit embarrassing as we could not see the bubbling paint at first glance (like a hypochondriac at the doctors!), but we found it on the second look. It would seem that the only sure fire way of sorting it is to re-skin the side panels from the rear wings to the nose cone treating the frame at the same time at a cost of between £1000 and £2000. Paul thought that a bit drastic for something you have to get in a strange position to see! It might be a bit different if I wanted to convert to cycle wings but I like my flared wings. He suggested removing the internal panels to get at the back of the side panels, cleaning and treating as required (anyone know of a corrosion inhibitor for ali? and then treating and painting the exterior of the panels. I will give it a go over the winter or before if we get more long periods of storms and rain forecast. We think the cause is salt and road grim building up between the internal and external panels. I'll post my finding on this site a soon as I get round to tackling it.

[Marius]

This has nothing to do with corrosion but I lately removed the end-panel of the passenger-footbox ´cause I had to shorten it for my external dry-sump-tank. It was a crap-job, really. Removing all the rivets is still the smallest problem but I had to do a new (shortened) sheet of ally, fit exactly the drillings for the rivets, seal it with silicon and put it in again. That job cost me two very long evenings in total, wouldn´t want to do it again. The hardest pain is to dive into the footbox, head first, and fit the new rivets and believe me .. there are a lot of rivets to be fitted. My chassis is pure-ally-polished and I also found some very little corrosion on it but if you recognize it early enough it´s easy to polish it away. Put some silicon-spray on, works well.

[Pierre Gillet]

I have injected pure (without additional solvent)WAXOYL between the footwells and the sides. I hope it will stop corrosion if it was starting.

Hope not. Knock wood!

 

 

 

 

Pierre

[Pierre Gillet]

Re-skin the side panels at a cost between 1000 and 2000 £ seems awfully expensive to me. Would the price to convert from flare to cycle wings be similar just to get rid of the bolt holes?

 

Pierre

[simonray]

1-2000 pounds for new side skins is rather wide of the mark. Arch re-skinned the sides of my car (when converting to cycle wings) for 400 pounds, though I did present them with a stripped down car. Painting, if necessary, is extra.

[Stuart Wallace]

Pierre,

 

The price was very approximate but would include stripping the front suspension and wings, removing the rear arches and scuttle and either sending the body to Arch to do the work or to do the work at Shoreham. I am sure if I had the room to do most of the work myself and get Arch or Paul to replace the skins the price would be much less. I think we talked about converting to cycle wings and the price may have included new parts for the conversion. The quote was “more than 1000 less than 2000â€. I hope this helps.

 

Stuart

 

[Pierre Gillet]

Simon, Stuart,

thanks for the info. I understand better now and am relieved biggrin.gif

I was not daring anymore to use the Seven in the Paris jungle.

sad.gif

 

 

 

 

Pierre

[Stuart Wallace]

I removed some of the pop-rivets that hold the footwell panel in place so I could have a look inside the void between the outer skin and the footwell, guess what no void! It would appear that I have panels of material about 25mm thick between the inner and outer skins. What is the purpose of these and can I get at the inside of the outer skin from the engine bay?