Wheel Arch removal - seized bolts/nuts - why not use stainless as standard?

[NeilCSR]

Why oh why didn't they use Stainless nuts / bolts / washers to fit the wheel arches?  Or maybe they did and it's just my (factory built) car?

A cry of frustration rather than anything else, an area that gets hit by every bit of water and salt going and is top of the list of potential corrosion places.

Just dealing with the galvanic corrosion where the exhaust bracket fixes to the body adjacent to the wheel arch corner, ideally need to remove wheel arch to clear out a bit of corrosion behind the rubber strip, but all bolts and nuts are heavily corroded and well and truly siezed.

Decision whether to proceed with removing wheel arch, drilling out seized parts and then reassembling with stainless items, or just try to bend the rubber back far enough to get at and deal with the (small) amount of corrosion behind.

Probably the latter and add the wheel arch job to a future list as it will need to be addressed at some point.

Guess this is fairly common, is there any advice about how to remove the wheel arches without resorting to major surgery?

Neil

[Hampshire West AR]

Got plastic ones on my car.

[Cookie Monster]

Plastic is better in case you pull anything up inside the wing like a cone on a track -ask me how I know! Plastic will snap and won't distort the side skin like a metal fastener will.

[DJ.]

Unfortunately, the factory don't seem to have heard of copperslip either.

I built my Seven with the plastic bolts, and Caterham charged me to swap them for steel for the IVA, they then lost the plastic ones I had bought! At least I got another set of plastic ones out of them free of charge

[Paul Deslandes]

Aluminium and stainless are fairly well spread out on the galvanic series table so you will get severe galvanic corrosion issues, especially with road salt in the electrolyte.  The ali will disappear and you'll be left with large holes where the bolts were.

Plastic bolts are definitely better from several points of view.

[Alan Reeves]

where can one get the plastic ones from...

[NeilCSR]

Thanks for the advice re. plastic bolts (and nuts), any further advice re. spec of bolts and where to source?

Neil

[TomB]

Caterham sell the plastic nuts and bolts on their webs store. Alternatively eBay.  

[Bricol]

While the two metals are reasonably far apart on the table, general assumption is there won't be too much corrosion between the two as there is so much more aluminium than stainless steel.  ie you will see ali fabrications, steps handrails etc assembled with stainless screws.

The problem theoretically comes if it continuously wet, or even if there is a small amount of exposed ali.  You won't see unprotected stainless used on ali washed by the sea for example - insulating spacers and washers will be used.

However, I used a stainless penny washers to secure a heatshield under my integrale - and it rattled after a year or two - the washers had corroded through the ali . .. second attempt is using insulators . . .

With a good coating of anti-seize compound (I use a Loctite marine grade - 40 quid a tub) it should be okay - but then a plated mild steel screw would be too.

 

[TomB]

Or some £2 for 20 plastic bolts 

[Tony Whitley]

As for spec. - racers saw halfway through the plastic bolts to make sure that on contact they snap off rather than ripping the rivnuts out of the bodywork.  I went mad and ordered 50.

[NeilCSR]

Thanks for all the advice, I'll now replace with plastic.....

Neil

[JNC]

Just to throw a spanner in the works !!! I think if it's  a road car not likely to get bashed like an Academy  car Stainless would be better, I only say this because of possible plastic fatigue of the bolts, once fitted to a road car they wont get looked at often, race cars on the other hand the wheels are on and off all the time and if any are gone replaced straight away vibration and fatigue you mite be blatting along and loose a wing !!.  

[TomB]

On the contrary, Ive found the plastic bolts provide a useful 'fuse', blowing and preventing more damage to the wing and body on at least a couple of occasions. Last year being lazy I reversed into a wheely bin trying to fit the car in the garage without getting out and moving it. The plastic bolts went 'pop' and no damage was done to the GRP or the skin.  With steel fasteners, the GRP would have to take more force and would likely have at least cracked.