s2 swinging arm idea

[kenpage]

hi guys ive had a thought im cleaning and painting my swinging arms and do any of you think it would be a good idea to fill the open ended round tubes with expanding foam after ive painted to keep all the crap out or am i just dreaming ? your thoughts please

[V6ish]

I personally would worry that if any moisture did manage to penetrate the foam somehow it would quietly rot away from the inside, and once the foams in, getting it out to re-seal would be a right arse!

You can't beat a good lick of hammerite following by wax oyl--get it sprayed in there thick...

or fill it with Helium, seal it and shed pounds from your S??

mmm..Helium filled tyres anyone

Edited by V6ish on Thursday 22 November 15:28

[tvrgit]

V6ish said:

I personally would worry that if any moisture did manage to penetrate the foam somehow it would quietly rot away from the inside, and once the foams in, getting it out to re-seal would be a right arse!

You can't beat a good lick of hammerite following by wax oyl--get it sprayed in there thick...

or fill it with Helium, seal it and shed pounds from your S??

mmm..Helium filled tyres anyone

Edited by V6ish on Thursday 22 November 15:28

That was my first thought - what if the foam actually soaks up or traps moisture?

Edited by tvrgit on Thursday 22 November 15:33

[kenpage]

the foam im told is completley waterproof i like the helium idea my car was lighter than all s2s judging by the amount of the old chassis that was missing im probably being over cautious

[loudandfast]

A big no no. The foam will absorb water and tust from the inside out. Just fill with cavity wax.
andy

[Barkychoc]

Ray S sealed the ends of his tubes off with body filler which I think is a top idea as at least you can break it out to inspect it.

Foam would make life interesting if you needed to weld your trailing arm.

Foam might be Ok in a building but they don't get thrashed down a dual carriageway at 70 mph! (of course us responsible S owners wouldn't go any faster )
The suspension gets a hell of a pounding, not sure how the foam would stand up.

Chris

[kenpage]

mmm i will scrap that idea and maybe seal the ends with filler many thanks guys

[Sweet Thunder]

The PU foam itself won't soak up any water, but moisture could get trapped between the steel and the foam. Car manufacturers use foam in cavities, with variable results, as it turns out to be quite difficult to guarantee a perfect seal: any impurity left on the steel could cause a cavity for moisture to collect in, which accelerates rust instead of stopping it.

Some twelve years ago I've used foam on a new mini subframe, and the guy who now owns that car reported to me last year that the subframe still was in a pretty good nick. This shows that foam could work, but personally I wouldn't use it on parts that are not brand spanking new: no matter how meticulously you clean them, there will always remain some waxoyl, silicon or other debris left on the steel which prevents the foam from sticking, causing the steel to rust twice as quick. Using waxoyl seems like a better idea to me.

BTW, foam will be a nightmare if you ever want to weld the arm (which inevitably will have to happen once).

[clarenceboddiger]

Having just got hold of 2 virtually new arms, I intend to make a disc to cover the hole, have a nut welded on the inside of the disc to allow a bolt and sealing washer to be screwed in, weld the disc over the hole and part fill the tube with a light oil (maybe Diesel), I reckon the movement of the arm should slosh the oil around enough to keep the surfaces coated. Can anyone see any pitfalls in this idea??

[kenpage]

thanks guys the foam is out and i will think up another daft idea but the body filler looks like a good idea at least i can remove it and check inside when im bored i am just trying to cover all the dodgy points while i have a bare chassis

[ketvrin]

How about protecting it using waxoyl etc and then fixing a rubber bung in place - I'm thinking of those rubber bungs used to seal demijohns in winemaking - you could even use one with a centre hole (itself plugged) to squirt more waxoyl in or to assist removal later ? I cant remember the relative sizes... ?

K

[Barkychoc]

ketvrin said:

How about protecting it using waxoyl etc and then fixing a rubber bung in place - I'm thinking of those rubber bungs used to seal demijohns in winemaking - you could even use one with a centre hole (itself plugged) to squirt more waxoyl in or to assist removal later ? I cant remember the relative sizes... ?

K

I had thought of that one too (honest) and I reckon it would work.
Just need to make sure you can get the buggers out again!

[GreenV8S]

Wouldn't it be easier just to paint them properly? They might only last 10-15 years before they need painting again, but by then the rest of the chassis will be a pile of rust anyway if you have such a bad corrosion problem that you need this sort of protection?

[kenpage]

sorted what a brill idea im into rubber so a bung it is i knew someone would solve it thanks

[ketvrin]

Barkychoc said:

I had thought of that one too (honest) !

I can believe that Mr Lateral

I do think that GreenV8S is probably correct though and have to say I just painted and waxoyled (and ACF50'd) mine ...

good luck

[clarenceboddiger]

GreenV8S said:

Wouldn't it be easier just to paint them properly? They might only last 10-15 years before they need painting again, but by then the rest of the chassis will be a pile of rust anyway if you have such a bad corrosion problem that you need this sort of protection?

Thats absolutely true I hadn't looked at it like that