RUUUUST

RobC · Post by **RobC** » Wed May 25, 2011 12:44 am

from above looking down. I've since had a poke around and the hole's got somewhat larger.

from below, where the exhaust hanger should be (eagle eyed viewers will notice that the tailpipe has rusted off too)

I think to make it 'good', a 1m x 0.5 m square box section needs to be cut out and a new bit welded in. all this decay blatantly worsened by never having had rear mudflaps fitted. lesson folks!

issues:

1. i am on the dole. so have no money (but plenty of time)
2. i don't own a welding machine
3. i haven't the faintest idea how to weld
4. i also don't have the faintest idea how to 'panel beat' (is that the correct term for making the replacement section?

most of the exhaust needs replacing too. anyone throwing (or getting rid of cheapish) various bits of 16v exhaust. bear in mind that everything bar the front section is shared with td/gti (i believe?)

i've had the old girl since 2002 (3rd owner), i completely stripped down and rebuilt the engine 20000 miles ago (runs beautifully), bodywork is mostly lush, hydraulics in good nick (but is it meant to sink down so much when you hold it on the foot brake at the lights?) and i can't imagine ever wanting another car. but tax is up at the end of the month, and i discover this. btw apart from the rear bumper mount, not much other rust cos it was well waxoiled earlier in its life.

anyway convince me not get rid!

Philip Chidlow · Post by **Philip Chidlow** » Wed May 25, 2011 1:34 am

I guess the upside is none of it it really structural from a safety point of view. You will need a new back box sure, and other bits: I have a CN151 transverse box here doing very little - but they aren't difficult to come by, unless you want the 16v straight tailpipe and trim. Mind you my local ATS replaced my GTi back box about 6 months ago and the tailpipe was straight, not 'bent' down...

If you can treat the rust, bolt a bracket to some reasonably solid metal and make your boot watertight with some mesh, aluminium tape and underseal, you'll buy some time until someone can help make a permanent repair. It'll be OK for an MOT in that state, I'm fairly sure.

Whereabouts are you?

citronut · Post by **citronut** » Wed May 25, 2011 8:09 am

the only reason that rust would fail a MOT is the rear exhaust hanger is missing,

although that is a relativly easy bit to repair/weld as its all single skin around there,

and as Phill says its not strutural

regards malcolm

Gibbo2286 · Post by **Gibbo2286** » Wed May 25, 2011 8:20 am

Well I'm sorry I have to disagree, I think that is certainly an mot failure and I think also the op has his priorities wrong, he should attend first and foremost to point number one on his list and maybe point number three. Gibbo.

Post by **Defender110** » Wed May 25, 2011 8:31 am

This is a very common BX rust area, if you don't want to weld it at this point I suggest you borrow a litlle hand grinder and totally cut out the section on the horizontal and vertical faces in a sqaured off format, paint the remaining good edges and then cut and fold a slightly larger flat piece of steel or aluminium plate, you can then srew this in place with self tapping screws or rivets with a polyurethane sealant around all the edges before a thick coat of underseal / stonechip. It is essential you cut it all back to good metal to get rid of the rust and not to just plate over it.
It's deffinately not a case of ''getting rid'', stick with it.

Linegeist · Post by **Linegeist** » Wed May 25, 2011 8:51 am

That's a neat idea Kev - but don't new MOT regs state that ANY repairs of this kind have to be seam welded?

I understand you can't even spot-weld any more - the whole piece has to be seamed all the way round - even if you're replacing a previously spot-welded panel.......

Having said that, how an MOT tester would know if presented with a car that had been carefully undersealed and then driven through mud is beyond me.....

Post by **mat_fenwick** » Wed May 25, 2011 9:37 am

I've got a draft PDF copy of the new MOT manual, and it states:

the repair must appear to be virtually as strong as the original structure with only continuous seam welding being acceptable for patch repairs (even if the patch extends beyond the prescribed area).

and

spot welded joints are acceptable where the original panel has been replaced to an existing spot welded flange (provided the original defective panel flange has been removed). Stitch or plug welding is acceptable as an alternative to spot welding in these cases.

I believe the first quote is only referring to areas that would cause an MOT failure, and I can see nothing in the manual that would indicate that this is a structural area.

Gibbo2286 · Post by **Gibbo2286** » Wed May 25, 2011 9:38 am

Linegeist wrote:That's a neat idea Kev - but don't new MOT regs state that ANY repairs of this kind have to be seam welded?

I understand you can't even spot-weld any more - the whole piece has to be seamed all the way round - even if you're replacing a previously spot-welded panel.......

Having said that, how an MOT tester would know if presented with a car that had been carefully undersealed and then driven through mud is beyond me.....

Back when I had the garage I had just down the road a 'bombed site dealer' he used to deal all the time in bangers, low deposit pay weekly etc.
He was known locally as 'Cataloy Jack'

He showed me a tool he'd made to roll along in the filler to make the impression of spot welds before he painted over it. Gibbo.

RobC · Post by **RobC** » Wed May 25, 2011 12:58 pm

Thank you, as always, for your words of advice and encouragement. I don't come on here often, but have been around since the days of Anders and Alan on the old "Q&A" forum in 2001.

Gibbo: trust me, I attend to point 1 daily!

Philip: I'm in East London, but parents live in Shrewsbury (where there's a workspace + tools).

News just in on the family grapevine is that my cousin is a bit of a handy welder, so i may well be paying him a visit...

I'm confident I can do all the prep work myself. I've made it watertight with some of those flexible sealant strips you get for flat roofs that my dad had lying around. and the rear box is temporarily tied to the section that holds the inner and outer wings apart (that the right term?) Won'y do more than a few hundred miles like this though.

Post by **Defender110** » Wed May 25, 2011 1:59 pm

Linegeist wrote:That's a neat idea Kev - but don't new MOT regs state that ANY repairs of this kind have to be seam welded?

I understand you can't even spot-weld any more - the whole piece has to be seamed all the way round - even if you're replacing a previously spot-welded panel.......

The honest answer to that Bob is; I'm not sure. My understanding is that this only applies if structural, chassis legs, sills etc. , floor pans near suspension mountings or seat belt anchors but who decides what is structural? To me every part of a monocoque structure should be classed as structural including the boot floor which I would have thought is certainly part of the designed crumple zone?
Being a qualified welder it is not an issue to me personally but having thought about my previous advice I think I should retract it.

citronut · Post by **citronut** » Thu May 26, 2011 7:18 pm

it is still acceptable to tack/plug or spot weld were it was originaly spot welded from the factory,

and were it is part of a solid panel it has to be solid weldall the way around any section that was not spot welded originaly,

also as i said earlier the only reason this area is/would be an MOT faliure it for the exhaust mounting and no more than that,

as the rules are any rust within 30cm of suspension, steering, seats and seat belt mounttings,

and the tail end of a BX boot floor/inner wing area is well outside that 30cm's,

and to add to all that it is no longer alowed to braze tin work together for MOT purpose's,

regards malcolm

Post by **mat_fenwick** » Thu May 26, 2011 7:59 pm

citronut wrote:it is still acceptable to tack/plug or spot weld were it was originaly spot welded from the factory,

and were it is part of a solid panel it has to be solid weldall the way around any section that was not spot welded originaly

Yes to both - as I quoted earlier...

Gibbo2286 · Post by **Gibbo2286** » Thu May 26, 2011 8:07 pm

I think you will find that should be 'withinn 30cm of any structural member', the rust in the pictures falls well within that for the subframe and its mountings.

The manual can be found here for anyone who wishes to decide for themselves.

http://www.motuk.co.uk/manuals.htm

Gibbo.

Post by **mat_fenwick** » Thu May 26, 2011 10:08 pm

I can't find where this quote has come from:

'withinn 30cm of any structural member'

All I can find is the reference to corrosion in load bearing areas (figures 1-4) which are things like the chassis rails, sills, inner wings etc; and 'prescribed areas' which are defined as

The load bearing parts of the vehicle to which the testable items defined in Sections 2, 3 and 5 of the Inspection Manual are mounted, and
any load bearing or supporting structure or supporting panelling within 30cm of the mounting location.

That said, I reckon it will have *some* effect on the structural integrity, but not be an MOT failure.

citronut · Post by **citronut** » Thu May 26, 2011 10:33 pm

sorry to dispute you Gibbo
but the very back end of a BX inner wing were the last exhaust hanger is atatched, is well outside the 30cm's from the rear most rear subframe mount

and more offten than not failed rust to door sills, is usualy within 30cm of seat belt anchoring points os sub frame mounts,

regards malcolm