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Alzax3
01-08-2007, 05:57 PM
Just took my Corsa in for its MOT - PASSED :D :D :D (didn't require me to spend a fortnight under it welding it all back together like the Fiesta Courier RUSTBUCKET)

Talked to the very helpful inspector bloke about Nova chassis problems (someone near here has one where the whole floorpan, including 3" drops is held together entirely with pop rivets, not a weld in sight.) His take on that was that so long as there were no seat belt mounts in the affected region, depending on the quality of the construction, there might be no MOT problem. That goes against all the 'must be continuous bead welded' theory that I've always heard. Anyone else come across this? If he's right, it's going to save me doing a lot of welding for someone........

Peter
01-08-2007, 06:03 PM
That is his very generous take on it, the book says continuos weld or spot weld.

Ben
05-08-2007, 10:27 PM
Hi all

I am a approved Vosa inspector for HGV's.

A pop rivet is a no go for me as made from alu they do weaken with age.

Ben

adrenaline
25-03-2008, 07:10 PM
but the floor pans on a nova aren't structural like a cill on an ordinary car might be.....??

Alzax3
25-03-2008, 07:19 PM
No they aren't, (though they are probably supporting your seats, and if they give up the outer edge of the pan is supported by habbit rather than structure) but that doesn't stop the MOT man from covering himself by demanding continuous welds. You might find one who doesn't but I don't see the point in risking it.

Ben
25-03-2008, 11:22 PM
Hi all

We have to live with blame culture and MOT man covers his back. But they will let you get away with a lot if you can simply explain an MOT repair to the chassis.


Ben

jimcub
26-03-2008, 12:37 AM
If the pans were carpeted and stuck down, how would he see what the fixing method was. I have seen some very untidy pop rivets, so would not want to be a Fred Flintstone at 50mph.
It's always a weld for me, continuous at that.

Alzax3
26-03-2008, 09:14 AM
Um, they look from underneath, Jim - and if they think shoddy work has been hidden with underseal, they'll scrape it off.......

jimcub
26-03-2008, 10:01 PM
If covered they would not show eg F/G, seen it done ( some scared me to death ) years ago, not all MOT people are as through as they should be, that's why some death traps are looking to kill some one today.

Alzax3
26-03-2008, 10:05 PM
True enough, but if they think that filler/fibreglass has been used to disguise poor construction, they can fail on that too.......

Ben
27-03-2008, 12:55 AM
Hi all

I have a MOT mans hat on A good weld repair to the beetle pan is ok.
from the front. A weld repair to the front beem is a fail being a stress member.
Fiting a new headstock is ok with continuous weld OK.
If you have to weld the rear frame fork the car is scrap.


Ben

Spacenut
27-03-2008, 09:06 AM
I agree - at the end of the day, you might be able to get away with pop rivets, but would you feel safe driving with that set-up? I'm not sure I would. Having said that, I have heard of full-length fibreglass floorpans being made for Beetle chassis, on the basis that only the "spine" is structural, but the whole area of chassis integrity is very subjective, and pop rivets don't inspire confidence at MoT time!

Hi Ben - interesting to hear your views about front beam welding, how does that sit with cutting and welding in Swayaways? There's quite a few of them about...

... But I couldn't agree more about the framehead and rear horns - both of them are flimsy enough as it is, altough in theory a good weld should be stronger than the parent metal - it just doesn't give the right impression again...

Lauren

Big Birds Car
27-03-2008, 01:02 PM
Lauren, the dropped pan on Big Birds was originally riveted in place with some rather large rivets and from what I can gleen it wasn't the only one done like it. To compound matters and possibly at a later date (maybe after an MOT test, but I don't know) it was then brazed which was fun when I decided to do some mig welding. The rivets where solid bugg*** as I ended up grinding them off and even then they didn't become loose in the holes. They must have been put in with one of those scissor riveters or a power one.
The thing is when it comes to chassis they keep changing what they think is acceptible, I can remember when an inch of weld every six was ok, spot welds were fine as well now it is fully welded.
If you bonded in a glass floor to the tub and then bolted it around the perimeter with the floors cut out, isn't that a sort of monocoque affair?
The Eagle I have which is Ford based is basically that, a bit of a chassis (couple of rails really going from front to back) and the floors are moulded into the body.


Ben. where does glass monocoque bodies stand with regards seat belt anchorage as the Rossa is just bolted through the glassfibre without any steel strengthening (standard for all K3 Rossa's)?

Spacenut
27-03-2008, 03:57 PM
You're right BBC, the standards do keep changing. The rivets you describe may well be steel pop rivets, which are stronger. I've had a bit of fun welding over brazed joints myself, but I don't see why a proper multi-tubular spaceframe can't be brazed instead of welded. A good braze joint is often stronger then the parent metal, even though it is essentially just the surfaces that are bonding.

All those 30's style cars like the Hudson TF replicas had marine ply floors bonded onto the chassis with fibreglass, so as long as there is an obvious chassis and it is clear that the floor is not a part of the structure, it must be OK. I think this is where the venerable bug falls over though - it is not clear to the MoT man what part of the floorpan is supposed to be structural, and what part is unstressed. Replacing the steel body with a fibreglass Nova shell does not increase his confidence (even though torsionally the composite Nova/Beetle chassis is probably more rigid than the original VW), so he errs on the side of caution and says no-go.

My floorpan drops were welded in place, using the patterns in the Nova manual. From what I can recall they were stitch welded in place - several beads of weld a few inches in length. It was all going a bit rusty when I got the car...

Lauren

Ben
28-03-2008, 07:15 PM
Hi BBC

I have the Comercial MOT hand book. 'A seat belt should be afixed directaly or indirectaly to the chassis.' There you go clear as mud. On my nova I did fit a good size plate behind the GRP.

As for my truck I took the seat belts out. :cool1:

Ben

Alzax3
28-03-2008, 07:29 PM
MOT Bloke was happy when he saw my plates, too - about 180x100x4mm - you could probably pick the car up by the bolts.

Big Birds Car
28-03-2008, 08:48 PM
I'm not that worried about it really, for the Nova I have two steel plates that are welded to the floor pan and go all the way up the inner wheel area to the top fixing point.
My point is with regards glassfibre monocoque bodies that have no steel support. The Rossa passed without issue but there again the Mot man likes the rubbish (oops sorry) cars I take for testing so not a major issue just wondering really how they get away with it.

Ben, that's cheating, it's not big and it's not clever :laugh: I think the only car I still have that I can get away without belts is the Mk2 Zodiac, but that is so far from getting back on the road at the moment I will probably be drawing my pension.

adrenaline
28-03-2008, 10:56 PM
It does get interesting doesn't it.....

I have a Midas Gold and in that the seatbelts are bolted through the glassfibre of the monocoque and in some places into a concealed box section....the MOT tester has no idea what is behind and passes the car on 'trust' that they are fitted correctly....


I have a MOT mans hat on A good weld repair to the beetle pan is ok.
from the front. A weld repair to the front beem is a fail being a stress member.
Fiting a new headstock is ok with continuous weld OK.
If you have to weld the rear frame fork the car is scrap.

More interesting here.....when lowering kits are fitted to the front beam isn't part of the front beam cut out and the adjusters welded in......?? Same process as a repair....?? Another problem, I suppose,ed is that a good weld repair is stronger than original and dressed and painted invisible.....??

I'm new to this Beetle stuff so I may have misunderstood what is involved.....but a lot seems to depend on the man on the day.....??

The other thing, my MOT man knows and trusts me (the fool).....that's said a lot....but can he really afford to knowadays...??

Talking about seat belts and plates......

On my Berlinetta (a pre-SVA car), it will fail SVA with inertia reels fitted...something to do with the shoulder mountings and their height/relationship compared to the seats.....the original mount is the box section chassis b-post....

The way around this was to fit harnesses fitted throught the floor, using spreader plates......the floor is an aluminium checkerplate sheet on my car.....

Ridiculous......given a choice between box section or checker plate.......... :scared: :scared:

Carl