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MG Midget and Sprite Technical - Wonky panel gaps

No, it's not a comment on a much loved car from around these parts but a question about my latest rebuild job!

At some point the car has had a new n/s rear wing and rear panel, presumably a minor accident repair. It can't have been too terrible a bash as it still has a very straight original passenger floor and boot floor.

The problem is, it wasn't a good repair job and has left things poorly aligned. I reckon it was a cheap body shop trying to get a quick turnaround. It's not awful enough to warrant doing the whole job again with new wing etc, just that the wonky gap between the door and B-post is noticeable.

The previous bodger had corrected the fault by caking the B-post edge with filler and shoving a thick spacer behind the door striker. I didn't think it looked right so started to delve deeper. With me being AR about silly little problems like this I wanted to put it right before my rebuild. Consequently, I stripped off all the filler and found this (see pic).

Can anyone offer offer advice via this pic? Or is there someone nearby that can have a look and maybe even sort it out for me?

I thought about cutting an narrow incision in the wing just rearward of the B-post and moving the edge of the B-post forward a few millimetres before welding the gap back up to correct it but this seems like another bodge to me.

Help!

(PS Excuse the grubby digit)

Bob T

A pic of the gap at the leading edge of the door. Seems pretty straight.

Bob T

Bob,
It looks to me as if the door itself is maybe hung a couple of mm too low. There appears to be a slight step downwards to the swage line at the door top at the rear, and the gap at 45 degree angled bit at the front could be a little closer.

Neither of these will help with the problem you have asked about. I have myself used the slit behind the B-post method and it seemed to work well on mine. It is certainly easier than removing the wing which has no guarantee it would align better at a second attempt. Easier than modifying the door, and a whole lot better than filler!

I would try the slitting method, using a thin 1mm disc in an angle grinder and maybe just cutting around 2/3rds of the way down from the top edge and easing the gap open with wedges until it looks "eye-sweet", then tack and then seam weld. Take care when welding not to get too much heat into the panel which will cause distortion and be difficult to conceal on the side of that rear panel. So just do small welds with plenty of cooling off time.
Guy W

Guy, I was kind of hoping you would appear to help on this one ;o) a shame you're so far away or I might have tried to tempt you round here with beer and biscuits :oD

Yes you're absolutely correct about the door being very low. It does need lifting a touch (about 3 or 4mm I reckon) but I've only fitted it quickly to try and see if the rear wing will line up. If I'm going to try "cutting and shutting" I will put it in the right spot. The thing is, once lifted the new position will probably exacerbate the gap even more so I know this does need sorting.

So the plan is, get the door lifted a few mm, make an incision where I have the yellow line in this pic, tease the edge across then reweld the gap.

I have some 1mm cutting discs so should be able to get a nice thin cut.

It will be quite a wide gap if I have to move the edge by 4mm at the top. I may have to cut a sliver of metal to go in.

Any other tips? or maybe just wish me luck!

Bob T

That's about it. And good luck is all I can offer now!

Heat distortion is the biggest threat I think. The thing I have learnt the hard way is that by the time you can see heat distortion in a panel like that - its too late! Frost make some magnetic backed copper blocks. Advertised for backing areas when spot filling hoes or bridging seams like this. I haven't tried these, but a friend uses them and reckons they are very effective as heat sinks that reduce distortion.
http://tinyurl.com/bvn6r2b Having added this link I realise that price is per block; I had thought it was for 4, which was just about acceptable!

Frost also do some heat absorbing putty that is supposed to help. Again, I've not tried it myself.
http://tinyurl.com/c3zdhrl

Searching elsewhere may locate other cheaper sources for these products. I doubt my mate would have paid £80 for his 4 copper blocks! And the paste may be available from plumbers suppliers at a lot less.
Guy W

OK thanks Guy. Much appreciated.

I have found that clamping a bit of 3mm aluminium sheet to the back of a repair does help stop heat distortion in many instances. The problem here is getting a clamp around this particular spot. Maybe I'll drill and cleco the ali in place then plug weld the holes after?

On the plus side, if I cut close to the seam overlap, that itself is double thick metal and should act as a bit of a heatsink. Plus the backbone of the flange should provide some structural strength against distortion.

Think I'll practice on some scrap sheet first though...
Bob T

Bob, that door top line looks out to me, from those pictures, the rear top rail looks to be getting lower as the line gets further back

Trouble is the image area is too short to check against

I'm wondering if the accident it had pulled the rear panel down at the back causing the out of alignment of the door shut

I've posted the 'old favourite geometry picture' so you can check the horizontals under the chassis points then compare the rear boot/wing bottom corners on each side for height if you like

But that still wont help much with rectifying and what you and Guy suggest is likely to be the best way forward

fingers crossed mate

Bill1

Hi Bill, yes I can see what you mean but I have checked this shell over carefully and its all measures right underneath. All diagonals match too. I think what looks like a wobbly rail line is just a symptom of the shot I took - it lines up fine in real life.
However, I have now realised that the B-post is leaning outward a little which won't be helping the door alignment. Maybe as much as 4mm. So I'm going to sort that before cutting and welding the wing. I was going to pull it in by attaching a ratchet strap to the opposing inner chassis rail and check alignment as I pile on the tension.
Will report back after I've f****d it all up!
Bob T

This thread was discussed between 17/04/2013 and 18/04/2013

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