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MG Midget and Sprite Technical - Frogeye A pillar flatness

I'm in the process of trying to get a decent front end profile/shape on the Frogeye following extensive patching and welding. With front in place and hinges fitted the general fit to the scuttle and A pillars isn't too bad but the A pillars themselves are not flat front to back, especially towards the top. They slope outwards towards the rear. Is this acceptable or are they normally flat i.e. if a straight edge is placed from, say, top of front wheel arch to rear of door, should the body be completely flat? The A pillars came with the basic replacement bodyshell but front end and doors are original. If it needs to be flat, how can I flatten the A pillars, apart from with a sledge hammer or a ton of filler?
Bill Bretherton

And picture:

Bill Bretherton

Bill, I assumed they are supposed to be flat, as you describe. So when fitting my A post covers I used a long string line down the side of the car and adjusted them to this before welding.

Yours sound like they may have a twist in them? Presumably at the bottom the surface is true and parallel to the sill so if the are not also flat at the top then there must be a twist. Bearing in mind these are A post covers, rather than the A post itself, it may be possible to do some adjustment. Maybe a vertical slit in the upper part of the forward face of the A post, then opened up with a flat bladed screwdriver befor welding along the slit again might get it right. It depends how far out the alignment is and how perfect you imagine you can get it!

But if welding, beware heat distortion or it could end up even worse!
GuyW

Guy, yes they are correct lower down but twisted towards the top. Strangely, both sides are the same. I'd say (as indicated in picture) they're too far in at the front and too far out at the back but only the upper half. If I could magically twist the upper half they'd be much better but that would mean cutting the weld to the scuttle, Which I don't really want to.
Bill Bretherton

the upper bit around the base of the screen pillar is supposed to be lead loded - if you are brave enough! that would get it much nearer to looking right
GuyW

Ah, did you use filler on yours? Much easier although weaker near the edge. Mine still protrude too much at the upper rear but that's hard to correct.
Bill Bretherton

I lead loaded mine and it went OK although I didn't think to check the screen angle before painting and so the screen is slightly too upright which effects the sidescreen fit. I'll correct it when I get around to doing some rebuild work.
David Billington

I built mine up with lead but was cautious about building up too great a thickness in case it all sloughed off again. So I finished off with filler to get the curves right.

On the second side I built up along an edge with a bead of weld, ground it to the profile I wanted and then used filler behind that. Hopefully the welded bead edge will be stronger and prevent the filler from chippingaway along exposed edges.
GuyW

This area was originally lead loaded by the factory to remove the 'twist'.
Bob Beaumont

Thanks Guy, David and Bob, very useful information. I've never lead loaded (but can solder quite well both with an iron and torch). I might try Guy's method of a weld bead along the upper front edge and then fill as needed. I presume you don't really want filler under where the screen pillars are screwed down to avoid cracks.
Bill Bretherton

Bill,

The solder normally used for lead filling is typically a Sn/Pb (Tin/Lead) formulation that has a wide difference between the solidus and liquidus temperatures so it has a wide pasty range where it isn't fully molten or fully solid which allows it to be worked. Sn/Pb phase diagram charts are easily found online. It's a bit different to electrical soldering or plumbing, more like what was done in the old days with wiped solder joints particularly on lead pipes.
David Billington

Bill
If you are prepared to weld that front edge like it sounds you are, would it be preferable to just weld some tags to it instead and bump it outwards with a slide hammer then grind the tags off
If you have an assistant holding something nice and heavy like a sledge hammer against the protruding rear near where you are bumping the front out, it could well twist it and line up better------
willy
William Revit

Thanks David. I've never used a slide hammer Willy but an interesting idea. However, the slide hammer would be fighting the weld to the scuttle surely? Unless done skilfully, I might end up making it worse. It's so easy to make a mess. I suppose it really needs a skilled panel beater to do it properly but that's not me.
Bill Bretherton

Bill
It'll surprise you how far it will come out with little effort---worth a try
If you havn't used a slide hammer before just be aware of where all your fingers are, don't have a pinky hanging inside the end of the handle----it hurts ,and you'll say words
OR
You could take it to a bodyworks and get them to pull that edge up and square the pillar up for you-it's not a big job and shouldn't cost much really, then it's done and you can take it home and finish it off-

willy
William Revit

On balance, I think I would still go with cutting a fine slit down the forward face where it will be hidden by the bonnet. Ease the slit wider with a screwdriver or wedges untill the outer face of the A post cover is aligned correctly, then weld up the slit again. I have used the same technique down the face of a B post ( not on my Frog) to get the door shut lines straight and it's very easy.
GuyW

Guy, if I slit the front edge then surely I'd also need to slit horizontally along the weld to the scuttle to allow the A post to move outwards at the front?
Bill Bretherton

Yes you might, for the forward part of the width of it, but if you kept the horizontal cut below the two screen pillar screw fixing holes that shouldn't pose a problem either.
GuyW

Ok, I think I'll try that Guy. Although Willy's got me interested in slide hammers I'll leave that method for now. Also I'd probably make a mess if I tried to lead load. So better stick to what I know i.e. welding and filling.
Bill Bretherton

This thread was discussed between 29/04/2019 and 30/04/2019

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