Welcome to our resource for MG Car Information.



MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG Midget and Sprite Technical - Collision repair - A pillar

Ladies and gents,

I had a bit of an unfortunate incident in my 79, resulting in a deformed front wing, A pillar, door, and sill. I am hoping to do the body repair myself, then have it painted by a pro. I haven't welded anything in 20 years, but I am hoping the very basic skills I had back then are still lurking somewhere!

It isn't too hard to find a used door and wing, but I need to obtain repair panels for the sill and A pillar.

I am trying to understand the body structure in that area of the car. LHS, although I doubt if that makes a difference.

I see repair panels in the Moss catalogue for A-Post Hinge pillar repair, and cowl side panel with flange. The repair section looks as though it has the flange also? Or does one mount to the other?

Is the cowl / scuttle one piece with both A pillar side panels, or is there a join at the top of each pillar?

The other thing I have to work out is sequence of repair. I am aware that I may have to brace the door opening, but am not sure in what sequence I should replace panels, bearing in mind panel gaps that will have to be adjusted. I am guessing sill then A pillar structure?

The actual damage looks worse than it does in the picture. If you look closely, you can see that the sill itself is shoved in somewhat, although the floor shows no damage.

Any advice is much appreciated!

Jim M.

Jim M

Just some quick thoughts Jim, might post again later but need to sort my tea...

Would it be possible that you can get away with just replacing outer sill and A post and just "bashing" the inner sill straight (if it is bent)? That should save you the hassle of bracing door gaps etc.

Unfortunate you had a shunt, but at least you were able to walk away.


Malcolm Le Chevalier

I am hoping to do just that, but thought that removing the outer sill AND the A pillar would require bracing anyway...

In fact, a local repair shop thought they could pull and straighten the whole lot, including the outer sill. I just prefer the idea of new, straight metal.
Jim M

Hi Jim,

I am working on a full restoration and need to replace most of my metal. During my research I found this forum that shows a guy replacing A-posts etc on his midget. This might help you when replacing your parts.

Make sure you go to the second page on the post.

Kind regards


James Paul

That was cool! Gives me a much better idea of the structure around there!
Jim M

Not easy to see the full extent of the damage from a single photo, but to me it looks pretty superficial.

If the steel is solid and with no rusting, then I would slice off the outer cover of the A post and then straighten up the structure behind, pulling it back into the correct shape with whatever tools, levers etc that suit. As the structure is then hidden by the A post it won't matter if there are slight ripples etc left, so long as it is pulled back into the correct shape and position.

Then weld on a new cover panel to the A post. These are available for the full height of the A post up to the windscreen frame. But I would cut this short so as not to disturb the area at the top of the pillar by the frame as this appears to be undamaged.

It looks to me as if the outer sill is only slightly dented just below the A post. If this is isolated damage and hasn't rippled along the length of the sill, then I would clean it back to bare metal and fill / skim with a metal based body filler. Similarly the door skin could very reasonably be repaired with filler to give an invisible and permanent repair. Or you could either replace the door, or get it re-skinned

The trailing edge of the front wing looks harder to repair. It could be done with a repair panel which are available for that bottom corner. Or get a complete replacement wing panel.

Guy Weller

I go along 100% with what Guy just wrote.

I don't know how much used wings and doors are over there, but both of yours looks pretty good to me, and only need minor fixing to be perfect again. I certainly wouldn't be replacing either of them. Pity you aren't over here, I'd have both of those, as it looks to be the same colour as my Midget.

Lawrence Slater

Guy is the bodywork master! *bows*

Malcolm Le Chevalier

This is a better picture of the damage. With this one you can see that there is a little gap at the base of the screen but I imagine that can be closed up with a bit of pressure.

Jim M

Actually, this is a better one.

Jim M

Who's paying Jim? Whose fault was it?
Lawrence Slater

Jim. The damage looks far worse in those later pictures and I think you may be better off replacing the outer sill aswell as the A post as it's pretty simple to remove the sill once the a post is off.
Moss part nos are..
Outer sill - czj695
A post. - ms21aL
A post cover - aha7956

I'll attach a few pics of my repairs to those panels..

first off is the side with the a post and sill removed.

note, i actually replaced the inner sill and footwell side but you may not have to. also, you don't need to cut away the bottom of the rear wing.

graeme jackson

sill welded on - drilled along top edge and spot welded, Inner sill drilled along bottom edge and spot welded

graeme jackson

the next two show the A post welded in place. - keep checking your lines.. it's worth fastening the door on to make sure the a post is correct..

graeme jackson

and the other side

graeme jackson

and finally the a post cover welded in place. again, worth having the door and the wing handy to make sure the lines are right before you weld it all up..

graeme jackson

with care, even an idiot like me can get shutlines way better than they ever came out of the factory...

graeme jackson

Yes, it does look a bit worse, but I am still not convinced that it needs a new outer sill. But the thing that sounds ominous is the gap that has opened up under the windscreen. This to me suggests that the impact on the A post/cill has pushed the outer end of the scuttle (cowl) upwards, lifting the screen off the scuttle top. This suggests rather more deformation of the main structure than appears in the photo.

I would also check for damage to the cross member inside the car, checking that it hasn't rippled or compressed, and hasn't transmitted any side impact forces through to the transmission tunnel. The good thing is that anything is repairable!
Guy Weller

This is excellent information. Great pictures, Graeme.

Tomorrow is the day I get out of work long enough to start ripping into the car. First order of business is to check the panels behind the obvious damage. I have ghad a quick look, without jacking it up, and didn't see any floor damage, but I haven't looked beyong what I could see peering from the side.

I think the gap at the corner of the screen is caused by the A post buckling and the top being pulled down. The scuttle still lines up perfectly with the bonnet, and with the base of the screen, except at the extreme outer edge.

It seems that replacing the outer sill might be actually easier than repair, as everything will be straight. I have no experience of dent repair, but I have welded a few new panels on!

Does the sill attach to the rear wing? If so, how do you access the join?

Does the A post cover attach to the inner wing, or to the A post, or both? It seems a bit odd to have the cover sit on but not welded to the A post itself.

I am assuming the screen bolts through those two huge holes in the chassis above the A post?

This is beginning to look like fun :-)

Jim M.
Jim M

The A post cover welds on to the A post along the front and is 'folded' (sure there is a more technical term for this...) at the rear.

Malcolm Le Chevalier

Wing bolts on to side of footwell using the holes as indicated.

Plenty of pics of my ongoing resto. too if you need a different view.


Malcolm Le Chevalier

Malcolm, did you weld or seal, at the pink arrow?

Lawrence Slater

Underneath at the A post? Neither as the cover panel has a wee flange that slots in under there which I assume is then welded to the sill.

Why do you ask Lawrence?

Malcolm Le Chevalier

Jus curious how you fixed the bottom of the cover to the sill. You say you assume. Weren't you doing the welding?
Lawrence Slater

Yeah I'm doing the welding, but haven't done that bit yet so hadn't really given it any though as to how to do it properly.

Malcolm Le Chevalier

Little flange as Malcolm describes, slots in and welds to the top surface of the sill. I did then fill the join with Sikkens sealer, but still shaped a groove along the join line, just for looks.

The issue, and this may be what Lawrence is getting to, is that water needs to be able to escape from the bottom of the A post. In my case it does so by draining through an extra hole and into the sill and then out again through more holes underneath. After 18 years since that build I am getting rusting in some places, but not apparently in the A posts which are usually one of the first places to go!
Guy Weller

I had thought about doing that too Guy. As you have done it it must be a good idea!

I guess water won't drain out from under the cover if the join is tight, even though you can't actually weld the flange to the sill inside the post.

Although water shouldn't be getting in there anyway should it?! Unless your windscreen seal is duff!

Malcolm Le Chevalier

Condens water gets everywhere!
Venting/draining is always better than sealing.
Onno K

Guy is always reading my mind.

I've got the Midget bottom door brackets to sort, and want to prevent future rust. I've concluded that it's not the windscreen frame seals that let water into the inside of the A posts, (water penetrating there runs down the face of the a posts inside the door. So it's either as Onno says condensation, or penetration from the bottom via splashing and dripping inside the front wings.

Drains seem the best way to get rid of the water, but how about sealing and filling the entire A post, with foam perhaps, to combat condensation?
Lawrence Slater

In the 1960's BMC tried filling the sills on some minis with expanded foam. It was abandoned as an idea as it didn't stop them rusting from the inside. I think the problem was still that condensation was forming in the cells at the foam/ metal interface, condensing on the colder, metal, surface.

That said, I wonder if the injected foam could be mixed with an oil or wax so that it was incorporated in the cellular foam as it expands and sets.
Guy Weller

Guy, how about some of the modern structural foams of today? The stuff goes in almost as a liquid, and sets like glue against a metal surface.

Have you tried removing it from a flat metal scraper blade? When you do, the metal underneath comes out very clean even if the rest of the blade has rust on it. I discovered that when I retrieved a "lost" scraper I left in my roof gutter for a year. Where it was covered in foam, it was completely protected.
Lawrence Slater

I hadn't thought of this at the A post but isn't it the same situation, at least structurally, at the rear of the sill? Is that supposed to be welded? And drained?
Jim M

Regarding the A post.
Once the A post is welded in place, the cover is not just the skin you see when the wing is on. It also includes the skin you see in my fourth photo and is welded to the inner footwell. I think you can get a part that is just the outer skin but then you'd have to find some way to remove the A post without disturbing the part that is welded to the footwell.
If you check the second A post photo you will see that the hinge parts are included but the outer cover actually comes as far forward as the scribed line by the wing bolt holes.

Regarding fitting the outer sill, it's spot welded to the inner sill all the way along. This makes it tricky to weld it in place behind the rear wing ( i was replacing my wings so it wasn't an issue). You should be able to tack it in a few places from inside the cockpit. There are access holes in the panel behind the B pillar.
Don't forget that there are also closing panels at each end of the sill.
graeme jackson

I am still not at all convinced that replacing the outer sill is necessary, or even desirable. Replacing it adds a whole extra dimension of complexity to the job.

(reposted comment having had a brain fart and put it on the wrong thread!)
Guy Weller

Making progress...

I have decided to repair the sill. I've been up and down like a whore's drawers on that one, but really it is just dent repair. I bought a $13 glue pulling kit at Harbor Freight and if that doesn't work I will get a threaded slide hammer.

My only concern really is lining up the scuttle with the base of the new windscreen frame.

Any recommendations for primer / rustproofing etc.? I used to put red oxide (?) on panels years ago. Can't remember the brand,but things have probably improved since then.

Incidentally, this is the car pictured in BWTM in Autoweek last year, with the tree in the passenger seat :-)
Jim M

The a-pillar and sill look to be easy repairs using a slide hammer and weld on studs. Going to the extent of replacing the entire panel would be fairly hard to justify.

The wing would be brought back to life by removing and dollying back to flat.

I recently brought a wing back to life that was involved in a 30mph full throttle into the corner of a building. So your damage is completely fixable without massive outlay in costs
Pete Moreland-Moore

I hope those who are interested, are keeping the pics from this thread, and those of all the links given in it. Great for anyone wanting a visual of what's involved in an A post repair or replacement.
Lawrence Slater

Just in case anybody wants even more pics, or at a possibly higher resolution, I have 125 photos covering the LHS A post and surrounding area here:

And then another 164 photos on the RHS A post here:

Please note, that my photos may not show THE way of doing it, just a way/my way of going about it!
S Overy

Simon, that is extremely helpful. Great details shots of how it all comes together.

I am not sure I would want to tackle such a large reconstruction, but it makes my task seem much more achievable!
Jim M

Heroic stuff, and great pics of it.
Lawrence Slater

What did you use to drill out the spot welds? I'm going to do pretty much the same thing plus a little more.
I have a spot weld drill bit but not too happy with the way to works. It looks like you have a good procedure.
Jon Saylor

I just used a spot weld drill bit. They do take some getting used to though, as I was punching clean through both panels to start with! You also have to be careful with the central spike on them as it can leave the centre of the backing panel, which is where I start my MIG spot welds, a little thin. If I was ever in doubt I always had a thin bladed screwdriver that was sharpened and used as a chisel to split the last little bits apart.

And one other thing to remember with all this metal bashing: if you can weld, you can always mess it up but still have another chance at it. The joy of steel means that if you break something you can always stick it back together again some how! I found being more confident in what I was doing made things easier to achieve with sure hits of a hammer as opposed to just tickling things.
S Overy

Drilling them out is by far the easiest way to do the job. Use a decent cobalt spot weld drill bit on slow revs. e.g. this one...

and the joint will 'pop' once you get through the first layer. Try to find them on ebay and buy a few.

Don't be tempted to use the cheaper spot weld cutter that has a sprung tip - they just wear out before the first weld is removed.
graeme jackson

"with sure hits of a hammer as opposed to just tickling things." How many times did I hear that when I was a kid? "Don't tickle it son, hit the f*cking thing". So true too, on many occasions.

Simon? Did you add strengtheners to the lower A post hinge brackets (black arrows)? I couldn't find that in your pictures?

Hope you don't mind I edited one of your pics.

Lawrence Slater

You can alter the pics all you like. I only took them to record the process, so edit away!

And to answer the question, no I didn't as there were none there to replace, so I left the structure as I found it, only newer. Given that the lower hinge box stiffens the bottom of the panel, and it's sat on the sill, I didn't even think about it.

Are there meant to be additional bits on the lower hinge box?
S Overy

Hi Simon,

Yup, you can just see the remains of the supports on your earlier pictures. The lower repair bracket doesn't come with them and I think most people leave them off too. But my Midget has lower hinge rot, and if those supports were still there, the door would still hang straight. So I've been looking for the easiset way to put them back, rather than have to think for myself. :).

Lawrence Slater

Here's a pic I found on the web of a pair of new complete inner A posts.

Lawrence Slater

Shows how much attention I was paying that day then!! Having said that, I bet those strengtheners trap a lot of the water/rot causing stuff within the A post so I doubt missing them out hurts overall.
S Overy

Yup you could be right. If the water is trapped at the bottom hinge, it explains why they so often give out there. I think I'll find a modified way to strengthen the ones on my Midget when the weather improves and I finally start fixing the rust in the bottom of the A posts.

Lawrence Slater

Given how close it is to the sill, I doubt you'd need to bother really with the plate on the lower hinge. But if you do, something that is shaped to curve away from the inner edges of the A post would be better that the factory option. Something I shaped would do it, and be dead easy to make...
S Overy

I added in those strengthening plates on mine. They span front to back, but not side to side, if you get my meaning. So there is ample gap for water to drain down past them. I don't think they are essential though.
Guy Weller

Thanks Guy. Didn't happen to take a pic did you? Why invent the wheel again if someones already done it? :)

I'm intending to repair mine, -- keyhole surgery fashion -- if possible. I'm only going to cut an acces hole and work within. The inner posts and covers are too good to take off completely. I know, just lazy really. But I'm hoping it will be less work actually.
Lawrence Slater

Hi all, as a newbie and first time post, please excuse if I tread over old ground but there is a thread from December regarding the A post and more specifically drainage. They talk about a tube which drains the water away from inside the a post and also the lower front wing, I think they were going to use plastic or rubber tubing but getting a good seal might be tricky?
I mention this as I am about to fit the outer sills on my 73 and wondered if anyone has done this and is it worthwhile. I was going to bore a hole through top of sill then roll edge of hole down using a punch to make sort of spout, butt steel tube (larger than hole) to underside and weld. The tube would fit snug through a hole in bottom of sill and be welded here too. i think the spout would prevent any water transferring into sill space,water straight down tube and out.
Just wondered why no one mentioned this, don't want to go hacking up my new sill in vain!

Oh, and thanks for all the help and info thus far, I've been lurking on here for about a year and it has been invaluable
G Smith

Yup, Guy has drains in his, and I wondered about a plastic pipe right through the sill, to act as a drain, and keep the water out of the sill. That's as far as I've got, until I fancy braving the cold. I've been thinking about how to seal the pipe as it enters the sill, your idea sounds interesting.

Are you going to use a stainless steel pipe? maybe it wouldn't need it, esp if it were thick walled.

You'd want to make sure the entrance to the pipe was flush with the sill, so no water could lay around the entrance. Is that what you mean by rolling the edge down? So you'd insert the tube from below, and hold in place whilst you weld. Sounds like a plan.
Lawrence Slater

You pretty much get it Lawrence, I was going to use steel tube right enough and so long as the diameter is larger than the spout then I was banking on water not being able to return upwards by capillary means to the butt join where I will weld. Planned to seal/ paint as much as I can inside sill before welding to inner and the tube will give good access for wax injection to A post later once body is painted. Might have to give a thought to the diameter of those wax injection probes in my plan too.
Didn't think to use stainless as I didn't think I could weld this with the mig ( I'm also a novice with the mig) .
Hope to get a start on this over weekend and if I can upload pics I will.

G Smith

Stainless to mild steel? Yup I haven't done it yet, one on my list, but you can weld stainless to mild steel if you use the right gas and a s/s wire. 97.5% Argon +2.5% CO2, and 309L wire. See here.

I've got some wire and a plan to fix my s/s quaterlights soon.

But for a one off, if you haven't already got the wire and s/s tubing I think it might be too expensive on the sills. So if I don't find some way to make it work with a plastic pipe, I'll use steel tube. But I'm sure there must be some kind of flush fitting plumbers fitting that will do this.

Lawrence Slater

Thanks,I've learned something new again. I'm sure this info will be used later in the project at some point.
Re flush fitting, I haven't spent much time looking for such a thing but I assumed most fittings would have an edge of some kind however small and this would mean water would lie on the sill top until it rose up to the edge over the fitting and then disappeared down the tube.
Maybe I'm over thinking the problem but having seen the extent that midgets can rot I didn't like the idea of water sitting for any time round the edge of a fitting.

G Smith

I added drainage holes in the bottom of the A post, that discharge directly into the sill. No added drainage tube, as was Lawrence's proposal. I don't think it has yet gone beyond a theoretical suggestion, has it?
I did this when rebuilding my '71 sprite shell back in the early '90s. It does seem to have been of benefit so I have done the same with my current Frog project.

I use a good sized hole, about 5/8" as I think that at least as important as drainage is to encourage air movement through those otherwise closed off areas. For this reason I would not add tubes down to isolate from the sill. I think the more air movement there the better! I do however add extra drainage slots in the bottom of the sill. Important to get them at the very lowest point in the sill, where the inner and outer come together. And of course to keep them clear!
Guy Weller

As you say Guy, it's still in my head, pending sufficiently warm weather to motivate me into actually start doing something.

I haven't ruled out what you've done Guy, but I'm starting with a fully assembled Midget, and the outer sills aren't really a problem.(Right front needs some attention, but not replacement). I hadn't wanted to intefere with them to any extent.

Guy, did you coat the insides of your sills with anything, to resist the extra water?

My inners need some patching along the middle on both sides (by the seats). I've been thinking that as I patch them, I might create an access panel (removable) to allow the insides of the sills to be painted and inspected. Yup I know they are structural box sections, but if a reinforced framed opening or openings were created, a panel(s) could be attached and removed with self tappers and still keep the strentgh of the inner sill. after all in the originals the inners have those useless oblong rubber bunged holes along the lower edge, that seem to be the first areas to rust.

Maybe water trapped on the floor, runs into the sills from here and rots the bottoms of the outer sills.

Lawrence Slater

Mmm, I suppose if water is going to get into the sill by other means other than A post then holes without tubes makes sense. Also, I am encouraged by the fact that this has been tried and tested and that Guy is confident enough to do this on another car.
So, 5/8 hole under A post, then slots along bottom edge of sill and ensure they are kept clear. I will coat inside of sill before fitting too.
Guy did you have hole in front of A post to drain wing area too?
Conscious that this thread has come along way from Alabama, apologies, Jim, maybe this info will be something that you will use even with the warmer climate and less salt on your roads.
G Smith

Lawrence,as I have rebuilt my cars, both inner and outer sills on both have been replaced. On my 1500 it was just the outers, which I did, both sides in one weekend when I first got it. Anyway, I paint the inside surfaces of all box sections before welding into place, and paint the jointed surfaces with weld through primer. Its hard after welding to know how much of this stays intact. The best one I have found for the insides of these various box sections is something called Electrox from It is a really heavy zinc coating and seems to withstand the heat conducted from adjacent welding pretty well.

I have also experimented with using a 2 ft length of washer tube with a 360 degree jet in the end, off a rattle can. Inserting it into box sections and then withdrawing it slowly whilst spraying. Never opened up the sill to see the effect though! I planned to try it with a cardboard mock up and then cut it open to see the effect, but never did.

I did think that the best way of painting the inside of sills would be with a ferret, dunked in paint and run through the sills a couple of times in each direction before the end pieces are closed off.

I think that the positioning of sill drainage holes is important. My replacement outer sills came with some small holes in the middle of the horizontal underside. Not the ideal place, as when the inner and outer sills are fixed together there is a "V" shaped crevasse all the way along, lower than the flat bottom of the outer sill. I drilled and enlarged with a Dremel to make slots that properly extend to drain from this crevasse.
Guy Weller

Sorry G (?) I was typing at the same time as you.

Area in front of the A post should just drain out the panel gap below the wing. But it is a well known rust area as it collects lots of road muck that then just sits behind the wing and rots it away. I certainly wouldn't add a weep hole into the sill there or some of that road muck would end up inside the sill which would be a disaster!

End of the day, these cars rust and I think that nothing is going to stop this. My 1500 had rusted out sills at 11 years old from new. My replaced sills on the 1275 car, with more attention to detail than the factory could ever give, are now 18 years old so is that any sort of evidence? I don't know if these slight modifications make much difference or not, and I wouldn't have done them unless I was already in there, replacing these parts in my own time. So don't take my ideas as dogmatic, they are just my personal take on things that might help.

Full body galvanising, or e-coating is probably the best solution if you really think the cost is worthwhile! In my case, either would have cost more than the car was worth!
Guy Weller

Thanks Guy ( and Lawrence ),your comments are much appreciated. 18 years is superb in my book, I am at the replacement outer sill stage of the build anyway so this is why I'm giving this so much thought. I certainly won't hold anybody responsible if it all goes pear shaped.
No doubt, now I'm posting I will let you know how I get on.

G Smith

Guy, re the idea of a drain in front of the A post, behind the front wing. I hear what you say, but I've sealed the fronts of the wings on my Sprite to stop the very thing you describe, namely road muck/mud and leaves, being trown in there by the front wheels and splashing up.

All I did was stuff in a length of copper pipe insulation, sliced down middle. It sits between the inner and outer wings fron the top of the sill right around to the ends of the inner wings. Nothing can possible get in there now.

That leaves rain water that gets in where the front wings meet the top of the A posts, and all the muck that gradually collect inside the front wings and holds this water. I think this contributes to the A posts rotting from the front behind the wings. So I drain here, might be useful too.
Lawrence Slater

Not sealed mine like that, as I think it better to keep air circulation there. Have you also sealed the gap between the inner wheel arch and the outer wing? That would need doing too to keep muck from working its way back into the wing cavity.
Guy Weller

I Don't think I explained myself very well.

I've sealed the gap between the inner wing and outer wheel arch, from the top of the sill, right around to where the inner wheel arch ends. I'll snap a pic tomorrow. There's still plenty of circulation to the insides of the wings, via the engine bay, the gap down the A post, and the gap along the top of the sill/bottom of wing, in front of the A post.
Lawrence Slater

No, sorry, I just misread what you had put. That makes better sense. I have seen people seal the wing to sill and wing to A post panel gaps, and thought what a bad idea that was!
Guy Weller

"I have seen people seal the wing to sill and wing to A post panel gaps, and thought what a bad idea that was!"

Agreed. Any water that is in there, can't thenget back out, or dry out.
Lawrence Slater

I haven't been able to use all this wonderful advice yet as I had to run home to Ireland on a family emergency. The hinge pillar and A post cover arrived in my absence so I will be able to get to work when I get back.
Jim M

This thread was discussed between 19/03/2013 and 15/04/2013

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.