1981 Manta Coupe Project.

[Nivlek2525]

My project is a 1981 Manta SL coupe rolling shell. As I understand from the seller, it was taken of the road about 12 years ago and dry stored since. The car still has plenty of rust but it's very localised and hasn't really taken hold.  Both swan necks from the top subframe mount down to the jacking points are pretty bad and there is definitely something going on under the vinyl roof. If decides to pick one corner and start to work my way around the car. Cutting out and repairing as I go. Today job was to remove the fuel tank before I did any grinding and to get the car up of the ground.

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Tank came out no problem and there's almost no rot at all on the inner arches or boot.

Even the spare wheel well is solid.

The only small bit of corrosion is on the driver's side but looks like an easy enough repair.

 

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[IanMc]

Lucky guy, looks like you have a good one there!

Good luck with the project and please keep us updated.

[Nivlek2525]

Thanks. 

Started with the passenger side front this afternoon. 

Theres no rust where the wing bolts to the car and the inner wing is generally ok. There's a small hole to the top of the A post and another at the bottom which has crept into the floor. Jacking points are solid tho.

I spent a long time scraping of the rubber underseal to reveal bright metal and can't help thinking I'm doing more harm than good. Exposing metal that's been covered for nearly 40 years. Id appreciate any thoughts.

I've started cutting out the rust and making template but had to stop for today.

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[jamie077366]

My thoughts are are get all under seal off, it can hide a lot. Iv been doing mine a bit at a time, some parts looked ‘ok’ then you strip it back to uncover lots of nasties. Tbh if I’d of stripped all mine off like I should of  to begin with I probably would of resheld mine. Sounds like you’ve a great shell though. 👍

[Nivlek2525]

8 hours ago, jamie077366 said:

My thoughts are are get all under seal off, it can hide a lot. Iv been doing mine a bit at a time, some parts looked ‘ok’ then you strip it back to uncover lots of nasties. Tbh if I’d of stripped all mine off like I should of  to begin with I probably would of resheld mine. Sounds like you’ve a great shell though. 👍

Thanks, your probably right. There's still surface rust around all the edges and seams so by the time I've cleaned that back I might as well do the whole job to be confident.

I hope I don't end up reshelling mine as all I got was a shell and a steering wheel!!

Any thoughts on coatings. Rustbuster 2pack 121 chassis paint gets good results.

[robah]

15 hours ago, Nivlek2525 said:

My project is a 1981 Manta SL coupe rolling shell. 

Pardon my ignorance what is an "SL "?

I have used the Rustbuster 2 Pack 121 on my Vectra Subframe and it is very good, but recommend spraying it on rather than brush. I did the latter and the finish is not brilliant. I will be doing my spare Manta front subframe in the 121 coating at some point. I used Dinitrol for my Manta chassis bought via Rustbuster 7 years ago and still looks strong underneath. I sprayed that on. I used the creeping wax inside the chassis legs to protect the inside from the elements.

Usual rust in usual places for a Manta, good luck with the project.

[Nivlek2525]

Hi well spotted. A typo sorry. The car is an SR but really it is just a rolling chassis it's been stripped of everything other than the headlining and the steering wheel. I bought it from a guy in Devon, I'm in the north east, who had been looking for a project and bought this one as although it had some rust it had never had any previous repairs. So what you see is what you get. I must say I'm quite pleased as I had a 10 year old exclusive years ago which was probably in similar condition structure wise.

 

I've heard 121 is better sprayed but I don't have the facilities to do that so I might have to look at alternatives.

 

Thanks for the info.

 

[Nivlek2525]

Not that much progress this week just some more digging around and patch/repair making. I'm hoping to start letting in some new metal this weekend but it's taking a bit of time working out the best approach.

In order to sort out the corner of the floor I have to sort out the bottom of the A post. To sort that I have to take off the end of the sill which exposed an inner skin, which has rotten through. 

So I've made up the repair patch for the floor as well as one for the A post and one for the inner sill. I've just got to cut out the rest of the rust and work out how to weld the inner sill/A post repair as access is not great. At least I have new sills to use which should make things easier.

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The plan is still to get the car completely rust free so I'll cut out all the rust and butt weld the repairs where I can.

The tech screws are just so I could make sure the repair was making contact with the right places on the outside. I can easily weld up the wholes.

I'll take the door off this weekend, mark around the sill so I know how much I can cut out of the outer sill and that should give me better access to the inner metal to clean that up.

Some photos of the floor, A post and sill end.

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And some pictures of the roof under the vinyl. Unexpected but there you go. I'll think of something.....

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[Mk5rjs]

A shame about the roof but you were suspicious. Good luck with it all! 

 

Rory

[Nivlek2525]

2 hours ago, Mk5rjs said:

A shame about the roof but you were suspicious. Good luck with it all! 

 

Rory

Many thanks.

Doors off!

Bit of a pain but managed to make a little tool and with a bit of brut force. The pins are out. 

Pleased I wasn't working with freshly painted panels.

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[Nivlek2525]

I managed to get a bit more done today and finally started to weld in some new metal. 

I decided not to use the whole sill as it was solid all along and I could see there wasn't any rust on the inside so I just replaced the section I removed to repair the inside of the A-post.

I had to use a number of sections to get the shape.

It's not pretty and the welds need dressing back further but it's solid now and all tied back together as it was originally.

Very slow work.

On to the corner of the floor and then the swan neck......

 

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[Nivlek2525]

Just a very brief update before I start the next part of the project. The A-post, floor and inner wing are all welded up now. I ended up cutting some of my work back out as I just wasn't happy but I'm pleased with it now.

So...today I started looking into passenger swan neck. The better of the two. I started by cleaning of the underseal and cutting into the chassis. I'd really appreciate any thoughts from anyone reading this. Two sides of the swan neck are really clean. The outer side is completely shot through what looks to be two layers of steel. Towards the bottom there is a third thicker box section that the large subframe bolts through. The box section looks good. 

I assume if the box section is good I can rebuild the swan neck around it and I should have any alignment issues when I put the sub frame back?

Anyway, the rest of the day was spent getting the frame off. I'm pleased I've been soaking everything in WD-40 since I got it. The anti roll bar, shock tops and top subframe mounds were fine. The two large lower bolts were hard work but I've got one out and the other one is free and should tap out like the passenger side.

I've looked through the other build threads but if anyone can point be at some good pictures or the swan neck being repaired I'd appreciate it. Always good to know what I'm getting into.

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[cam.in.head]

You have definately been lucky. The swan necks are a major rusting point of our cars and usually require work or replacement. If your inner face and bottom are good then you won’t have any alignment issues and should be just a case of rebuilding the side from inside out to original spec.albeit  with much more internal rust protection.

its a matter of personal taste but I tend to repair with galvanised sheet now rather than plain steel .just be carefull with the edges and the fumes if you do.

[Nivlek2525]

12 minutes ago, cam.in.head said:

You have definately been lucky. The swan necks are a major rusting point of our cars and usually require work or replacement. If your inner face and bottom are good then you won’t have any alignment issues and should be just a case of rebuilding the side from inside out to original spec.albeit  with much more internal rust protection.

its a matter of personal taste but I tend to repair with galvanised sheet now rather than plain steel .just be carefull with the edges and the fumes if you do.

Thanks for the response. I need to get the subframe off to be sure but the rot seems pretty localised. Seems to be a theme with this car.... luckily.

I'm using something that is labelled, 'not zintec', for all the repair so far. It has a thin zinc coating. I'm also using lots of rust converter for area of surface rust I can't clean up and soaking everything in zinc primer. yes, I have a good mask, thanks.

I don't mind buying replacement panels if I have to but if I can do a good repair on what's there I will.

I'll post some more photos with the frame off and the swan neck cleaned up.

Cheers.

[cam.in.head]

If the chassis is good inside and no signs of any bubbling or otherwise once you have got subframe off(if you need to ) then get as much cleaned up / sanded/ scraped / hoovered etc ! Etc your choice . Then once you are sure it’s cut back to good sound metal start building the inner sections up and work your way out layer by layer. Then its a case of getting some good protection inside afterwards.or before if you can eliminate it setting on fire !.

when i did my sills 20 years ago I filled them up with paint right up to the footwell corners and then drilled a couple of drains underneath. They took a few days to stop dripping but the sills are still perfect now .

looking back to when the cars were new if we knew we would have done all sorts to help future issues .filling bits up and draining them out .old oil,paint ,etc but no one did so now we have to repair the damage !. 

All doable thou and good fun and well worth the end result.

[H-400]

I suppose you checked my thread:

 

[bris jas]

Looking at your chassis leg i would go about replacing the inner box section as well as the outer skin, if you can make this up yourself great if not as Hermans link above shows you can buy the section you need.

I used the same chassis sections on my last build (Full restoration of D91 MOP), best out there i would say and once done you know its done!

Last thing you want is to be revisiting this section in a couple of years if the inner starts to bleed through, i always just to mention use Hydrate 80 for rust treatment.

Good Luck

[Nivlek2525]

3 hours ago, H-400 said:

I suppose you checked my thread:

 

Yes, I did thanks. About 2 minutes after I posted mine. 

A great threat, and just what I was looking for.

2 hours ago, bris jas said:

Looking at your chassis leg i would go about replacing the inner box section as well as the outer skin, if you can make this up yourself great if not as Hermans link above shows you can buy the section you need.

I used the same chassis sections on my last build (Full restoration of D91 MOP), best out there i would say and once done you know its done!

Last thing you want is to be revisiting this section in a couple of years if the inner starts to bleed through, i always just to mention use Hydrate 80 for rust treatment.

Good Luck

Thanks for the advice. I'll finish dropping the subframe this afternoon if I can sneak off into the garage unnoticed.

Once it's off I'll have a good look at both sides and take some more photos for comment.

My main concern is cutting too much out and not being able to get the subframe back in the correct place.  At least if I leave those bottom mounts alone I can be pretty sure all will ok with alignment. I'll know better when the frame is off.

Thanks again all.

[H-400]

Start with one side, so you can aligne the new mount with measuring the other (original) side.

Maybe this can help:

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[cam.in.head]

Hi. Cannot see your pictures anyway but if inner and outer is ok at bottom and inside faces and the internal tube is in place then theres no alignment to worry about .if you are just repairing the outer facing  side metal then nothing will move  at all. Subframe doesnt need removing unless you are wanting to br 100% sure .most cars have bad bottoms and inners by now but usually starts on the outer face first..repair as required and protect well 

[Nivlek2525]

1 hour ago, cam.in.head said:

Hi. Cannot see your pictures anyway but if inner and outer is ok at bottom and inside faces and the internal tube is in place then theres no alignment to worry about .if you are just repairing the outer facing  side metal then nothing will move  at all. Subframe doesnt need removing unless you are wanting to br 100% sure .most cars have bad bottoms and inners by now but usually starts on the outer face first..repair as required and protect well 

Hi, there's no engine in the car and I want to paint the subframe so I'll take it off anyway as it's no hardship as long as I can bolt straight in. I'm pretty sure the swan neck I'm working on can be built back up as the rust is localised. The driver's side isn't quite as good and repair panels may be needed. I've not managed to get at it today but should be able to later or tomorrow. I suppose if I can keep one mounting points in its original place it shouldn't matter if I have to cut the other out as I'll still have three points of reference for the frame.

Again, many thanks all.

K.

4 minutes ago, Nivlek2525 said:

Hi, there's no engine in the car and I want to paint the subframe so I'll take it off anyway as it's no hardship as long as I can bolt straight in. I'm pretty sure the swan neck I'm working on can be built back up as the rust is localised. The driver's side isn't quite as good and repair panels may be needed. I've not managed to get at it today but should be able to later or tomorrow. I suppose if I can keep one mounting points in its original place it shouldn't matter if I have to cut the other out as I'll still have three points of reference for the frame.

Again, many thanks all.

K.

 

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The first two are the passenger side inside from inside the engine bay, the second two are the driver's side which is worse as the rot is around the mounting point.

[®evo03]

You know this is available, right! 

 

 

[Nivlek2525]

On 15/12/2018 at 21:31, ®evo03 said:

You know this is available, right! 

 

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Hi yes thanks. I'll need one if not two of these or something similar.

First I need to remove this

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4 minutes ago, Nivlek2525 said:

Hi yes thanks. I'll need one if not two of these or something similar.

First I need to remove this

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I've spent two evenings trying to get it out without damaging anything. I've tried everything except heat but it's seized solid in the subframe bushing.

I've now decided to cut of the head of the bolt and drill it out. Slow progress but all good fun!!

Edited December 19, 2018 by Nivlek2525

[®evo03]

Ah should have tried kerosene, not to burn it, ☹️

To soak it, you can soak a rag and wrap it, once cleaned you could have reused it. Aw well, No permanent harm done

 

[IanMc]

I gave up on mine and just cut thew bolt head off and bashed it through to the center of the car (with the help of plenty of penetrating fluid).

Once the arm is off with the bolt stuck in it, I cut through the old bolt between the washer and the rubber. Once the nut and washer were out of the way the thing came apart quite easily. This of course assumes that you are going to replace the now useless bushes like I did. If you have a look at my project thread you will see the bushes fitted and a link to show where to buy them - they are relatively cheap!

By the way, to do what I have described on the drivers side requires the exhaust to be out of the way - otherwise the bolt hits the pipe as you drive it through.

Best of luck matey.