1971 MGB GT - Almost finished now - see page 13

[danthecapriman]

14 minutes ago, Dyslexic Viking said:

I don't know about any products but if you do some research you will probably find something.

Like this?

https://www.3m.co.uk/3M/en_GB/collision-repair-uk/car-repair-and-refinish-processes/car-body-repair/panel-bonding/

That’s the stuff! 

As I say, I’ve never actually used it but just know of it. If it’s suitable for use on modern stuff with all the crash protection and safety cells etc etc it’s got to be good enough to patch up a few small bits on a classic?

[Surface Rust]

28 minutes ago, Peter C said:

@danthecapriman

@Dyslexic Viking

Sounds reasonable, thank you.

Could you please point me in the direction of a suitable adhesive?

I've been very impressed with 3M dp490 at work. It's an aerospace epoxy adhesive and it's incredibly strong. £50 a tube from RS.

[Dyslexic Viking]

4 minutes ago, danthecapriman said:

As I say, I’ve never actually used it but just know of it. If it’s suitable for use on modern stuff with all the crash protection and safety cells etc etc it’s got to be good enough to patch up a few small bits on a classic?

I would think so.

But I don't know if I would have dared to glue together bare metal if the instructions say so, I would rather have taken the chance and painted the surfaces before the glue. But someone may know what is best, but untreated metal seems wrong to me.

[Peter C]

@Minimad5

A few years ago @Talbot kindly welded up a couple of holes in my W124’s rear arches. He had professional welding equipment and knew how to use it. He made use of years’ of experience to achieve high quality repairs. I would need a decade of practice to get anywhere close to that level of skill.

[Carl1981]

I’d definitely be looking at the adhesive route, by the time you’ve glued the repair sections in, applied some seam sealer and a coat of under seal, no-one would be any the wiser (I’d still declare it when it I sold it though).

My company does some prep work for modern aluminium construction vehicles where extensive use of glue is utilised in place of welding. Most of the glues require a compatible pre-paint (we use electrophoretic paint), so the metal needs to be clean and well painted before the glue is applied. 

[Homersimpson]

If you are going to use the glue method then I would make sure you follow the manufacturers instructions which are almost certainly to only apply to bare metal, otherwise the glue is only fixed to the paint and the bond from the paint to the metal is all that's holding it on.

Its impossible to say with any certainty whether this repair method would be safe/sufficient but a lot of older monocoques tended to be massively over engineered as the understanding and materials available when they were designed weren't what we have today.

Ultimately its a judgement call as to whether the holes are repairable without welding depending on whether they are anywhere near anything structural such as suspension, seatbelt mountings etc.  The MOT rule is anything within 300mm of a structural point is a fail so presumably anything outside that would pass and hence could be (in theory) repaired without welding.

Have a look here:

https://www.gov.uk/guidance/mot-inspection-manual-for-private-passenger-and-light-commercial-vehicles/appendix-a-structural-integrity-and-corrosion

Personally I would go for welding because if the holes are small enough to fill then it shouldn't be expensive and if not then its probably a bad idea to not weld them.  Also if you declare how its been repaired when selling you will probably find no one wants to buy it or will want to pay nothing for it and they will then go and buy an identical or worse one that's full of filler for loads of money because the seller wasn't honest enough to tell them.

[Honey Badger]

40 minutes ago, Dyslexic Viking said:

I would think so.

But I don't know if I would have dared to glue together bare metal if the instructions say so, I would rather have taken the chance and painted the surfaces before the glue. But someone may know what is best, but untreated metal seems wrong to me.

If you paint the surfaces your bonding, then the adhesion is only as strong as the bond the paint has to the metal, in some circumstances the paint could interfere with the cure of the adhesive and make the joint even weaker.

 

[Dyslexic Viking]

3 minutes ago, Honey Badger said:

If you paint the surfaces your bonding, then the adhesion is only as strong as the bond the paint has to the metal, in some circumstances the paint could interfere with the cure of the adhesive and make the joint even weaker.

 

But won't an unpainted surface start to rust? Or will the glue act as paint and prevent rust?

[Honey Badger]

I would make sure if your going to bond patches on make sure that you make the patches 20 mm bigger all the way round than the hole so you can increase the bond area which will give better strength.

Nothing wrong with a few rivets but you need to make sure you maintain a consistent bond line depth, I've seen people use 2 to 5 % of glass beads mixed in the adhesive, if your going to rivet as well maybe use some washers as packers as long as they match the bond depth spec of the adhesive.

You can also double up with one patch inside and one outside over the hole.

[Honey Badger]

8 minutes ago, Dyslexic Viking said:

But won't an unpainted surface start to rust? Or will the glue act as paint and prevent rust?

If water is getting into the bond line, then you have much bigger issues than a bit of rust as that means the whole joint is compromised.

You can seam seal and paint over adhesives like you would a welded seam.

[captain_70s]

1 hour ago, Honey Badger said:

If you paint the surfaces your bonding, then the adhesion is only as strong as the bond the paint has to the metal, in some circumstances the paint could interfere with the cure of the adhesive and make the joint even weaker.

Fond* memories of affixing a curtain rail with No More Nails and being woken up in the night a few days later by it falling off the wall and leaving a strip of missing paint where it had been...

[Zelandeth]

 

Okay, because this editor is a piece of trash this text is in the wrong place and I can't get rid of that one photo...

But yeah, what you're suggesting sounds far less dodgy than half the bodges I've found on supposedly professionally sorted cars.  

Adhesive is a good shout, some of the modern ones are stupidly strong, and should seal any gaps way better than trying to squidge old school seam sealer around riveted patches.

On a car like this at this price point it definitely wouldn't put me off.  

Know I'm likely a long way from the front of the queue, but if it did pop up at that sort of price I'd still be calling dibs!

5 hours ago, Peter C said:

 

 

...I will easily find a buyer for that money, even if I disclose the condition of the underside. 

[Westbay]

Firstly let me say well bought, it is a good 'starter for ten' ..

"If you don't like what I am going to do, switch off, go and read someone else's post or if you feel that strongly, call me rude names and tell me that I will go to hell if I don't get the welding done. I really don't care. "

I read this and thought 'good man, knows his own mind' , however, can I sound a (last note) of caution, get proper professional advice on your repair ideas before embarking on them.

You may well be taking photographs of the the work and repairs to share with a potential buyer, but have you considedred that the repairs may well not be to a 'standard' acceptable to an (any) insurance company(s) ?  plus it may well put off potential buyers ... don't forget, insurance companies will look for ways to mitigate their lossess.

MoT exempt it may be but, "... it has to be maintained in road worthy condition ..." how is this measured ? a rough guess would a) reference to the Construction and Use Manual , b) the current MoT tester guidance manual and the opinion of a qualified assesor/automotive  engineer...

As for using specialist 'glue' , yes a good option on an appropriate vehicle i.e it's usually used on panels that do not constitute part of the vehicles core structure which has been designed for that purpose, I'm not sure  applying modern techniques to a design penned 70years ago counts .

Please note that nowhere above have I said don't do it, you'll go hell etc ... 

[Mally]

Providing you 'stick' to holes outside the MOT 300mm structural I can't see a problem.

But I'd probably just leave them as is until I'd driven it.

Any hole within 300mm needs welding, and if you have a few of those,  you/someone is welding anyway.

[Peter C]

33 minutes ago, Mally said:

Providing you 'stick' to holes outside the MOT 300mm structural I can't see a problem.

But I'd probably just leave them as is until I'd driven it.

Any hole within 300mm needs welding, and if you have a few of those,  you/someone is welding anyway.

Patching up the holes and coating the underside will make me feel a lot better. I’m doing this work to enable me to drive and enjoy the MGB, not to please a future owner. It’s just the way my mind works.

As suggested by others, I don’t think that my proposals will have an adverse effect on the desirability of the MGB. If nobody will want it, I will park it outside my house and enjoy how beautiful it looks.

[Dave_Q]

As the owner of an MOT exempt vehicle it's your responsibility to maintain it to an equivalent standard to an MOT.

Riveted or glued patches would not pass an MOT if within 300mm of suspension or seatbelt mountings which is most of an MGB.

[ETCHY]

Got to say a decent adhesive is probably preferable to shit welding. A shit weld is probably no stronger than a pop rivet.

One thing would bother me though, what would happen if you had an accident & you've glued/ pop riveted. Would it be deemed as unsafe/ not road worthy  & invalidate your insurance ?

 

 

[danthecapriman]

59 minutes ago, ETCHY said:

Got to say a decent adhesive is probably preferable to shit welding. A shit weld is probably no stronger than a pop rivet.

This!

Some of the MOT ‘standard’ welding repairs I’ve seen over the years have been shockingly bad. You can just peel the plates off with your hands or a screwdriver! Doing crap work like that is one thing but to actually charge people for it is quite another!

[captain_70s]

2 hours ago, ETCHY said:

Got to say a decent adhesive is probably preferable to shit welding. A shit weld is probably no stronger than a pop rivet.

One thing would bother me though, what would happen if you had an accident & you've glued/ pop riveted. Would it be deemed as unsafe/ not road worthy  & invalidate your insurance ?

Both statements are true, I should expect.

In reality I'm not sure anybody would dig deep enough through the underseal to find a patch attached with adhesive rather than an MOT spec welded patch.

I've seen MOT'd vehicles with a run of sealant made to look like a bead of weld... I suppose in that case ignorance is your defence, in that you were presuming the MOT was an indication of repairs being suitable.

[Peter C]

Please rest assured that if I find significant rot close to a major structural element, I will arrange for a proper WELDED repair to be undertaken. Otherwise, I am sticking with my plan.

I consider the fixing of metal patches with rivets + adhesive a more robust method of repair than application of newspaper or chicken wire + filler. How many thousands of cars have been bodged this way and still survive today? I've seen videos of people pulling off three inch thick layers of filler from the sides of pristine looking Bentleys and Jags. Does anyone remember that Capri that had inches of filler on top of the roof panel? I have no intention of replicating such artistry.

Christmas came early today. I bought a pair of metal snips, a rivet gun, Rust-Oleum black paint for the underside and Rust-Oleum paint matched with the MGB's shiny red coat. The paints cost me £99.

I had a go at cutting a section of steel sheet. The snips work well.

And the red paint is a decent match. I applied a little bit of it along the top of one of the rusty rear wings and I am happy with the result. You may recall that the two tins of blue paint that I had made up for the Sierra were completely different from the original Mariner Blue colour.

Sorry about the crap photo. 

I'm going to get stuck in on Saturday morning.

 

[Peter C]

https://www.classiccarsmagazine.co.uk/blog/features/marvel-at-this-epic-restoration-of-a-decrepit-capri/

[danthecapriman]

7 minutes ago, Peter C said:

https://www.classiccarsmagazine.co.uk/blog/features/marvel-at-this-epic-restoration-of-a-decrepit-capri/

Holy shit!!🤣 

Ive never seen that car before, but that’s absolutely incredible how much filler was on the thing! It must have weighed twice what it was supposed to! Why was there any need for so much?

[busmansholiday]

Going back to the early 70's when I started driving, newspaper and filler, not to mention pop riveting bits together was a normal weekends pass time.

Things have moved on these days and I've spent some time this afternoon welding the exhaust bracket back on my Matiz. 

 

It's totally your choice, and as a fellow MGB owner I follow this, but be a bit 'careful' of what 'botches' you post as there's still a few Class I ***ts on here who'd shop you just for the fun of it.

 

[Zelandeth]

21 hours ago, danthecapriman said:

Holy shit!!🤣 

Ive never seen that car before, but that’s absolutely incredible how much filler was on the thing! It must have weighed twice what it was supposed to! Why was there any need for so much?

Turned out that the rear quarters of my XJ-S weren't that much better.  It's astonishing and terrifying what some filler and a cheap respray can hide!

For those wondering what happened to this car after I sold it, my friend who bought it is having all the metalwork that needs sorting sorted by a professional (and well regarded) restoration company.  Bill for sorting out the rust and a respray is expected to be somewhere in the region of £15K.

He still doesn't seem to feel he's had a horrendous deal given what you'll pay for a good V12 XJ-S these days, and once this is finished it will be pretty much spot on.

[ETCHY]

Wasn't there once an AA book of the car type thing from the 1960's/'70's that actually showed you how to use chicken wire & filler to fix holes in sills?

I may have dreamt that though..

[captain_70s]

3 minutes ago, ETCHY said:

Wasn't there once an AA book of the car type thing from the 1960's/'70's that actually showed you how to use chicken wire & filler to fix holes in sills?

I may have dreamt that though..

Readers Digest DIY book deffo does, I have a 1972 copy. I think it mentions not doing this to structural bits but I'm sure the illustrations show it being done to a sill...

Most "restored" examples of normal cars are mostly filler, as there is no money in doing the job well and most of the cars will do 100 miles of dry motoring a year so it'll take a long time to show.

It's very easy to end up with a panel which is a half inch out in places if you're rushing through a welding job, which then equates to 12+ inches of filler in length to get the line looking smooth again. By that point you're probably skimming whole panels and end up chasing your tail to stop it being lumpy.

Personally I hate working with filler so much I'd prefer to get the metal finessed as much as possible first, but the sills on my Acclaim can still only really be described as wonky...

[Shite Ron]

15 minutes ago, ETCHY said:

Wasn't there once an AA book of the car type thing from the 1960's/'70's that actually showed you how to use chicken wire & filler to fix holes in sills?

I may have dreamt that though..

You didn’t dream it, I have that book somewhere:

[Wibble]

I have that book too, not a dream!

[Matty]

^^^ I also have that book lads and know where it is! Haven't looked at it in years but I'll get it down tomorow night and take some pics 👍

[Wibble]

Mine was the later paperback white cover but the same chicken wire advice prevailed😆