MOT Advisories

[simians]

Assuming the van was actually recorded as failing on a Dangerous or Major Defect I don't think I would have posted up on a public forum how I got around avoiding a Dangerous or Major Defect Fail of a MoT test on a public forum TBH. Quick get it deleted, AIB for one seem to roam the forums! The MoT tester has nothing to worry about of course.

Unless postponed April 1st jest?

Probably one of the first things I learnt about welding, is never weld to rusted steel, especially in load bearing structural areas, waste of time and effort. Cutting back to sound steel as they say, is the only way. Or complete replacement of the component of course.

[John52]

1 hour ago, simians said:

Probably one of the first things I learnt about welding, is never weld to rusted steel, especially in load bearing structural areas, waste of time and effort. 

Depends how thick the steel is - on a rusty car bodyshell I quite agree, I wouldn't trust welds either.  But people do weld them and it passes.  Wheras bolts would not pass the test. 

Whats wrong with bolts?

Bolts have a known strength.  Welds on thin rusty metal don't.

[simians]

1 hour ago, John52 said:

Depends how thick the steel is - on a rusty car bodyshell I quite agree, I wouldn't trust welds either.  But people do weld them and it passes.  Wheras bolts would not pass the test. 

Whats wrong with bolts?

Bolts have a known strength.  Welds on thin rusty metal don't.

Bolts act on a limited area of contact, the sheet metal around it will shear even if the bolt doesn't. It is recognised that welding produces stronger connections than bolting, given like for like circumstances. The weld if carried out correctly creates a joint as least as strong as the surrounding parent steel (fusion) it becomes one and the same. Some bods try brazing which just bonds the steel and paint over, but brazing as for bolting isn't allowed in structural repairs to vehicles for the MoT. The engineers who set the standards for the MoT aren't stupid. An MoT tester will use his discretion on the degree of corrosion acceptable, no doubt one mans opinion will differ from another.

In building frame joints, as found in say portal frame structures welded joints are specified for a far stronger than pin joint(bolted). Its a well established fact. 

It's likely the Titanic would not have sunk if of welded construction, rather than hot riveted (similar to bolting). 💪

[Hans]

At last  in Belgium as in  NL. There is no longer MOt. The garage will take care of it. No longer  cues for  Hours. and hundred starts of your engine.

[Hans]

1 hour ago, simians said:

Bolts act on a limited area of contact, the sheet metal around it will shear even if the bolt doesn't. It is recognised that welding produces stronger connections than bolting, given like for like circumstances. The weld if carried out correctly creates a joint as least as strong as the surrounding parent steel (fusion) it becomes one and the same. Some bods try brazing which just bonds the steel and paint over, but brazing as for bolting isn't allowed in structural repairs to vehicles for the MoT. The engineers who set the standards for the MoT aren't stupid. An MoT tester will use his discretion on the degree of corrosion acceptable, no doubt one mans opinion will differ from another.

In building frame joints, as found in say portal frame structures welded joints are specified for a far stronger than pin joint(bolted). Its a well established fact. 

It's likely the Titanic would not have sunk if of welded construction, rather than hot riveted (similar to bolting). 💪

 

3 hours ago, John52 said:

Depends how thick the steel is - on a rusty car bodyshell I quite agree, I wouldn't trust welds either.  But people do weld them and it passes.  Wheras bolts would not pass the test. 

Whats wrong with bolts?

Bolts have a known strength.  Welds on thin rusty metal don't.

 Rivits  poppet or counter sunk are eas strong as a full penetrations' welding. 

[John52]

5 hours ago, simians said:

The weld if carried out correctly

Exactly

In factory conditions on new metal I would agree

But working upside down under a vehicle on thin rusty corrugated sheet.

How do you know how strong the weld would be? 

[John52]

5 hours ago, Hans said:

 

 Rivits  poppet or counter sunk are eas strong as a full penetrations' welding. 

Gawd how old are you Hans 😄

 MOT testers stopped accepting pop rivets about 50 years ago. 

They are only thin hollow aluminium

[thebishbus]

Or stainless steel.

                   Brian B.

[simians]

11 hours ago, John52 said:

Exactly

In factory conditions on new metal I would agree

But working upside down under a vehicle on thin rusty corrugated sheet.

How do you know how strong the weld would be? 

How do you know sufficient number of bolt/nuts have been used, correctly tightened, or the holes not oversized.?

 Rusty steel, then cutting back to sound steel is the answer. If you don't possess the tools, skills, or resolve, mental and physical then farm the job out to those that can..... simple. The thing is we have to work within the rules as they are, if someone wants to gain the system by carrying out what 'they' personally consider adequate repairs then so be it. I'm sure there's some would justify a wood glue repair if it suited them.😀 

As for checking the qualities (strength etc.) of a weld, the MoT tester is entrusted to make that judgement, after all he is, on balance better qualified than most of us. Someone has to be the arbiter.

I'll let you have the last word, busy getting the welder set up.😁

[simians]

57 minutes ago, thebishbus said:

Or stainless steel.

                   Brian B.

Or Monel, superior to s/s for many usages.

[Derek Uzzell]

For what it's worth (!!) this appendix to the MOT inspection manual provides MOT inspectors with guidance regarding structural repairs and what methods should be considered acceptable and what should not.

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

[Brian Kirby]

  4 hours ago, thebishbus said:

Or stainless steel.

                   Brian B.

Or Monel, superior to s/s for many usages.

But it seems that welding stainless to mild steels is not straightforward, and welding stainless steel to monel is even more tricky.  So, for practicality, it will be simpler and cheaper to stick to replacing any corroded bodywork with mild steel.  

What Jeremy seem not to have been able to ascertain is the extent of the corrosion both in terms of surface area and depth of penetration.  If the corrosion were superficial, I assume it would not have been cited as an MoT advisory.  How it might be repaired can't really be resolved until the extent of the damage has been assessed.  It seems that gaining adequate access will require the van to be raised on a hoist and examined by an experienced welder.

The best we can do at present, methinks, is to wish Jeremy good luck until he has obtained that final verdict.

[Hans]

I repeat once again what welding means. But it is related to the titanic. Their poppets where strong. Electric welding or auto genic was not invented yet.

[simians]

2 hours ago, Brian Kirby said:

  4 hours ago, thebishbus said:

Or stainless steel.

                   Brian B.

Or Monel, superior to s/s for many usages.

But it seems that welding stainless to mild steels is not straightforward, and welding stainless steel to monel is even more tricky.  So, for practicality, it will be simpler and cheaper to stick to replacing any corroded bodywork with mild steel.  

 

You have misunderstood, I was adding Monel, to thebishbus's reference to stainless steel RIVETS which in turn referred to Hans's rivet post. I was not advocating welding to mild steel bodywork. Mr. thebishbus I'm sure can reply for himself LoL

[thebishbus]

Correct. My original suggestion  of "POR 15" would be fine if it is just surface rust. Anything  more serious  would have been an MOT failure I would have thought.

                         Brian B.

[Brian Kirby]

15 minutes ago, simians said:

You have misunderstood, I was adding Monel, to thebishbus's reference to stainless steel RIVETS which in turn referred to Hans's rivet post. I was not advocating welding to mild steel bodywork. Mr. thebishbus I'm sure can reply for himself LoL

Then you're right, and I did misunderstand.  I had thought his somewhat Delphic reply was in response to John's earlier post regarding welding, and was advocating using stainless steel sheet in lieu of mild steel when when patch welding.  That made me check the practicality of so doing, and reach the conclusion I did.  Hey, ho, crossed wires!  🙂 

[John52]

13 hours ago, Hans said:

I repeat once again what welding means. But it is related to the titanic. Their poppets where strong.

I think something has been lost in translation Hans

'poppets' (pop rivets?) are hollow and fixed from one side, making a 'pop' sounding noise as the bit that goes through the middle snaps.

Not solid rivets fixed from both sides like on the Titanic.  (My understanding is they faied due to inferior metal and thermal stresses exacerbated by a fire in the coal bunker) 

[John52]

The only rivets I have experience of are aluminium.  I guess stainless steel etc would have been too expensive for the guy I was working for 😀

Presumably they would be stronger than aluminium.  But still hollow, and not with a flat washer spreading the stress like on a nut and bolt.

[John52]

19 hours ago, simians said:

As for checking the qualities (strength etc.) of a weld, the MoT tester is entrusted to make that judgement, after all he is, on balance better qualified than most of us. Someone has to be the arbiter.

Of course.

But if he can look at a weld and tell how strong it is why not a nut and bolt?

[laimeduck]

Ahhh Well.... in my book you are mostly all out of order as I was quite specific in my original post. I asked for "DIY solutions"!

So .... all this discussion about welding is all academic as it ain't going to get welded at this stage because:- 

a) I can't weld

b) I haven't seen the extent of it yet and there are 12 months before the next MOT.

I will let you know what I find but hopefully it will ge a scrape/cure/ paint job which I can do.

Jeremy

[Brian Kirby]

Did you get the chance to have a chat to the tester, Jeremy?  If he can remember your van, he may be able to give a verbal description of what he saw that just might give you a greater insight into extent, and how deep it has gone.  He may even be prepared to give an opinion on whether your "scrape/cure/paint" job should be enough, or whether he thinks it needs a more invasive cure.  Bearing in mind that MoTs are annual,  I'd be a bit surprised if it has progressed from "nothing to see here" to requiring anything much more severe than a clean up and phosphating type remedy since the previous test.

I was going to suggest starting with phosphoric acid, but then thought trying to get that onto the underside of the van without phosphating yourself in the process seemed a hill too far! 

Halfords used to sell Waxoyl, but it seems they no longer do.  I've used it from a pressurised can with a spray lance.  It's filthy stuff to apply but seemed to work well enough.  The main problem for underbody application is that it needs to be warm to thin it for application, but it then drips off all over whatever the van is standing on at the time which, apart from the mess, is very slippery.  However, if you can overcome that disadvantage, the spray lance does allow you to apply it "from a safe (ish 🙂) distance".  It's still available on the web.  Any use?

[laimeduck]

2 hours ago, Brian Kirby said:

Did you get the chance to have a chat to the tester, Jeremy?  If he can remember your van, he may be able to give a verbal description of what he saw that just might give you a greater insight into extent, and how deep it has gone.  He may even be prepared to give an opinion on whether your "scrape/cure/paint" job should be enough, or whether he thinks it needs a more invasive cure.  Bearing in mind that MoTs are annual,  I'd be a bit surprised if it has progressed from "nothing to see here" to requiring anything much more severe than a clean up and phosphating type remedy since the previous test.

I was going to suggest starting with phosphoric acid, but then thought trying to get that onto the underside of the van without phosphating yourself in the process seemed a hill too far! 

Halfords used to sell Waxoyl, but it seems they no longer do.  I've used it from a pressurised can with a spray lance.  It's filthy stuff to apply but seemed to work well enough.  The main problem for underbody application is that it needs to be warm to thin it for application, but it then drips off all over whatever the van is standing on at the time which, apart from the mess, is very slippery.  However, if you can overcome that disadvantage, the spray lance does allow you to apply it "from a safe (ish 🙂) distance".  It's still available on the web.  Any use?

Thanks Brian 

No I did not take it to the tester....  my small garage chappie organised the MOT ... he is old school ...100% reliable and does all my vehicles. It was done at an HGV testing station in Old Romney ... they have their own fleet of mega HGV's and have done our Benimar for years. 

I'm with your sentiments on this....When the weather improves I'll have a look underneath and go down the phosphoric acid then covering paint type route. In theory I'm confident that if they see that the advisory has been addressed sensibly, then major surgery can be avoided for a few years ... but we'll have to see?

Jeremy

[Hans]

My Range rover diesel fuel tank is rusty. On my VW in PE. New tank or repair? How thick are They.? New? The corrosion Rate has done his work.  Salt.

[John52]

26 minutes ago, Hans said:

My Range rover diesel fuel tank is rusty. On my VW in PE. New tank or repair? How thick are They.? New? The corrosion Rate has done his work.  Salt.

Years ago cars leaked oil and the sump pans were lathered in it.  Sump pans rusting through was unheard of.  But since we got engines that don't leak we got a problem with sump pans rusting through.  ECP are even listing Ducato pattern parts sump pans like a service item!

So I just spread a bit of oil on them.  And anywhere else that looks like it might be damaged by rust -like the fuel tank.  Some people might not want to do that, especially if selling the vehicle,  because it looks like the engine is leaking oil.  But that doesn't bother me because I know it isn't.

We've got cars with MOT advisories for corrosion going back many years - but not getting any worse because we give them a brush off and a wipe over with oil every year