Acceptable rigging repair (metallurgy)?

[Makinus]

Hello,

I've got my boat (Albin Vega 27') a year ago and haven't inspected the rigging before now.

Upon inspection I found that the toggles on the mast, which holds the lower aft and forward shrouds had some elongation in the holes that hold the shroud pin. The exact same thing happened to both toggles, but I will only be showing one, since they are very similar.
Here is a picture showing the elongation:

The elongation was from 8mm (diameter of hole) to 9mm in the elongated direction.
Here is a 3D render of the part and dimensions to give you a better idea of how the toggle looks like:

I was prepared to pay a shop to bend 2mm stainless to those shapes, but I met a friendly oldtimer-blacksmith in the yard who were willing to give the toggles some love . "Us DIY'ers need to stick together" he said . After a bit of bashing with hammer and a tiny bit of welding they ended up like this:

The elongated holes are now down to 8.5mm (from 9mm), and as you can see it's flush at the end.
The smith said he will guarantee it will hold, but I'm always worried about stuff like this. It's not like I don't trust him but I'm always worried about vital parts of the boat, and since I don't know anything myself a second opinion is always nice. What do you guys think?

As of how this damage happened, I'm afraid I can't blame the (damn) PO for this one . I assume the elongations happened when I myself accidentally started lifting the mast with a crane, while some shrouds were still holding on!

For those interested, I also did a bit of static stress simulation in CAD, but I couldn't make the numbers makes sense when the elongation was the same as mine:

 

[penberth3]

If you're taking the academic route, will your CAD model any potential cracking from your friend's grinding marks?

 

[Fr J Hackett]

You are over analysing it the loads are not significant and everything will be fine.

 

[Makinus]

If you're taking the academic route, will your CAD model any potential cracking from your friend's grinding marks?

I'm not, I have no idea what I'm doing, and that's why I'm in here asking.
Is this a good enough repair, or if I should still have two new ones manufactured?
I don't know anything about metals, and I don't know whatever this part has been under so much stress that is should be binned, or if some hammering and welding will make it as good as new.

 

[PaulRainbow]

One thing is for sure, you did not cause the elongation of the holes by lifting the mast with a crane, guaranteed !!

In the meantime, these will work fine, make sure the bolts are nice and tight.

 

[VicS]

I'm not, I have no idea what I'm doing, and that's why I'm in here asking.
Is this a good enough repair, or if I should still have two new ones manufactured?
I don't know anything about metals, and I don't know whatever this part has been under so much stress that is should be binned, or if some hammering and welding will make it as good as new.

The word "metallurgy" in the title will hopefully catch Vyv Cox's eye

 

[vyv_cox]

The word "metallurgy" in the title will hopefully catch Vyv Cox's eye

It has but it is not easy to answer it. The first question is whether the elongation is due to wear or overload. The deformation of the outer edge suggests it is overload. If this was a one-off event as suggested it is likely that a repair will fix it well enough. Deformation during the damage and the repair will have work hardened it a little, which may be harmful dependent upon the condition of the plate beforehand. Welding will correct this if it has been done well.

I think there is every chance that the toggles will be OK for use but I would inspect them regularly.

 

[Fr J Hackett]

With rigging loads of less than 25% of the rigging BS which I guess for a Vega is probably 6mm or less and as a maximum BS of say 3000Kg (generous) then the expected loads in the rigging are going to be in the order of 600KG probably less. That is not going to deform 2mm Stainless. My guess is that the fitting was press fabricated and the holes punched with some peripheral deformation, there has in addition been wear at the holes. The fitting is not going to fail.

 

[Makinus]

It has but it is not easy to answer it. The first question is whether the elongation is due to wear or overload. The deformation of the outer edge suggests it is overload. If this was a one-off event as suggested it is likely that a repair will fix it well enough. Deformation during the damage and the repair will have work hardened it a little, which may be harmful dependent upon the condition of the plate beforehand. Welding will correct this if it has been done well.

I think there is every chance that the toggles will be OK for use but I would inspect them regularly.

Thanks for your and everyone else response.

I'm very pleased to hear that there seems to be an agreement towards keeping the toggles.
I will be inspecting them regular - after every season, since it's a custom here to take the mast down and boat out for the winter anyway. I guess I'll take some more picture and measurements for comparison after the season.

 

[Makinus]

With rigging loads of less than 25% of the rigging BS which I guess for a Vega is probably 6mm or less and as a maximum BS of say 3000Kg (generous) then the expected loads in the rigging are going to be in the order of 600KG probably less. That is not going to deform 2mm Stainless. My guess is that the fitting was press fabricated and the holes punched with some peripheral deformation, there has in addition been wear at the holes. The fitting is not going to fail.

5mm rigging, and yeah 600kg-800kg sound in the right area from what I've checked too.
Maybe the deformation was due to someone using a way too small pin in the eyes? Since you and PaulRainbow suggest that it probably hasn't happened because of the one time overload?

 

[lw395]

Is the oval hole for the cap shroud and the round one for the lower?
If so, is it possible to turn them around and use the better hole for the more loaded cap shroud?

I think I'd want some convincing these parts are stronger than the wire.
I'd be happier with some new ones either in thicker metal or with more depth below the holes.

Also, are the two shrouds pulling at slightly different angles? Could that have caused one of them to put all the load on one face of the toggle?
Maybe you could replace them with two independent rigging links?

 

[johnalison]

Since the subject has now been raised, it might be a case of doing what would be acceptable to your insurance company.

 

[Keith 66]

My Sabre showed similar wear on most of the chainplates & mast fittings.
In her case we knew that the mast had stood since 1982 & had never been down in 20 odd years. The rigging was not that tight & vibration & movement had simply worn & elongated the holes. Stainless steel is prone to gallingand is not a good bearing material anyway. The cap shroud chainplates were so worn they were replaced, A bit of judicous tig welding & re drilling on the rest plus new pins sorted it out. I have had no further problems.

 

[Makinus]

Is the oval hole for the cap shroud and the round one for the lower?
If so, is it possible to turn them around and use the better hole for the more loaded cap shroud?

I think I'd want some convincing these parts are stronger than the wire.
I'd be happier with some new ones either in thicker metal or with more depth below the holes.

Also, are the two shrouds pulling at slightly different angles? Could that have caused one of them to put all the load on one face of the toggle?
Maybe you could replace them with two independent rigging links?

Both holes (or rather, the two pairs of holes), are for the lower shrouds. The elongated ones are for the lower forward shrouds, the non effect ones are for the aft shrouds. Cap shrouds goes trough the spreader and to the top.
But yes I was also thinking about flipping the toggle over, I'll keep that in mind.

The pull is the same, but at a small angle to either forward/aft, so not exactly vertical.

If I was to have new ones manufactured I would probably have a few more mm of materials past the hole, I wouldn't however feel safe about replacing the part completely with something different.

Since the subject has now been raised, it might be a case of doing what would be acceptable to your insurance company.

There are no rules that I have to apply to for my insurance to cover. Northern Europe is a bit of a wild west when it comes to regulations and sailboats . I don't even have a single piece of paper showing that I own the boat, nor is it registered anywhere.

 

[lw395]

On thinking a bit more, my idea of using two independent toggles would be poor, it would put bending force on the pin.
I think you just want a new part in thicker metal with a bit more meat under the holes.

I'm always a little suspicious of 'stained stainless'.
I suspect what's happened is the forward leeward lower goes slack and the pin frets when sheet and backstay tension are bending the mast.
Stainless rigging parts have a service life.

 

[Makinus]

By the way, this is how the corresponding U-bolt style chainplate looks like. Pretty deformed as well.


I will be changing all 6 of them.

 

[PuffTheMagicDragon]

Unless my eyes are deceiving me I think that the elongated hole in your first photo might have been caused by a loose clevis pin, e.g., could there be a 6mm pin in an 8mm hole?

 

[Makinus]

Unless my eyes are deceiving me I think that the elongated hole in your first photo might have been caused by a loose clevis pin, e.g., could there be a 6mm pin in an 8mm hole?

I didn't even consider that, but thinking about it now I remember that some clevis pins were of the wrong sizes (too small) when I took the rig down. I don't remember which, and they have all been mixed up now, so I don't think I can confirm it was the case for that hole.