Should I Worry About this Mast Tang?

[rogerthebodger]

To me its a classiccase of too much weld causing a over stress sharp stress raiser.

It looks like the 2 plates were joined with a packing plate with a gap between the side plates.

2 comments the pcking plate does not need any welding and only at the top of the tank not down to the gap in the tang.

there is no need to the packing plate as the bolt through the mast will hold both tang plates vis the top hole.

On my current boat I had a similar setup with cracks I made new ones from thicker material but did not weld the 2 side plated together.

As no welding not stress riser so no racks.

The real issue is that welding between the side plates is not possible so a stress riser is unavoidable.

In correct design as people think the more welding the stronger the fitting which is not always the case

 

[steveeasy]

Deleted

 

[Rum Run]

I'm totally ignorant..... I don't think I'm alone

Aero Nuts?

Aerotight Nuts | Aerotight Lock Nuts | Self-Locking Nuts | Fastenright Ltd

Jonathan

Yes, Aerotight, my misremembering..

 

[ducked]

Are such

 

[ducked]

Some no doubt horribly naive questions...

I think I;ve heard of gaff rigged boats running a continuous shroud between a chain plate on each side, with a clove hitch around the mast, in the middle, and I've done this myself with guys for sheerlegs. I suppose a clove hitch would require a lot of mast modification to locate it and take the compression/abrasion on an aluminium mast, but couldn't you just run through the compression tube for the bolt, with suitable plastic sleeving/wedging to avoid a sharp change in wire direction and to friction locate the mast laterally? That'd make these bits go away.

Failing that, perhaps a flexible strop through the bolt tube? That dyneema stuff seems to be trendy, but I dont know how easy it would be to sleeve it against UV, so it might need replaced too often.

Retaining the bolts and pins, would alternative (more flexible) replacements for the tangs be viable which would avoid these corrosion and fatigue issues, for example either high strength cordage lanyards or fibre and resin tangs?

How would/do aluminium tangs cope?

 

[William_H]

Some no doubt horribly naive questions...

I think I;ve heard of gaff rigged boats running a continuous shroud between a chain plate on each side, with a clove hitch around the mast, in the middle, and I've done this myself with guys for sheerlegs. I suppose a clove hitch would require a lot of mast modification to locate it and take the compression/abrasion on an aluminium mast, but couldn't you just run through the compression tube for the bolt, with suitable plastic sleeving/wedging to avoid a sharp change in wire direction and to friction locate the mast laterally? That'd make these bits go away.

Failing that, perhaps a flexible strop through the bolt tube? That dyneema stuff seems to be trendy, but I dont know how easy it would be to sleeve it against UV, so it might need replaced too often.

Retaining the bolts and pins, would alternative (more flexible) replacements for the tangs be viable which would avoid these corrosion and fatigue issues, for example either high strength cordage lanyards or fibre and resin tangs?

How would/do aluminium tangs cope?

No to me the original arrangement of tangs and bolts is best. Aluminium for a tang is more likely to fatigue or corrode. Any stay through the mast wouild be laible to chafe or damage at the corners. Even with dyneema stay I would still go tangs and bolts with ss thimble. ol'will