Boom end fitting

I would remove the shackle .... grind out / punch out whatever way necessary - the failed insert.

Measure up a new stainless insert that is an interference fit to the lower circular section. This leaves a 'hole' above ...

This can be filled with Plastic Metal - the sort that has actual metal in to give it strength.

The idea another gave of using a threaded tube with nut - post 16 - ... is an excellent idea and basically with Plastic Metal could solve it without actually needing to remove plate to take to metal shop...

I look at the picture and it actually worries me seeing the damage .... to do that would need a lot of action .... I would also look at the shackle used ... is the pin smooth ? Why is it gouging what should be a hard sleeve ?
 
What I would do, similar to what Refueler suggests, with only usual home tools:
Remove the insert, enlarge the hole, drilling with the minimum size allowing it to be round: 10, 12, or 14 mm. Take a stainless steel bolt of the chosen size, cut away half the hex head, leaving 2.5 mm thickness, cut the nut in half leaving 2.5 mm thickness, insert the bolt in the hole anf fit the nut, cut the bolt flush with the nut, pierce axially through the bolt 7, or 9 mm, depending from the shackle pin diameter. Hopefully the total length of the bolt should fit in the shackle width. Otherwise thin the bolt head and the nut and shorten the bolt.
I suppose the boom end will not be wet with sea water often enough to cause different metal corrosion problems.

Edit: if the enlarged hole reachs too near the aluminium boom end plate edge, the hole (and the bolt) could be smaller, leaving a 'hole' on top but I would not bother filling it. This solution could be stronger, leaving more meat in the aluminium boom end plate.
 
Daydream believer said:
Cut & fit 2 ss plates each side of the existing triangle. Bolt them with a couple of 5mm bolts where there is enough material to do so. Then put a bigger bolt through the hole ( having first cleaned it up)
Make the plates long enough to allow you to put 2 holes aft of the aluminium piece & put the shackle through those 2 holes. A packing between the plates at that point would be sensible.

If you do not want to go that route, you could just drill a new hole on front of the old hole & bolt on 2 ss extension plates a couple of inches long. Fasten them very tight at the optimum angle so they do not swivel. Then put the shackle through the other 2 holes which will now be clear of the plate.
Click to expand...
....and use a suitable medium, such as Tefgel to isolate the s/s from the ali.
 
Stainless pad eye with a female thread. Dome head set screw cut to exact length and bolt through the existing hole using loctite on threads and suitable washers and duralac for separation. Then attach topping lift to the pad eye. No more wear to speak off, stainless on stainless. No fabrication needed as such.
 
bome_4269_10-236-1.jpg

The end fitting on my boom is like this.

There isn't any really satisfactory means of attaching the topping lift using a shackle (although the photo shows two) because if attached to the thin aluminium crossbar they rattle annoyingly and will wear through it.

So I use a soft shackle.
 
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