William_H
Well-Known Member
A trap for young players or am I just stupid. It all started with a post here about a failed cap shroud tang at the mast. Now the little boat is home for winter on a trailer and I am a bit neurotic about rigging integrity. Now on 4th mast. Although this one must be 20 years old.
Anyway decided to remove tangs to look at them. You know 2 plates close together then spread apart with the wire swage thimble between the plates and the top end plates close together with a bolt right through mast so a tang on each side. Same for cap shroud and intermediate shrouds. At both cap shrouds and intermediate where spreaders are based there is as stout stainless steel collar around mast so bolt goes through the collar and mast.
I found that i had done a foolish thing and at one stage replaced the manky looking studs with new bolts. 5/16 diam ww with nylock nut. All good except that the bolt was of such a length that on one side the tang was loaded on to the threaded part of the bolt and in fact the threaded part was also pressing on the ali mast and ss collar with all the load of the stay wire. Not good but apparently OK for 20 odd years.
Now originally the bolt was actually a bit of 5/16 ss rod with thread tapped on each end. I found one of the originals. However I also found that the originals must have had nut on each side done up tight onto end of thread with a fair bit of looseness. Perhaps made for a different width mast. Now I don't know if that matters but seems to me it should be pretty close but loose enough to allow alignment of tangs when loaded.
So after much battle with an old 5/16 dye nut trying to thread down another bolt. I discovered some 8mm bolts and a dye nut that actually cut the thread with not ease but at least success. Had to cut the thread own to the point where when fitted enough shank of bolt (is that what you call the smooth unthreaded part?) extends out enough to take tang thickness but thread close enough to allow a very close if not tight fit when nut goes down to end of thread.
It seems to me the bolt will act like a clevis pin except that there must be some force pulling outwards due angle of the stay away from the mast.
So hopefully all good now. Any comments. have I done it right? PS funny thing here one chandler I go to has lots of whitworth bolts etc while another has only metric. ol'will
Anyway decided to remove tangs to look at them. You know 2 plates close together then spread apart with the wire swage thimble between the plates and the top end plates close together with a bolt right through mast so a tang on each side. Same for cap shroud and intermediate shrouds. At both cap shrouds and intermediate where spreaders are based there is as stout stainless steel collar around mast so bolt goes through the collar and mast.
I found that i had done a foolish thing and at one stage replaced the manky looking studs with new bolts. 5/16 diam ww with nylock nut. All good except that the bolt was of such a length that on one side the tang was loaded on to the threaded part of the bolt and in fact the threaded part was also pressing on the ali mast and ss collar with all the load of the stay wire. Not good but apparently OK for 20 odd years.
Now originally the bolt was actually a bit of 5/16 ss rod with thread tapped on each end. I found one of the originals. However I also found that the originals must have had nut on each side done up tight onto end of thread with a fair bit of looseness. Perhaps made for a different width mast. Now I don't know if that matters but seems to me it should be pretty close but loose enough to allow alignment of tangs when loaded.
So after much battle with an old 5/16 dye nut trying to thread down another bolt. I discovered some 8mm bolts and a dye nut that actually cut the thread with not ease but at least success. Had to cut the thread own to the point where when fitted enough shank of bolt (is that what you call the smooth unthreaded part?) extends out enough to take tang thickness but thread close enough to allow a very close if not tight fit when nut goes down to end of thread.
It seems to me the bolt will act like a clevis pin except that there must be some force pulling outwards due angle of the stay away from the mast.
So hopefully all good now. Any comments. have I done it right? PS funny thing here one chandler I go to has lots of whitworth bolts etc while another has only metric. ol'will
