Its hard to say what might be causing the failures.
mine is still fine as originally supplied after 7 years of hard sailing. My suspicions are that many have their rigs waaay too loose and simple repetitive movement, shock loading, and wear is making them fail, but this is only conjecture on my part.
Mac 26X Spar Fatigue and Bending
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craiglaforce
- Captain
- Posts: 831
- Joined: Fri Jan 02, 2004 8:30 am
- Sailboat: MacGregor 26X
- Location: Houston, Tx
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Duane Dunn, Allegro
- Admiral
- Posts: 2459
- Joined: Fri Jan 02, 2004 6:41 pm
- Sailboat: MacGregor 26X
- Location: Bellevue, Wa '96 26x, Tohatsu 90 TLDI and Plug In Hybrid Electric drive
- Contact:
Makes me want to switch back to the original folding spreaders my boat had on it. The early X's had a U shaped bracket on the mast which the spreader went into and was held in place with a vertical bolt through the assembly. It was a much less rigid structure that had no binding points. It also let the spreaders swing down so there was no conflict with the lifelines when raising and lowering the mast.
If I recall they switched because they felt the fixed socket inproved the sailing ability.
As a result of this original spreader system, my uppers have swages on them at the spreader attachment point. There was one above and one below the spreader tip. The instructions that came with the fixed sockets conversion kit said to move the spreader tips above the upper swage. These give the speaders a bit of an up torque to my eye, but they do keep them in the proper place. There certainly is no problem with the speaders sliding down with the swages in place.
I did have a tip come loose one time. The forward screw backed out completely and the plate rotated down on the other loose screw. Only the rig tension kept the wire on the spreader in the tip groove. When I lowerd the mast the wire fell off.
I have since put locktite on all 4 screws and there have been no further problems. Be sure to check the screws regularly to make sure they're tight.
If I recall they switched because they felt the fixed socket inproved the sailing ability.
As a result of this original spreader system, my uppers have swages on them at the spreader attachment point. There was one above and one below the spreader tip. The instructions that came with the fixed sockets conversion kit said to move the spreader tips above the upper swage. These give the speaders a bit of an up torque to my eye, but they do keep them in the proper place. There certainly is no problem with the speaders sliding down with the swages in place.
I did have a tip come loose one time. The forward screw backed out completely and the plate rotated down on the other loose screw. Only the rig tension kept the wire on the spreader in the tip groove. When I lowerd the mast the wire fell off.
I have since put locktite on all 4 screws and there have been no further problems. Be sure to check the screws regularly to make sure they're tight.
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Don T
- Admiral
- Posts: 1084
- Joined: Fri Jan 02, 2004 7:13 pm
- Sailboat: MacGregor 26X
- Location: 95 2600 "SS OTTER" - Portland OR - Tohatsu 50 - Hull#64 (May 95)
Hello:
The problem I had with my spreaders was that the sockets were not at the correct angle for the amount of rake they call for. This always loaded them aft with a slight bend. Once the spreaders bent the first time they were weakened substantially and bent easier each time. Compounded by loads induced bouncing down the road while trailering. Even though the SS tubing weighs more I used it to make new spreaders. I like the idea of having a dowel pressed inside because it does not allow the tube to deform when loaded and gives it memory to straighten out. I did a deflection test comparing the aluminum and SS with dowel. Aluminum deflected 1" per 10lbs. It took 50 lbs to deflect the SS that far.
I didn't weigh them to find out how much I increased the weight aloft. I know I should have so I would know how much ballast I negated. Ok, I'll estimate 6 lbs were added. Lets see, thats about 18 feet above the center of gravity so I lost the equivilant of 60 lbs ballast. Oh boy, more tender! Of course I added 150 lbs of fresh water so maybe it all worked out. The results have been very good. The rig is very stiff. They no longer bend and are perfectly straight after 5 years. My shrouds are set to 270 lbs tension.
The problem I had with my spreaders was that the sockets were not at the correct angle for the amount of rake they call for. This always loaded them aft with a slight bend. Once the spreaders bent the first time they were weakened substantially and bent easier each time. Compounded by loads induced bouncing down the road while trailering. Even though the SS tubing weighs more I used it to make new spreaders. I like the idea of having a dowel pressed inside because it does not allow the tube to deform when loaded and gives it memory to straighten out. I did a deflection test comparing the aluminum and SS with dowel. Aluminum deflected 1" per 10lbs. It took 50 lbs to deflect the SS that far.
I didn't weigh them to find out how much I increased the weight aloft. I know I should have so I would know how much ballast I negated. Ok, I'll estimate 6 lbs were added. Lets see, thats about 18 feet above the center of gravity so I lost the equivilant of 60 lbs ballast. Oh boy, more tender! Of course I added 150 lbs of fresh water so maybe it all worked out. The results have been very good. The rig is very stiff. They no longer bend and are perfectly straight after 5 years. My shrouds are set to 270 lbs tension.