Spreader Help

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Spreader Help

Postby ekendall » Fri Jun 06, 2014 8:28 am

I am knew to the forums and a new 1967 Daysailer I owner. After my first trip out I broke one of the spreaders when taking the mast down. I ordered a replacement from D&R Marine but the cut out hole to attach to the mast is about 1.5 inches away from the end of the spreader. On my current spreaders, the holes are about 1 cm from the end of the spreader. The length of the old and new spreaders are the same the only issue is the location of the hole.

Is it safe to drill a hole closer to the edge so that it matches with the current one or should I get another spreader and new hardware to attach to the mast?

Thanks in advance for your help!
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Re: Spreader Help

Postby UCanoe_2 » Sat Jun 07, 2014 10:27 am

ekendall, welcome to the forum! There is loads of helpful advice here. D&R lists two sizes of spreaders, 1/2" and 5/8" diameter. You probably got the 1/2" size which would fit the original cast aluminum brackets. I doubt it would be a problem to drill a hole as you have in mind -- the forum engineers will come along shortly to tell you if I am wrong. BUT if you have the cash, the new stainless steel brackets and heavy duty spreaders are much stronger and well worthwhile. You may also want to upgrade to the new 1/8" standing rigging.

If your boat has spent much time in salt water, check for galvanic corrosion (white powdery stuff) and pitting where aluminum parts and stainless steel parts contact each other. The mast on my '64 DS I broke just below the spreaders a couple years ago from such corrosion. Search the Repair and Improvement forum and you can find my threads on mast and centerboard repair. When I installed the new mast, I put isolating shims cut from plastic milk jugs or .050" phenolic wherever aluminum and stainless parts touched. I also put Teflon pipe dope on all stainless fasteners that went into holes in aluminum.

Hope this helps.
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-- Mark Twain
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Re: Spreader Help

Postby GreenLake » Sat Jun 07, 2014 1:54 pm

I have the old Javelin design for spreader brackets on my DS and those have the pin very close to the mast, so the holes are very close to the end. I did get correctly drilled replacement spreaders when mine broke some time ago only to see them fail immediately.

Now, what I did the first time the spreader broke right across the hole was to make an emergency "repair" so I could get back on the water right away. Realizing that spreaders are loaded on compression, I figured the task of the repair was to hold the remaining spreader to the bracket, but that any "give" in any other direction was fine.

I had black tape and zip ties to work with.

I cut a length off the "tail" of a couple of ties, threaded them through the bracket and taped them to the spreader. (Essentially replacing the last fraction of an inch of spreader near the mast with a U of Nylon). That repair done, I set out for a test run. Worked fine. Replaced that a week later with the "proper" replacement to see them fail again one day when raising the mast.

Repeated my "repair" right then and there. That was several seasons ago, and I've not bothered to improve on the improvisation in any way.

Yes, it's unorthodox, but it's actually more resilient during rigging and transport, because if the spreader gets a knock in any direction where it's not designed to take the load, the U is not a "stiff" hinge and will give a little. Meanwhile, when loaded under sail, as long as the spreader rests against the pin, it will take all the compression loads that are being transmitted by the rig.

Given that, I probably would cut off a bit off the end of the spreader, just short of where the holes would go. I would create two slots, instead of holes, for the pin to go in, and I would rig a strap that threads behind the pin and is attached to the spreader and which has the purpose to keep the pin in the slots. This strap is only needed when there's no load on the spreader, that is, to hold it up during transport, rigging and when it's on the lee side (and the spreader comes unloaded).

The reason I would do this, is because of stray bending loads that the rig can experience when transported or during rigging/de-rigging. My experience is that these occur on land and that the original spreader design (or the Javelin version that were put on some model years - per Rudy) is simply too rigid to handle them, leading the spreader to break at the attachment point. Allowing some flex to the joints is the answer, and doesn't compromise their intended task.
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Re: Spreader Help

Postby GreenLake » Sat Jun 07, 2014 3:07 pm

Forgot to add: What would I make a strap out of if this was a permanent design? Beefy zip tie tails are not a bad choice, but Nylon may succumb to UV, and I wouldn't know how to fix it to the spreader shaft without electrical tape :).

But, I figure, the strap could be made from a strip of metal, aluminum or stainless. Hardware stores sell them in short lengths that can be cut to size with shears. Could be epoxied or riveted to the shaft. Imagine both would work. The U of the strap would partially double the shaft in a critical area, but also make the hinge have a little give on bending loads (up/down) compared to the holes which is what we are interested in.

Now, some people retrofit spreaders with solid bar. Given the diameter of the holes and the ID of the spreader, there isn't much additional air space that a solid bar would fill, meaning, right at the critical juncture, it only adds limited strength. And a hollow tube is rather stronger for the weight than a solid bar under compression - and weight aloft isn't good...
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