Spreader broken at the mast bracket

[GreenLake]

Getting back to the spreaders. The way they are designed, they seem to fail many times not because of loads under sail, but because they are sensitive to misalignment and corresponding stresses during mast raising.

But it looks like the beefed up spreaders transfer that problem to the brackets (see Seans post). If the rivets hadn't come loose all the way, he might not have noticed that anything was amiss, and that bracket could have come off on the water...

[Alan]

GreenLake,

You mentioned in your first post that your spreader broke "at the mast bracket. Where the holes are for the pin. In other words, the last .25" broke off."

Were there different designs, or did I mis-read your post? I just checked mine (original and new heavy duty from D&R) and the holes for the pins at the mast bracket are 1-7/8 inch from the mast to the center of the pin hole.

The heavy duty spreaders, by the way, are larger diameter but look like the same wall thickness (1/2 inch OD for what's on my boat vs 5/8 inch for the heavy duty D&R spreaders).

[GreenLake]

Yep, the brackets that I have are different than the brackets that they show for the heavy duty spreaders. The clevis pin on my brackets is approx 1/2" away from the side (foot) of the bracket.

Increasing the OD with same wall thickness should still make the spreader bar stiffer, which is something you need when you add nearly 2" of leverage at the bracket.

Hope when I get the replacements I ordered, they aren't drilled at 1-7/8".

[seandwyer]

Yea - the chainplate issue is something I've been wondering about too. I upgraded to the heavier duty shrouds last fall and so far haven't really had any troubles, but Friday afternoon while single handing in about 15 knots, I kept hearing a creaking coming from the same chainplate / shroud area where it goes through the hull. I inspected the area after I was on dry ground, but everything seemed in order, nothing damaged or loose. but something was complaining and I'm wondering if it might be in the fiber glass - but like I said - nothing looked suspicious. I'll look again, but if I can't find anything I'll just regard it as a mystery noise I guess.

[seandwyer]

This may be a stupid question, but as far as the connection between the end of the spreader and the shroud: are those rubber boots I see on boats essentially performing this task, or are they just a barrier to keep the wire from coming into contact with the sail? If they fasten the two together, I may try those out. Greenlake saying that his spreaders have lasted almost 50 years makes me feel like I'm doing something wrong. I've owned the boat for about 18 months and have replaced spreaders a few times already. The ones that came with the boat were old and mismatched. One of them broke pretty soon after I became the owner. Then I made 2 different spreaders which broke at different instances over the summer. Then this year, the other "original" broke and I decided to just get the new heavy duties from D&R. Rudy didn't seem surprised at all with my spreader breakage rate, but I'm really questioning things now that I hear some folks get so much more time out of them. And yes - Greenlake is correct, the weakness is in misalignment when raising the mast, then the thing breaks. I've had them fail at both the shroud and bracket end too.

[jeadstx]

When I got my boat (about 5 years ago) one of the spreaders was damaged and I bought new standard ones from D&R. They were as described with the pin hole about a 1/2" from the end. They didn't last long tho. The spreader snagged on something while trailering (mast down and secured) and broke at the pin hole. I then ordered heavy duty spreaders from D&R that have worked well since then. Other than the pin hole being further from the end, the extrusion is also rectangular instead of round on that end that fits into the bracket. I believe this makes it a little stronger. I had a piece of one of the original spreaders from my dad's 1969 Mariner and it had the rectangular extrusion on the end also.

I also got the spreader boots to protect the sails from damage by the spreaders.

John

[Alan]

I have the rubber boots. They cover the joint, but they're not tight enough on the shroud to keep the outer end of the spreader from sliding up and down. The shrouds are secured to the ends of the spreaders by the thin wire that GreenLake mentioned.

[Alan]

My spreader brackets have three holes in them. Since my mast is a Dwyer, they're probably the Type A bracket on this page at the Dwyer website:


http://www.dwyermast.com/items.asp?cat1 ... Airfoil%29

They've also got airfoil spreaders that are probably overkill, but they sure do look strong. And I bet they'd look flashy, if a little high-tech for a Daysailer...

[Alan]

Afterthought: The thin wire that secures the spreaders to the shrouds is available on the Dwyer website.

[GreenLake]

Years ago I purchased small quantities of stainless steel wire in two different strengths as well as very thin stainless steel rod (really just stiff wire). I keep coming up with new uses.

[GreenLake]

Alan, thanks for your pointers on spreader design. I got back with D&R Marine today and found out that my spreader brackets match those for the O'Day Javelin.

I don't know whether that is true for all boats of that age (mine is a '63), but Rudy at D&R suggested that O'Day may have "run out of" some parts and substituted.

They'll do a custom order for me.