Detached jib sheet tracks

[pbobbitt]

Yeah... I've been having a ball on my new (to me) '85 DSII... Last week we were blasting at 18Kts (gusting over 20) and managed to get it up on a plane... Last Sunday it was closer to 12, but I had the port track rip out on the forward screw. The track was bent to hell, but no real damage on the fiberglass.

The previous owner noted that he'd 'fixed' the issue by installing inspection ports on both sides, and replacing the wood... the screw was a tiny wood screw... The starboard side track is similarly mutilated.

I want to replace the track with modern t-track. My questions:

1) Are there any class rules as to how long the track can be? The existing ones are 12"... the shortest I can find are 18".
2) Are there any class rules on placement? I seem to remember reading that they had to be so far back from the cuddy wall, but I can't find it.
3) Is the any reason why I need to replace the wood? Can't I just use through bolts with 1" stainless washers on the backside? What am I missing?

[GreenLake]

The same thing happened to me many years ago on the maiden voyage with a new to me DS.

I ended up with Harken "small boat" tracks.



From the picture those look more like 12". So they were available at one time.
I see it listed on the Harken site, but as a "dealer only" item.

https://www.harken.com/en/shop/22-mm-sm ... e-spacing/

Perhaps with the product number (Part No. 373.12) it might be easier to find any still on offer somewhere.

The placement of the tracks, or their length, is not prescribed (https://www.daysailer.org/resources/Doc ... bylaw3.pdf) and while 18" would be overkill, I don't see an obvious downside. I would assume it's possible to cut down oversized track. My sailmaker suggested using the most forward position exclusively, my (very) expert crew disagreed and even used manual adjustments (not in a sanctioned race) as can be seen in this picture.

[GreenLake]

About the wood anchoring the track screws. I used a penetrating epoxy to provide some more strength to the wood to give more "grip", others have used a waxed screw in a hole filled with regular epoxy (which will thus harden into threads around the screw, but the wax still lets you remove the screw later).

Or you can combine both techniques. And go to the largest diameter screw accepted by the track. I was able to up the diameter by one step. I did not know the waxed screw trick, but thinks have held nicely for many seasons now, and even survived removal and replacement for refinishing without losing "grip".

However, if there's significant dry rot you may opt for removal.

If the rear is accessible, you can of course throughbolt as well (with or without the wood). I'm not sure what surface area you need for successful backing if you've removed the wood. Fender washers may be fine -- the reason the builder used wood is that it allows installation without access from the back; but that gives you no hint as to whether the stiffness of the wood is in any way essential or whether the laminate is strong enough on its own.

[pbobbitt]

When I 'm racing on big boats, we slide them suckers forward when it's blowing. the idea is that the geometry of the bull allows for a twist in the jib let out some of that energy...

I have no idea what happens on a daysailer.

I really got to get new sails the ones that came with the boat are truly beat. That said, I can manage to keep up with Flying Scots up wind mostly... Dead Down wind I get crushed, on reach I'm generally a little faster.

[GreenLake]

The direction of pull matters, and the principle should be the same. However, each sail is cut a bit differently and the guy I bought from, since retired, once upon a time was the goto sailmaker for fast boats in some of the DS fleets. So, he clearly thought less twist was faster in all winds.

We don't have other DS here, most of the time, but one showed up for a bit, and I managed to outsail them fairly consistently which surprised me. I'm used to being hopelessly behind all the fancy boats.

[IslandFarmer]

I thought I would post my planned repair ... after 4 years in the barn, I think I'm ready to replace the port jib track. Comments welcome.
1. Access port is cut in the bulkhead wall under the seat through which I removed rotten wood and fiberglass.
2. I patched the cracks around the holes in the cockpit.
3. I have a piece of G-10 (1/4-inch) and a little bit longer than the track to use as a backing plate. I have marked where the holes need to be using the track as a template ... plan to check with a paintbrush inserted through the holes before drilling.
4. Plan is to replace screws with through-bolts as shown in Roger Conrad's book on page 95.
5. There was a lot of discussion on another post about using SS nyloc nuts. Given that I'm reaching in blind to put the nuts on, I opted for regular SS nuts over SS lock washers over the recommended SS flange washers. I went with 2" bolts (32 threads per inch) at West Marine — raised Philips heads for the ends and recessed Philips heads for the three in the middle. I got the largest diameter they had that fit through the holes and for the recessed ones, allowed the jib block to slide over. See image.

I'm still trying to work out in my head how to proceed. I know I will need a helper.
1. Pre-drill holes in the G-10 backing plate ... check the vertical spacing by having one person mark the plate with a small paint brush inserted through the holes in the seatback while I am lying in the cuddy holding the backing plate up to the top of the combing.
2. Put the jib car on the track and place track over the holes. Partner inserts the two outer round-headed bolts one at a time through the patched holes. I apply washers and nuts. Same with the three recessed bolts. Have handy a magnet on a string in case I drop anything. Partner holds the head of the bolts with Philip's head screwdriver as I finger tighten and then use a wrench.

Some have suggested using epoxy to hold the backing plate in place ... perhaps more important if I were screwing into wood. Others mention taping the backing plate. If my partner can get two bolts through the holes while I'm holding the G-10 in place, I'm thinking epoxy/tape may not be needed.

[GreenLake]

Àny bolt will be stronger than a screw, so details likely don't matter much.

Really? Why not use glue to temporarily hold your backing plate? No need to pre-drill to a precise pattern and easier if you don't need to hold it in place. Almost any glue will do. You are not looking for permanence or strength other than opposing force of drilling. Something that doesn't need clamping and sets quickly but allows a doover if you managed to stick it on crooked.

Instead of nylock, a dab of threadlocker. You don't want the nuts to work loose out of sight.

With what I read about G10 I imagine any washers are fine and probably overkill. The loads on these bolts will not be enough for that to matter. They are enough to pull screws out of failing wood but that's a low bar.

They use to make a Y wrench for use on bicycles. Easy to grip and might be more convenient in the confined space. Except for that last 1/4 turn you're mostly using it to get the nut positioned against the turning bolt. Doesn't work if bolt protrudes more than necessary. So trim any extra.

[IslandFarmer]

Thank you Green Lake. Always good common sense.

After I posted on Friday, I reviewed all the old posts on this topic and remembered my dissatisfaction with the jib leads BEFORE my jib track pulled out, so have done some re-thinking. And your post had me wake up this morning realizing that I should have known just how long the bolts need to be: thickness of the seat back (not much) + 1/4" for G-10 + extra for being able to find the ends with my fingers. So I will exchange the 2" bolts for 1" bolts; exchange the flange washers for smaller washers; and return the little lock washers and buy/borrow thread locker instead.

Of course it makes sense to glue the backing plate first, which I will do. I'm just a little nervous about glues as well as power drills, but I have the extra G-10 on which to practice the drilling.

I also now realize the difference between the Ronstan Series 40 Orbit Single BB Block with Cleat Swivel and the Ronstan Orbit Series 40 Single Block w/ Becket Swivel Cam Cleat and Fairlead is the all important becket. Defender here in CT has the becket one for $99. Back in 2023, I made a paper mockup of the one without the becket and got discouraged. I have now removed the fairlead/cam cleat from the jib car and plan to put the clevis pin through the becket. I just added a paper clip "becket" to my model and now see how great it will be.

Once I get back out on the water next summer, I can see how it works in practice. With the clevis pin I can always put on a plain block and add cams on the CB trunk. TY TY

[GreenLake]

For best results with glues: clean the surfaces. Isopropyl 91% should work to get any accidental grease off your pieces.

Remember, the worst that can happen is that the piece pops loose while you are drilling. Not ideal, but easily recovered.

I didn't quite get your discussion of the blocks. It looks like it should have been part of the discussion on the other thread. Here's a link to one of my posts in that thread, explaining my setup and preferences which are different from what you seem to be planning.

A becket is usually provided to be able to terminate a purchase. Like so:



Here the "buntline hitch" is tied around the becket of the upper block.

In the picture, the lower block also has a becket, but it is unused. (That particular design is apparently not secure. I recently noticed that the pin had disappeared).

Given that, I'm a bit of a loss as to understanding what you are planning to use a becket for in this particular application.

[RaleighRancher]

FWIW: I didn't install a backing plate when I repaired my jib tracks. I just used ~2" stainless washers and called it a day. I haven't noticed any issues - no cracks developing around the tracks or anything that would suggest too much strain on the fiberglass.

[GreenLake]

When the jib sheet is cleated at the car, there is no force component directed inboards. Only forward. That means all bolts are loaded entirely in shear, which is where they are strongest and least dependent on backing plates, washers or whatnot. If you mainly sail with the jib sheets cleated, this applies to any load peaks from sudden changes in wind force, for example when filling the sail with a snap after going through a wave.

While you are trimming the jib, there's never more force on it than you can hold. We therefore have an inboards component that is capped by how much force you can apply to the sheet (any peak loads beyond that would, by definition rip the sheet out or your hand, or force you to temporarily yield a bit, both would mean that the force is now spent on moving the jib rather than straining against the jib car).

As long as you cannot pull a single bolt (or screw) out of the fiberglass if you apply all your force in pulling, then you would not exceed the limit. What is unclear is how much of a safety factor you have in that scenario. Few of us would test this to destruction. Clearly, the designers thought that wood screws would be sufficient. The safety factor in that design, however, is so low that it doesn't account for natural degradation of the wood over time. (This same problem exists on the DS1, where the wooden coamings are held in by wood screws and the tracks are screwed into both the coaming and the fiberglass layer with wood backing behind them).

My take on the backing plate, especially if you use G-10 instead of homemade layup, is that a single plate is more convenient than multiple washers, and in fact, you can do away with them completely. I also suspect that with the correct diamater hole, self tapping or sheet metal screws would work just fine.

But, there's nothing wrong with a bit of overkill, especially if you need it to get to the correct degree of peace of mind.

[IslandFarmer]

Very helpful explanation of the forces on the jib track, with jib sheet cleated and held. TY.

I got the G10 in place with 2-part body filler on Sunday. The cool thing is that I had cut the vertical width (3-3/8") so it fit perfectly between the little ridges of the sawed off fiberglass along the top and bottom and even stayed put without the glue. So, though the "glue" set very quickly, I also stuffed some bits of swimming noodles in the space under the combing for good measure. The previous owner had used them to protect spars etc. when trailering. They fit that space perfectly.

I had put wood matchsticks in the holes to keep them a little open when I was repairing them, which turned out to be quite helpful. Before removing the furthest forward stick, I put some electrical tape about an inch+ forward and then used that "touch guide" to get the fore-aft placement of the backing plate just so.

And I should say that when I went back to the store, I opted for 1-1/4" bolts ... to give myself a little more to find with my fingers. Will do my drilling this coming weekend. Such a hurdle I'm almost over.

Yes, I did mix up two topics. Will respond about my planned replacement jib block/cleat on the jib car thread.