Wednesday, September 30, 2015

New Standing Rigging!


Heads Up!


We were incentivized to pay attention to our standing rigging this year when we read two Moorings service bulletins that one of the Leopard owners posted on the Yahoo Groups web site. One service bulletin was #205-05, dated 9/16/05, and recommended upgrading several pieces of standing rigging to Dyform wire for hull numbers 001-020. LUX is hull #009, so we started checking the rigging and found that some of the upgrades had been done. The other service bulletin, #06-10-29, dated 29 Oct 2006, cautioned that two Moorings 4000s had been found with broken wires in the forestay at the top fitting. The first service bulletin had not changed the forestay to Dyform wire, even though hulls after 020 were outfitted with Dyform forestays. This second bulletin recommended watching for problems.

During our investigation, we heard from multiple sources that 10 years is the maximum life for standing rigging, particularly on boats that have been in charter, as LUX was. LUX is a 2005 model year Leopard 40, launched Nov 2004. That means that we're now at 11 years. There wasn't anything that looked suspicious and we go up the mast about every 6-12 months and take a close look at everything.

Hmmm. It's been almost 11 years, charter service, and 1x19 wire instead of 1x19 Dyform wire. It's time to get new standing rigging. This consists of a pair of inner diamonds, two outer diamonds, two cap shrouds, two lower shrouds, and the forestay. We still had several major decision points in the process of getting new standing rigging.

Questions

 Question 1: Do we do the work or do we hire a rigger?
We contacted two riggers in Annapolis and received verbal quotes of around $7,000. Both suggested that we'd have to replace the roller furler, so count on another $3,500. The last boat I did this with went from an estimate of $5,000 to a bill of over $10,000. The five co-owners talked among ourselves - do we buy the parts and use mechanical fittings (e.g., Sta-Lok) to make up the rig ourselves? We decided against it - use a professional rigger to make swaged fittings, except for the forestay, which will require a mechanical fitting at the top. Companion Leopard owner Troy Bethel, who has a lot of experience with rigging, recommended Dennis Schryver to build the rigging for us. The installation process is simple.

Question 2: Do we do it in place or take the mast down?
We could save some money by doing it in place. Troy noted to us that there is risk of a tool becoming embedded in the deck when working aloft. :-( One of the other Leopard 40 owners did his one piece of rigging at a time, taking it to a rigger to make the replacement, then going aloft to fit it in place. This requires a number of trips aloft. However, the Moorings service bulletin recommended upgrading one of the diamonds from 6mm 1x19 to 7mm 1x19 wire. We were going to have to replace the backing plates for the larger size wire and that job is *much* easier on the ground. We had also purchased a Raymarine HD Color radome to go with our new a75 MultiFunction Display chart plotter and it needed to be mounted on the mast. So we decided to take the mast down.

Question 3: What size wire?
One of the diamonds should be upgraded from 6mm to 7mm wire. But everything else was either 10mm or 8mm Dyform. So we decided to go with two sizes. The forestay and cap shrouds are 10mm 1x19 Dyform. The diamonds and aft shrouds are 8mm 1x19 Dyform wire. It is a little more weight aloft, but simplifies the rig. Here's a brief description of Dyform wire: http://rigworks.com/yacht-rigging-services-in-san-diego/standing-rigging/wire-rigging/dyform-compacted-wire-rigging/.

Note: The maintenance bulletins say that Moorings sent new wire for the inner diamonds but that since the mast has 6mm lollypop backing plates, they had fixed the rigging to fit those backing plates. Looking carefully, we found that 6mm lollypop end fittings had been welded to the threaded stud that connects to the turnbuckle. I don't know any welders whose work I would trust that much.

 Removing the Mast


Before we went to the marina, we removed the sails and boom, which we stored on the foredeck. We tied a tape measure to the spinnaker halyard and ran it up to the spinnaker block, which swivels. We took measurements to the two bow D-rings and to the toe rail outboard of the Waste deck fittings. Stbd rail at waste: 51' 8-7/8", Port rail at waste: 51' 9", Stbd D-ring: 54' 2-3/4", Port D-ring: 54' 2-1/2". The mast was centered left-to-right on the boat and we had fore-aft position measurements.
Marking the wiring inside
Wind Instrument Wiring
Feedthrough at the foot of the mast

We also removed the electrical connections inside the mast step, marking them with hashes to indicate which wire went where on the terminal block. The two bottom pairs of wires are ground so their order on the bottom two terminal block screws does not matter. The wind instrument wires are color coded.

It was easier to unscrew the drip fitting outside than to try to slide the wires out. We later discovered that the fitting was filled with clear silicon caulk, so the wires are effectively glued in place.

So down came the mast when we hauled for bottom painting and saildrive maintenance.
Removing the Mast

Rigging Measurements

Troy pointed us to Dennis Schryver at Bay Sailing Equipment in Fall River, MA (owned by Frank Colaneri). He was easy to work with and we had clear communications throughout the process. We measured the old rigging, going pin-to-pin or to the middle of the lollypop fittings, using a 100ft metal tape measure. Troy recommended shortening the measurements by 1/2 inch, to allow for stretch. (Note: The diamonds were sized just right with the shorter measurements. The shrouds were a little shorter than I'd like, with 4 threads showing, but we've only just put up the rig and we should see it stretch over time. Curious about the stretch characteristics, I checked the stretch of Dyform wire at http://www.secosouth.com/mm5/pdf_for_web/1-marine_rigging_introduction.pdf. Sure enough, at 1000kg, it stretches about 1/2 inch over the length of the shrouds. Now, do we expect a 1000kg load? I didn't run any numbers, but I'll bet that the shock loads of a poorly controlled jibe are at least that much. Maybe a mechanical engineer can leave a comment about the anticipated loads. The measurements were compiled into a measurement document and sent to Dennis. We made sure that the turnbuckles had been marked prior to removing the rig and repositioned them to make the measurements. Each wire was clearly labeled. We also measured the pin diameters and the holes that the pins fit into. (You do have a set of calipers on board, don't you?) Everything was checked multiple times by more than one person.
Lollypop measurement 24' 5"

Pin measurement 29' 1-1/4", Stbd Lower Shroud













Measuring a Pin
Measuring a Chainplate Hole
Furler set screws
The furler came right apart, with the exception of two screws, one on one of the sections and another where the lowest foil section goes into the furler drum assembly. So we left them alone. The roller furler bearings (upper and lower) were good - smoothly rotating, so we don't need to rebuild them. We didn't need a new furler. Each furler section was labeled with tape so we could reassemble it in the original order.

Furler Lower Pin Keeper
Furler Lower Pin Connection









Forestay Pin and Toggle























Mason String at Boom Support
Mason String at Masthead
We used a mason's string to measure the mast prebend prior to removing the old diamonds. We found max bend at the spreaders of 7-7/8 inches from the string to the mast. We averaged the distance that each end of the string was from the mast to arrive at a true bend distance of 3-1/4 inches.












Preparing for New Rigging

We couldn't find the lollypop threaded stud fittings that were used on the original diamonds, so we decided to move the turnbuckles up the wires about 3 feet. Dennis said that he needs that much length to keep the wire from turning into a bird's nest when cutting and swaging it.

Old 6mm Lollypop Backing Plate
Sizing Up the New Backing Plate
We had to replace the 6mm lollypop backing plates in the mast with 8mm versions, which Dennis obtained for us. The old backing plates were held in with monel rivets, which we drilled out with a 1/4-inch drill. We made wooden plugs that fit into the old holes left by the 6mm backing plates and tapped them into the holes with a hammer. A piece of mylar was created to align with the single hole of the 6mm backing plate and show us the location of the center of the 8mm backing plate hole and its two new screw holes. A short time with a sharp hole saw (1-5/8), then drill two 1/4 inch holes and we had new backing plate mounting holes. We cleaned up the hole edges with a round file.
A 1/4-inch drive socket fits into the opening of the 8mm backing plate. So we used a couple of 1/4-inch extensions and bolted the backing plates in place, covering the backing plate's mounting surface with Duralac to prevent dis-similar metal corrosion. The screws were coated with Tefgel, also for dis-similar metal protection, before inserting them and screwing into the nylock nuts held by the socket. These backing plates could be mounted with rivets, but we had problems finding monel rivets without a steel mandrel. Aluminum rivets aren't strong enough for this purpose. 
Mylar Drilling Template


The Hole Saw Plug


Drilling the New Hole




Finished 8mm Backing Plate

While the mast was down, we took the opportunity to do a couple of other things. The foot of the mast was removed and the screws cleaned (one was broken and it was replaced).  We ran new pull cords in both mast conduits, tied to short wire tails at the top of the mast so that UV doesn't destroy the nylon cord. We replaced the anchor light, which had a cracked lens. We didn't replace the VHF antenna and cable, which we hope we don't regret. It has been operating well and shows a good SWR when connected to the VHF radio. The mast contains two conduits, shown here with the foot of the mast removed. One conduit was empty, which we used for the Radar and PA speaker cables.
Two Conduits
Masthead with Wire Tails on Pull Strings
Mast Internals

Radar

We added radar to LUX and decided to go with a Kato Marine radome mount, which looks real nice. It is boat show season and every new boat that was being assembled had one. They are $540. We mounted it just above the spreaders, using mylar separators to keep the stainless mount from contacting the aluminum mast. Tefgel was used on the screws. The 10 meter cable from Raymarine reaches this point with about 2 feet of cable inside. A second 10 meter cable extends from this point to the helm, where it connects to power and to the Raymarine a75 MFD. The radar comes with this second cable - the extension cable must be used to go up the mast. We cut a 1-inch hole in the mast, aligned with the conduit that runs the length of the mast on the starboard side. It is empty on LUX, so we didn't have to worry about cutting any wires when drilling. A short session with a file rounded the edge. We were barely able to work the end of the radar cable into the conduit with this size hole. A PA speaker was added to the radome mount and a wire was run for it. After both wires were in place, we used a 11/16 ID grommet with a 1-inch diameter by 3/16 groove to finish the edge of the hole and prevent the wires from chaffing. A pair of wire ties prevent the wires from sliding down the conduit. The final installation looks very good.
Radome Mount

Final Radome Mount
Radar & PA Cables
Rigging Arrived!

The Rigging Arrives! Assembly Starts

The rigging arrived and we checked its measurements. The turnbuckles had to be unscrewed to reach the measured lengths and everything looks good. The diamonds were positioned on the mast and we began tensioning them, working back and forth between the four turnbuckles, doing no more than two turns each. We checked the mast for straightness (port to starboard) and prebend (fore and aft) as the prebend approached our target number of 7-7/8 inches. We had to experiment with which turnbuckles to adjust to keep the mast straight. After the mast prebend was set, we let it sit a night and found that nothing had changed the next morning. So we pinned the turnbuckles with cotter pins.
Turnbuckle Location on Inner Diamonds
It Looks Straight

The roller furler was reassembled on the forestay using medium thread locker on the set screws. The overall length was double checked. The mark Dennis left for us was exactly what we had specified. We used a cutoff wheel in a drill to cut the forestay cleanly. The Sta-lok mechanical fitting worked smoothly. We took a few minutes to watch a YouTube video on assembling it. Some LifeSeal caulk was used during the final assembly to keep salt moisture out of the fitting. Dennis made us a new pin and toggle for the bottom of the forestay. There is a temptation to reuse some components, but this should be resisted. We replaced everything, including all the pins. The spreader boot is by Isomat and fits better than the old leather boot. It's much smoother too. We used silicon tape (e.g., Rescue Tape) to tape it in place.
Furler Joint Marked

Reassembled Joint with LocTite

Cutting the Forestay
Sta-Lok Ready for Assembly
  
New Spreader Boot
We were finally ready, brought LUX back to the boat yard, and stepped the mast. Unfortunately, we had the lower shrouds mounted on the wrong side of the diamonds, so the yard crew shimmied up the mast and fixed them for us. We pinned the rigging in place and tightened the turnbuckles hand-tight and took LUX home. The next day we spent more time to tension the rig, mount the boom and add the sails. We're now waiting for some wind to go sailing to do final adjustments. The forestay should sag about 6 inches in 15-20 kn of breeze (3-4 inches in 10-15). After that sail, we'll insert the cotter pins in these turnbuckles and wait a few months to check the rig again.

Boom Work

While doing this work, we found several shackles that had significant wear spots, so they were replaced. The main halyard was swapped end-for-end while the mast was down. The bails on the aft of the boom were worn so they were replaced, using mylar under the bases to separate the stainless from the aluminum mast. One of the rivets had popped a boom bail before we took the old bails off, so we used 1/4-inch bolts and nylock nuts to reinstall them. Tefgel was used to protect the aluminum from the stainless screws and nuts.
Boom Bail Popped a Rivet
Reassembled Boom Bails
Worn Shackles with Replacements

Summary

The rigging was about half of what we would have paid a rigging company. We had to spend a few weeks without a mast while the rigging was made and delivered. We had a lot of other things to do, so there wasn't much wasted time. Dennis has the lengths now and that should make the job go much faster for anyone else doing this job.
The Completed Mast Going Back to LUX
We checked the mast's location using the tape measure and we're exactly back to where we were initially. The measurements to the D-rings on the bows and to the toe rails at the waste fittings are within 1/8 inch of the initial measurements.



When to Replace Anchor Chain

A Potential Bad Link
I noticed this summer that the anchor chain was flaking rust when anchoring. I've never had an anchor chain rust enough to flake and was concerned. I started investigating engineering rules for safe chain to determine when we should replace it. Looking on the boating forums was not helpful. Many people just say "It was rusty, so I replaced it." I couldn't find an engineering analysis of chain and corrosion guidelines. Weren't there guidelines? This is a situation for facts, not opinions.

I checked the existing anchor chain and found it stamped "G4", whose links are .394 in diameter with a 1.22 in inside length (called pitch in some documents). This is 10mm or 3/8 in chain and fits our chain gypsy.

After much searching I found that the Peerless Chain web site has a nice document (http://www.peerlesschain.com/catalogs/catalog-2012/files/assets/common//downloads/Peerless%20Industrial%20Group.pdf) that tells the minimum thickness due to wear for Grade 80 chain (the same dimensions as our G4 3/8 chain). The link thickness when new is .394 in and should be replaced when it is .342 in, or an erosion of 13%. A ship web site (see link below) mentioned that a reduction of 12 percent is allowed before replacing a vessel's chain. .394 * .88 = .3467

To put these figures in perspective, the next smaller chain is 5/16, which has a diameter of .329 in and has a Working Load Limit (WLL) of 3900 lb. A new G4 3/8 chain would have a WLL of 5400 lb. The WLL is 1/3 of the minimum breaking strength of the chain, providing a safety margin. (Note: G70 and above chain have a WLL that's 1/4 of the breaking strength because those chains are certified for overhead lifting of loads.)

These pieces of information gave me a start on deciding if our chain was safe. I decided that .350 was my threshold for replacing the chain (11% erosion). I then looked for the most rusty links I could find and sure enough, the first link I tried was .350 thickness. The link was cleaned with a file to clean, shiny metal to prevent false readings. Our chain needed to be replaced.
Hmmm - 0.350




















I checked around and the best price was at Bacon Sails in Annapolis. An order for 200ft was placed and they had it in less than a week. Wire ties were used to mark the chain every 25 ft, clipping the tails so that they are long enough to see the color. LUX was out of the water at that point, so I simply backed my car under the boat and loaded the chain right into the chain locker. Now we can sleep on the hook without wondering if the anchor chain will fail.

We are also planning to wash the chain with fresh water after anchoring.

Colorful Wire Ties for Markers 
Loading the Chain