Mast Rewiring and Spreader Rebuild

Pearson Vanguard #181 - Blue Angel

This article is copyright 2006 by Ralph L. Vinciguerra. Contact me for permission to use it elsewhere.

The Blue Angel, a 1964 Pearson Vanguard, has a mast that has been suffering after many years without being unstepped for maintenance. For some reason in the Boston Harbor area few people step their masts and few marine services offer the facilities to do so. In our case, the connector at the base of the mast had degraded so that ALL electrical elements in the mast except the VHF were non-functional. Also, the Sitka spruce spreaders had weathered badly as well, see the picture to the left to see how the spreaders, those horizontal wooden spars halfway up the mast form a critical part of the mast rigging. This picture shows Lori back in 2003 fitting lazy jacks to the mast while we vacationed at Marth's Vineyard. It was time to unstep and refit. This project is focused on rewiring and on spreader work, although other elements may be replaced as needed. It is our hope that the sturdy old running rigging will be deemed sound after close inspection. Also, the plan will be to refit in a manner that will provide many years of weatherproof ability with negligable attention.

Here's the collection of weathered elements from the mast. The non-metal elements seem to degrade the fastest. However, the main reason for these devices to fail was an extremely corroded connector at the base of the mast.

The project began with an unstepping of the mast and a careful measurement of the key dimensions that can be used to determine the wire lengths and also to remove the spreaders for work in our home shop. Work then proceeds first on the spreader rebuilds and then on the rewiring.

Here we see the spreaders in their weathered condition. The tops had lost all their protective coatings, probably due to the constant exposure to UV from sunlight. It was my original hope to simply sand and refinish these spreaders.

Here are the outboard ends that contain the outer shrouds. The boots have been removed and the aluminum end fitting can be seen. Some surface corrosion was present but not serious. The black stained holes are for bailing wire that runs out around the shrouds when in position to keep the shroud in the slot during rigging.

Now, the bad news. Water that was being trapped underneath the inner bracket ends rotted the wood badly, rendering these spreaders unsafe. We sail the Blue Angel in some pretty stiff breezes in outer Boston Harbor and a failure of these elements could lead to a de-masting. New ones needed to be constructed. Actually, one of these is newer, having been made after a hard accidental jibe snapped one of them many years ago. However, inspite of the different ages, they were both degraded.

Fortunately, some scraping and light sanding brought these unique end brackets into shape for reuse. The inner brackets are stainless steel and just needed simple cleaning.

Here's a nice piece of sitka spruce that I purchased from a nearby wood specialty shop. The rough board has just the right thickness so that after sanding and being coated (many, many times) it would be the right size to fit inside the inner brackets.

Using the old spreaders as templates, they were traced onto the rough board, and then cut approximately using a table saw. The gentle curves were just straight enough to prevent the blade from binding. Then, by clamping them together, final forming using a wood rasp and an orbital palm sander produced the right shapes. I have to admit, at this step I made a tragic mistake. The outboards ends of the spreaders ended up being too narrow to fit the end brackets due to some of my overzealous sanding. Fortunately, I had enough raw material to repeat this part. I tell myself it was good practice.

Using a power router with a quarter-round bit provided a fast way to soften the edges along the spreaders. However, at each end, the corners remain square to properly mate with the end hardware. The burn marks are from my somewhat old bit which doesn't have a proper ball bearing guide, but they sanded out easily.

After alot of sanding with finer sand paper, the basic spreaders are formed and are ready for their first expoxy coatings. Holes will be overdrilled later and filled with resin and then redrilled. The little screw eyes make it possible to manipulate and hang the spreaders from the shop ceiling when they are wet with new coatings.

These are the test attempts to learn to coat wood with epoxy resin on test pieces. The oddly colored samples are from an incorrect mixture of resin with hardener (too much of it). It never cured and remained sticky weeks later. These tests also helped me decide to eliminate the single layer of glass fabric, since its not required for strength, is hard to apply, and may produce different expansion rates than the underlying wood, potenitally causing a future degredation of the resin seal. I also used one of these pieces to practice double size drilling, resin filling, and redrilling, the holes. When filling the holes I used a small syringe to steadily add drops of the resin mixture as it soaked into the wood grain. The 105/207 combination is similar to a thick varnish in viscosity and this allows it to soak into the wood.

Here are the new spreaders are fully coated, 4 layers of epoxy resin (West System 105/207), 2 coats of epifanes varnish. Also, all holes are drilled double size, and resin filled before drilling the final mounting holes. This provides a weather resistant encapsulation of the wood. You may have noticed that this was the dominant source of the rot in the original spreaders, right around the inner bolt holes. I could have spent more time sanding the material between coats, as you can see some small patterns of excess resin mixture, but I wanted thicker coats and was able to take advantage of the ability of the 105/207 mixture to be applied during a special curing phase without additional surface preparation.

Lastly, the top surfaces received 2 coats of a "durable white topside paint" from West marine, for an extra measure of weather resistance since the white reflects most of the sunlight.

Based on a computation using wire run length, acceptable voltage drop (3%) and expected current, the spreaders required AWG 12 wire, and the bow and masthead lights use AWG 16 wire.

Proper connectors were extremely hard to find. I wanted somthing that would handle the 12 and 16 AWG lines in one connector, but this was too expensive and hard to define in a military style configuration. These two "trailer" connectors from west marine handle the AWG 12 size and with two of them I have sufficient contacts. I've added some hose clamps to secure the rubber boots, and I plan to tape then to prevent water entry and wire them together when unstepping the mast to make up for their lack of a locking action. Two wraps of tape and an untwist should be sufficient to uncouple them in the future.

Here are the completed spreaders in the full shot. the only other elements to add are spreader boots to the ends, and small eye bolts and pulleys for the flag hoists. You can also see the dividing line between the top paint and the clear wood undersides.

This closeup of the outboard ends shows some modifications. The aluminum rods that used to hold the tips on are replaced with stainless steel through bolts. Also, the shroud securing wire is routed through new small holds in the alumimun end bracker instead of holes in the spreader core wood (which lead to additional water ingress).

Here you can see how the spreader lights are mounted with a slight tilt, one forward and one aft, by placing small wedge shaped spacers made of plexiglass. I used a bench grinder to taper the thin plexiglass sheet. All the bolts are in position.

Now, on to the wiring. This shot shows the new wiring harness for the mast. The cable bundle has been secured internally every 4 feet with a cable tie along with a plastic coated steel cable to carry the weight of the cable inside the mast. This way each individual cable is suspended evenly. The ouside is wrapped with a pipe wrap foam that has adhesive strips on each edge to keep it closed once applied. This should minimize any noise for the cable bumping the inside the of the mast when rocking.

This view of the bottom connectors shows the pair for the lights, masthead and bow in one, and spreaders in a second, and the independent VHF cable.

Here's the mast step, being disassembled. Water has been leaking into the cabin top in this area for the past few years. The original aluminum beam assembly is in workable condition and needs to be removed and repainted before reinstallation with new caulking.

A spacer block was placed underneath the mast to make a channel for additional wiring that has been added later. This needs to be replaced. The elevation tube for the cable bundle will be retained as it is a good way to protect the cables. This original one was threaded into the galvanized steel beam and had broken off.

The wire guide tube has been replaced by a double ended coupler, an adapter, and a larger tube. At the bottom, the coupler was ground flush on the bottom, and all the edges are ground smooth to prevent wire chafing. Although the coupler is the same interior diameter, the larger tube just above should still make it easier to thread wires. This final assembly was also made shorter than the top of the beam to prevent mast installation from breaking it off again.

This entire galvanized steel assembly has been given 2 coats of cold galvanizing primer and two coats of latex enamel (as recommended on the galvanizing primer). Also, the new and old base plates are shown.

Here's a closeup of the spacer block that needs to be replaced. Note the compression of the wood fiber under the weight of the mast. The new spacer block ought to be aluminum or some kind of dense composite material. Note the old corroded lag bolts and screws. A new scheme is in the works, where we'll drill out the old holes oversize, and fill then with resin and some kind of captive nut or bolt creating a watertight seal into the cabin top before applying any caulk.

The new base plate is made of plastic composite planking (very common now). I used a router to shave the thickness down to 0.75 inches. WARNING: Do not use this material. It later collapsed under the load from the mast. Instead I carved a small opening in the bottom edge of the mast and let the remainder rest directly on the steel beam. No compression now.

The router was also used to cut a wire channel from the corner to the center. I tested this material compared to the original hardwood and it withstood more compression force on my bench vice, so I presume it will withstand the mast weight combined with the shroud and stay tensions. The alternative would be aluminum or steel, which would require special stock and a milling machine. The bottom edges are all chamfered to clear the metal weld joints.

Here are two of the 4 new captive bolts being glued into the cabin top. The over drilled holes were filled with epoxy resin and the new bolts aligned with a small guide plate of wood with markings to center the bolt positions to match the steel beam. The resin flowed down into the wood beams below to help strengthen the region.

After the first resin application, there were still voids. However, be careful here! As I kept pouring in resin, it kept flowing in. Although I thought it was running into the headliner space, it instead found small holes and flowed into the cabin to run down the central bulkhead. This was a mess to cleanup with many, many paper towels and alcohol, which managed to desolve the epoxy resin before hardening! Next time I'd mix thickener into the early resin pours.

After several additional resin pours, each time letting the hardening begin, the flow paths finally closed. Here the final flush level has been achieved.

A picture of the old kapoc packs being used to quiet the mast wiring (not working).

A photo up the bottom of the mast after removing the wiring and the old kapoc padding. Each wire has a string that will be used to pull the new wires through. In order to be able to pull the wire along without striking the bolts, the mast was rotated 90 degrees from this picture and ALL the bolted items were removed to make a smooth passage where gravity would pull the wire against the mast.

More to come....

Blue Angel