Thursday, September 12, 2019

Giant bow cleats

Living through a few hurricanes, I've learned to get the biggest, strongest bow cleats I can get. These are 12" long, solid bronze. For some reason no bolt-holes have been drilled in their feet. I think I'll go with 5/16th stainless steel bolts, and with appropriately-sized 1/4" G10 laminate backing plates.

Hurricane Dorian

Hurricane Dorian was a near-miss for us in St. Augustine, Fla. However that didn't mean I still didn't have to pack up everything and prep the boat for a hurricane.

The workshop came down, all the tools and supplies are now in storage units, but I kept a fridge and electric kettle under the boat. All of that took quite a bit of time but having prepped for hurricanes twice already, it was all old hat. I'm not resetting-up the work shed because I have to move this boat in a couple of months anyway

Dorian brought us a few inches of flooding in the yard. Irma and Matthew each brought about 2 feet of flooding, in comparison. I stayed onboard through Irma and Matthew but this time, due to the cats, I decided to go to a hotel. Having air conditioning for a few days was nice.

I feel awful for the folks in the Bahamas however. Those places weren't 20 feet above sea level, not sure how anyone can survive once the surge alone is over 20 feet. The whole place would have been underwater. I think we're going to need new charts too.

Wednesday, August 7, 2019

Safe working loads of shackle blocks

I'm a fan of Garhauer Marine's blocks because they're pretty solid things that seem like they can take a pretty good beating, and relatively inexpensive. Practical Sailor has rated them well too, and they generally get good reviews on various forums and websites. People have good things to say about their quality and especially about their customer service.

However I am somewhat disappointed in the statements regarding the safe working load (SWL) for their shackle blocks. I bought several of their single stainless steel 60-13-sized shackle blocks and noticed that the shackles seemed a little smaller than what I expected. So I read the website a little more carefully: The Garhauer website states they use 1/4" shackles, and that the blocks have a SWF of 3500 lbs.

The 1/4" shackles made by Wichard have a SWL of about 1800 lbs. So I don't understand how the Garhauer shackle blocks could have a SWL of almost double a high-quality 1/4" shackle.

I sent an email to Garhauer to ask; they replied that the website was incorrect and that these were 5/16th shackles. So I measured the shackles on the 4 blocks I had purchased:

The pin diameter was 19/64th, which is  I guess within tolerance of 5/16ths.

However the shackle body was not that size. The shackle body is slightly rectangular, not round. The "inside" diameter of the saddle was 15/64 and the "outside" diameter was 9/32 -- these are both pretty much 1/4".

I wrote back to Garhauer and they replied that shackles are measured by their clevis pin diameter. They are not actually,

Shackles are sized according to the diameter of the bow section rather than the pin size.

(Specifically by the diameter of the "saddle" in the bow-section.)

But in any case I replaced the shackles on my blocks with "true" 5/16th shackles. (I measured it to be sure)

It is important to note that the strain on shackles have to be centered on the pin, by using washers to act as spacers. If the strain is placed on one end, you could end up losing 70% of the SWL of the shackle.

Starting on rewiring the sailboat mast.

I was hoping to dedicate August to the mast, standing rigging and the stanchions entirely but the weather is not cooperating to allow me to finish the paint job from last month.

The 40' mast itself is in OK shape, no big dings or anything but it needs a good cleaning with vinegar and maybe an aluminum cleaning compound. I don't plan on painting the mast since that's a lot of work and really not necessary. All the old blocks, shackles and internal wiring will of course be replaced.

Looking at the masthead: The VHF antenna base was still there but seeing the singed marks on the cable, I assume it was zapped-off by a lighting strike at some point. The masthead light is the old incandescent variety, broken. The windex has fallen off.

The sheaves in the masthead sheave box are aluminum and seem to be in good shape; I will just need to replace their axle pins. The boat's original halyards were a combination of wire cable spliced to 1/2" cruising line so the existing sheaves are designed to handle wire cable. I have already bought 5/8" cruising line, and was considering changing the sheaves to use all-line rather than cable (sheaves for cable have a groove in them) but now I see switching the sheaves will involve a lot of metalwork on the sheave box (the existing slots for sheaves are too narrow to accommodate the wider halyards). So I'm going to have to go back to the combination cable-line halyards and will be splicing some 7x19 1/4" stainless cable to the line I have already bought. Since I had already bought enough line to run the lines back to the cockpit plus an extra 10 feet, that will leave a lot of extra line cluttering the cockpit - an issue to deal with when the running rigging project starts in a couple of months.

In the meantime I need to rewire the mast too. The mast doesn't have a built-in raceway for the wires; the previous owner had zip-locked the wiring together every few feet and wrapped it all in some foam insulation. I spent some time pulling out the old wiring, which was not marine-grade stuff. There was a big ball of wire, an old bird's nest, some errant foam bits and leaves blocking things up in the mast so I resorted to clearing it all by ram-rodding the mast with 4x10' lengths of PVC pipe until I was able to clear out all the junk plus the old wires.

The wires had wrapped around the internal bolts for the spreaders so I had to take the spreaders off, which was a good thing because I got a chance to inspect things and clean off the white aluminum oxide corrosion that had formed under the stainless steel spreader tangs. However the bolt threads had galled, and also I was not able to find replacement fine-thread 1/2" nyloc 316 nuts locally. The spreader tangs are currently at a machine shop so the bolts can be rethreaded, and I have ordered a couple of new nyloc nuts from

I replaced the blocks for the spreader flag halyard lines with small Harkens. The old Sunfish brand spreader blocks had started to leave chalky residue so I'm guessing they've just about had it. I'll replace the rest of the blocks later, when I handle the running rigging. 

As for electrical wiring, I have bought a couple of Caprera 2 red/white LED spreader lights by Lumitec, to be installed in addition to a steaming/deck light. I will also need to wire the new VHF antenna plus the radar dome and the Echomax XS active radar reflector.

Mast steps are another project - I will be installing folding aluminum ones by Sea Dog, and using 1/4" aluminum rivets to secure them. I know that some insist on using Monel rivets but I don't have a rivet gun capable of handing steel rivets, and three 1/4" aluminum rivets per step should be strong enough anyway (no issues with corrosion that results from steel-aluminum contact either.)

Meanwhile, I'll just watch the dragon flies and hope for better weather... I have to remind myself this is all supposed to be fun and not a reason to stress out.

Sunday, July 28, 2019

Sailboat sanding and priming continues

A proper paint job is all about surface preparation; the actual painting takes just a couple of hours but the preparation can take weeks. And if you don't prepare the surface correctly, your lovely paint job will be ruined - you'll have to scrape it all off and start over again. Aside from the time and labor required, primer costs more than a hundred dollars per gallon, and paint is about $80/quart - so a screw-up from lack of attention or cutting corners can be expensive.

After sanding off the old paint, I washed down the topside and deck/cockpit surfaces with Tide detergent applied with a deck wash brush, followed with a thorough rinse using a high-pressure washer, and then wiped it all down with alcohol applied with multiple clean paint rags. The goal was to remove any surface contamination that could interfere with the primer bonding properly to the surface.

Awlgrip Hullgard Extra primer applied to deck and cabin top

Some people use acetone to wipe down the surfaces prior to priming or painting, however acetone evaporates far too fast on a hot, sun-baked hull, so I use alcohol instead. You have to use multiple clean rags too, otherwise you'll end up just spreading the contamination around instead of removing it. Also, there can be no moisture (dew) on the surface prior to applying the primer and paint, and don't touch the surface with your bare hands either since that will transfer sweat and skin oils to the surface, which will require another alcohol wipe-down.

Patched and faired, ready for Highbuild primer

Then I applied Awlgrip Hullgard Extra primer to the topsides and deck/cockpit, using 9" Glasskoter 1/8-nap roller sleeves. Hullgard Extra is a bonding primer, intended to be used before fairing. It contains extra epoxy, to make sure it binds well to the surface it is applied to. One gallon was just barely enough for 2 coats on the cockpit/deck. For the topsides, one gallon was enough for 3 coats per each side, and just barely enough for 2 coats on the stern and one coat on the rub rails.  So that added up to three gallons of Hullgard Extra in total.

Two thick coats of Highbuild Primer, somewhat tan-colored

I panicked for a few hours because the Hullgard Extra had not really hardened after 24 hours. You could still put a dent in it with a fingernail. I was convinced I had screwed up the mixture ratio. Hullgard Extra comes in a gallon base plus a quart converter. According to the Hullgard Extra technical data sheet, the mixture was supposed to be 10:1.5.  I just poured the converter into the gallon can and mixed them up with a paint paddle attached to a drill, without a second thought to the proper mixture ratio, assuming that the converter/base kit arrived pre-measured for the proper ratio.

But when the primer had not hardened, I assumed that it was because my quart-to-gallon mixture was of course quite wrong. There are 4 quarts to a gallon, so I thought my mixture was 1-to-4 instead of 1.5-to-10. I started planning on scraping off the entire coating though it just didn't make sense to me that Awlgrip would sell so much more converter than necessary per gallon of base. I re-read the labels on the cans more carefully: while the converter can boldly states to be "One US Quart" it also said (in parenthesis) "1.05PT/.493LT". In other words the "One US Quart" converter was actually about half that amount. Similarly, the "One US Gallon" base was actually "3.785Le" ("Le" meaning liters, apparently). So the mixture ratio was correct after all, straight out of the cans. Awlgrip really needs to do a better job labeling the volumes of its product contents.

Spray-on guide coat

Anyway after 36 hours, the Hullgard Extra was hard enough to be sanded with 150 grit. That took one day per side, and two days for the deck/cockpit due to all the inside corners and details that had to be hand-sanded.

Fairing was next. The topsides came out quite fair; the problem areas were mostly around the area where the rub rails were located. I lightly filled-in those problem area with 3M Premium Filler and sanded it all smooth. I wasn't as concerned about fairing the deck because the anti-skid paint will hide most of that; I paid more attention to fairing the cabin sides and vertical surfaces of the cockpit which will not be covered with anti-skid.  There were a few pinholes and  other areas where I had sanded through the Hullgard that need some attention. Fairing only took a couple of hours in total.

I then applied two coats of Awlgrip Highbuild primer to the topsides and sanded that down with 150 grit. The Highbuild Primer was supposed to be white but it actually came out a little tan. That was actually a good thing because the contrast with the underlying white Hullgard shows the few spots where I had burned through the Highbuild by sanding too much. A two-gallon kit of Highbuild was enough for 3 coats on each side on the topsides.

I am now waiting for the delivery of some more Highbuild to prime the deck/cockpit. I plan on applying three coats for the vertical areas that will remain smooth with no anti-skid applied, and 1 or possibly 2 coats on the rest of the areas.

This whole process of removing the old paint and priming has taken about a month of sanding. Needless to say I am getting sick and tired of it. I am using a 5" Makita random orbital sander on the vertical surfaces because it is much lighter than the 6" Bosch, which I use on horizontal surfaces. I've figured out that the sanding process goes faster if you change the sanding discs quite often instead of trying to force a dull paper to last longer. Inevitably that leads to leaving scuff marks that will need to be faired.

Sanding off stipple marks
Approaching the sanding process in a systematic, section-by-section method also helps, so I broke up the areas to be sanded into approx. 4' square sections and used 2-3 discs per section. Guide coat is useful to show your progress, it helps keep track of the areas that still need to be sanded versus areas that have already been sanded. The goal was first to remove the stipple-marks left from the roller, then to go over the entire area to make it as smooth as possible. Guide coat also shows any major indentations that require more attention but I'm relying on the Highbuild to take care of most of the lighter indentations and smaller pinholes. I used the SEM spray-on variety of guide coat, but later switched to Mirka powder form. It is hard to get an even coating using the spray type because I am not working in an interior space protected from wind which blows away the spray. A little of the powder guide coat goes a long way, but dropping it causes an unholy mess.

Had fun scaring my cats with my dust mask

Once the Highbuild primer is applied to the deck/cockpit, and sanded down, I will apply the 545 finish primer and sand that down with 220 grit to 320 grit, Then, I will start the painting process. Hopefully that will be by next week, weather permitting. I expect the application of the KiwiGrip non-skid to take a couple more days, and so painting should be done by mid-August, at which time I will start on rewiring the mast, installing the stanchions, painting the locker lids and companion way hatch, and installing teak over the coamings. I will also be redoing the standing rigging in August, using Hayn fittings. Winches, cleats and other deck fittings will be installed after the mast is raised, about the time the boat goes into the water, which hopefully will be by the end of November.

Friday, July 12, 2019

Sanding off the old topsides paint and saving the boot stripe

I expected that sanding the old paint off the boat's topsides was going to be a pain. It took more than a week. I used 60-grit 6-inch sandpaper on a Bosch random orbital sander with a soft backing pad, attached to a shop vacuum. The paint was in bad shape; chalky, cracking and flaking off. Along the way I saw some repair patches where the boat had taken some bumps. I guess that the paint had been patched there too. The gel coat under the paint was still in acceptable shape - it was crazed but not cracked or falling apart, so thankfully I didn't need to sand off the gel coat too.

Since the waterline was going to be sanded away, I put some notches on the hull to mark the location of the top and bottom of the boot stripe for future reference, to paint it back with its original shape and location. Laser marks can be used to strike a straight boot stripe but boot stripes are not supposed to be perfectly straight; they're supposed to have some shear (widen, and rise up at the bow and under the counter-stern) to prevent the boat from appearing as if it is "hogging". There is no easy way to do that, except by eye-balling it, so using notches to keep track of the location of the boot stripe and waterline is the best option.

Salvaging the rubrails

My sailboat has wooden (red oak? definitely not teak) rub rails which were in bad shape and which had to be removed for the paint job. It took some effort to take them off in one piece. My goal was to try to salvage them since making new 35-foot rub rails and steam-bending them to shape was going to take a lot of time and effort.

Each rub rail actually consists of two long pieces of wood. The first was bolted onto the hull side, and the second one was glued and screwed onto that piece. (The glue holding the two parts had failed along the way in most places.) The bolt heads holding the rub rail to the hull sides were hidden underneath the second piece of wood, and the nuts were glassed-over on the inside on the hull in inaccessible places. Getting to the bolts without further damaging the rub rails was going to be difficult, but luckily the sealant used between the rub rails and hull was damaged enough that I was able to run a hacksaw blade under the rub rails to cut through the bolts holding them in place. I didn't bother trying to dig out the fasteners; I just ground them back flush with the hull.

I was able to remove the rub rails largely intact though the wood cracked in a few places along the way. I sanded the rub rails to remove the old paint and sealant, scarfed-in some patches to replace the cracked portions, epoxied the two parts together where separated, and then primed them in preparation for painting. I plan on painting them the same color as the rest of the boat.