Thursday, January 6, 2022

Marine diesel engine rebuild, part 1: removing propeller and shaft

WHIMSY came with a Beta Marine 28 diesel engine built in Sept 2000. This is a marinized version of the Kubota BD 1005, meaning among other things that it is cooled by a seawater heat exchanger rather than with a radiator and fan like in a car. They've also added a convenient handpump to make oil changes easier, but mine has been dangling in a wet bilge apparently and has rusted bits that will need replacing. The engine paint is chipped off, there are bits of corrosion and rust, etc.  However, despite cosmetics, diesel engines in general are tough, and will run forever as long as they get regular TLC in the form of clean fuel, regular oil changes and plenty of ventilation. 

Though I discovered the anode zinc pencil on the heat exchanger had been eaten away to a nub, suggesting poor maintenance and additional possible damage to the heat exchanger, the engine ran fine when I had the first test sail back when I first bought the boat. It has been sitting around since then, gathering dust. I can turn the prop shaft in both directions easily so I don't expect it is siezed. I needed to pull it for a rebuild, including head gasket change, and to make improvements (larger capacity alternator, for example, to handle charging a large lithium LiFePO battery bank) 

I wanted to get access to the bilge area and the area under the cockpit too. I plan to generally clean, fill-in the areas of the bilge that are inaccessible by hand (under the prop shaft log in particular) and paint the entire area with white gel coat followed by anti mildew paint on the upper areas (as in the anchor locker, which also tends to be a dark humid environment.) While the engine is out, I plan to reroute bilge drain hoses, install the autopilot, etc. The galley sink drain standing pipe is an open question, I may just glass-in and brace the drain standing pipe more securely, or seal it up and reroute the galley sink drain through a sump pump arrangement overboard above the waterline? I am tending towards the latter for safety though it will be more inconvenient to clean out a sump pump of bits of food and grease.

I also need to repack the prop shaft stuffing box. I had considered a watertight shaft seal but I think this many-hundred year old solution to having a rotating shaft through a hole underwater without leaks, is a pretty good one as it is, even though there will be a constant drip from the stuffing box. Maybe I'll find some way to direct the drip into a the sink sump I was thinking of building...

So anyway, the first thing to do is to remove the propeller, to be able to further disconnect the prop shaft from the engine transmission box. After removing the prop nuts, my prop just popped off easily using a gear puller, no drama no fuss. I just had to push the rudder hard to starboard to get the prop entirely off the prop shaft. The prop shaft zinc anode is new, and I had the cutlass bearing changed already.

Checking the prop, it has some minor nicks but seems fine. I noticed it had a nylon bushing, so it was probably designed for a 1" shaft, while WHIMSY has a 7/8" prop shaft. The bushing may be responsible for the wear on the prop shaft key, so I guess I am buying a new propeller and saving this one as a backup. This is a three bladed 12" diameter bronze prop, so we're talking about $500 new. (Have to figure out the old prop pitch.)

The prop shaft coupling unscrewed easily, though it looks very rusted. It includes an R&D flexible coupler to take-up torsion forces. Ideally I'd like to install a thrust bearing and cv joint (but I don't think there is enough room left over along the drive train that would allow me to also service the stuffing box.) As it is, the forward force of the engine is transfered to the hull via the engine mounts, which is not ideal; a thrust bearing would remove that force off the engine mounts, and the cv joint would resolve alignment issues. (When installing marine diesel engines,  you're supposed to make sure the the prop shaft coupling is aligned to the transmission correctly, checking with feeler gauges, but there is now way to check alignment once the engine is operating. CV joints actually require a little misalignment. )

Once the coupling was unbolted, it was easy to just pull the prop shaft from inside the engine compartment. I had made sure there were no bolts or keys on the other end of the shaft before just sliding it out of the stuffing box. 

The prop shaft seems fine, there is no corrosion, no groves, etc.and no indications that it was rubbing inside the shaft log due to misalignment Prop shafts often are subject to electrolytic corrosion due to stray current, or crevice corrosion esp. in areas along the stuffing box, where the packing deprives the steel of oxygen. The problem is that what may seem like surface discoloration can be evidence of very deep and so invisible corrosion on a prop shaft. Mine thankfully had no issues though I was surprised how short my prop shaft was, about 3 feet. 

Anyway, because I had pulled the prop shaft from inside the boat, there was no need for me to remove the coupling itself off the shaft. This was a relief because with the very rusted set screws on the coupling, I could tell this was a job for a professional machine shop (that will probably end up cutting off the coupling: if you do this, make sure to cut the coupling over the shaft key, to protect the prop shaft itself in case you cut too deeply, then use metal wedges to loosen the coupling off the shaft. If you do manage to get the coupling off easily by just undoing the set screws and using a coupling removal tool (or maybe you have a split shaft coupling, which consists of two parts bolted together over the prop shaft which can be removed much more easily) note it is generally a good idea to not reuse old couplings since they may be warped. Installing a new coupling on a prop shaft should also be done at a professional machine shop to make sure it is mounted square to the shaft. If the coupling itself is warped or misaligned, then the prop shaft and engine will never be aligned right, resulting in excessive transmission and prop shaft wear, maybe even a permanently damaged prop shaft or engine. A new one-piece coupling is about $70.




Saturday, December 18, 2021

Installing the windlass and spurling pipe

 



I went with a Lewmar H2 windlass with a gypsy and capstan combination. There are many pros and cons for vertical or horizontal windlasses as well as as above deck and below deck ones. Horizontal, above-deck windlasses are just easier to deal with as far as I am concerned. It is a pretty substantial piece of gear, both in terms of size and weight. It can pull at least 1000 lbs, so it should be able to handle the weight of my Rocna Vulcan 40 kg anchor and 250 ft. of chain (just about 300lbs including the swivel.) My complaint about the Lewmar H2 is the cost of additional "optional" manual re kit, over, which is actually pretty much necessary so add on another $500 or so to the cost. 



The location of the windlass installation was a bit of a problem because cause Whimsy has a teak anchor roller platform which extends aft from the bow for about 2ft, then there's a few inches of space followed by about another 2 ft. of space taken by the new anchor locker lids. So the windlass is mounted about just about 4 ft from the bow, aft of the anchor locker. This meant I had to split the anchor locker lid into two opening parts, in order to allow it to open with the anchor chain passing above it. I actually prefer this arrangement over having a one-piece lid which would be bulkier. 



The windlass is therefore located on the foredeck about 4 ft from the bow, which puts it over the v-berth in the forecasle area which is particularly prone to leaks (the foredeck a boat is pretty wet when sailing, as waves break over the bow with great force.) Since a soggy v-berth mattress is about the worse thing there is to sleep on, I would have preferred not to install anything over this part of the foredeck at all,  but choice have to be made (locating a heavy piece of gear further aft has advantages in better sailing performance too.) I am just going to have to live with deck penetrations for the bow cleats and windlass over the v-berth and do my best to make sure they're installed well so they won't ever leak!  



So aside from the leak issue, there was the question of how to get the anchor chain to feed into the anchor locker, which is separated from the v-berth with a bulkhead. There used to be a little hatchway in the bulkhead to allow access to the anchor locker from below, but I sealed that up when I cut a new anchor locker opening on the decktop instead. 



My solution was to make a spurling pipe  (not to be confused with a hawse pipe) shaped with a gentle curve that feeds the chain from the windless on deck, down past the v-berth interior space, past the bulkhead and into the anchor locker. 



Designing the spurling pipe and its installation took some doing, as there are many variables. For example Lewmar recommends at least 1 foot of drop from the windlass for the anchor chain to be able to self-feed under its own weight, and yet I also had to make sure the outlet of the spurling pipe was high enough in the anchor locker to prevent the chain from castling. A few dry runs with the old anchor chain showed that it chain slides through the stainless steel pipe, and a gentle curve starting from about 8"that terminates about 1 ft from under the windlass, proivded enough drop for the chain to fall through the pipe easily under its own weight. This location also provides another 2 feet or so of vertical drop inside the anchor locker, which should be adequate to prevent the chain from piling up too much. 



The spurling pipe is made from heavy-gauge 316 stainless steel, with a 2" diameter. It has a has an approx 5" flange plate that I had welded on, that secures it to the bulkhead with 4x 11/2" bolts through the bulkhead. I had a tab welded (badly) on the pipe lip on decktop after installation, thus securing it from both ends. On decktop, the spurling pipe lip is located just under the windlass gypsy so the chain falls into it neatly. In the anchor locker, I placed a roller in front of the pipe opening, so the chain can easily slide in and out of the spurling pipe with minimal wear and noise. (I made a curved part from aluminum, used to make sure the chain doesn't jump out of the roller.) I painted it with anticorrosion paint though technically stainless steel doesn't need it; exposure to air is what keeps it rust-resistant.



Others have used PVC pipe for similar spurling pipe arrangements but it seems to me that steel chain (covered with bottom sand too) will quickly wear through PVC. Also, some have arranged for the spurling pipe to feed into the locker underneath the v-berth rather than into the chain locker, this moving the anchor chain weight farther back. I decided against this because I didn't want to lose the foot space in the v-berth and I have other plans for the storage area under the v-berth. I plan to move the chain even further back into the bilge in preparation for long transits anyway. 

Lewmar requires the H2 windlass to be lined-up just right with the anchor chain, so I had to make a platform or plinth to raise the windlass about 2 inches from the decktop to line it up vertically with the teak anchor platform and the anchor rollers. I decided to make this plinth out of teak, for looks, but I found a 2"-thick cutting board on Amazon.com for less than the price of buying the raw teak. All I had to do was trim it to shape, and seal it up well against the elements. For this, I followed the same procedure as for the teak anchor platform: First, two or three coats of West epoxy with their special clear part B, followed by several coats of Perfection Plus clear gloss varnish (5? enough to create a glass-like surface effect; this is helped by using a heat gun on low setting to blow out bubbles that inevitably form when varnishing.) Though the varnish is supposed to have UV-resistance, this was then covered with 3 coats of sprayed-on Nyalic clear coat, resulting in a tough, UV-resilient and deep clear gloss surface on the windlass plinth (as with the anchor platform.) But before the plinth could be installed, I glassed-in a solid plate of G10 fiberglass, to account for the camber of the decktop. The teak plinth sits on top of this plate. 

The Lewmar H2 windlass requires 4x12mm bolts to secure it in place. They helpfully provide the bolts and nylon lock nuts (along with a pre-cut rubber gasket seal to fit under the apparatus) however the bolts were too short for my installation especially due to the 2" thick teak plinth that the bolts would have to pass though, so I had to order some 12mm threaded rod of 316 stainless steel to cut-up my own custom length bolts.  I had to calculate the length of the bolts to make them long enough to fit into the windlass housing body for about 1", then through the plinth and the decktop, then past the filler & backing plate for the windlass below, followed by enough threads to use a washer and locking nut on them ... or about 6" (including a little extra to account for the butyl sealant.)  

The backing plate was made from 5/16 aluminum diamond plate. I got it for free, it easier to cut than steel, and it seems plenty strong enough to secure the windlass. Normally I would not use aluminum backing plates as steel bolts in combination with aluminum will result in galvanic corrosion, but this installation was in the dry interior of the boat so corrosion is much less of a concern. I used nylon washer spacers just in case though.

Since the steel bolts were inserted into the aluminum body of the windlass, I made sure their ends were well-covered with generous goops of Duralac anti-corrosion compound. 

I also used gob of fiberglass filler when installing the backing plate to flatten out the reverse camber of the interior roof of the forecastle, under the windlass installation area, so the strain from the windlass is distributed as evenly as possible under the deck.


 

 

Wednesday, September 8, 2021


 

Building new stairs

A ladder is useful short-term, but carrying paint buckets, tools and other heavy things up and down a boat 25 times a day using a ladder is an invitation to disaster; all you need is one slip to ruin everything. So I decided to make some stairs put of treated lumber, which could also serve as a tool storage shed and outdoor kitchen space. I was able to knock it out in a day. It isn't perfect but it is safer than a ladder. I overbuilt it of course...the fellas at my previous yard told me later folks were fighting over the stairs I had built but had to abandon there when I moved the boat. Most prebuilt boatyard stairs, if not already being used,  are pretty rusty and dangerous themselves, or they aren't the right size & fit. For bigger boats it is sometimes worth renting commercial scaffolding, which can be built as high as two or three storys. 

For my particular project I just want to make sure there was about 2-foot gap separating the stairs from the boat to allow me room to freely work on the hull on that side. I built the top platform as kinda a Frank Lloyd Wright-ish cantilevered bit that provided cover for my outdoor boatyard kitchen located behind the stairs and also served as a ramp to step over the gap between the stairs and the boat safely. Other design features were solid, secure handrails and good lighting in the form of a solar-charged yard light. All this may seem like overkill but staging a project site is actually important, for efficiency as well as safety.











Wednesday, December 11, 2019

Investigating the rudder shoe

When I started the bottom job project, I had a chance to check the rudder fittings. I noticed a crack in the fiberglass over where the rudder shoe was located at the aft-end of the keel. I was concerned that the crack may be a sign of corrosion in the bronze rudder shoe itself.  Bronze doesn't rust but it does suffer from electrolytic corrosion. The boat rudder rests and rotates on top of this shoe, which is bolted onto the keel. If the rudder shoe fails, the rudder may fall down to Davey Jones' locker.  That would be bad. 

A crack in the fiberglass over the rudder shoe.


Sanding away at the fiberglass layer over the rudder shoe, I discovered that the rudder shoe is fine, with no external signs of corrosion. (Can't find the photo! But trust me.) Because the rudder shoe is made of bronze (note the green oxidation stains) which suffers far less from crevice or pit corrosion in oxygen-deprived environments, there's no need to remove it entirely to additionally check the inside of the shoe for corrosion (unlike chainplates made of stainless steel which do suffer from crevice/pit corrosion and so should be removed entirely when checked.)  The crack was just a thin layer of fiberglass matting that had delaminated off of the bronze rudder shoe. Bronze is far superior to stainless steel for underwater use but like any metal it is subject to electrolytic corrosion aka stray current corrosion. Also, fiberglass-to-metal bonds never last, and inevitably will delaminate. Potentially this exposes the bronze underwater fitting to stray current corrosion once the bronze touches seawater. But this was not a big problem to fix since there was no corrosion. All I had to do was scuff up the shoe surface so it had some "tooth"and then encapsulate the bronze shoe under new layer of fiberglass to isolate it from the external sea water & so avoid electrolytic corrosion. 

The rudder post seemed fine but
we'll see more once I drop the rudder entirely

Investigating further, the rudder post seemed fine, the rudder itself seems fine and is made of solid fiberglass (as with the centerboard) with no signs of water intrusion or delamination. I had repacked the rudder stuffing box but since I've decided to drop the rudder entirely, I will be loosening that up again too.

Here's the funny thing. While stripping the bottom plain off of the rudder, it became apparent that someone had put epoxy barrier coat (gray) over the bottom paint (red). Bottom paint which is not meant to be permanent, is hardly a good base for epoxy barrier coat paint, which is meant to be permanent. I'm guessing someone was doing a rush job, ad instead of sanding off the red bottom paint, decided they could hide it all under a layer of gray barrier paint anyway, so who would know? Not the owner.  Luckily the epoxy barrier coat did stick, mostly.  I'll have to it all off of course, but this, to me, is yet more proof that in the marine services industry, you really have to do it yourself and can't rely on yard workers to care as much about your boat as you.  


Stripping Bottom Paint

One of the benefits of the new yard location for Whimsy is that we're allowed to do our own bottom-jobs. (Due to environmental concerns, most yard won't allow this.) Needless to say the red anti-fouling bottom paint on my boat had long expired and needed to come off. I also wanted to check everything under the waterline, to make sure there were no hidden surprises under the anti-fouling, and to take care of a couple of projects including checking the rudder shoe.




Options for removing old antifouling bottom paint layers are: sanding, stripping with chemical stripper, or blasting (usually with something relatively soft like walnut shells, to avoid damaging the fiberglass gelcoat beneath the antifouling). Since blasting was not allowed in the yard and I wasn't a sucker for punishment of sanding, I decided to try the paint stripper option. Let me emphasis just how horrible sanding a boat bottom is: the paint is a biocide so you have to wear protective clothing and masks, in 90+ hot muggy weather, as you exhaust yourself  waving a heavy grinder upside-down, pressing it up against the bottom of the boat, as sweat mixed toxic dust rolls down into your eyes and you can't breathe easily through the mask. This is one of the worst boat-repair chores there is.

I bought pail of Peel Away paint stripper from the local hardware store (about $50/pail), and tried a test patch on my hull. This material is basically drain opener chemicals but in cream form, which you smooth over the hull with a 1'4" notch trowel. Cover it with the paper/plastic sheets provided, tape the sides of the paper down to make sure the stuff stays moist for as long as possible, and wait overnight.

 The chemical stripper worked amazingly well when washed-off with a power washer.  It came off easily, leaving only small stubborn spots of red bottom paint that sanded-off easily.   

The area around my boat was an environmental atrocity, flooded with several inches of orange-colored slurry. (The main ingredient of bottom paint is copper, which is a biocide.) And once it all dried, the antifouling turned into dust and settled on everything including my car and my coffee cup. Yet this is normal in the yard, and worse has been happening here for several decades since the Navy owned the place. I suspect this is where I will catch cancer!


WARNING: Peel Away is highly corrosive so I suggest taking all the necessary precautions (especially eye protection and gloves.) A little bit of it was accidentally smeared on the inside of my wrist, under the glove, and now have a scab there. I'd hate to think what could happen if even the dust from the dried-up material got into anyone's eyes - so I suggest not only eye protection but also keeping a water hose nearby and handy as an emergency eyewash station.
 

The stuff I used was the regular hardware store version of Peel Away that comes with a plastic spreader, some pH testing strips, and the plastic/paper sheets used to cover the area being treated, and a packet of neutralizing powder (which I suspect is a mild citric acid. Vinegar also works.) Peel Away makes a "safe" version for use on boats that won't damage underlying gelcoat, which I also tried. (Since my boat had an epoxy barrier coat under the antifouling, I wasn't worried about gelcoat damage using the regular stuff.)  The "safe" marine version is slightly runnier, so you need a better trowling technique especially on the upside-down surfaces of the keel, to avoid plopping the stuff all on the ground. They were both equally effective.


I had to buy 6 pails of Peel Away to complete the project but in the end I got a nice clean hull with no sanding. Of course, then I had to sand it all with 80 grit in preparation for the new coat of barrier paint. While sanding, I occasionally accidentally went through the old barrier coat and got to see the gelcoat underneath, which while crazed was still in decent condition. There's no sign of pox or blisters; boats as old as Whimsy generally didn't have problems with blisters. I figure, if there was going to be osmotic blistering, she would have shown it by now. However a couple of extra coats of epoxy barrier coating won't hurt either

Also, while the antifouling is gone, I want to check out the rudder shoe and investigate a worrying crack in the fiberglass around there.








Moving to new boatyard





The boatyard where I started working on Whimsy has decided to gentrify, cater to big fancy catamarans and open a seafood restaurant. Needless to say DIY-type liveaboard types were no longer welcome and we were given a deadline of Nov 30 to leave the yard. Which is too bad because it was a great location, very centrally-located to all the stores I regularly visited plus relatively close to my storage lockers where I keep my tools and supplies.

St John's River

Unfortunately the new yard is not nearly so well-situated, though only 30 minutes West of my previous location. The nearest store is a 20 minute drive; the nearest hardware store is an ACE branch that is not really adequately stocked compared to the large Lowes and Home Depot I used to visit, and getting to my storage unit is a pretty long drive. Not to mention the new yard is almost twice as expensive and the boats are jammed together quite tighly (that may resolve as more of the snow-bird Canadians splash their boats soon.)



On the more positive side, the new boatyard is obviously more oriented towards the DIY crowd. There are grizzled old snaggle-toothed guys here who look like they've been working on boats their entire lives. Actually some of the boats here look like they're pretty permanently on-the-hard too. Yet there are plently of cruisers -- lots of Canadians -- who are working diligently on their boats from early in the AM when the rooster crows (yes, there are chickens and ducks running around too) 'til dusk and sometimes into the night, sanding and polishing and painting things. It reminds me of the mothership scene in Water World, the post-apolocalyptic movie with Kevin Costner. 

But I see all this as just further encouragement to get going and finish up my project.

More importantly, this yard allows people to do their own bottom-jobs (though no blasting) so that allows me to save a lot of money rather than having a yard do it. The estimates I was hearing were well over $2500. The cost of the move to the new yard was $1400 but apparently most of that is in the loading/unloading of the boat, the mileage itself is quite reasonable. That means that I could have kept going south to a boatyard that was a in a warmer clime  - and I may still do so, since I can't paint the boat with the average temps around here for Jan and Feb. On the other hand, there are enough other  projects to keep me busy until the weather warms up.