No Turning Back Now!

Time to switch away from structural items and move onto arguably the biggest job for this project: the electrical system.  From my testing when I bought the boat, most of it is intact and mostly functional, but there's no doubt that it's a rats nest of madness that I can't rely on fully because I don't understand it.  The Alberg 35 had an even older and sketchier electrical system but it was an entirely different animal.  It literally had only 3 circuits; the engine, running lights, and cabin lights.  Each circuit consisted of old, brittle wires that were always in danger of giving up the ghost, but it was dead simple and I could understand it just by taking a look behind the distribution panel.  

Velorum is a much more complex beast and even though the electrical system seems mostly functional, the amount of wiring in this almost 40 year old boat is daunting.  To tackle the problem, I started by tracing every single wire as best I could.  I set my multimeter on the continuity buzzer setting and connected a 30 foot wire to each breaker and walked around the boat to see what went where.  Digging around in the recesses of the boat quickly led me to the conclusion that there was quite a bit of dodgy wiring throughout.  Probably quick and dirty additions that previous owners had done over the years that may have made sense to them, but didn't hold up in the long run.  

After a few hours of testing, re-testing, and scratching my head, I realized that I needed to re-wire the entire boat with one exception: the cabin lights.  Clearly these had been done at the factory before the deck and headliner were glued together because most of the wiring runs between the two and replacing it would be a terrible (maybe impossible job).  Fortunately, all of the cabin lights work and are divided into port and starboard circuits, so that's something I can live with. 

For the rest of the wiring, it was time to start ripping it out, but before I did, I made a map of all the circuits currently in the boat and how I would run new wire to replace it.   I found a free electrical wiring diagramming tool and layed out the wiring paths to each 'appliance'.  It should serve as a good reference for troubleshooting down the line.

Once completed, I took a deep breath and started dismantling the system.  Some of the factory wiring was pretty decent and I could have probably saved it, but since I already purchased several hundred feet of marine grade tinned duplex wiring in 10, 14, and 16 awg, it was time to go.  I pulled the old distribution panel (will be replacing with a Blue Sea 20 position panel #8379) and started yanking wire.  There were at least 5 dead circuits that clearly hadn't been used in years and when I found them, I realized I had made a good choice by replacing everything. By the end of the first session, I had the cockpit pretty well filled up with old wire.  It took me a few sessions to track down and remove everything, but it felt good to have it done.

The navigation instruments introduced a bit more anxiety, but because I'm replacing those with new equipment (except maybe the windvane), I feel good about this choice as well.  The mass of wiring from just the Raymarine chartplotter and old tiny NMEA 0183 wires connected to everything was so confusing. I'll be much happier with the Garmin system replacement (7607xsv chartplotter).  

Now that I had a clean slate (except for cabin lighting), it was time to re-design the way the wires are distributed.  Unlike systems of old, where the wiring goes directly to the distribution panel, I opted for the more modern approach where the wires from each appliance terminate on a series of terminal blocks (positive side) and a bus bar (negative side) located behind the main distribution panel. Installing these allows for much easier troubleshooting, and the individual breakers on distribution panel connect to each terminal block. If some wiring (nav lights, instrumentation) needs to share a breaker, a jumper can be added to the terminal block so the breaker can be shared.  

I also added an unswitched fused circuit block to control appliances like bilge pumps that are essentially connected directly to the battery so they can't be turned off.  I went through several layout iterations, but finally ended up using an epoxy coated piece of plywood glued to the hull and painted white. On it I mounted all the necessary components needed, and will be the foundation of the new electrical system.  Next up, I'll start running new wire from this panel to all the appliances.

Low Capacity Bilge Pump and Shower Sump

 It has been ridiculously hot for Central NH this year and as a result, working on the boat in the afternoon (when I'd prefer) is just not an option.  After 10AM, the temperature in the boat is absolutely stifling and I just can't work with sweat pouring off me.  So I've switched up my schedule a bit and I'm doing work from 5:30 - 7:30AM most mornings.  It's not a lot of time, but every minute helps to chip away at my list.

After a seemingly endless series of internal arguments with myself about where to locate the low capacity bilge pump and the shower sump pump, I decided it was time to make a decision and settled on a location.  As with everything in a boat the reasons for my waffling had to do with trade offs such as 

• Easy access
• Shortest hose run
• Discharge location

For these particular installations, I'm using Whale IC pumps (IC stands for Intelligent Control) for both the low capacity bilge pump and the shower sump.  The pumps and sensors are identical, but the attachments are different.  They consist of a pump unit that can be located in a dry area out of the bilge connected with a long wire to a solid state sensor unit that detects when water is present. If found, it turns the pump on and it pulls water up and discharges via a diaphragm pump.  I think they are pretty nice pieces of technology and hope they are reliable, but time will tell. 

Anyway, I ended up choosing a compartment under the v-berth forward to house both pumps.  The arrangement should work well because it is located on the centerline and minimizes the need for a big loop before discharging to prevent backflow when on a heel (I will probably install one anyway just to be safe though).  It also is close to where both sensors (and corresponding hoses) will be located.  I plan on a side discharge just above the static waterline in the head compartment.  

Of course, nothing is easy on a boat (especially if you are 6'5") and even though the Niagara is comparatively spacious compared to the Alberg, I still found myself in some stupidly awkward positions.  The pumps themselves were easy to mount and access, but feeding the hose and wire to the sensor required some gymnastics.  Directly below the compartment where they are mounted is a space about 12" high that allowed me to run the wires and hoses to their respective locations. 

To access that area, I drilled 2 - 1" holes in the bottom of the compartment where the pumps were mounted.  from there I was able to snake the hose underneath the stringers to the sensor/pickup locations.  For the discharge, the hoses runs vertically up to the top of the compartment and then through a bulkhead (1" holes for each) and into the adjacent compartment where the sewage tank is located.  In that compartment the 2 hoses 'Y' together into a single discharge that runs to the head compartment where it will discharge overboard.

I considered teeing into the existing sink drain, but I read enough accounts where people who had done this would frequently have bilge or shower drain waste 'burping' up into the sink. I really don't want that so I came to terms with another hole in the boat.  I've already closed up a few holes, so I guess I'm still ahead of the game. 

For the wiring I used a terminal block for each pump (as I did with the other bilge pump). This will facilitate easy removal and troubleshooting if there are problems.  I'll save the wiring from the terminal blocks to the distribution panel for another post (or several, because there's a lot to unpack), but spoiler alert, all the wiring back to the panel is new and the photos below show the fully wired installation. Once the new distribution panel and wiring is completed, I'll be able to test these installations and hope they work.

One note on the shower sump installation: the pickup manifold is mounted and the hose and wiring is installed, but I'm still working on the connection to the shower drain.  Because the original drain was located between the 2 - 3" frames that support the mast, running the hose underneath the frames could potentially cause an airlock situation where air trapped in the hose running to the manifold could prevent the pump from turning on. To eliminate that possibility, I'm relocating the shower drain so that it flows over one of the beams to the manifold.  That work is currently in progress and will probably do a quick post on that once it is complete.  

Also note that the manifold is capable of handling multiple discharge sources and I plan to eventually run a drain from the anchor locker to one of the manifold ports, but for now I'm going to just use a single port and cap off the unused port.

The pumps fully installed in the compartment underneath the v-berth

Let the Installations Begin

I'm juggling about 10 different projects on the boat right now and all are in various stages of completion, so I thought I'd post each one as I finish them (or almost finish them) even though there are a lot more things going on in the boat at the same time.  The one that will take the longest and tie them all together is the DC electrical system, but I found that once I got that underway, I needed to know what's going to be installed and where they are going, so I'm going to wait to discuss the electrical until I'm farther along.  

Aside from the electrical, there are 4 main systems going in; the high capacity bilge pump and float switch, the low capacity bilge pump, the shower and anchor locker drain sump pump, and the pressure water system.  Since the boat is a clean slate with no systems in it, I spent a lot of time deciding where these systems should go.  I've been through several iterations based on a number of factors such as:

• Ease of serviceability and access
• Efficiency of plumbing runs
• Eliminate conflicts with other systems (ie. do hoses from the bilge pump conflict with water system)

I ran into a number of system conflicts along the way (mainly hose locations) that required me to relocate the planned installation of several systems. I think I've finally got it and started moving forward with all of them, but I mostly finished up the high capacity bilge pump and float switch today.  

The pump is a Rule 3700 Gold with a Rule 40A caged float switch.  Because this is a high capacity pump, it's intended to be used only when the water level in the bilge can't be removed with the low capacity pump, so the float switch is located about 6 inches above the bottom of the bilge (just below the bottom of the fuel tank.  If the water level reaches that point, this pump will kick on and hopefully drain the bilge.  

Once I had settled on the location of the pump and float switch, I decided to 3d print a platform to locate the float switch on.  I designed the platform to 'notch' into one of the keel boat riser plates. A few iterations later, I had the finished product and got it installed along with the float switch.  For the pump itself I epoxy coated and painted a small block of 1/4" mahogany and mounted the pump frame on it and then glued it to the bottom of the bilge with 3M 5200 and left it for the day to dry.  

After the adhesive had cured, I installed the pump and wired both the float switch and pump to a terminal block where the electric service will connect.  In the past I've generally half-assed most electrical work, but I'm spending the time on this boat to do things right. All the electric appliances will be wired to terminal blocks and the electric service will connect to the block.  Doing this eliminates dodgy butt connections or wire nut splices and makes troubleshooting much easier because voltage can be easily measured at the terminal block.

So even though this was a fairly easy project, finding the right location took quite a bit of time and taking other systems into consideration made the project a bit more complex.  All that's left is to run the hose to the transom for discharge and get the 10 gauge wires to the pump, but for those I'll wait until the electrical system is done and I can do some testing.

Shiny Blocks and Boat Holes

I was happy to receive a package from Xometry (online CNC machine shop) and find the new tie rod blocks I designed exactly as specified and after a test fit I was relieved that everything fit well.  They will be replacing the old ones that are in varying states from good to terrible and the 7075 aluminum coupled with hard anodization should provide many years of service. 

As you can see in the photo to the left, the old ones (the 2 in the center) are in less than perfect condition and one of them is literally crumbling apart. It was definitely time to replace them.  I'm really pleased with how they turned out and I was even more impressed with how easy it is to turn a design into a finished product.  All you need to do is load a CAD drawing to the Xometry site, pick materials, finishes, spec tolerances (there are a number of levels going from prototype to mil spec).  You can also choose production location (some companies require U.S. made products).  Although none of this is cheap (I paid $460 for 6 blocks), it was likely less than what I would have paid locally, and the only supplier that I know of (rigrite.com) has photos of the blocks but no price listed and based on the cost of other discontinued items they have for sale, it would have cost a fortune.  

Anyway, while that was happening I was busy building the G10 chainplate 'islands'.  Originally, I was going to have these sent to Xometry as well, but I have enough tooling on hand to machine G10 plates myself. The design was simple (see last post) and using a series of jigs that I 3d printed, I was able to cut out perfect oval shapes and round over the corners for the tops and then glue the top and bottom (the part that inserts into the deck) together to make the final assembly.  For the bottom inserts, I used .5" G10 that I had leftover from my Alberg project (G10 is expensive), so I saved some money there.  All told, I spent $28 for .25" G10 plate for the top section and $40 for a new .5" flush cut router bit. Everything else I had on hand.  Once everything was cut out, I epoxied the top and bottom halves together and tapped the holes for the deck mounted chainplate.

Once that was completed, it was time for the scary part: cutting holes in the deck so the assemblies would fit, leaving the top flange resting on the surface.  Again, I employed a series of 3d printed jigs to locate and mark the cutout area and then used a hole saw and oscillating cutter to remove the top skin and inner core without removing the bottom skin on the underside of the deck.  This was really the only tricky part because it was hard to tell exactly how far to drill without damaging the bottom skin. I opted for a conservative approach and left the cut about 0125" proud of the bottom skin and used a chisel to get the remaining core out.  The good news was that despite clear water intrusion into the boat, the core was not wet (or rotten), just compressed.  After I chiseled out the bottom part of the core and cleaned everything up, I fit the assemblies and was delighted to find that the bolt holes lined up nicely and the top flange covered up the hole.  

The last thing to do was to epoxy it all in. I cut out 2 layers of biaxial fabric to epoxy to the bottom skin, wet them out and laid them in before starting on the assemblies.  For the assemblies, I decided to use Thixo, the ready to go epoxy from TotalBoat that uses a standard caulking gun with a mixing tube to glue everything up. It is much more expensive than raw epoxy, but it keeps mess to a minimum and has a long working life.  With that said, I spent alot of time taping the holes from the underside of the deck and then taping a large area around each hole so I didn't get epoxy all over the deck.  Once ready, I cleaned up all the mating surfaces with acetone and then splooged a bunch of epoxy into the holes and onto each assembly (I did these one at a time).  Then I simply mashed the assembly into the hole until epoxy squeezed out the edges of the flange.  Finally, I cleaned up the squeeze out with a tongue depressor and weighted each assembly down and left for the day.  Once everything had kicked the next morning I pulled the tape and and test fit the chainplate on each 'island'.  I still have to paint them and of course get all the chainplate/tie rod assemblies bolted back in, but I'm really happy the way this project turned out.  I think it's a solid design that will prevent core compression and the raised chainplates will discourage water from entering.

I Didn't See That Coming

Now that the engine is happily rebuilt and running, I've started planning for what I need to do to get it back in the boat.  This is a huge task that brings the phrase "How do you eat an elephant" to mind.  The answer is of course: "One bite at a time", so the first bite in the process is to get the tarps and part of the frame off to make overhead room for hoisting the engine back in.  

Unfortunately, the deck isn't wateright at this point and that needs to be done before the tarps come off, so I guess the real first bite is: Getting the deck watertight.  The hatches and most of the deck equipment are well sealed and I have re-plumbed the scuppers, but the chainplates are out of the boat and all 7 chainplate assemblies and underdeck tie rods have to be reinstalled.  On paper, it seems like a simple job, but reality always gets in the way.

I pulled the chainplate assemblies out of storage and took them apart to see if anything needed replacing. I should note that these are not your standard stainless or bronze bar chainplates that fit through a slot in the deck and bolt to a bulkhead. These are NavTec chainplates which consist of a deck plate with 2 bolts that go through the deck and connect to an aluminum block which connects to a tie rod which connects to a bulkhead mounted chainplate.  

In theory, they are a nice solution because you don't necessarily need a bulkhead located directly where the chainplate goes through the deck.  They also only have 2 bolt holes that go through the deck and are easier to seal than a slotted bar with a rectangular hole in the deck.  However, what I found when I took apart the chainplate assemblies was less than ideal.

Most of the NavTec chainplate system is made up of nitronic 50 which is essentially a super corrosion resistant stainless steel (better than 316) and a yield strength nearly twice that of 316 stainless.  All of these parts look brand new and will be re-installed as is, but there is an aluminum backing block that ties the above-deck chainplate to the tie rod and on 4 of the 6 blocks, I found serious corrosion that would need to be addressed in several ways.

First, the backing blocks would need to be replaced, but I wasn't able to find a source for replacement so I decided to digitize the blocks and have new ones machined.  I haven't used CAD in years so I was pretty rusty but my son has a Autodesk Inventor license and he helped me get up to speed on the software and once I got the hang of it, I was able to get it done without issue.  To make sure my design was within tolerances of the originals, I 3d printed one of the blocks in PLA to make sure everything fit and once I was satisfied (I did a few iterations), I sent the designs off to a machine shop to CNC them out of 7075 aluminum with a hard anodized coating.

The second, and more concerning issue was why the blocks corroded in the first place. The only way that could happen was if water was making its way down from the deck to the blocks mounted underneath.  A quick inspection of the deck revealed that the core underneath the chainplates on deck was crushed (probably from overtightening the tie rods that attach to the bulkheads).  I was surprised that an area as crucial as the chainplates would have a plywood core and not solid glass, but I shouldn't be surprised by that sort of thing anymore.  The Niagara is a well built boat and a lot of thought went into isolating through hulls from the core, but I feel that they missed the mark with deck fittings.  Time to get to work.

When I re-cored the decks on my Alberg 35, I epoxied in 9 layers of 1708 biaxial cloth where the chainplates went through the deck so no core could be exposed. While this was effective, it was part of a bigger, messier job so I didn't have to be careful about the surrounding deck surface.  For this job I wanted to do something similar, but without having to re-core the whole deck.  After some discussion on several online forums, I settled on the idea of creating oval inserts with flanges made of G10 plate that would replace the existing deck top skin and core material.  The inserts would be .25" proud of the deck and would create an 'island' around each chainplate that would help keep water out of the holes.  I drew up a schematic of what I wanted it to ultimately look like and then did a few 3d prints to make sure my measurements were correct before I started cutting expensive G10 plate for the actual installation.  Next time I'll go into the gory details of cutting holes in deck and epoxying the 'island' inserts into place.

 

  

A Big Milestone - A Fitting Day for a Westerbeke Resurrection

So after 3 weeks, I finally got my pump back from the injection shop on Friday.  It was all rebuilt, shot blasted and painted. Hopefully it would work, but unfortunately I had a bunch of family Easter stuff going on for most of the weekend so I had to put it on hold until this afternoon.  When I finally freed up, it was go time.

It only took about 10 minutes to re-install the fuel injection pump and timing shim, and getting the governor tie rod and spring back on the pump rack in the little hole in the side of the block was surprisingly easy because I had tied on a piece of fishing line onto them so if I dropped them inside the case I could retrieve them easily.  Because I've done it several times already, the rest of the fuel system was easy, but time consuming (2 hours). 

Once everything was back together and everything checked and re-checked, I rolled the engine over to the shop door, grabbed a pail of water and starting battery and hooked up the ignition panel. My son came over to the shop and we checked to make sure power was going to the glow plugs and fuel pump. It took a bit of time to get the high pressure side of the fuel system primed, but once it was, it fired right up and sounded great.  We ran it through the throttle range with no issues other than adjusting the throttle idle setting (a bit too low).  Also notable was that there was zero smoke and there was good water flow out the exhaust.  

I'm ecstatic that this milestone is complete. My original plan was to get the rebuild done 'over the winter', so technically spring has started and I missed my deadline, but I'm still calling it a win.  Of course there's still a ton to do to get the motor back in the boat and installed, but this was a big one.

Here's a link to the YouTube video if you want to hear it purr: It's Alive!

While I wait

With the injection pump at Diesels Fuel Injection Services for a rebuild (should be completed next week) and the weather still a bit too cold to work on the boat itself, I decided to tackle rebuilding the propeller. With previous boats I've owned, I've only had 2 blade fixed props, but Velorum came with a MaxProp classic which is a 3 blade automatic feathering prop.  I've seen them before on other boats at the yard, but never really paid attention or gave them a second look.  I'm not convinced that a slowish cruising boat needs a feathering prop but I'm sure I will appreciate the additional power a 3 blade will deliver and not be concerned with the drag that a fixed 3 blade would have on performance.

Anyway, the prop was in a box in several pieces and covered in grease and barnacles, so I wanted to clean it up to assess if it needed to be serviced.  I started by degreasing all the parts and doing a rough scrub to get as much old marine growth off as I could.  

After the first round, it really didn't look any better than when I started except there was less grease. 'Less' is the keyword here because even the industrial strength grease remover I was using didn't seem to do much other than spread it around.  Close to a roll of paper towels and more degreaser finally proved effective and I was finally able to handle the parts without my hands turning black.  

Next, I tried a brass wire brush to get the rest of the barnacles off and finally resorted to a wire wheel, but it still looked pretty sad.  After a little online research, I picked up a gallon of vinager and soaked all the parts in a bucket overnight.  That seemed to loosen up the remaining barnacle 'roots' and I was finally down to a mottled brownish bronze finish. 

I felt like I was finally making some progress (albeit slow). My wife suggested I use Bartenders Helper to get it shined up.  Apparently, it's a powdered form of oxalic acid with some sort of abrasive in it.  Once again, I'll admit my wife is brilliant, that stuff works great.  Just shake some on the part and scrub it with a wet sponge and it works wonders. After a few rounds of that stuff, it looked great (at least the pieces did).  

Now it was time to put it all back together and hope all the pieces were there.  I found that PYI Inc is the distributor and service center for MaxProp in addition to the very popular PSS dripless shaft seal (I'll be installing that once the engine is back in the boat).  They have a great site and even though the MaxProp Classic (the model I own) is discontinued, PYI still services them and sells parts.  I contacted the service department and they got back to me with all the info I needed along with a detailed pdf on assembly.  They even took the time to run Velorum (displacement), along with engine size, and transmission gear ratio to give me a recommended pitch setting for the prop.  

Putting it back together was pretty straightforward given how precise everything needs to be in order to have a smooth, balanced, and powerful propeller.  It's really a lovely piece of kit and the engineering is downright elegant. It's simplicity is deceiving, it really has a difficult job in a very unforgiving environment.  Once I got it back together for a test fit (once it goes back on the boat it will be stuffed with grease like a turkey), it looked amazing and operated smoothly.  I was told by support that it should have a tiny amount of play, but more than an 1/8" and I should think about a rebuild.  Fortunately, everything checked out and it's in remarkably good condition.  I don't know the history of this prop, but it should last me for some time as long as I keep the internals greased every year and don't back it over a rock :)

 

Rattle Can Rebuild Part X

I decided that I wouldn't subject people to any more engine rebuild updates until it was finished, but even though I was technically finished last week, it turns out I wasn't.  I won't go through all the gory details of the final pieces of the rebuild, but I will say that I thought it was going better than I expected.  I picked away at it almost every day since the last time I posted, focusing on each system individually.  By far the biggest challenge was figuring out the new wiring harness, sensors and a new low pressure fuel pump that was not a westerbeke product, but with a little advice from Hansen Marine Engineering, I got it all done.

With everything back together and after lots of electrical testing, it was time to fire it up.  I wired up the battery to the starter solenoid, plugged in the new Admiral panel and oil/water alarm harness and got a bucket of water to run through the raw water pump.  I turned the key and hit the preheat button for 10 seconds to fire up the glow plugs and then pressed the start button.  The engine cranked and cranked, but wouldn't catch.  I stopped and re-checked everything and repeated the process.  Still nothing. The engine cranked fine, but wouldn't catch.  

First I tested that the glow plugs were working; they were. Then I moved onto the only other possibility: the fuel system.  I knew that fuel was making it through the low pressure pump and into the secondary filter and to the injection pump.  However, when I cracked the fuel line at one of the injectors, I found no fuel...  It appeared that the injection pump wasn't working properly, but I spent a day or two scouring online forums to definitively prove that the injection pump was the problem.  I found my answer quickly on the Cruisers Forum where one of the users (SkipperPete) gave me the answer I needed. Yes it was more than likely the injection pump.

During the rebuild, I studiously avoided the injection pump because I naively hoped that it would run after 10 years sitting without running and with old fuel in it.  An additional problem with the injection pump is that it is difficult to get at and in order to remove it, you have to disconnect a very fiddly spring and tie rod that attaches the govenor to the rack on the pump.  I honestly thought it was 'above my paygrade' and seriously considered putting the engine on a trailer and taking it to a diesel repair shop.

I'm glad I didn't and the help I got from the Cruisers Forum gave me the courage to tackle the project. I did have to disassemble the entire fuel system surrounding the injection pump to get at it, but at this point I was sure that I could reassemble it again without too much trouble (but I took lots of photos). However, in the end, pulling the injection pump wasn't actually that bad and I probably saved at least $500 just in the disassembly process.  Now I have the pump out of the engine and will take it to a injection pump shop to have it rebuilt. Yes, this will be expensive, but this is something that is not for amatuers and requires specialized high pressure testing equipment and expertise that I just don't have.  

So tomorrow morning, I'll be dropping it off at Diesels Fuel Injection shop to have them rebuild the pump.  I used them to rebuild the injectors (which also require specialized equipment).  Hopefully, my next post will include a video of the engine running.  Below are a few shots of the injection pump:

Rattle Can Rebuild Part 5

Since the end of August until late December, I had been singularly focused on boat projects, but over the holidays, I decided that I needed a bit of a break. I tend to get hyperfocused on projects and everything else falls by the wayside, but I was on schedule for the engine rebuild so it was time to shut the project down for a few weeks.  I'm glad I did, I really needed a break but didn't realize it at the time.

Now that I'm back I was able to tackle one of the bigger projects of the build and hopefully will be about as deep as I go on this motor.  When doing the initial inspection and research on the engine, I noticed a bit of oil staining on the bell housing underneath the flywheel. After a bit of googling on the usual forums, all signs indicated that it was a problem with the rear main seal.  

 

The oily liquid in the photo is mostly from PB Blaster that I was using to free up bolts on the damper plate, but the black oily residue on the bell housing is coming from behind the flywheel.  I know that these old diesels tend to leak a fair amount of oil, but since I had a rear main seal on hand, I decided it was worth tackling the problem.  

In theory, it's a very simple process, but this task was quite the struggle.  First of all, I had to take it off the stand (it bolts onto the bell housing).  I lowered the engine down onto the rolling cradle to secure it before removing the damper plate (this connects the the transmission and dampens shock loads from the transmission to the crankshaft and vice versa).  This part was straight forward, remove 5 allen bolts and it pulled right off. I was really amazed that I didn't strip or break them off because they were very tight.  This is where things got difficult.  With the damper plate off, the bolts that fix the flywheel to the crankshaft were exposed.  They weren't rusty or corroded, but quite dry and Very tight.  Initially I tried the 19mm bolts with a standard 1/2" drive socket wrench and couldn't budge any of them.  Next I tried my cordless impact wrench.  Nothing.  Finally, I slathered multiple coatings of PB Blaster on each bolt and called it a day.

The next day I tried a 2 foot breaker bar and while I did crack one of the bolts, I was starting to strip the heads on several of them... Time to rethink my strategy or I'd be in for a lot of trouble.  I finally dug out my old compressed air impact wrench and fired up my 33 gallon compressor.  At the wrench's 90 psi maximum rating I got the same result as with the electic impact wrench, which is to say: nothing.  I decided to go for broke and turn the psi up to 140.  I figured it would probably blow the seals on the wrench, but incredibly it actually wor ked and I didn't break a single bolt.  All that banging on the bolts also freed up the flywheel from the cranshaft and it came right off the flange.  All my reading up until that point lead me to believe that the flywheel was going to be stuck hard onto the crankshaft and would need a solid beating to get it off.  

With the flywheel off, I had to lift the engine again with the chain hoist and then unbolt the bell housing before lowering it down onto wood blocks (the bell housing is cast with 2 of the 3 engine mount brackets, so when it comes off, the engine has to be supported another way).  Technically, I could have replaced the rear main seal without removing the bell housing, but I wanted to replace the gasket between the engine and bell housing so it had to get pulled. I degreased and cleaned it all up before priming and painting it. Once the paint dried, I put a thin layer of permatex #2, re-gasket'd it and set it aside until the main seal was replaced.  

Replacing the main seal was pretty straight forward. The seal is held on the crankshaft with an aluminum housing and the bolts holding that to the block came off without issue.  With the housing and seal off, I inspected the crankshaft surface and it appeared to have some minor scoring marks on the surface where the seal was.  I installed a shaft sleave (a thin ring of metal, interference fit), but realized that the flywheel wouldn't go back on with it in place so I had to cut it off.  Hopefully the scoring in the crankshaft won't cause the new seal to leak, but I'm not going to pull the whole crankshaft (it would require a full engine teardown, and I'm not going there).  So I just pressed the seal into the housing and then slid it over the crankshaft and bolted the housing back in place (along with a new housing gasket).  

I re-installed the bell housing and with the help of my son, we wrestled the flywheel back in place and bolted it on with the new OEM bolts I ordered. I wasn't going to re-use the original bolts after the beating they took getting them off. Finally, I bolted the damper plate back on and called it a day. Time will tell if the seal still leaks, but it will be better than before.