Hatch is welded

What was a big hole in the cabin roof, is now officially a removable hatch.

Now I have to make a decision on how to finish it.

The combing came out nicely, there is a 1-1/2" flat portion on the top perimeter that will accept a gasket seal.

Then the lid, or hatch portion itself fits on top with an overhanging lip. No way for water to get in. The expedient way to finish this part would be to just bolt it down and end up with a semi-permanent, yet removable opening.

Or I can proceed with cutting yet another hole in order to fit a piece of 1/2" lexan into the lid, install hinges, catches and have a see through opening hatch.

Haven't decided yet, for now I'll just be looking at the inside of the shiny new aluminum panel while focusing on some more pressing items.

Now that the major structural welding items are completed, I'll be bringing some of the creature comfort systems on line.

Installed the hot water tank a couple of days ago, right now it's just working on shore side AC power, but I gotta tell ya, even though I only have hot and cold running water at the galley sink, it feels like bloody luxury.

On Monday, I tackled the refrigeration system. Up until now, I basically knew what most people know about the fridge. You open the door and it's cold inside. Well on a boat, nothing could be that simple. Firstly, it looks nothing like what you think of as a fridge. Ours is built into an L-shaped galley counter, has a freezer on one side and a fridge on the other. Access is through top opening doors.

Nice color eh? Not!

Haven't worked out the cubic footage yet, but it's substantial for the average boat.

It has a rather large compressor, you know, the part that hums away nicely, letting you know that all is well in your world, and the beer is staying cold. This compressor is located in the engine room beneath the main salon. Now I understand why. Not only is it a pretty good size, but it needs to pump seawater through it's system as part of it's cooling operation. Have learned that systems of this type, only on a much larger scale, are used on the commercial fishing boats.

In order to fire up the compressor to see if it worked, I had to fool it into thinking that the boat is in the water. So I filled a 55 gal drum of water outside, and ran the seawater pump hoses into it, to act as a cooling heat sink. Then I started it up, ran it for about and hour while checking the freezer. No cold? Now it was time to learn about refrigeration. Cracked open Nigel Calder's boat maintenance bible and read and reread the chapters on refer systems. This opened up an interesting can of worms. All about CFCs - ozone depleting banned R12 refrigerants and so on. After going through the text and doing a couple of tests, I determined that the system required re-charging, much like an AC system on a car does. I thought, no worries, I'll get the stuff I need, like a set of gauges, refrigerant, and do it myself. Not so easy. Seems it's illegal for the average Joe to go out and buy himself refrigerant gas. You need to be licenced. It's all about the EPA.

After making a few calls, I finally located a guy that would come aboard a boat with a bottle of gas and pressure it up. After much grunting, groaning, crack of butt showing, he declared the system topped up and we could test it. Viola, cold freezer almost immediately. Big relief, compressor is a heavy duty commercial unit and seems to be in good order. I can put away the cooler, stop lugging home blocks of ice and enjoy some cold beer. Cheers!

More on the Bow Thruster

Getting the bow tube mated to the hull worked out well. Today it was time to attach the machinery to it. This sucker is heavy, at about 85 lbs, it's a blend of precision engineering and brute force, will completely drain six average car batteries in 3 minutes flat. It's my pride and joy and I can't wait to throw the switch.

The idea is, to place the prop (nice red job) precisely on the center line of the boat, and centered in the tube. The spec in the manual says, minimum of 1.5mm clearance between the walls of pipe and the prop. Given that this spins at 4250 rpm, it's really just a big food processor and will eat up the walls of the tube in no time if not aligned perfectly. So it's back to making holes, 4 of them, 3 x 9mm & 1 x 30mm, in just the right spot. Again it's measure, measure, measure and viola, I got it right.

Tube then needed to be aligned precisely in the hull because the motor housing and motor itself reside inside the boat where it is dry. It also needs to fit within a specific space which requires a tilt to it's angle. So it was more fitting and unfitting, marking , checking before I was confident enough to mark for the final cuts.

I've also cut out 1-1/2" wide flat trim pieces that will be welded to the exterior of the opening to act as double plates making the hull twice as thick around the tube weld. This will allow a smooth fairing job and a nice radius on the transition.

Must think up something to do with these cut offs, they look kinda modern artish don't you think? At one point while I was fussing with the fit, I had the prop set on it's shaft without the key so as to be able to turn it by hand. A gust of wind blew through the tunnel resulting in a nice pinwheel effect convincing me of how well this was going to work. If you're on dialup you may not want to play the video. Welding is finally all done, took four spools of mig wire to finish it but it's strong as hell. I'll be adding a ton of epoxy fairing compound around the aperture to finish it up and smooth out the transition. Very happy with the result, this is going to be bulletproof. Here's an interesting addition, anyone seen one before? I hadn't. This hook I added to the bow is about a foot below the water line. It's about 8" long, sticks out about 5" and is sharpened to a knife edge on the top curve. I learned of the device from an Alaskan fisherman I met down here. He has one on his boat and swears by it. Seems there are all kinds of nets, fishline, ropes and crap of all sorts floating out there in the ocean, this will cut whatever gets trapped in it before it gets wrapped around the prop. I like it! I like it a lot!!

1/10,000 of an inch

Once the engine was positioned roughly where it needed to be and I had determined how much of the original rails needed to be cut out, I moved the engine and went at it with the saw.

I ended up with what seemed like an alarming pile of scrap aluminum.

Next step was to build new engine bed rails out of 3/4" x 4" aluminum flat bar about 5" lower than the originals. We were careful to replace any structural integrity lost in the cut out with additional reinforcements, and then some.

Once these main structural components were in place, the engine was moved back and measured for the actual pads that the mounting bushings would attach to.

These pads were then fabricated using TIG welding process for increased strength, dry fitted to make sure they were right and welded in place.

At this point, the rubber bushing mounts could be fitted to the engine and the assembly loosely positioned.

Final alignment could now proceed.

How does one determine this? Most of you aren't asking, and eyes are surely glazing over, but I'm going to answer anyway. The end of the transmission and the prop shaft have matching couplings that have finely machined surfaces. The two plates are about 6" in diameter and are ultimately bolted together to form a solid bond between the engine, prop shaft and ultimately propeller. In order to determine alignment, the engine is eased toward the prop shaft until the two surfaces are almost but not quite touching. Now the gap is measured on all four axises. Using built in adjustments on the four engine bushings, the engine is then moved up, down, or sideways until one has an even measurement on entire circumference of coupling surfaces.

Just how anal one wants to get at this point, determines how long a process this will be.

Took me all afternoon, resulting in an alignment that is within 1/10,000 of an inch.

How thick is that? About the thickness of a human hair. How important is it? Very.

Misalignment translates into vibration which not only creates noise that is transmitted throughout the entire vessel, but results in accelerated wear and premature failure in drive line components. John Deere designs it's engines with an internal counterbalance to keep vibration to a minimum, this feature combined with the care taken in the installation translates into a quieter running power plant which in turn will be appreciated every time we start the engine.