Thursday, January 22, 2015

Mast installation

Along with no ice on the boat roof, and a break in the weather, I decided to install the mast. Unlike most things boat building, this particular phase of the project actually went fairly smooth and took about as long as I figured. Getting all the parts and gear loaded on the truck took as much time as the actual installation.

I don't know what the  mast weighs, but I'd have to guess around 150 lbs. Getting it up on top of the boat was a simple matter of leaning it against the boat above the swim platform and with me on top, and with my helper lifting from the bottom, we quickly had it on the roof. The layout work for the pins and bushings was spot on, so it was a simple  matter of first installing the upper pins and bushings, heavily tack welding the bushings ( with the pins in place ), standing the mast up, then heavily tack welding the lower bushings in place. Once everything was tacked in place and I verified the pins were not in a bind, it was final welded with a stick machine.

If push comes to shove, a stout person probably could step the mast by himself.  Once the mast is standing, it's just a matter of getting the fore and aft thing just right so the bottom locking pin can be pushed home. I should probably turn a pin with a heavy chamfer on it so it's self aligning and can easily be driven home while one person both holds the mast up and drive's the pin home. For the sake of safety, it's a two person job, but like I said, if push comes to shove, one person probably could handle it.
Having never really been on a boat with a mast before, once we had it welded and standing in place, it seemed ginourmous. I know 20' isn't squat when talking about sailboats and  mast, but standing on my roof while looking up at the mast, it seemed to be way up there. With the mast standing unstayed, and me pushing on it, there was a little flex in the framing. The turnbuckles I used were capable of taking up 6". Pulling the cables as tight as we could by  hand, then swagging the thimbles to the turnbuckle eyes left what appeared to be a decent sag in the cable. Once we had the three stay cables rigged, I was impressed by how little it took to tighten them up. I should  have probably measured, but I don't think we took up more than 1 1/2" before the cables were as tight as I thought they needed to be. I'd like to hear from one who knows about how tight these cables need to be, but to me they feel pretty comfy. The two shroud cables are about five degrees off of 90 degrees to the mast, so the fore stay cable pulls against the shroud cables. Shrouds are athwart-ship while stays are fore and aft. With the cables tensioned, the mast now felt rock solid.

Having spent the last three weeks fabricating in the shop and dry fitting everything together, getting the boom in place and rigging the electric winches took practically no time at all. Using a spare battery from the shop to temporarily electrify the winches, we were finally making things go up and down. We played around for a short time and hoisted the 200 lbs generator to the roof and back down. The winches are remote controlled, and have different frequencies, so that's going to make things easier.

Because of the winch location the boom cannot be raised plumb to the mast. The  boom goes to within maybe 5 degrees of being plumb to the mast, and that's plenty high enough. When the boom is about as high as it can go, when moving it to starboard, it will hit the boom winch. This is really not a big deal as the boom will probably never be this high while lifting a load, but it's something to be aware of.

To  wrap up this project, I need to build a dedicated battery box and decide how I'm going to charge the battery. All the solenoids, and fuses for the winches will go in the battery box. I'll probably build the box big enough to hold some tools slings for lifting.  I'm leaning towards a dedicated winch battery vs pulling heavy wires from the main distribution panel.

A wire chase is already framed from the wheel house to the mast step, so getting wires to that point will be easy. I have a 6x6 splice box already on the mast step, and this will be my transition from interior to exterior. I'll make water tight connections in the splice box and bring cord out of the splice box using cord grips. I don't think I'll be able to do this with the radar cord, so a custom split cord grip will have to be used.

The heavy work is finished on this project and I'm pretty  happy with how it's turned out. I'm going to finalize fabricating the wiring harness's for the winches and getting a battery box built so I can use the hoist for the hand rail build. most of the hand rail will be fabricated and welded in the shop so I'll use the boom to hoist the three sections along with holding them in place while I weld the rail to the roof. It will also be nice being able to hoist the welder to the roof. Heck I might even bring the big MIG welder down to do this job now that I can get it along with the large tank up top.

I'm liking this project.



Saturday, January 17, 2015

More mast

All my fabrication on the mast is complete and it is ready to haul to the boat yard. That being said, this simple dinghy lifting mast turned out to be quite a bit more work than I  had figured, and I for those who know what I'm going to say next means, I used a large bottle of Argon for the welding. I would have never guessed a large Argon bottle would have been consumed, but it was.

Of course, having never done this type of project before didn't help with me getting finished in a reasonable amount of time, nor did my lack of putting a pencil to paper for some design work help much either. The mast step is already welded to the boat, and is comprised of two heavily gusseted pieces of 1/2" stainless plate welded into the heavily reinforced roof framing. The two plates have bores through them that the mast will pin in to allowing it to be easily laid down. The upper pin in the mast will bear the load, and the lower pin will be for locking it in place. In order for the mast to be able to pivot, I laid it out so that there is 1.5" of free space between the bottom of the mast and the step base. Once the mast is stepped and stayed, solid blocking will be wedged between the bottom of the mast and the step base. Because the bushings are going to be TIG welded in to the mast, I had to do a bit of compensating to allow for weld distortion. I decided to bore the bushings .006 over the pin diameter, and as luck would have it, that turned out to be the right amount. The fit is good with no tight spots and every so slight end play. When the pin engages both bushings, there is no side to side play. The lower pin used for locking the mast in place has no bushings welded in place.

The blocking should be 1.5" if I measured once and cut twice correctly.... or is it measure twice and cut once? Because the upper pin is going to bear the load, I decided to weld in heavy bushings to spread carry the load in the masts along with a more tolerant fit. Each bushing is two inches long, with 3/8" wall thickness ( the mast pin is 1.25" SS ).

In order to get the install alignment on the mast step perfect, I decided I'd have to weld bushings in the step when  we install the mast. To build those bushings I used some  two inch aquamet prop shaft from the scrap pile at Washington Marine. Gregg at Washington let me pick some scrap pieces for my pins and bushings, and it was much appreciated.  Stainless steel is really nice material to work with on the lathe, and machines great.

Instead of butt welding the shroud and stay plates to the mast, I thought it better to use solid plates that ran through the mast. Eventually a steadying sail will be fit on the mast, along with a paravane rig, so I wanted the plate connection as stout as possible. The plates are 1/2" material, and because I don't really know the final configuration, I drilled what I thought was enough holes in each plate for possible future use. Drilling these holes 1.30" on center allows for shackles to fit next to each other.

A pad was framed at the top of the mast for the radar array along with a spreader bar that will hold work lights, a masthead/navigation light, weather center, and blocks for flags. The spreader bar is large enough antennas if we need.  I bored a two inch hole above the spreader bar for wires to exit the mast and fasten to the spreader bar.

The 4" boom will have an electric winch on it for hoisting a load, and the mast will have another electric winch on it for lifting the boom. The plan is to hoist the load with the boom winch, then raise the boom with the mast winch to get the load over the rail and on to the roof. We'll control the side to sided with tag lines. The winches have remote controls, so that should make things a little easier to operate. I"m not 100% sure, but to power the winches, I'm going to have a battery on the roof with a small dedicated charger in the wheel house, or possibly a small solar panel to keep the winch battery fresh. Either way, the battery will be in a weather tight box along with the winch fuses and solenoids.  All the winch brackets are in place along with test fitting the winches.
The cables used for the mast are 1/4" galvanized. All the shackles and turnbuckles are also galvanized. Because I'm always on a budget, I used hour glass type swage fittings to make up my cables. These types of fittings are not as nice as the single pass stainless swage fittings used on sailboat rigging, but they're for sure in my budget and look much better than cable clamps. I did use stainless steel on the thimbles since this point will see some abrasion. Years down the road when I start doing maintenance and repairs, I hope to upgrade to all stainless.

The next step will be to fit the mast to the step by welding in the step bushings with the mast in place. Once that's complete, we'll stand her up and be on the right side of having this job close to complete. I'm pretty pumped about having a way to hoist loads to the roof. This is going to be big time handy for getting bikes, kayaks, and of course our tender to the roof. I know I'll also be  using this to hoist the welder for the handrail job along with hoisting the handrails. I hear of cruisers loosing tenders to theft because they have too much difficulty getting the gear out of the water and leave it out overnight. I"m hoping our rig is going to make our lives easier.