For my main engine cooling I've decided to use a keel cooling system. Engine cooling seems to be one area of operating a boat that tends to give boat operators a large percentage of their problems and it is for this reason I've decided upon using the keel cooling method.
With a more conventional cooling system one sees on production trawlers, the engine sucks water in to the cooling system from outside the boat, cools the engine, then pumps the water overboard. The problem with this is that screens get plugged, impellers go bad, engine's overheat ( this can kill an engine in a moment), and maintenance for sure increases. Overall, the reliability of such a system is not very high and detracts from the boat as a whole in my opinion. The last thing I want to be dealing with on a night time passage is an overheating engine due to a Walmart baggie being sucked into the engine intake screen, or worse, loosing an engine due to a baggie that costs 1/10 of one penny.
My main engine cooler consists of 60' of 5" channel welded to the hull. The water basically goes in one end of the channel cooler, runs its route through the channel, then returns back to the engine out the other end of the channel as cooled water. I've seen other builders use split pipe on the hull, but for me the channel was easier to work with and I'm pleased with it's form. A young guy from our neighborhood was an engineering student at Utah State University ( Justine Gastrich), and needed a project during his senior year as a requirement for graduation. He calculated and designed the requirements for cooling my engine by using the 5" channel as a cooler. His report was very thorough and it was kind of neat seeing the boat build put to that use. The report that Justin developed was very much in line with all the rule of thumb designs other builders used, so I went with what Justin recommended.
I had to alter the engine a little to make the keel cooler work better but this was not a big deal. Because of the large volume of coolant I needed an expansion tank to give the coolant a place to go as things up to operating temperature. I also will use this expansion tank as the fill point to add coolant and a way to get the air out of the system. My engine modification was basically removing the fill cap from the engine heat exchanger and moving it to the expansion tank, then connecting the expansion tank back to the engine heat exchanger. The expansion tank is at a slightly higher elevation than the engines heat exchanger so getting the air out should be easier. I'm using extended life coolant that is premixed using distilled water and coolant. I'm also thinking of adding coolant filters as part of my system. Coolant filters need to be compatible with ones coolant ( either organic or non organic).
I've had the engine running since I've finished the keel cooler and all seems to be OK. I only had the engine running at a high idle but it did get up to operating temperature and stayed that way for the times I ran her. One good thing about the keel cooler is the ability to run the engine while on the hard.
I also decide to keel cool my air conditioners that I'll have on board. I'm going to have two air conditioners ( one for the lower forward cabins, and one for the Salon and Wheelhouse). I think the lower AC unit will be around 12,000 btu, and the upper AC unit will be around 18,000 btu. I know of quite a few boats in our harbor that are always having problems with maintenance regarding their air conditioner from junk getting sucked up into the units. Keel cooling these air conditioners, while much more expensive, will eliminate most problems associated with a marine type air conditioner. While traveling down and aroun various harbors, I'm amazed at the number of boaters that leave their air condtioners running while away from their boats for extended periods of time. I know of one boat that has been sunk due to the marine air conditioning unit failing and pumping water into the boat. While I don't think I'll leave the air conditioners runnig while I'm not on the boat, with keel cooling I will have the ability to leave boat and not have to worry about the air conditioners. For the air conditoner coolers I used 2" sch. 40 pipe split in half and welded to the keel. Becuase the air conditioners will be used while the boat is sitting still I wanted to get the coolers as low in the water as I could. There is a cooler on each side of the hull for each air conditioner. The cooler for the forward cabins enters and leaves the hull amid ship, and the cooler for the upper areas of the boat enter and leave the hull more aft.
Again, the hardest part of building these coolers was air testing my welds. I air tested all the coolers to 10 psi. Tacking the coolers to the hull went relatively quickly with me having only a few hours in the fitting and tacking. Air testing on the other hand found me spending at least a full day fixing leaks for each cooler.
While these types of coolers might seem a little labor intensive in some folks eyes, the robust nature of the cooling systems adds to the boat as a whole in regards to function and safety. That robustness will also translate into lower operating costs in the future witch, in my opinion, will easily off set the cost of my labor to build these devices.
Tuesday, September 22, 2009
I'm now walking around on a nice level floor. The floor feels very firm and is squeak free while only being fastened down with maybe 50% of the screws. I'm very pleased with the amount of head room I ended up having. So now it is time to lay out the various partitions and interior walls. Just in case anyone is wondering, I'm talking about the lower forward area of the boat in this post. The other thing I should probably say about boat building is that there are very few things that are plumb, level, or square on a boat. Certain things might look skewed or goofy, but that's just the way things work out on certain parts of a boat.
I have a two cabin layout in the lower forward area of the boat. The master cabin witch is amid ship on the engine room bulkhead, and and a cabin in the "V" for the kids. There is a shared shower and head between the two cabins and each cabin has it's own sink. The space's worked out better putting the sinks in the cabins vs a sink in the shower area. It might not make the most sense, but it made more sense to me to have sinks in each cabin.
Coming down the four steps from above one will stop at a landing. By turning left you will pass through a door and enter the master cabin witch measures 11' x 11'. There will be a full size queen bed with drawers underneath, a sink/vanity on the right side along with vanity/dresser for Shannon also on the right side. On the left side will be a desk for me and a locker to hang things in. Bookcase's and shelves will make up the wall above the bed, and a flat screen TV on the wall opposite the bed. A watertight door leads to the engine room on the left side of the bed and another door leads to the common shower/head on the right side of the bed.
If you choose to go straight vs left while standing in the stair landing, you'll enter a hall leading to the "V" cabin area. In this hallway will be a small sitting area and a vanity with a sink. Past the vanity you enter the kids cabin with it's bunk beds and storage underneath. There is room on the bathroom wall for a small TV, and there is also an opening hatch in the kids cabin. I laid out this cabin so there will be a bunk area and the hallway area, so people could have some privacy to change or be by themselves without having to go into the bathroom. The hallway/sitting room works out nice in my opinion and it gives this area a much needed private space.
There is a port light in the landing, a port light in the hallway/sitting room and two port lights ( port and starboard ) in the kids cabin. There is a port light in the bathroom, and two port lights in the master cabin. All the ports are fixed and cannot be opened. I'll post more on ventilation later down the road, but in a nutshell I have a hatch in the "V", and two six inch vents for the master cabin leading up through the wheel house. The bathroom has force ventilation leading up to the Portuguese bridge. The lower forward area will also have it's own dedicated air conditioning system.
I framed the partitions with 2x3, and will sheath them in 3/8 Cherry veneer plywood. The outboard walls will get a 1x6 ceder plank, and the ceilings will be a painted bead board. I decided to frame now vs after the insulation because I think this is way makes more sense. Once the insulator gets finished with his work it will be extremely difficult to attach anything to the steel frames. I used screws to fasten all the framing together in case I needed to take something apart while I move forward with the finishing work. My insulator stopped by the boat one day recently and commented that I was getting a little close to the steel with some of the framing. He suggested I hold some parts of the framing a little farther away to give him some more room to work. The insulator also said I'd be a lot of the lumber would still be clean when he left so more blocking could be added after he finished.
My next step is to layout all of my boxes for my 12v and 120v fixtures. Once I know where all my various light fixtures and appliance's go, I'll run conduit and boxes similar to conventional house wiring only I'll use stranded wiring instead of the solid wire one would see in a house. I also will run as much of my waste and water lines along with anything else I feel comfortable having buried in the foam. I've been using urethane adhesive to glue nailer blocks to certain parts of the hull on the recommendation of the insulator. He told me to go ahead and use only adhesive, because once he sprays that particular block into the foam, I'll not be able to get it out and that block will become part of the insulation. Because of the ease of just slapping some glue on a wood block and sticking it to the hull I'm putting up blocks any place I remotely think I"ll need one.
Having the framing completed really closes the boat in. But for all of those who know boats I know you'll appreciate when I say that the areas I've created are very roomy and very comfortable. The "V" cabin is a little snug, but it still works good and I'm able to move around with ease. I'd love to have another 10' to work with, but I must say I'm very happy with what I have and the space's I've created.
Saturday, September 12, 2009
The forward cabin is painted, the water tanks are installed, the firing lumber is bolted to the frames, and now it's time to install the forward sole. Sole is to a boat what a sub floor is to a house ( it is to me).
I've had to make the choice of screwing the plywood sole down directly down to the steel flange I welded to the frames or build the steel frames up with 2x lumber, then screw the plywood down to that lumber. I will loose 1.5" of headroom by using lumber, but I feel as if I'll also loose a lot of future complications by using lumber vs straight to the steel. Using a firing strip over the steel flange costs me some headroom, but it also gives me more square footage on the floor since I've raised the floor profile and allowed the plywood to "slide" more outboard against the frames. It's amazing how much more room I have since the sole grew outboard when I mocked up the sole framing system. Screwing the plywood directly to the steel in my opinion will make lifting pieces of the floor a real pain in the ass years down the road as screws rust and break. I'll end up with about 6' 2" of headroom once the finished ceiling is installed. This 6' 2" seems to be my minimum as some areas will be a little more ( 6' 7" in some areas). I'm 5' 11" tall and I'm totally happy with the headroom I"ll end up with.
The forward cabin are is where my cabin will be, the kids cabin, and the common bathroom/shower shared by both cabins. Both cabins will be carpeted and the bathroom/shower room will be hardwood or tile.
I'm using #1 southern yellow pine as my firing lumber, and CDX for as the plywood on the sole. The firing lumber runs perpendicular to the frames and is screwed to the frame flange using a self tapping screw of sufficient size and thickness. Even though the salesmen who sold me the self tappers said I would not have to drill a pilot hole, I found things went much faster by drilling a pilot hole. I also used polyurethane adhesive to glue the firing lumber down to the frame flange. I don't want to rely totally on the self tapping screw as I could see the lumber shrinking, the screw getting loose on the lumber, and a squeak developing. It if for all the reasons I just listed that I think the adhesive will give me some a little better job.
I've also had to make a decision on how I'm going to frame my partitions that will make up the cabin walls. My current boat just uses plywood stood on edge for the partition. This boat is much bigger and has more in her regarding systems and things like wiring and plumbing. I posed this question on metalboatbuilding.org and after receiving the usual good comment, I decided to frame the partitions out of 2 x 3 lumber. The reason I've had to decide this now is because I want to be able to remove all of the cabin flooring without having to remove any partitions. For this reason I'll have to frame the cabin sole in a way that allows the sole to be supported from below while the partitions remain in place. I also have to frame in all my access panels in the floor for access to water tank valves and whatever else I need to maintain below the floor. In a nut shell the cabin sole is basically made up of lots of small pieces that fit together to make the sole system.
I knew where all the access panels had to be located so framing those areas of the sole required very little layout. The partition walls on the other hand would take some more thought. I decided to handle this by framing and installing the sole, then once the sole was complete I will be able to get more precise with the various cabin partitions and cabin components. Once I new where most everything will go regarding living space, I will put layout lines down on the sole and alter the sole to accept the framing above. Doing it this way allows me days to ponder locations and do mock up's to see how things fit. Now is the time I start fighting for every square inch so I want to make sure it works for me and works for the boat. Most of the decisions I'm making have me giving most of my consideration to how easy things will be to service and maintain.
I screwed the sole down with a # 12 stainless steel wood screw using a tapered bit with a counter sink that had a depth stop so all the counter sinks are at the right depth.
The sole is now complete and I'm loving how much better the boat feels now that I can walk around on a firm flat surface. The sole is very solid and has no give or squeak as I walk across it. My next step will be to start the framing of the interior partitions so I can have all the cleats and nailers installed prior to insulation.
Tuesday, September 8, 2009
I have eight water tanks for my potable water supply located under the forward sole of my boat. The first tank I built I measured for cubic footage, then filled it with water, and by using a shut off valve and a five gallon bucket I was able to measure the amount of water in the tank. My method of measuring cubic footage and measuring with the five gallon bucket gave me about the same volume of water within two gallons, so I'll stick with measuring for cubic footage vs filling each tank to get volume. I have 325 + gallons worth of water tanks.
After the boat is insulated and I'm assembling components of supply, vent, and filling of the tanks, I'll post more regarding the system as a whole.
I'm mounting the water tanks using a flange welded to the tank ends and a corresponding bracket welded to the hull of the boat. Where the bracket is deeper in the hull ( by the center line of the boat), I used studs welded to the hull bracket that the tank flange will drop over. On the less deep end of the tank ( outboard ends), I used nuts welded to the hull brackets that the tank flange will bolt to. I used 30 mill pvc pond liner I had laying around the shop to act as a gasket to go between each tank flange and hull bracket.
I had installed the tanks prior to final painting to make sure all the brackets would work and also that the tanks would finish out below the sole framing. I also needed to verify that the valves I was using on the supply end of the tanks would clear all the steel framing. I ended up having to adjust the access holes in the frames for the tank fill lines ( I guess I screwed up on the cut twice measure once thing). 4 3/8" clearance between the front of the tank and the center longitudinal frame of the boat is barely enough ( it fit) room to get a close nipple, valve, close nipple then a "T" for the tank supply. I don't think the Governator would be able to get his arm down in that space to operate this gate valve, but I'm able to so I'm happy with the final fit. Because I had installed the tanks prior to painting the tank install went fairly smooth. My 13 year old son helped me as the tanks are to large for one person to handle. The only real issue we had was that the amount of paint on the hull brackets caused me to use a tap or a die to clean up the threads on the respective hull bracket. The tanks are a tight fit between the frames so we used as much care as possible lowering each tank into its "bay" so we would not damage the paint. It would take a hard hit to get through all the coats of paint in the bilge area, but I still was very carefull.
I held off installing the tanks as long as possible to try to keep the trash generated from bolting the firing lumber to the frames from getting under the tanks.
Thursday, September 3, 2009
The interior painting of the hull is, for the most part, complete...well it is complete in the forward area of the hull. I still have to finish the engine room, but for now that will wait. It's amazing the amount of light I now have in the hull now that she's painted bright white vs the dark primer I've been living with for the last five years. I feel as if I've reached a milestone of sorts since now I'm close to hauling the welder off of the boat. I still need the welder on the boat to do some work on the fuel tanks and some other odds and ends in the engine room.
The next task at hand is to bolt firing lumber to the frames. My title to this post refers to lumber as sticks and weeds. I know an aluminum skiff builder up in Alaska who's been known to use this phrase and somehow it just seems to fit. Sticks and weeds baby...sticks and weeds. I think Steve Earle covered this phrase in a song... or maybe I'm thinking of seeds and weeds.
For all of you who are not familiar with the metal yacht building process I should probably mention few words on the interior finishing system. All the metal on my boat has had the mill scale removed prior to the start of construction. After all the welding was completed the boat had welds ground, splatter removed, tacks and other garbage removed, sanding/cleaning with 60 grit, more sand blasting, and then multiple coats of epoxy primer, and epoxy top coat paint. One step I should mention prior to painting was that I drilled holes in all the frames to accept 1/4" bolts for attaching the firing lumber. I drilled these holes 1/16" over size and beveled the holes with a counter sink to help the paint stick better. The next step in the interior is to bolt lumber to the frames that will later be used to attached the finish hull liner. The hull liner is the plywood or planking that will be the finished wall surface. In my case I'm going to use planks on the hull sides, and plywood on all the partitions. Once the firing lumber is bolted to the the frames, I'll install some conduits, some of the electric runs, and some of the water and waste piping. Once that is all complete I will then be ready to have the boat insulated. The insulation I'm using will be a sprayed in, closed cell polyurethane foam, that will cover everything down to the water line. After the foam is complete I will now be ready to start the finish joinery work witch will include the hull liner, berths, cabinets, etc...
Bolting the lumber to the frames was pretty much a straight forward job. I'd clamp a 2x3 to the frame, drill the holes in the lumber, then drive a 1/4 x 2" carriage bolt through the board. I would then remove the board, apply a generous bead of polyurethane adhesive, put the board back on to the frame, put on washers and nuts, then use my air ratchet to tighten the nuts. I pretty much use air tools exclusively as I just like them better. Air tools are less expensive, don't break when you drop them, and last longer. I have a nice compact right angle drill that works extremely well for drilling the bolt holes in the lumber. This right angle drill has for sure been my tool of choice for most of my drilling jobs on the boat. For the hull side frames located towards the center of the boat ( station 9, 10, @ 11) I was able to just bolt a 2x3 to the frame without any custom ripping as there was not much curvature of the hull in these areas. As I move forward and the curvature of the hull increased, I had to give each board a custom angle rip to keep the face of the board parallel with the hull sheathing. The frames are not square to the hull sheathing but the face of the lumber must be parallel to the hull to allow my finish hull liner to go on nice and fair. Using a bevel gauge, I'd come up with an average angle as measured in a few locations on the particular frame. I'd then climb off of the boat, head down to the shop floor, transfer the angle to the table saw and make the rip. All the lumber was held about 1/4" - 3/8" proud of the frame to allow for some insulation to cover the frame flange. Once the boat is insulated no metal will be seen and the only lumber you will see is the face of the board that the hull liner will be screwed to. The cabin roof was a little different than the hull sides as it has a camber to it vs the straight line of the hull side. Bolting the firing to the cabin ceiling would have been a little easier if I ignored the camber and just bolted a straight board to the frame. I like the camber look of the cabin roof, and since I'm fighting for every square inch of space I kept the camber in my framing. Because of the camber of the cabin roof I had to use a 2x4 vs a 2x3 for the cabin roof. I just had to clamp the 2x4 to the frame, mark the cut line, then use my band saw to make the cut leaving the line. I'd then re clamp the board making sure the board face was held proud, drill the holes, install the bolts, apply adhesive, run the nuts home with the air ratchet. I had some conduit runs in the cabin roof frames that I had to transfer to the lumber, but for the most part it was straight forward.
I've built my lasts two houses and when you look at the size of the forward cabin area of the trawler you'd be amazed at how much longer it took to bolt the firing on the frames vs something like framing the first floor of my current house. Everything regarding building boats just takes longer than what most of us are accustomed to. I'm not really tracking my time, but when I say it takes longer than lets say "Y", I"m talking like five or six times longer, not just the cliche' "double the time".
The firing of the frames is now completed, but there is still lots to do before I can insulate. I still have to install the water tanks, build the forward sole ( cabin floor), install all the cleats or nailers that will be buried in the insulation yet are needed for attaching finished lumber, frame all the partitions so I know all cleats and nailers relating to partitions work prior to insulation. I also plan on installing some of the waste and water piping, conduit runs, and electric wires. Once the insulation is installed it will be a huge pain in the ass to add cleats/nailers to the hull so I want to get as much of this work done now. I've never built a boat before, but having built some house's helps me regarding stragegic placement of some sticks. Since I just got done preaching on how much time it took for my firing, I'd be afraid to guess how much time one would spend attaching even the smallest pieces of lumber once the insulation is completed.
Tuesday, September 1, 2009
When one hears the words interior painting you might be inclined to think of paint and how it relates to ones house. The interior painting system on the trawler is more about function than making her pretty. Most of the interior painting will never be seen again and it's sole purpose is to stop corrosion from occurring. The interior paint we will see will be down in the bilge area and again the paint serves as a corrosion barrier. Steel boats of the past have earned a not so favorable reputation due to rust corrosion. The steel boats of yesteryear rusted away from the inside out. I've seen quite a few older steel rusting hulks that had little or no paint on the inside sheathing and framing. These old boats got built, some paint slopped on them, then covered up with plywood...out of sight, out of mind. The materials and methods offered to us builders today will give steel boats the ability to outlive all of their builders without turning into rusting hulks.
I'm building my boat using wheel abraded and primed steel. Wheel abrading is a method of removing the mill scale from the steel utilizing a machine that throws steel shot or some other abrasive at the steel then the metal is primed as it exits the wheel abrading machine. Mill scale is the dark coating one sees on new steel and must be removed prior to painting. Since I'm building inside of my shop and I had the mill scale wheel abraded off I do not have to do any heavy sand blasting of the boat. Because I'm inside I've not had to worry about heavy rust forming during the build. The designer of the boat was also careful to not design corrosion trapping pockets in the framing where water could sit or accumulate and cause crevice corrosion to start. All the frames and longitudinal stringers have "mouse holes" cut in strategic areas to allow water to pass freely and collect in the bilge's.
To prepare the inside of the hull for painting the first step was to grind all the tacks, splatter, and garbage off of all the metal. Then I used my shop sand blaster and blasted all the welds and areas I had ground. I then used my sand blaster to give the interior a light blasting to "tooth" the existing primer so my primer would stick to the existing primer. I'm using epoxies for all the paint and for the primer I alternated between white and gray so I could see the coverage. I applied three coats of primer then three more coats of top coat. For the top coat of paint I used acrylic enamel.
The areas above the water line on my boat will get insulated with sprayed in polyurethane closed cell foam. The areas below the water line will have no foam. For the below the water line areas I added another coat of paint utilizing an insulating additive in the paint. This insulating additive is a NASA technology that gives an "R" value to the paint and prevents condensation. I used the "insul-add" in a primer coat and have no real complaints as to how it sprayed. The material was not that expensive and if it does half of what is claimed, I'll be extremely happy.
These pictures are of the forward bilge area. I'm showing these pictures because these shots also show the mounting brackets for the water tanks.
Saturday, August 29, 2009
I have four fuel tanks on board of my trawler. Given this first sentence seems to sum things up I could be getting off easy in regard to this post and leave it at that. But since I'm a little on the long winded side of this world, and the fact that I'm totally into all things steel boats, I feel as if I should elaborate a little on my fuel tanks.
The four fuel tanks on board are integral tanks meaning they are now part of the hull. The tanks are on the outboard sides of the hull in the engine room between station 9 @ 14. I am using the term station as this is how the prints describe frame locations, and these two locations are actually steel bulkheads. I framed the tanks using 1/4" plate. All the tanks have a baffle located @ 30" on center witch is also what the frame spacing is. The baffles have the corners clipped off of them and also have 2" holes in the center to let fuel flow freely between them. The baffles are welded on all four sides of the tank walls and by using the slug welding method I was able to weld the baffle to the tank top. All four tanks have a drain valve at the lowest point in the tank in case I ever have to empty the tanks completely.
I could not in good conscience build these four tanks without providing a way to get back inside of them if I ever have to. I added an inspection port between each baffle for future maintenance. The inspection covers are made of 3/8 plate and are attached to the tank by a 3/8 stud that is welded to the inside of the tank wall. The inspection ports are 12" in diameter and are in the front wall of the tank. Because of the size of the tanks, putting the inspection ports on the top of the tanks made no sense as it would serve little use due to the depth of the tank. Getting the inspection covers to pass the air test proved to be the most difficult part of building these tanks. Using fuel rated gasket material I cut a gasket for each cover and punched holes for the studs. I then used a fuel rated gasket sealant applied to the gasket to improve the seal of the gasket. Because I did not want to stretch my mounting studs I used a torque wrench to tighten the nuts to the correct torque for a 3/8 bolt. My first air test showed each stud to leak! Next I tried using a heavy thread sealant on the studs. My next air test showed the studs to leak! The problem was the weld holding the stud to the tank was not air tight and my 7 psi air test was leaking past this weld and then past the mounting nut. My solution to making the covers air tight was to mill a counter sink in each tank cover to accept an "O" ring for each stud. I milled the counter sink in the covers to a precise depth so that the washer under the nut would compress the fuel rated "O" ring and provide a seal once the nuts were torqued down. My next air test proved all the studs passed the 7 psi test. I spent another day or so finding pinhole leaks in the tanks and making weld repairs. The final air test was to have the tanks hold 7 psi for 24 hours.
My two forward tanks ( port and starboard) hold 200 gallons each. The two aft tanks ( port and starboard) hold 500 gallons each. I intend to use one of the forward 200 gallon tanks for running the main engine and generator and the other three tanks will be used for storage. I'll have to transfer fuel from the various tanks via an electric fuel transfer pump. I'll probably use this same pump to polish my fuel from time to time to keep it clean and keep the condensation water out of the fuel. The total fuel capacity on board will be around 14oo gallons. This 1400 gallons is more than what the boat was designed for so I contacted the architect who designed the boat and reviewed this with him. Hal Wittacre ( the naval architect) did some stability calculations and recommended adding more ballast to the boat.
Each tank has a pick up tube for fuel supply and return. These pick up tubes go to within 1" of the tank bottoms. There is a fill point for both port and starboard on the aft deck of the boat. A two inch steel pipe will be used as the fill tube, with a vent that leads back to the fill port. The fill ports on the tanks just dump into the the top of the tank but I want to change that and add a tube that goes to the tank bottom. Bringing the fill tube to the tank bottom is a better design element for fuel tanks and I will make this change.
The fuel management system is fairly complex and really needs it's own post to get into the details. Once I start work on this part of the fuel system I'll add a fuel management post.
The tanks are shown in these pictures with a plywood cover. I did this so that I could protect them during construction. Plywood will also be the final cover as there are many things that will be attached to this plywood.
Monday, August 24, 2009
The rudder on my trawler is a rather large device. The approximate dimensions are 2.5' wide by almost 5' tall. Having installed the rudder a few times I'm going to guess it's weight at 200+ lbs. The rudder looks more like a wing and is constructed in such a way as to have two skins wrapped around the wing shaped frames. It is very sleek looking and more reminds me of a sailboat rudder vs a rudder you would see on a work boat. Compared to the rudders I see on house boats around my home port, this rudder has a tremendous amount of square footage to aid the steering of the boat. By looking at the rudder alone, I would guess this boat will be very responsive to the steering wheel. Becuase of the way the rudder is fabricated it is impossible to paint the inside to protect the steel. Because of this type of rudder construction I air tested the rudder to 10 psi to insure that no oxygen gets inside of the rudder and speeds up rust corrosion.
The rudder is connected to the boat via a large skeg or shoe that is an integral part of the keel. The rudder has 2" stainless stock welded to itself that is flanged on both the top and bottom of the stock. The bottom flange bolts to another flanged piece of 2" stock that sits in a bearing in the skeg. The top flange bolts to piece of 2" flanged stock that passes through a bearing that goes up into the lazzarette of the boat ( rear room) and connects to the steering gear. The flanges for the rudder system I fabricated out of 3/4" stainless stock and bored them to accept 5/8 bolts to hold them together. I'll have to design some sort of locking ring to retain the nuts or use a castle type nut with a key to hold the nuts fast. The bearings for the rudder in the skeg and where the rudder stock enters the boat @ the lower end of the rudder log ( rudder tube) are made from a material called Vesconite. Vesconite is designed just for this application and is claimed to be top of the line material for what I'm trying to do with it. I will not have any galvanic worries with this type of rudder bearings.The rudder tube terminates inside of the boat about 8" above the water line. I added another bearing at this point of termination for a total of three rudder bearings. With the rudder installed I'm able to move it with just a little pressure from my finger tips. I'm totally happy with the bearings and the rudder alignment. Because of the mix of a stainless steel rudder shaft and mild steel boat I will add a zinc or magnesium annode to the rudder to slow down any galvanic corrosion.
The actuall steering system on the trawler will be what most would consider a power steering system. My main engine has a port on it to accept a pump that will power the steering helms that in turn will power the hydraulic rams connected to the rudder shaft. I will have two helms on my boat; one helm in the wheel house, and another helm on the roof as a fly bridge. In case of a catastrophic failure of the steering system, I have an emergency tiller device in place to steer with ( see my earlier post " emergency tiller"). The hydraulic rams are more a heavy duty set up I purchased from Hydro Slave Co. The steering gear consists of a heavy cast bronze quadrant, two hydraulic rams, and an integral arm to limit travel of the rams. If you look at the first picture posted you will notice my attempt at rudder stops welded to the hull. I know they look a bit odd, but at least I made some attempt at aero dynamics and they also wont increase any corrosion issues. The quadrant connects to the rudder shaft via a heavy clamp and a 1/2" stainless key way and key. I went with this type of dual ram set up becuase it causes zero side load on the rudder shaft. I am totally pleased with this piece of equipment, and while it was pricey, I feel it was money well spent. I'll be adding to this blog once the steering system is fully connected and operational with the helm pumps in place along with the hydraulic lines.
Friday, August 21, 2009
The first time I heard "Bash Bars" was the last time I called steel round bars used to cover frames edges "steel round bars used to cover frame edges".
From what I know of the origin of this description is that it came from a guy I know in Australia who is building a steel sailboat. His name is Martin ( Idlerboat is his web name) and he is one of the founders of Metalboatbuilding.org . So from this time forward I use "bash bar" .
A bash bar is built by welding round stock to a frame edge to protect that frame edge. It is much easier to get paint to stick to a 1/2 round bar vs the ground edge of a frame. When that frame gets banged into and paint chips, the stainless steel round bar will be exposed and will not rust so touch up and repair will be a breeze without the unsightly rust stain in these high wear areas. All the frames on the exterior of the boat that will not be covered up and that are subject to getting banged get treated with this bash bar. I used 1/2" stainless for my bash bars. On the foredeck of the boat I bash protected the frames, the bulwark cap edge, freeing ports, the door frame and the toe kick areas of the door. On the Portuguese bridge I treated the frames only as the cap for the Portuguese bridge will be covered with teak. On the cockpit area or aft deck, I treated the frames, door, freeing ports, and left the bulwark cap untreated as this too will be covered with teak.
On the freeing ports and hawse holes I held the bash bar flush to the outside hull sheathing. This gives the hull a great finished look, and I also like the look on the inside of the hull too. While the bash bars are held proud on the inside of the hull sheathing, it gives the hull a more finished look albeit a utilitarian look, and I like the utilitarian look for a steel hull. I've used some effort to fair the hull and hide the welds. I don't know if this was a mistake or not as I think a good looking weld is something that does not need to be covered up. A lot of people will tell you not to fair the hull and let the welds stand proud, and with the money saved both in fairing and repairing dings, I can't say I don't dissagree with the no fairing method. Almost all commercial boats use no fairing, and I love the look of a commerical boat.
Saturday, August 15, 2009
My current boat ( 28' Carver Mariner) has a whopping 25 gallon water tank and I'm amazed at how long we can make that 25 gallons last. On the current boat we use water primarily for washing dishes and an occasional quick shower. The head on the Carver is raw water flushed so we don't tap into that precious 25 gallon supply.
The water tanks on the trawler ( I guess I'm going to have to name her soon so I stop calling her the " trawler ") are constructed out of stainless steel. I went with stainless steel vs plastic for a few reasons. Stainless is considered top of the line in regard to potable water tanks. Due to where I'm placing the tanks it made more sense for me to fabricate the tanks vs having them fabricated out of plastic. I used 14 gauge 316L for fabricating the tanks. All the associated fittings for the tanks are 3/4 NPT stainless ( fill, vent, supply) couplers welded in place. All the tanks have one center baffle running across the width of the tank. The tanks fit between the frames of the forward area so the tanks have to fit into a 30" wide space. Because of the 2" flange I welded on to the frames I had to make the tanks 27" in width to give me a little room for the install. I might be kicking myself in the ass years down the road, but I decided to not install inspection covers in the tanks. I have a total of 8 tanks giving me approximately 350 gallons of water.
The tanks are held in place with a flange welded on to the front and back of each tank. The forward mounting system consists of a bracket welded to the hull with 3/8 studs welded to that bracket. The forward tank flange fits over those 4 studs and is bolted down. The rear mounting system consists of a similar bracket only I welded nuts to that bracket and used four 3/8 bolts through the tank flange to mount the rear part of each tank. I used studs on the forward mounting system because the bracket is so deep it was easier to get a nut started vs getting a bolt started. It was also easier installing the tank by dropping the tank over the studs then having a little wiggle room to get the bolts started in rear of the tank. For 3/8 studs and bolts I drilled the corresponding mounting flange to 1/2 " and used thick washers for the mount. I made a gasket out of flexible PVC to help isolate the tank bottom from the mounting brackets ( no metal to metal contact other than the mounting hardware). I allowed myself 4" of clearance between the front of the tank and the center longitudinal frame ( center spine). 4" of clearance was barely enough room, as it is a tight fit to get my arm in there. All the tank mounting hardware is stainless steel
To supply water to the pump I welded a 3/4 stainless coupler in the the bottom of each tank. Having given this a little more thought I now wish I had used a pick up tube entering the top of the tank and going to the bottom. Too late for the pick up tube method now, but again I wish I had gone that route. So each tank has a coupler welded in for supply, followed by a gate valve for each tank,followed by a "T" for each tank, all of this terminates into a common supply line leading to the pump. I went with this set up so I could isolate each tank vs all eight tanks having a shared liquid level. If I ever have a catastrophic failure of a tank, I can take that tank off line and not loose all my water. I also have the choice of just filling a couple of tanks if I want. Since I am able to isolate the supply side of the tanks, I also have to be able to isolate the vent side of the tanks. All the vents will terminate at a manifold that can be valved before venting at the wheel house deck above the fill point. The tanks will fill from two points on the wheel house deck via port or starboard fill pipes. Because of the large cabin and wheel house roof areas I'm making provisions to be able catch water off the roof to fill the tanks.
I air tested each tank to 6 psi as this will be more than the static head the tanks will see once the vent tube fills to the deck level. After I fabricated the tanks I installed them to check fit and make sure all my brackets would work so I could start the interior painting. If I had been a little more careful with my measuring and fabricating I could have squeezed another 50 gallons of storage in my system, but all in all I'm happy with 350 gallons.
Monday, August 10, 2009
The phrase "fairing the hull" took me a while to figure out it's origin. My interpretation of what is fair is just that... it feels fair. Running ones hand across the hull sheathing reveals more than what your eyes can see and as you keep running your hand across that hull skin you start to get a feel for what's fair. Fair is not perfect and fair is not feeling bumps and gouges in the metal... fair is fair...it feels pretty fair. Sort of like how Manana does not mean tomorrow, it just means not today.
I bought my steel wheel abraded, primed and plasma cut. The wheel abrading removed the mill scale and left a good profile for the primer to stick to. I'm building inside so rust has been a non issue for me and my original primer has remained intact. I started the fairing process ( above the water line only) by grinding all welds smooth. I also hit some of the "weld through" with a grinder if the bumps felt abnormally high. Weld through are areas where the metal pushed out from the welds I created welding the longitudinal stringers to the hull sheathing. After I had all the grinding done I spot sand blasted all the grind marks, rub rails, and any spot that had rust blooming. I then gave the whole hull a light blasting to tooth up the existing primer. I blew off the hull with compressed air and applied three coats of epoxy primer alternating colors between the coats ( white and gray). I then began the process of mixing epoxy ( Gougon Brothers) fairing compound and filled all the areas I had ground such as weld seams and deep weld through marks. After multiple applications and sanding of those areas I sprayed one more coat of epoxy primer then gave the hull two coats of high build primer with the tendency to lay it on thick.
High build primer is like liquid filler putty being extremely easy for one to sand. Using a 30" flexible sanding block and rolls of self adhesive 80 grit 2" wide sand paper I sanded the hull. The high build primer shows every little dip and doodle in the hull. While "long boarding" the hull I'd find areas where I'd sand back into the metal ( very high spots). If these areas were really high I'd hit it with a the grinder, re blast, re prime with epoxy, more filler if needed, more high build, re sand. I really did not use much filler as the hull was very fair when I began. Most of the filler was used up creating a smooth transition from the hull skin to the rub rails, around the port lights, and in the area of the freeing ports and hawse holes. Once I was pleased with the long board sanding I blew off the hull, vacuumed the hull, wiped her down with tack rags and applied two more coats of epoxy primer to seal the high build primer.
I faired the hull one side at a time, working at a pretty steady rate since I was doing this over the winter in the shop. Each side took two months to complete and has landed on the top ten most nasty jobs to date.
Having now looked up at the hull thousands of times in varying light I have found a few areas that will need more a little more fairing before I apply the topcoat. I'd guess I'll have two more days in fixing some of these areas so I don't consider them a big deal as most will just involve some sanding and high build primer. My future plan for the top coat is to scuff the few areas that need attention, epoxy prime, high build, sand and repair, more epoxy primer. The whole hull will get a good washing, a scuff with 80 grit, one more coat of epoxy primer, then I'll spray the top coat.
I only have a few pics of the faired hull. For the most part all the body work is finished and she's ready to paint. I'll be able to topcoat a few areas of the hull in the shop prior to attaching the wheel house and salon, but I'll probably save the bulk of the hull topcoat until after the wheel house and salon are attached.
Sunday, August 9, 2009
All of the cleats for the boat were fabricated by yours truly in "Conallville" ( that's what my brother calls my barn).The cleats are made from 1.25" 316 stainless round stock of the L variety. I copied the style of cleat that I see on all of the boats in this area and this style seems to be the best fit for me in regard to where I'm positioning the cleats on the boat. I purchased a 3/4" rounding over bit for my lathe witch does a fantastic job of giving me a perfect radius on the edge of the cleat ( vs the homemade done on the grinder look). The round over bit cost about $40.00 witch I consider a small price for quality, and there will be many other jobs I'll be able to use it on as I do some more finishing type work. Hopefully, folks who know what they are looking at will appreciate the details as I do. I used the lathe to cut all the bevels on the round stock for maximum weld penetration by the MIG. All the parts were pickled, passivated, then re polished once installed. All the cleats are welded in place and while I don't foresee them being torn off, I still think I'll make a few spares cleats to throw in the on board parts warehouse.
I have two aft cleats, two spring line cleats ( mid ship), and four cleats on the bow. I added two more cleats on the pulpit to get the total of four bow cleats just because I had the space and I figured it would also help with the anchors. The two stern cleats, and two of the bow cleats are welded up high off of the deck so that the lines pass through hawse holes I fabricated myself. I used 1" round stainless stock and bent it in an oval shape then welded it to the hull. I also added a doubler plate in this area of the hull to spread out some of the point loads the hull sheathing might see from the 1.25" round stock. The mid ship spring line cleats were held as far out on the hull as I could. I welded this cleat directly to the center bulkhead of the boat also create another frame to move the load to the floor of the cabin vs the hull side sheathing. My experience on spring line cleats is they tend to take the brunt of the load of the boat and I don't want paint popping off the boat by having the hull sheathing flexing. My intent of holding the spring line cleat as close to the cap edge as I could was to minimize line chafe and prevent the spring lines from rubbing the paint off of the hull. After the weld up I was not satisfied that my lines and hull would be protected so I took a some 1" stainless pipe, plasma cut/ripped 1/3 of the pipe away, added some decorative pointy ends and welded it to the hull to act as a rubbing strake. The length of the rubbing strake is 3' and I'm pretty sure it will work just fine. I did create a small issue by adding the rubbing strake in the area of the strake between the cleat and the bow. Because of the height of the strake and the shape of the bulwark cap, I created a small ( 2 square inch) area for water to pond. I'll have to either drill a drain hole of some sorts or add epoxy fairing compund to raise the area and have the water shed overboard. This is a pretty minor deatail, and it is the only place on the boat I know of that will trap water.
I think I'm going to add a sampson type post on the pulpit right above the door because I think it will look good and will also help with the anchors. I also have a sampson type post on the swim platform for the sole purpose of tying off my dingy when she's not stored on the cabin roof.
Saturday, August 8, 2009
I've purchased a 10kw, three cylinder, diesel powered generator for the boat. The generator will be cooled by sea water using a closed cooling system with a single pass cooler. The exhaust from the generator will be injected with this cooling water to lower the temperature, then that mix will be pumped overboard via piping and through a water lift muffler. The generator will reside in the engine room.
I think 10 kw is to big of a generator for this sized boat but I got such a good deal on it I had to make the purchase. I'm going to have a washer and dryer so the extra amperage will come in handy for powering the dryer as this device will by 230 volt ( unless I go with one of the expensive 120 volt "marine" dryers). The boat will have two air conditioner units and these units also tend to be large consumers of power.
I'm installing a hydraulic system for the boat and the person who has been giving me pointers on the system design ( that would be Jim at Key Power) has recommended I install a hydraulic powered generator along with my stand alone generator. I think this is a good idea and I'm planning on doing it. Since the main engine will be powering the hydraulic system, taking advantage of the relatively free power and not having to run the stand alone gen-set will lower fuel consumption. I also intend on installing an inverter to power the fridge and a few AC circuits while we're at anchor so we don't have to listen to the generator. The engine room is going to be heavily insulated so I'm debating if I should fabricate a sound shield for the generator. My thinking is that I'll probably install the sound shield to ensure a quiet boat. I intend to get into a little more detail on AC and DC power and how things are going to work on the boat, but for now I'm posting the basics.
Thursday, August 6, 2009
Not that I'm counting on the steering system failing, but I do want to make sure I have a back up method of steering the boat.
I'm using a hydraulic steering system on board that is similar to a car. I have a pump mounted to the engine witch powers the helm station witch sends oil to the hydraulic cylinders that are bolted to the rudder post. In the event of a failure of the steering system, I can by pass the hydraulic system and attach a manual tiller to my rudder. I should probably note that I had the end of the rudder squared off for this reason.
The emergency tiller consists of a tiller, a custom made end to fit over the rudder and into the tiller, a bearing welded into the deck, an "O" ring seal, and a cover. All this was designed by me so I have no one to blame if it self destructs. I have tried it out, and I must say it goes together quickly, and locks on to the rudder rather well. It seemed important to me to have the tiller on deck so the tiller mate and the helmsman could communicate.