Water tanks are an important part of the restoration and modification to the Far Reach. With our boat being rebuilt around the needs of four people--two adults and two children--water capacity is important. My plan was to get as close as possible to 140 gallons total capacity. The original tanks were fine except for one major issue; they took far too much of the storage space. Originally, Far Reach had a water capacity of about 120 Gallons--not bad really considering most boats this size have less than 100 gallons. There was a 25 gallon tank under the V-berth, a 30 gallon tank under each of the settees and a 30-35 gallon tank under the quarter berth. However, with a 30 gallon tank under each settee there was practically no room left for storage. I wanted those settees open for storage of food and other supplies.The new settee design will have tremendous capacity and be very convenient to access--if I eliminated the tanks. Those two tanks had to go and since I had removed the fuel tank that had been in the bilge under the main saloon cabin sole I knew that was the perfect place for the new tanks. In my mind, that is the best place for water tanks--on the center-line and in the middle of the boat. As the water is used up and the tanks become lighter there is less affect on the trim of the boat, when they are located in the bilge, than if they are located any other place in the boat.
The tank design needed to take maximum advantage of the space in the bilge. In other words, the tanks needed to conform as much as possible to the shape of the space in the bilge--narrow at the bottom and wider at the top. The current plan for water tankage is three tanks on the centerline with a capacity of about 70-75 gallons. We will keep the 30 gallon quarter berth tank. We will built a new tank under the V berth at about 30 gallons which will get us to about 130 gallons.
I researched various tank materials. SS was high on my list. SS tanks are strong and there are no lack of facilities that can repair them. But, the more I read about them and the more sailors I talked to that had experience with SS tanks the less confidence I had in my ability to get tanks that would be reliable and at a cost I could afford. Crevice corrosion plagues SS water tanks.I heard of tanks lasting 20 years. But I also heard about many tanks that had a far shorter lifespan . . . some less than three years due to massive pinhole leaks along the welds.If the design allowed them to be square or rectangle then the cost would not be out of range but as soon as I got into custom complex design the cost went up very quickly. I drew up the design and faxed it to a number of SS tank builders. The number one metal for water tanks is monel. The estimate for monel tanks were $4500! Way to high. SS 316L was next on the list but the cost ran to about $2500-$3000. 304L from $1800-$2500. This was more than I was prepared to spend--plus there remained the issue about getting tanks that would last.
I tried finding prebuilt roto-molded tanks. These were not my preference because they don't have full baffles and they can't really be repaired.But they are the least expensive and can be pretty reliable. I thought they would be a good choice if I could find ones that would closely conform to the bilge area. I contacted Kracor who at one time made bilge tanks to fit the Cape Dory 36.But, they destroyed the mold in 2003 and wanted $3000 to build a new mold.I contacted RONCO tanks in SOCAL but they did not have tanks that would fit my bilge.I took a hard look at building epoxy tanks.This seemed like a good option.It was not too expensive and I had the skills.I found an epoxy approved by the FDA for potable water tanks . . . but it was a big undertaking and I already had a full plate. Then I heard about custom welded plastic tanks.They are FDA approved.They can be built to fit any space and can have full baffles built in.Unlike roto-molded tanks these can be built very thick and can be repaired, though not in as many places as SS.I faxed the design out to three companies and got references and called them.I decided to go with Dura-Weld tanks.They have a great reputation and were easy to work with.
Overhead View
To the left are the drawings for the water tanks. The forward tank (tank #1) is 34 inches long and 31 inches wide. One baffle runs fore-and-aft and the other runs across the tank giving four compartments. Every compartment has an inspection port (IP). I had to divide the other tank into two smaller tanks or else they would not fit through the companionway. It wasn't the length of the tank that would have been the issue but the depth. The middle tanks is also 31" wide vice 36" as indicatedin the drawing. The aft tank is a bit narrower as the bilge gets narrow as it runs aft. I wanted the fill tubes all in a line from tank to tank so that access would be easier. There will be no deck fills. I'll fill the tanks by leading a hose directly into the tanks. I carefully measured the bilge area and then built cardboard mock-ups to make sure the tanks would fit.
After revising the drawings I faxed them out for quotes. After selecting Dura-Weld to build the tanks I called them and spent some time discussing the tanks with Garreth. We talked though the design and made sure we were both on the same sheet of music. It only took them about two weeks to build the tanks.
Side View
These are the water tanks. I think they look great. Dura-Weld did a great job. Compare these photos with the drawing above. The top picture is looking from what will be the forward end (shallow end of the bilge) of the tanks to the aft end (deep end of the bilge). The "down angle" of the tanks reflects the bilge sloping down as it runs aft. I am not sure of the capacity but I think somewhere between 60 and 80 gallons. When the weather warms up I'll fill the tanks with water to determine their capacity. There are three tanks. The forward tank is about 34" long and the aft tanks are each 16" long. The tanks are made from polypropylene and were nitrogen welded. They are FDA approved for potable water and are supposed to impart no taste to the water. They are supposed to be very strong (3/8" thick). Each baffled compartment has an inspection cover.
I'll build shallow fiberglass trays, molded to fit each tank bottom. I'll fastened the trays to fiberglass runners that I'll glass into the bilge. The trays will keep the bottom of the tanks from moving around. I'll use blocks on the top end of the tanks and SS straps to hold them in place.
Looking from front to rear
Looking from rear to front
I wanted the tanks to sit in the bilge but not on the bilge floor. I wanted any water that got into the forward area of the boat to have a clear unobstructed path to the sump area. After considering many different options I decided to fabricate runners (or stringers) out of epoxy (bottom left picture). I would glass them into the bilge. I built the plug for the runners from 2X4s I bought at Lowes. I cut them to length (74") and ripped 30 degree angles on each side and made them just wide enough that 4" wide biaxial tape would just fit side to side. I think they are 1 ¼" on the two sides and 1 1/2" across the top edge. I started to sand them thinking I would wax them and then glass directly to the wood plug. However, I decided that covering them with "painters plastic" would be a lot easier. I laid three layers of 17oz biaxial tape wetted out with West System Epoxy over the plugs. After I removed them cured epoxy from the plugs I cut them to length. The front runners support the longer forward tank and the other half supports both the aft two tanks.
The middle picture depicts the trays I built for each tank. They were simple to build. I turned the tanks upside down. I covered them with plastic sheeting and laid four layers of 17oz biaxial cloth wetted out with West System Epoxy over the tank bottom. The next day I removed the cured trays from the tanks and trimmed them down with a grinder.
The bottom right picture shows how it will look in the boat. The forward tank is sitting in its custom molded tray.The tray will be secured to the runners with mechanical fasteners so I can remove the trays for cleaning, etc. The runners will be glassed into the bilge. All three tanks will be lined up and spaced to allow the floor timbers to fit between them. I will drill 3/8" holes in the lower aft corners of each tray to allow any water that gets into the trays to drip out into the bilge.
Image:
Today, I epoxied the stringers in place in the bilge. First, I laid down a wetted out 1" wide piece of 17.7oz biaxial that each edge of the stringer would sit on (this was just to provide some more cloth between the polyester glass over the lead ballast and the edge of the epoxy stringer). Then I placed each edge of the stringers on the wetted tape and then filleted each side of the four stringers with 406 thickened epoxy. When it had kicked sufficiently, I laid down a 3" wide strip of 17.7oz biaxial to each side of the stringers. Tomorrow I will attach the trays to the stringers. I will use self tapping screws to fasten the trays to the stringers. That way I can remove the tanks and trays when I want to wash the boat out. The design of the stringers holds the tanks 1.5" above the bottom of the bilge and allows any water that gets into the boat to run under the stringers to the sump. The tanks will eventually be held in place with wedges and straps so they can't move around.
The bottom two pictures to the right are photos I took this winter and they show how the whole thing fits together. The forward tank is the closest to the front. The tanks get deeper as they go aft because the bilge slopes down and back. The aft two tanks were divided otherwise they would not have fit through the companionway hatch. Each tanks has baffles and an inspection/clean-out port for every baffled compartment.
Today, I also filled the tanks with water to see how much each tank would hold. The forward tank holds 35 gallons, the middle tanks holds 18 gallons, and the aft tank holds 20 gallons. With the 30 gallon quarter berth tank that gives me just over 100 gallons. I'll add another 25 -30 gallon tank at some point.
Stringers for the water tanks.
Each tanks sits on a custom molded epoxy tray and the tray sits on the stringers.
Three tanks for a total of 73 gallons.
There are things you will never know about your boat until you rip it apart and rebuild it. I have learned many things about the Far Reach during this project. Today I learned there are few, if any, horizontal surfaces that are level with each other anywhere on the boat.
Today, for example, I installed the water tanks. All went well. After I sat them in the trays I installed yesterday, I checked that there were level both athwartship and fore and aft. I removed them from the trays then I used #8 SS self-tapping screws to secure the trays to the stringers--they are temporary screws as they were the shortest ones I had on hand. After I reinstalled the tanks I sat back to admire them. I was thinking how much more proper they look in a boat than on a garage shelf. Then I noticed they were not level with the forward floor timber. Hmmmm. So I checked the tanks with the level. Dead on. Then I check the floor timber . . . high on the right and not just a little. I check it against the other floor timbers. They were also high on the starboard ends. I check the cockpit-- dead level. I check the cleats the supported the settees "back in the day." Level. Very interesting. Either the deck is on crooked or the boat was not level when the builder installed the floors. I will investigate this more tomorrow.
Before I can install the floor beams in the saloon area I needed to reinstall the water tanks. The bottom of the trays are a little rough and I have been concerned that with the boat bouncing around in seaway there could be some abrasion to the tanks. So, a few days ago I ordered some 24" X 12" X 1/8" thick EPDM rubber from McMaster-Carr. This will put a thin layer of rubber between the polyethylene tanks and the epoxy trays. I trimmed the rubber with a box cutter and cut it to fit in the bottom of the trays. Once I was satisfied with the fit I cut holes in the rubber with a 1 1/2" hole saw to match the holes in the trays that are intended to allow any water that gets into the trays to drain out. The tanks fit snug in the trays so I think this was a good move.
