Project Logs

September 24, 2011

The sump tank construction is fully complete.  The valves have been installed which will allow the 3 forward areas of the boat to be individually sealed off from the rest of the boat.  Access to these valves will be quite tight.  If I had to do it again, I would have likely increased the access to these, though in truth, I would only be able to give a few extra cm of clearance, due to cabin sole head height requirements.  To help with being able to open and close the valves, I’ve drilled holes into the PVC valves so I can attach small chains to pull the valves close, without needing to have my whole hand in the sump tank.

The tank lid has also been test fit and just needs to be installed firmly in place.  The lid I used was an access lid, which I’ve often seen installed on the deck of boats, but will work well for the sump tank as there isn’t any need for the tank to hold liquid.  Here’s an image of the sump tank as it is now:

This image shows the sump tank with the round opening with the forward diesel inspection port aft of the sump opening. 

August 11, 2011

The sump tank is now essentially complete.  The plastic access hatch I purchased has been test fit and I can confirm that it fits the sump tank access port. All the valves and PVC drains are installed and in place.  The area around the opening to the sump drain has been faired.

If it wasn’t already clear, the sump tank is a small area that collects water from the forward-most water-tight compartments.  The sump drains into the bilge via a 1″ PVC drain and can be shut off with a PVC valve.  Inside the sump are 3 PVC valves which I can use to shut off the forward-most water-tight lockers.  This means that I am able to completely seal the forward area of the boat by managing the valves in the sump area.  Here’s an image of the PVC pipes as they run into the sump:

This image shows the PVC pipes in place. Their outlets are in the sump tank and each pipe connects to a different locker compartment.

I’ve also been working on the diesel tank lids.  I am making templates for the eventual stainless steel pieces which will create a lid.  The diesel tank has 3 access ports overall, and each lid is a custom fit.  As Tomahawk Boatyard has a welder in the yard (Leonard), I’m going to work with him to get some aluminum lids created.  The lids will have the fittings welded to them and will likely be made of aluminum.

 August 2, 2011

I added a couple images of how the cabin sole has affected the lid access to the diesel tanks.  Basically, the cabin sole will be built all around the lids.  The reason for this is that I poured foam above the tanks to support the cabin sole and construct a drip pan.

I should also mention that I added images of the original gas tank that was in place when I purchased by Bristol sailboat.  I believe it was made of monel and was in good condition.   As I had no plans to use the tank, I ended up selling the tank on Craigslist for $75 (with strong urges to the next owner to verify it didn’t have any leaks; he was a mechanic).

As far as future gasoline tankage, at this time, I have no plans to use gasoline on my boat.  I may need gasoline to power a generator eventually, but my plan is just to use jerry cans.  I may end up stowing the jerry cans in the lazarette sea chest/chain locker (to be added later), though I’m not 100% sure on how well ventilated this area will be, thus giving me some concern as to the ability to safely stow jerry cans of gasoline in this area.  Likely, I will do more research on this as I build the Lazarette locker, so I would check there for future information.

 July 25, 2011

As I’ve been working on the cabin sole, I realized I needed to lower the middle diesel tank flange.  This meant that the extra high flange I had built previously had to be cut down.  It did represent a fair amount of wasted effort, but that’s just how things go and I was never 100% sure about the flange height while building it anyway.

The reason I had the tank flange higher was due to the tank’s design.  Since the tank is built in two separate compartments with one compartment being slightly higher than the other, I had built the flange higher to accomodate the elevation difference.  This would mean that if I filled the tank to it’s heighest fill level, the liquid inside wouldn’t be resting agains the lid.  This would allow me (if I wanted) to fill the tanks with an extra liter or so without the liquid pushing against the lids.  (I hope that makes sense, but the photos may explain more and if I you have any questions or need for clarifation, leave your question in the comments section below)

The other reason I built the mid flange higher than the others was due to the fact that the sole between the nav-station and galley would be quite a bit higher than the normal sole.  As it turned out, the raised sole would be noticeable lower, which meant less room below the sole and less room for fittings if I had a raised flange. I want it lower.  Here’s an image of the diesel tank lid flange in discussion:

This image shows the two aft-most diesel tank flanges. The forward of the two had to be trimmed down so the cabin sole height could be reduced.

Today also marks completion of major construction of the diesel tank.  Last weekend I installed the lid onto flanges that I had built.  Here’s the basic steps for how the installation of the lid was done:

  1. 2 layers of 6 oz fiberglass cloth were epoxied to the underside of the lid, then coated with 7 coats of resin rich epoxy.  After the resin was all laid on the underside of the lid, the lid was heated for a high post-cure temperature.
  2. After doing some minor repairs to the underside of the flange, the lid had a final fit and I cut all the glass for the installation.
  3. Once everything was ready, I wetted out some Baletk mat, placed it on the pre-constructed lid flange and then placed the lid onto this.
  4. I weighed down the lid with cinder blocks and while the weights were in place, I poured unthickened epoxy into the area between the lid and the hull, effectively filling any possible voids between the hull and the baltek.
  5. Once the baltek had kicked, I removed the weights and wet out the top of the lid in the areas that would receive glass (the entire thing).
  6. With the unthickened epoxy warming up, thickened epoxy was also placed in all same seams as the unthickened epoxy.
  7. A thin strip of 1708 biaxial cloth was pushed into the thickened epoxy.
  8. 4″ strips of 1708 biaxial cloth were applied to all seams.
  9. 6″ strips of  1708 biaxial cloth were applied to all seams as well as to all areas on top of the tank
  10. With everything kicking, I reached into the tank and coated the Baletk mat with 4 coats of resin rich epoxy, then left the tank to cure at a higher temperature using a shop light stuck inside the tank.

Once the lid was installed, I did some fine tuning of the lid flange to ensure it was a flush fit for the eventual meta lid.  I just templated the lids for all the tanks I made and I will be giving those to the local welder soon so he can begin fabrication.

 July 14, 2011

I’ve been working on the diesel tank for a week or more and so far, it’s  been one of the most involved projects to date.  Building a fuel tank of any kind requires a lot of careful fiberglass and epoxy work as well as careful planning of each step, because once the tank is in, there’s no chance to go back and make changes.

I made a big design change just prior to installing the tank.  That decision was to build the tank in two different sections which are connected via a channel.  The channel is below the new bilge area and overall, the design increased my diesel tankage by over 10 gallons. An image is probably are the best way to describe the channel:

This image shows the area I decided to convert to the diesel tank. The forward two flanges are the bottom of the soon-to-be-created bilge. Note the small gap below the bilge sole; this allows fuel to flow to the forward portion of the diesel tank.

June 24, 2011

I’ve installed the tank and the PVC lines that will drain into the sump.  I’ve also created a sump tank lid using some old fiberglass I had from the original fiberglass water tank.  Overall the sump proved to be a simple installation, however there was key measurement to remember: cabin sole position.  The sump’s height dictated where the final sole’s height could be above the sump.  Here’s an image of the sump tank lid before I installed it on the sump’s lid flanges:

This image shows the odd shape of the sump tank lid. The rough epoxy is the beginning of the lid flange for the sump tank.

I’m not exactly sure when I’ll get around to the final construction of the kerosene tank, but I’ve installed the forward bulkhead of the tank already.  The reason for this is because I needed to run two PVC pipes for the chain locker and forward-of-kerosene-tank locker.  I also installed a PVC tube that goes through the head which, eventually, will allow a kerosene line to run down to the heater without compromising my water-tight compartments.

The tank wall installation was just your basic template, cut, and fiberglass job.  I decided to go with a 3/4″ piece of plywood for the tank wall, not because it was necessary for the kerosene, but because this was a forward location in the boat that I felt could use a bit of stiffening up in an area that will be constantly crashing into waves.  Here’s an image of the new forward tank bulkhead I added to create the sides of the kerosene tank:

This image shows the forward kerosene tank bulkhead supported so it can be epoxied in place. Once hard, the thickened epoxy holds the piece firm, allowing for easier fiberglassing.


Diesel Tank
  • A key concern is that the engine must have clean fuel. Since fuel tanks collect sediement, many yachts have experienced fuel problems in rough weather, when sloshing about stirs up dirt. Of course, tanks should be cleaned periodically and before long passages…  ( Desirable and Undesirable Characteristics of Offshore Yachts )
  • Fuel tanks should vent overboard so diesel fumes or over filling fuel will not foul the interior of the boat.  ( From a Bare Hull, p. 280 )
  • To have fuel tanks near the engine is good. The shorter the fuel lines the better.  ( From a Bare Hull, p. 164 )
  • There is a great image of a fuel tank and all it’s pieces – IMAG1366.jpg (In “Plumbing” photo folder)
  • Naval architect Roger Marshall suggest that fuel tankage hold an amount equal to three or four percent of total displacement.  (Upgrading the Cruising Sailboat, p. 148)
 Greywater Tank
Inspection Port & Lids
  • Any future maintenance on the tank (like cleaning) will have to be done via the 6 inch inspection port mounted on the top near the aft edge. As long as 9 inches is kept clear aft of the tank, the hold down bracket can be unbolted and the tank slid out to reveal the inspection port. Should something foul the tank beyond use in the future, that cant be fixed via the inspection port, it will need to be abandoned in place, until fuel tanks and/or engine come out (hopefully never). (http://www.westsail42.com/2008/12/grey-water-tank-is-in.html)
  • Whatever a tank is made of, it ideally should have inspection ports large enough to permit cleaning when necessary. There should also be easily accessed aperture through which the tank can be sounded with a rod, as mechanical and electrical gauges are often unreliable.  (The Modern Cruising Sailboat, p. 256 – 7)
  • All tanks need inspection hatches large enough to accommodate getting inside to clean out the interior  (Cruising Handbook, p. 216)
Kerosene Tank
Securing, Support & Placement
Rainwater Catchment
Tank Fills
Tank Material
Tank Plumbing
Water Filters
Water Preservation
Water Tank



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