The boat came with two water tanks (under v-berth and under cabin sole) and a diesel tank (under the galley sole). All of them are made of fiberglass with an interior gelcoat coat that presented blisters and some areas where the gelcoat was already chipping off. All tanks were fiber glassed to the hull. The decision was to separate them from the hull and try to get them out of the boat for evaluation. The water tank under the v-berth was too big to get it out and we had to cut it in pieces. It is no longer a tank 🙁 . We are currently evaluating if we are going to install an second water tank and if so… Where? bladder or permanent tank? if permanent… what material? $$$?

DECEMBER 2018

We managed to get the water tank under the cabin sole out of the boat in one piece and brought it to my garage.

JANUARY 2019

We cut the top off and we are trying to get rid of all the old gelcoat so that we can re-coat the interior. It appears to have blisters forming in the gelcoat with stains visible throughout the surface. Our plan is to re-coat the tank and then re-assemble it. Let’s see how it goes…..

A lot of sanding / grinding… I am using a grinder with a 36 grit sanding disc and a small belt sander. This gelcoat is very hard!! And creates a big mess!!

 

Yes, I know, my neighbors are probably thinking and I am cooking metanphetamin… LOL

More discussions about the water tank refit here.

The diesel tank would not go through the companionway so we are working it inside the boat… Not easy!! A lot of nasty cleaning and getting ready to replace all fittings and add a fuel gauge.

There is another post where we explain what we are doing with the fuel system.

 

January 2020

We have reached a critical decision point regarding the bow V-berth tank. With the removal of both starboard bulkheads as part of the head rebuild, we now realize that some of our original size restrictions of replacing the bow tank has been removed. Originally, any replacement tank was limited to the width opening of the forward passageway, about 16 inches. Now, with the bulkheads gone, we can get a larger tank into the forward cabin by taking it through the head space.

Our size restriction is now only the width of the companionway hatch, about 20 inches. So, we are proposing to make two new smaller tanks using the original tank as a mold and then setting them back in the forward cabin. Like the main cabin tank, the interior of this bow tank also had deteriorated with blisters and blemishes on the inside. Now in pieces, it could either be scrapped or still be useful.

We have looked at new replacement tanks but everything we have seen would be some form of rectangular box shape and thus give only a small capacity when set into this sharply curved space. In addition, we would have to add new support shelves or blocks to accommodate these flat sided units.

So, our plan is to make two tanks that will look very much like the original but cut in half so they will sit one in front of the other. In the top picture above you can see the 20 inch line marked vertically on the side of the tank; this represents the maximum size that can enter the cabin through the companionway. We plan to re-assemble the original tank, (it has a degraded interior finish so it had to be scrapped), cut it down to the 20 inch size and use it as a mold for laying up a new tank. This will be the larger of the two new tanks; the other will be formed from the front section of the original tank. Both will be re-set into the V-berth bilge and connected together. Once in place, we can move back to replacing the bulkheads.

As you can see from the picture above, the tank profile is really quite complex so care was needed when marking out to ensure that our maximum dimensions were not exceeded. The original tank was cut down to allow for a narrow gap (about 5-6 inches) between the two new tanks; this will allow for access to the connection fittings and hoses. To make up for the slight loss in capacity, we intend to add a 5 inch lip extension to the top of the new tanks which we estimate will give us about 20 additional gallons capacity. We believe there is sufficient clearance space under the V-berth floor to accommodate this lip riser.

Once the two molds sections were complete, they were ready to have a lip extension section added to the top. The first part of this was to add a simple 2′ x 2″ wooden strip around the edge and seal it with vinyl tape. This will become the first stage of the finished lip riser. Our plan is to form the tank by laying up glass fiber mat over each mold, then after release, add the full lip riser using reinforced epoxy /ply or similar that will be tabbed onto this 2″ section. Finally, the tank tops will be added once the tanks are located in the forward cabin. This work may be some months away when the weather warms up. In the interim, we can carry on with bulkhead carpentry knowing that the tanks are now safely positioned in their new home.

Prior to laying up glass on these tank molds, we have prepared them by adding several coats of gloss white paint followed by a liberal application of Partall paste after which coats of Partall Film were applied. This should allow the newly formed tank to release easily from its older parent mold. Let’s see how it goes…..

February 11, 2020. Time to remove the tank shell from its mold. It took a lot of effort which may be due to the strange curved shape that we had or perhaps the layer of release agent was not as thick as it should have been but anyway, the first tank shell was successfully pried away from the old tank mold. This shell was made up of about 3-4 layers of 1708 mat with some chopped strand; both of which provided both strength and flexibility for the removal process.

The next stages are to double check that it will still fit in the forward berth bilge then add additional layers of mat to build up the thickness and strength of the tank. Also, we will build up a ridge on the open top which will add additional capacity to the finished tank as well as providing a base for the top plate to be bonded to. The interior will be cleaned and gel coated prior to the top cover plate being bonded.

After the shell was removed from the tank mold, a wooden former was made and fitted into the open top of the tank so that additional fiberglass layers could be added to build up the top lip. Once sufficient layers of mat have been added, the former can be removed and the edge trimmed up. We plan on adding a return lip to the tank top edge or bonding in a wooden strip so that the top can be sealed down to a solid surface. Later in the process, we will give considerable thought and attention to decide on a suitable sealant for the tank interior.

May 2020. We are now back to working on the water tanks, both V-berth and main cabin. A work station has been built inside the boat shed, right under the bow where new V-berth tanks will be fabricated. Meanwhile, Carlos has started working on refurbishing the existing main cabin tank in his garage.

For the new bow tanks, we are going to use the originals as a mold and form a new shell by laying up fiberglass over the original after it has been covered in peel ply and a release agent. For this project we are using 1708 bi-axial mat which can be seen on the roll above the bench.

After pre-cutting pieces of mat, they were applied wet to the tank former and worked in to maintain the bilge profile of the original.

Once the tank shell was released from the mold, additional fiberglass mat was added to build up the complex corners and the lip. Each additional layer of mat increased the overall thickness and weight of the tank.

Next, it was time to see how it would fit in the bow.

The tank was positioned in the V-berth bilge at the same place as the original large tank and apart from some rough edges, it looks like it will work. So now, we move on the adding more material to complete the shell.

The next steps are to add a layer of epoxy and mat to the inside of the tanks shell, plus add a reinforcing layer of fibeglass around the lip to form a solid, flat surface for the top to bond to. This work will be done in the weeks ahead, after the second, larger tank shell is complete.

June 2020 Now for the larger, second tank. If you rember, I made a lightweight fiberlass shell from the reconstructed original tank a few months ago, before I left for a trip to New Zealand.

The larger tank will be made in a similar method to the small one but in this case I will lay up the fiberglass mat on the inside of the shell and form a new tank after removing it from this mold. Next steps are to check the fit of this shell in the bilge before starting work.

June 2020 – Next steps for the large tank; add additional glass to build up and finish the top lip of the shell; clean the interior and add a release agent. Liquid wax, polypeel and polythene sheet will be used to cover the interior of the shell to facilitate easy removal of the new tank. The tank top has been raised on the shell to add more volume to the new tank and this will be included in the final build as long as it can be fitted around the cabin entrance step.

We have also managed to make progress with the long bilge water tank that was located in the bilge under the main cabin sole:

Tent is up, before grinding I decide to removed the old fiberglass around the edges of the tank:

Then… a couple of grinding 2 hour sessions!!

After grinding, I cut a new top for the tank, a half in marine grade ply that will be fiberglassed both sides

June 30, 2020 V-berth tank fabrication progress. On my last post, we were left with the mold shell being prepared for fiberglass layup. Since the plan was to form the new tank from the inside of the mold shell, it was lined with a thin poly sheet to ease the mold separation. The poly sheet was held with double sided tape then the sheet itself was coated with Partall Film wax. Pre-cut segments of mat were cut then laid up inside the mold to form the basic tank shell. This was not easy due to the compound curves of the hull forming shape. Eventually sufficient layers of mat were in place so that it was strong enough to be pulled away from the mold.

It did take some effort to remove the new tank form from the mold shell even with the poly sheet and wax film. With nothing to grab on to, removal was a long and delicate process. Eventually it was free and could be worked on away from the mold.

Once the tank shell had been built up with multiple layers of overlapping mat, paying particular attention to the corners, it was time to trim down the top and form the lip that will bond to the top. The tank lip was cut straight across then a wooden lip former was added to the inside of the tank shell. Layers of fiberglass will be added to the tank edge and wrap over these formers to make the lip.

The next steps are to add strips of mat that will wrap over the wooden formers and bond to the tank sides, producing a continuous inset lip that the top plate can bond to. After several layers have been built up, the formers will be removed, (they have been covered with clear poly tape), and additional mat will be tabbed in on the underside of the lip to increase strength. For the cut-out section on the rear face, a box section will be fabricated, complete with top edge lip and this will be bonded in direct to form on continuous top edge. After that, a layer of epoxy bonded mat will be used to line the tank interior to ensure its long term stability.

The open box section that will form the tank top insert was fabricated using a simple box former and layers of poly resin. Once cured, it was removed from the former, trimmed to shape and test fitted to the tank shell. A rough set-up was made to evaluate the finished tank before moving on the the next stages. This insert section was needed since we had made the new tank taller than the original in order to add capacity. Without this insert, the tank would have fouled on the forward cabin step and would not have fully located into the hull. So, we add something then take something away.

With this phase complete, it is now time to decide on the size and location of any internal baffles. Interestingly enough, there were none fitted to the original tank. We will also now be better able to locate any tank inspection plates and fittings for a depth gauge and breather vent.

September 2020

During these months, both forward tanks have now now been completed and the internal surfaces coted with Aquapura; a special two-part epoxy finish designed for food prep surfaces, pools, water tanks and similar. This is designed to form a barrier between the fiberglass surface and the water in the tank. The product is made in Canada and naturally is not cheap, plus, it is normally sold in 15 liter tubs. In our case, we were able to purchase some surplus from a fellow boater who had just resurfaced his water tanks and was prepared to sell on his unused product.

The next stage is to cut and dry fit fit a top to each tank so that access plates and fittings can be placed. It is planned that the tops will be sealed in place once the tanks are secure in the hull and fittings connected. This will make it easier to handle the heavy tanks as they are placed in the cabin.

October 16th 2020 – Finally, the two new freshwater tanks have been set in place in the forward cabin bilge! After a long summer of fiberglass fabrication and design reviews, both the large and small tanks have been lifted on to the deck, lowered through the companionway and maneuvered into the front cabin space as planned. Remember that the reason we set out on this course of action was the removal of the head bulkheads that allowed full access to the front bilge for these large units.

Here’s the sequence of steps that saw them placed into the hull.

The two freshwater tanks have yet to be secured in place and still require the hose fittings to be completed. The smaller front tank will feed the larger rear tank via a short connecting hose link. Once this has been done then they can be tabbed in place. Plumbing connections for the tank tops will be carried out later when we have decided on the best layout for hose runs under the floor space. After that, the front cabin floor can be re-made and set in place on the support rails.