After working through the main cabin, we have reached the head and with the toilet long gone and just some shabby cabinets left in place, we decided it best to open it all up and start again.
A bare space that was once the head showing the chainplate knees on the hull and a sea cock opening.
The floor had been cut out some months ago to deal with rotten wood and the mast support issue so removing the remaining panels and old fittings was a simple task. The question now was what to put back after the bulkhead repairs were finished. With the limited space available there are not many changes that we could make to the overall layout. One thing that we are considering is to fit a holding tank up against the hull, in between the chainplate knees. This would be covered by the back cabinetry and eliminate the need to have more plumbing through the bulkhead. A simple three way valve would be needed to select the outflow.
There are several designs of head plumbing layout to consider in addition to options for pumping, holding and processing waste liquids so we will take all this into consideration before we commit to a final configuration. Ease of use, ease of maintenance, overall requirements and equipment cost are all factors to consider.
The head lining panel was removed from inside the head space since it was scratched, discolored and had several spider cracks in the gel coat surface. It was placed into storage whilst this re-build continues and will either be re-furbished or renewed. The void space behind it will probably be filled with a foam sealer to provide strength and insulation prior to the panel being re-fitted.
The head also contains four chain-plate knees, one on each end bulkhead and two in between. These were all in a terrible state of decay due to water ingress and were all removed as part of the clean-out. You can see some of the chain-plates temporarily re-placed in the pictures here.
With both the original head bulkheads removed, the first new one is positioned for a dry fit prior to assembly. You can see two of the starboard chain plates resting against the hull on the right side of the picture.
Here’s the new bulkhead in the head in its dry fit state. Later, it’s two halves will be joined, the panel covered in a laminate and then it will be tabbed in place. After that, the head will be built out then the second bulkhead replaced.
Each of the head bulkheads are also the anchor points for a chain plate so it is imperative that they are strong and secure. The original bulkheads had suffered from severe rot and decay which had compromised the mast integrity. Additionally, the chain plate knees in the head space had fiberglass de-lamination and broke away easily from the hull surface when stressed. So, as part of the head re-build, we will be replacing the starboard chain plate knees.
October 2020 The two halves of the first new bulkhead were taken to the boatshed and a planer used to make a rebate step on the edge where they will be joined. Then they were taken into the cabin for fiberglass epoxy bonding. This type of joint should give us the required strength for the finished bulkhead.
Remember, the reason that we had to make it in two pieces is that the finished bulkhead is too large to fit through the companionway.
When the boat was built, it appears that the laminate was added to the bulkheads after they were installed. Screws under the original laminate secured the bulkhead to the corner post. Since this would be difficult to achieve in such a confined space, I opted to add the laminate first then tab in the bulkhead later whilst it was clamped in place. Construction adhesive would be used to bond the plywood edge to the corner post. A cut-back on the laminate would allow the edge to sit snug into the post.
With the first new bulkhead now fabricated, it was now time to move on the other plus the mid-position chain-plates. We decided some time ago to make the head center chain-plate knee a structural part of the sink base. So as you can see in the picture, it has been cut out to provide support for a sink top and storage locker. Beside it is a smaller, conventional knee that sits close to the second bulkhead chain-plate.
Marking out original dimensions on a curved hull surface presents numerous challenges and by looking at our earlier photos plus measuring parts of the original structure we think we have things line up. With no fixed supports to use as temporary attachment points, this is difficult work. The head door posts were maintained in their original position by means of temporary fixings but a lot of activity has gone on around them over the months.
The second new bulkhead will be fabricated in the same was as the first; make a template in two sections that can be removed from the cabin, cut the marine plywood to shape then join the two pieces inside the cabin after final fitting. After that, add laminate then tab in place. From the above picture, you can see that we have used the door post to provide a straight cut design for the smaller part of the template. Temporary fixings and the chain-plate allow this panel to be held whilst final marking out takes place.
The plan is to fabricate these next knees and bulkhead, then as the weather warms to make it suitable for fiber glassing, go ahead and tab them in place, starting with the one facing the front cabin then moving back to complete the head and the second main bulkhead. Once secure, we can remove and replace the narrow laminated panel between the main posts. It is the narrow panel on the left side of the picture above and all its lower section has been rotted away.
September 2021 – update!
The boat is moving to a new home and we need to finish the bulkhead work before it can be lifted and transported. So, in the past week I have fabricated a second bulkhead from ply sheet, joined the two sections inside the hull and tabbed the single panel in place. The process was much the same as that for the first bulkhead except that I did not finish this one with laminate sheet. It will be sanded and finished at a later date.
Here’s a few pictures of the work undertaken.
