Clipper's Vera Cruise Build

Clipper's Vera Cruise Build

Wednesday, July 12, 2017

Cabin Floor Supports - Part 1

I am at that stage in the build where there are many small parts to make, lots of experimenting with ideas, and generally just trying to figure out what needs to be done, all the while trying to make sure I don't forget to allow for some aspect of the build. 

Fortunately (at least as far as building is concerned), my building rate is fairly slow, so I have lots of time to think about things before I do them. That's no guarantee that it will be right, but I am trying.

After completing the initial work on the V berth, I felt that it would necessary to have the next section somewhat worked out since there will be parts that have to work with the things I've already done and the next section aft which I had not done yet. Gobbledygook? Yes.

What I am trying to say is that when I start matching up the aft cabin with the V berth section, there are going to be vertical pieces that have to be designed and fitted in there. Since I have trouble visualizing the end result, other than in a general sense, I have found the best thing to do is work on small sections at a time. This helps to better see what has to come next. Sometimes this working on a small section means doing a preliminary design, such as the seat boxes I included in the last post.

I heard a saying once, something like "You can't really see the mountains in the distance until you climb the hills in front." Poorly paraphrased to be sure, but what this has always meant to me is that if I can complete some small section of work, it makes it easier to understand the next part. I used this same philosophy when I was fairing the boat several years ago. It looked hopelessly complicated when I first started, but each section was easier to do as other sections were completed.

Anyway enough of the rambling. This last ten days I have been making the floor support structure for the forward cabin. There are two sections of floor in the cabin and they will be similarly designed, however I am temporarily out of Mahogany to complete the second section.

I had several criteria I wanted to satisfy with this support structure. First and foremost, I do not want any springiness in the floor. Secondly, to keep mold and mildew away, the bilge area needs to have good cross ventilation. This means that any supports cannot extend from the floor to the bottom of the boat with out providing some way for air to flow through. And thirdly, like the V berth, I want to make the floor removable in case I ever need to work in the bilge.

This first photo, which I've posted before, was the original idea and inspiration for the flooring supports. This was drawn when I was still considering a full width floor up front. But it helped me to understand something of what I needed to do.

The photo shows what look like full height supports. This would not have worked for ventilation unless I cut holes in them. Furthermore, trying to fit these to the bottom and the frames would have been difficult because of the changing curvature and angles of the planking.

So I sat in the boat one evening playing around with various pieces of wood, trying out ideas. I wanted to see how stiff the floor would be using the 12mm plywood I have in mind for the flooring. Here is one shot of that process. It shows the concept of a center support on the spans and the plywood served as a test to see how much it flexed under my weight.

I decided to make four supports per section. Two inboard that would have center supports on the span and two outboard that would not. The reasoning for the outboard was twofold. First there is insufficient room under the forward section for this and secondly, I did not want any support structure resting directly against the hull planking. 

These supports would be made from 2" by 7/8" Mahogany. On the outboard supports, in order to get them to be stiff enough, I epoxied a 9mm piece of plywood to the Mahogany. The inboard supports were going to have a center span vertical support tie into the battens in the hull bottom. All four supports would be cleated on the ends and attached to the frames.

It took a fair amount of work to get these fitted, especially the outboard ones, because the hull curves up sharply at the bow and the supports mount very close to the planking on the forward end. I wanted there to be a gap so that none of the supports contacted the hull planking.

From this point on the visual progress slowed to a crawl while I worked on the remaining pieces and assembled them. The first thing I realized was that the inboard supports did not conveniently mount directly over the battens. Rather, there were approximately in between the battens and the center keel. 

What that meant was that the vertical center span support for these inboard pieces was going to have to be supported by the batten and the keel.  I created two parts to straddle the batten and keel and then mounted a vertical support to them and to the floor support pieces. The following picture shows this as well as another piece which I will explain in a moment.

The flooring will eventually have a access hatch over this center section. Since this access hatch won't be connected directly to the rest of the floor, I felt it was going to be weaker and need some additional support in the center. Hence the cross support seen in the last photo.

I also realized that this area of the bilge might be useful for longer item storage, especially if I can extend it into the next section aft. This might provide a place for fishing poles or an oar. We'll see as I get further into this. But in order to accommodate a long piece, that center cross piece would need to be temporarily removable when the hatch is open. So I built it that way.

This last photo also shows some plywood spacers at the forward end on the frame. These are necessary in order to provide an even surface for a long cleat to support the forward end of the floor. Of course, none of this is mounted permanently yet.

So here are a couple of extra views. 

What may not be readily apparent in these pictures is that the seat boxes will mount outboard of and above the outboard floor supports. The seat boxes have their own internal structure that will need to tie into the floor support structure. I need to start figuring that out next. This is exactly what I meant earlier when talking about working small sections at a time.

The first of these last photos shows how there is plenty of under support airflow. It will be quite easy to keep the bilge clean in this area when the floor access panel is removed.

The last photo also shows the next section aft. It's floor supports will be similar, however, I have extra battens to work with here, so I will probably provide center span vertical supports on all four supports in this area. This area will likely get an increased amount of foot traffic than the forward area, so I definitely want it to be stiff.

Also in this aft section will be the first two bilge pumps which I'll cover in the future sometime.

So that's it for now. There's a bunch of grunt work coming up, sanding, encapsulating, and painting. There is also a bunch of thinking/experimenting/designing work ahead as I figure out how the above floor structure connects to the below floor structure. A lot to think about.

Take care.

Sunday, July 2, 2017

V Berth Compartment - Part 1

With the initial interior mocking up completed and the cabin profile verified, I could finally get started on the next section in the boat. The plan is to work on the cabin interior floor and cabin fittings for a while and then eventually move to getting the fore deck installed. It will take some time to get the cabin interior done even though I will only be working on the basic fittings for the time being.

This means the floor and and it's supporting structure, the V berth including the aft section of the berth (which doubles as seating), the head box, and the cabinet box. Additional trim and fittings will come later after the fore deck is completed. I may also work on getting the cabin housing structure designed and built before returning to the interior. We'll see on that.

What I've been working on for the last few weeks is the V berth forward compartment. There are two areas of concern that I am tackling for now. The V berth platform which forms the forward part of the sleeping berths as well as it's support structure, and the area below the platform.

The plan for the forward V berth section is to use 12mm Okoume plywood for the platform, supported by a mahogany structure underneath. I want the platform to be strong enough to support two people's weight while sleeping and one person's weight if they are standing in the overhead hatch.

Additionally, there will be access panels in the top to allow entry into the area below. This area below is sort of a free area for now as I am not really sure what I can use it for other than storage. For that reason, I have decided to make the platform removable as well. This gives me flexibility to make changes in this area in the future if needed.

The picture below shows the mock up of the platform in position. There will be a 4 inch foam cushion on top of the platform which will end just below the hatch opening in the forward bulkhead. You can also see that the chine blocks extend up the sides above the level of the platform, so there will need to be allowances for this.

On the aft end of the platform, there is a vertical panel that will drop to the level of the floor. In this vertical panel, will be an additional hatch to access the compartment from this direction. All of this is between frame 5 and frame 6, a distance of approximately 3 feet.

In order to provide the necessary strength to the platform, in addition to it's 12mm thickness (approximately 1/2 inch), there needs to be a supporting structure which I have made from African Mahogany. It consists of a cross brace attached to frame 5, at the aft end of the platform, supported vertically in two places on both sides of the previously mentioned hatch.

These vertical supports are attached to the cross brace and to the floor timbers in the frame. Where they connect to the floor timber, I created 9mm plywood gussets. Then running forward in two places, are two additional supports which connect from the cross brace to the floor timber on frame 6 (under the forward bulkhead).

The following pictures illustrate this. In the third picture, you can see the gussets on the vertical supports. The second, third, and fifth pictures show the hatch opening and the vertical supports. The fore and aft braces are shown in the second, third, and fourth pictures. The hatch is sized to be narrower than the seat boxes that will eventually be installed aft of this location. The scrap plywood temporary floor shows how big this piece will be. It will extend from frame 5 to frame 3 and is approximately 31 inches wide.

To make the V berth platform removable, I will be adding threaded nut inserts into the support structure and use screws through the platform to secure it to the structure. The fore and aft braces will get additional bracing to support the access panels in the platform, but these have not bee designed yet. The platform has been rough cut from plywood, but still needs to get final fitting done. I delayed on this step because I wanted to complete the work on the section below the platform.

As mentioned previously, I am not sure how this area might eventually get used, so in order to make it usable as storage for now, and to give it the flexibility to be changed later, and to give access to the bilge area below. I have constructed a removable lower floor assembly. This will be secured in a similar manner to the platform above via screws and threaded nut inserts.

The floor assembly also needed a support structure, however not nearly as robust as the platform. So that structure consists of two cleats. One mounted aft on the frame and one mounted forward across the stem. I am still finishing up the encapsulation and painting of these parts but all are made and in various stages of completion.

The floor assembly is made from 12mm plywood and has 1/4" mahogany strips across the sides and forward edges to keep items from sliding off. It is a partial floor assembly and leaves some open areas around it for ventilation. The topside has received a fiberglass cover and the entire assembly is encapsulated with epoxy.

Before installing the floor assembly, I wanted to paint the bilge area. So this was encapsulated with epoxy first, masked off (including areas that the platform structure will bond to), and then painted with white bilge paint. When I complete encapsulation of the floor assembly and forward mounting cleat, they will also be painted with the white paint.

This is where I am at as of today except for some additional design work on the next section aft of the forward V berth.  Most of that will be covered in the next posting, but one area I will cover now is the design of the seat boxes that make up the aft section of the V berth.

These seat boxes have to serve two purposes and allow for several considerations. I'll cover that first and then get into the proposed design.

The seat boxes, when used as seats, must not be too deep but at the same time allow sufficient depth (inboard to outboard) for storage underneath. They also need to have enough width to allow sufficient room for a sleeping person. These two measurements are different. Furthermore, I am trying very hard to maintain an openness in the cabin since it is quite small. This means keeping as large a floor space as I can manage. The 31 inch width of the floor came about by raising the floor and was mentioned in my previous posting about mocking up the interior.

I want to preserve this floor space when the seat boxes are used as seats. Additionally, for consideration of my wife's need to get out of the bunks after sleeping, I want to maintain a narrow area of the floor space to swing her legs down instead of having to slide off the end of the V berth if it extended all the way across the aft section when used as a bed. And finally, extending the bed across the cabin would have required a large platform that would have had to be stored somewhere on the boat. I wanted to avoid that.

So the plan is to make the seat boxes approximately 20 inches deep and have a flip up extension on the inboard sides which add an additional 10 inches of width. This will leave a floor space gap of approximately 10 inches in the center between the two seat boxes.

This flip up extension box needs to be supported on the bottom side when flipped up and when flipped down, not take up any additional floor space. So it will fold into a pocket on the inboard side of the seat box and will have fold down legs hidden in the underside. To use the extensions, they simply need to be folded up to the horizontal position and the legs folded down to support them. When not needed, the legs are folded up into the extension box and the extension box folded back into the seat box.

There will be an internal wall outboard of the pocket for the extension box that will separate the storage area from the extension pocket. Finally, the top of the seat box will also be hinged so that the storage underneath can be accessed.

The drawing below is a concept drawing that is neither to scale nor properly proportioned. It also contains a few ideas that may not get incorporated (folding flap at the bottom of the extension for one). But it adequately illustrates what I am trying to accomplish.

So that's it for now. It's been fun working on this and I've started working out the design for the floor support structure that comes next. Once that is built, I will start on the previously mentioned seat boxes. So until next time, take care.