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.

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