Building Logs

Step right up

Posted by Paul

Slow going the past couple of weeks. I have been working lots of shifts which rob me of most of my available build time for very little return. I have gone from working few hours for good pay to working long hours for poor pay, but such is life. I am grateful to be employed and able to continue with the build as a result, I just cant imagine how I would have been able to get anything done had I had this type of work from the start.

The other reason for the slow going is that I am making up the design as I go along. Well, that is not quite true but it feels that way. I am building the rear steps, some of which was built a long time ago and I hope to incorporate with a little modification, so that I dont waste both the time it originally took to build them or the time it would take to build them again now but far more importantly, to save the materials. The step design is now very much dependant on the very little material I have left of can afford to buy. In fact, I could not get any work done for the first week of the month because I had run out of double bias cloth and had to wait until I could afford to buy more.

So starting at the bottom step and working back up the steps I have been designing what I want in the steps as I go, within the broad brush strokes of the design idea I have had in mind for some time. I have always greatly admired the bottom steps of the Fusion 40, so I am trying to replicate that as much as I can with the material I have left and within the confines of the different hull shapes and the heights I have to work within, and with the materials I have left or can afford to buy.

I long ago ran out of duflex, but fortunately, I made my front 2 saloon windows on the flat part of the saloon front, had I made those windows more to the sides and larger then the panels would have continued around the curve of the cabin top and be curved offcut panels and I would have had to keep them as templates for the window maker, so the out take of those cut outs is 2 flat squares of duflex 800mm square that I dont have any other use for. When I cut the saloon windows out, I kept each cut out as a template for the window supplier, should we need to make a mould for each window. Having come out of the opening, these templates will be of the exact shape minus 40mm all around in size to account for the solid glass flange, to fit each opening. I am quite sure I will need to fair the outside of the cut out of the very curved front corner windows so that it can act as a cooling mold for a sheet of perspex that will come out of an oven almost molten. But the others have either only the slightest of curves (the bedroom wrap arounds are also very curved but not tall so also should cold form) and should be able to be cold moulded (pulled in to the window cold or with just a heat gun blown over it) or they are dead flat so wont need anything other than being cut to size. This is the case with the front 2 saloon windows and it is these 2 offcuts that I found and realised I would not need to keep them for templates.

I also have a few other off cuts, that have allowed me to create close to what I would have, had material not been in short supply. I like the way fusion have extended the bottom step past the hull side inboard so that it becomes a very versatile platform. I have long dreamed of sitting on the bottom step fishing, so I wanted to be sure my bottom step was a similar size. Below is the bottom step of a Fusion and what I am trying to replicate.


To complicate matters, a very long time ago, to facilitate fitting a larger than usual outboard under my rear steps and for it to be able to be raised far enough for inward swinging doors (rather than the plate attached to the fin of the outboard that Schionning advocate) I raised the height of the bulkhead that the outboards are hung on. This in turn created a steeper rise for the stairs than previously existed (the kit was originally for walk through transoms, but they only work with inboards and rob you of way too much internal volume).

In order to alleviate the steepness of the steps, without having too great a rise in less steps (one possible solution but one I did not favour) was to extend the stern. I only needed another 250mm to achieve my aims, all above the waterline and, in the time since I started building, Schionning have altered the design to add 200mm anyway, so in effect I am bringing the build up to current spec! Winner all around. Except for the tedious work involved! One small step in the making of a small step at a time.

As I usually do in this situation, I resorted to the cardboard templates to design each part, and utilising skills I learned when building my dingy I cut and glued each chine as I went along, then trimming to glue the next chine on until all the parts are glued (and glassed inside) in place ready for outside glassing and re-faring to complete the hull extension and bottom step fitting. This is a slow process as you can only do one step each time, then wait for it to set to start on the next chine.

Along the way I also fitted an underwater light into each hull and a shiny new boarding ladder (also part of the reason I didnt have the money for glass, its one week at a time now with purchases!)

Although it was a couple of weeks ago when I first discovered the window cut outs would fit, I held my breath whilst I put them in place in the bottom of each hull hoping like hell they would, knowing that if they didnt, it would mean a few weeks delay whilst I saved for a sheet of ply. The hull sides taper to wider the higher you go, so the width of the panel would dictate at which height it could be reasonably fit. I already had a height I needed it to be, so the panel would need to fit near to where I need it to be. At the height I needed they are about 20mm too small width wise and about 40mm too small length wise for what I had in mind originally. Close enough! I can fill the 20mm easily enough with filler as I glass it in and to accommodate the 40mm shortfall I have added something that is part of the design anyway but I was willing to not do to save time, so again I come out almost a winner. That something is an angled taper from the bottom step to the vertical stern plate. It adds a little more work but it means I can use the duflex offcuts I have for the bottom step and dont have to buy another sheet of ply (I certainly cannot afford another sheet of duflex, I could buy another sheet of un-glassed polycore and glass it, but I now dont have to, and all the other parts of the steps are very small parts that can be made from offcuts I have. Below is an image of what the plans stipulate the bottom step should look like, with the added angled panel from the bottom step to the vertical stern plate, that I am now adding to make up for the 40mm shortfall in the size of the bottom step panel I have.

mikes stern step

After deciding the largest part, the bottom step platform will fit I set about scrounging the rest of the parts I will eventually need. Having found what I felt would be enough bits and pieces, some duflex some ply, I started cutting them to shape, starting with cardboard templates.

First things first though. The hull extensions. I decided the extend the stern for 3 reasons. First and most important reason, I needed just a little extra hull length to get my step riser sizes and angles because of the added 200mm of height I put on for the outboard raising space. Second reason, Schionning have since revised the designs from 1230 to 1250 meaning they have added 200mm to the boat. I added 250mm, close enough. All of the extension is above the waterline, but I guess it will get wet when the boat rolls from bow to stern in waves (this curved section of the hull and the amount of curve is called its “rocker”). I have maintained the angle of the rocker when I extended. And the final reason is that I have a number of people that have completed cats all advise me to extend the hulls now, I will only want to do it later. They advised between 500mm and a meter. I wont go that far, the designers cant be that wrong! I experimented with different length extensions, restricted by the lengths of ply and duflex I had to make the webs and settled on 250mm. In the end, due to a measuring mistake I could have extended 210mm, closer to the length Schionning have changed the design by, as the bottom step panels were 40mm short of the 250 I decided on anyway and I could have done away with the angled parts but I decided it all fell into place well at 250mm so kept it at that.

I figure the forces that the hull extension might come under could be quite large, so I made sure I secured the extension properly. The chine extensions are scarfed, that is the ends are not butt joined square, but bevelled. And inside the sealed extension is a web designed to prevent the panels from being able to move without pushing the web as well which in turn means the entire structure would need to move. The web serves another purpose, as it does in the hull proper, it compartmentalises the volume so that should a leak occur the water can only inundate a small section and have no dangerous impact.

web dry fit for bottom step

bottom step web dry fit

Once I had glassed the web in I was able to glass the first panel in the hull extension. I started with the keel board then worked out from there.

transom extension keel

In order to get the shape of each chine right I used cardboard templates, looking down the chine join to ensure I was continuing the correct lines.

cardboard template for first chine

first chine panels dry fit

first chine panels dry fit 1

As with the hulls, although I could have made the pieces fit more accurately with angled sides to more closely meet the next panel, I have left the outside of the join open and filled with filler. This will aid with rounding the join before I glass the outside (the inside joins are coved with filler then glassed).

The final chine sides are made to the height of the underside of the bottom step panel (made oversize then trimmed until the bottom step panel was level.

second chine dry fit

second chine dry fit 1

Then, once the hull extension was effectively in place (it is still to be glassed on the outside, but that wont happen until the entire structure is complete) I started making provisions for the boarding ladder. I have purchased one rather than made one. I had a friend have one stolen, so I made provisions for having a rope boarding ladder on the other hull, 2 U-bolts in the stern plate of the other hull. These can also be used to tether the dingy or hang crab pots from, or even a berley bucket (you can never have to many tether points). Not sure why, but I decided on the port hull for the boarding ladder and starboard for the U-bolts. To accommodate each I used plywood because the nuts for each would compress balsa but not ply.

boarding ladder base dry fit

boarding ladder base dry fit 1 boarding ladder base dry fit 2

To mount the swim ladder I need to be able to bolt it into a sealed compartment. How do you get to the nuts to tighten them? You could use self tapping screws, but I worry they would loosen. The answer is nuts that grip the inside of ply and are permanently locked in place with blades that bury in the underside of the ply. They are called T-nuts. They work like any other nut with the correct thread but dont move once buried (by pulling them into the underside but tightening the bolt from the top side) in the timber.

T bolt

Although I will put thread sealant on the bolts to ensure no moisture can enter the bolt hole, I worry that as people climb up and down the ladder eventually everything loosens through movement and the bottom step is a very wet area, and a slow drip would eventually fill one of those sealed compartments in my stern, so I counter sunk (oversize drilled) the first few millimetres of the hole on the underside of the ply so as to bury the T-nut under a few millimetres of filler and a layer of glass. I also soaked resin into the bolt hole by taping over the underside of the hole and filling it with resin. Then when I glassed the ply ladder table in I put long bolts in to ensure no resin got into the threads and ruined the nuts.

boarding ladder base glassed in

Next step, the stern plates. On the starboard side I used ply as I am mounting the U-bolts in it and duflex on the port side starting with a slightly oversize offcut. In the pic below I am in the process of trimming it to shape. And the pics after as I glued and glassed it into place from the inside.

offcut for transom back

port transom plate glued and glassed

starboard transom plate ply with u bolts

With the transom end plates on I angled the webs to the angle of the plate that angles down from the rear step to the transom plate (not sure if it even had a name).

port transom almost closed

Then I cut the opening from the port step for the boarding ladder. Eventually the piece that comes out of the cut will be made into a lid for the recess so as to restore the bottom step. The lid will hinge up to reveal the ladder, it will swing over and into the water and the lid will hinge back down, and the reverse for stowing it. It will have a latch to keep it shut to ensure it doesn’t come open unintentionally especially from wave actions.

swim ladder recess cut out of bottom step

Next step is to add the inside hull, bottom step extensions and glass it all in and fair it into the hull side with a very large cove so as to gently deflect any wave actions below it.

starboard bottom step dry fit

Over the next few days I will be adding another 2 thickness’s to the overhang. I had toyed with continuing the angle of the stern around the corner and into the added thickness but it adds too much to the size of the overhang underside (the side that comes into contact with water) so I will maintain square sides and gradually fair around from square to angle as the panel goes around the corner from side to stern.

bottom step extension mock up 1

bottom step extension mock up

Once I have shaped the rear step overhang on each side I will glue the pieces to the bottom step panel, then glue and glass (as much as I can reach through that little opening on the angled sections from underneath. Then to finalise it all close the openings with the final stern parts. Those small parts will only be glued on for now. They will get glassed all over once the final shaping (rounding of the all the chine joins) is complete.

I have one further idea with these overhangs. I will mount stainless steel press studs so that a round padded roll can be clipped onto the steps when at anchor so that the dingy and boat are protected as they bash into each other, which is inevitable when boarding either vessel from the other on rough days.

Once that is done, the next step above it has to be made and glassed in, then the step set above that. But more on that as we go.

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