Building Logs

Top step prep

Posted by Paul

The section of boat aft of the last bulkhead, including my hull extensions are now sealed. Well, almost sealed. In the starboard hull there is a conduit with the underwater light power lead coming through and with some sealant in the end of that conduit around the wire, it is sealed. In the port hull, same thing, but I also have a 4″ inspection port. Funny thing, just to show how dumb I can be. The inspection port is smaller than the underwater light, its a 5″ light. So if it stops working I can get my arm into the well to perhaps undo the holding screws but it also glued/sealed in with sealant, maybe I can get a screwdriver or chisel in to break that sealant (I doubt it though) and get the light free from the hull and into the cavity (it is bigger than the hole it is mounted into because of the flange on the back of it so it cant go out through that hole), but then I wouldnt be able to get it out of the inspection port either! Doh. Dumbhead move. Of course I could get lucky and the light might work flawlessly and be sealed in permanently and that inspection port never gets opened except to check for water in the chamber, and if the light ever fails or water gets in I will worry about that then.

hydraulic ram table dry fit

The second step is glassed to the bulkhead that the rudder is hung from. To recap, I made a top box to house the bearing and tiller attachment  that also acted as a web to support the middle of the step more. The bulkheads needed to be raised to meet the step to seal the space. But first I glassed the hydraulic ram tables to the top of the bulkhead. And replaced the arm hole cutouts I made to enable me to glass the underside of the second step. First thing was to dry fit the ram tables, then once everything was correctly sized and positioned, prepare the ram tables to be glassed in by sheathing the ply in glass to seal the ply and to provide a glass surface to which to tape to, rather than the ply and spreading the surface loads of the tape over the larger area of the entire glassed table. Probably over engineering, but it certainly cant hurt. The hydraulic ram is going to be pushing and pulling the entire steering loads so I wanted the table to be really well glassed in to ensure that the loads dont come close to troubling it.

ram table ply glass sheathed

The ram tables are triangles of 20mm thick ply, so the gap to be filled from the top of the bulkhead to the underside of the steps was reduced by that 20mm, the port side was 50mm so needed a 30mm strip of duflex to fill, the starboard side, for reasons I dont really know (I have measured everything and the steps match in every way except that bulkhead height) and 40mm on the starboard side so a 20mm filler strip. By glassing the ply onto the top of the bulkhead I was able to run a tape from the top of the table onto the inside of the bulkhead. Then when the filler piece was put in, I ran another tape from on the step, down the bulkhead filler and onto the table, along with a tape on the underside of the table. From the hull side (chamfer panel) above and below I also ran a strip of uni covered with another layer of double bias.

port ram table glassed in

I glassed the armhole cutouts back into the holes from the inside of the bulkhead through the gap that will soon be filled by the ply and filler piece then glassed the ply table to the top of the bulkhead with the tape that went over the top and around onto the inside of the bulkhead and waited for it to set. Then I glued the filler peices in and glassed it all down sealing the space. The conduit filled most of the gap between the edge of the ply and the chamfer panel, some filler coving and the uni and double bias over it before peelply finished it all off. I didnt bother to decore and back fill the back edge of the step because the edge will not be in a traffic area and also wont be a visible curved edge being inside the outboard well but the balsa edge did wick a lot of the resin away resulting in a slightly dry tape needing to be patched in a couple of places. Still a couple of patches used a lot less time and resin than de-coring and back filling would have. Next time I have to glass  a raw balsa edge I will pre coat the edge with resin to ensure I dont get a dry tape again.

starboard ram table glassed in

port steering ram table glassed in

I may have to glass another smaller table onto the other side of one of the wells if the autopilot I eventually buy needs a rudder reference tiller. That would be the starboard hull as the helm is on the starboard side (shorter distance for the transducer cable). The other thing I will need to glass in, or somehow attach is tiller arm bump stops. When the helm is hard over I dont want all of the pressure on the rudder to be borne by the fully extended ram arm. It would be much better if a solid block was stopping the tiller from rotating any further than 35 degrees.

ram tables finished

What I will do is glass a ply pad to the boat under the ram table (one each side of the cavity) with 2 or 3 T nuts on the inside, to which I can bolt the bump stops to, what they will be made of I am not yet sure, probably also timber. As you can see from the next 2 pics of the tiller at 35 degrees either side of centre there is ample room for the stops.

ram table tiller arm angles

tiller bump stop set up

Ages ago outboard leg tunnels were glassed into the space between the bulkheads to reduce the size of the column of water the outboard legs would travel down through and out of the boat, without them the entire well would flood. The tunnels are about 100mm higher than the dwl. A lot of previous Schionning’s that have outboards used 9.9hp motors, which are relatively small and the cut out through the hull is basically a T shape to take the prop and cavity plate. I had wanted to upsize to 2o to 30hp motors and had settled on Evinrude  E-tec’s as my preference. I borrowed one to size the tunnel and through hull size requirements. They have a double cav plate system with the bottom cav plate extending some 200mm past the prop and the top cav plate some 100mm in front of the leg and prop meaning the entire opening front to back is about 400mm and the prop requires 150mm either side of centre so 300mm wide. And because I thought their might be a need to initially adjust the trim of the motor to find its optimum angle, I added in a margin of safety front to back and made the opening 500mm giving me 50mm movement forward or aft from centre. That makes the opening quite large in comparison to what would be required with a 9.9hp.

outboard well

Ironically, because I have run out of money, I am going to initially use…..yep, you guessed it, 9.9 high thrust Yamaha 4 stroke. Older ones that were pre the conversion to the upsize 8hp they currently run, instead of the old detuned 15hp that everybody prefers. I have flanges at the bottom of the cavity that are a skin to skin solid glass (about 5mm thick). My plan is to use those flanges to mount a removable door plate. I plan to make 2 of the door plates for each hull, one of which I will cut out doors to fit the 9.9’s the second of which will have doors to fit the larger e-tec’s or maybe the Suzuki V-twin 25hp 4 stroke. I am limited in the outboards that will fit under the steps in the up position and only outboards with quite low motor head cowlings will fit. The e-tecs are a modern 2 stroke and are quite low profile, the Suzuki v-twin being a V motor is also a lower profile as opposed to most other 4 strokes that are 2 or 3 in line, one above the other cylinder heads are much  taller and wont fit under the steps unless I keep it permanently lowered, which is not ideal. Having said that, it would be the equivalent of having a stern drive leg, so not unimaginable but it would be a shame to have the ability to retract the motors removed. So by making 2 sets of doors I will have the ability to easily retro fit the better motors when the budget recovers, some time after launch. I could just make the doors bigger to start with but I think I may have the yammies a couple of years!

To make the plates I will apply packing tape to a sheet of mdf or chipboard and wedge it up against the hull from below. Packing tape will also be applied to the flange (both sides inside and out to be safe) and up the tunnel sides about 50mm. I will then lay layers of glass to the bottom of the tunnel onto the mdf board. When set it will be formed to fill the space of the opening and maintain the fair line of the hull meaning I wont get turbulence in front of the rudder from the doorway. I will drill holes through the plate and the flange so that I know they align, then I can remove and replace that plate easily and it will self align. It can then be attached via bolts with rounded heads on the outside to minimise turbulence. Then I can cut the doors into that plate on a table rather than fiddling around in that tunnel. Repeat the process to make the second plate and cut different sized doors into it and store them for the day I fit the bigger motors. I can also figure out and set up the opening and closing mechanisms and make sure I position them so they work for either size doors so that when I retro fit the other doors the mechanisms dont need realignment or repositioning.

Whilst all of this is going on I have also started on the prep work to fit the top steps. Again to recap, I rather niavely made the step tops with 20mm overhangs (10mm gap plus 10mm thick foam front edges) that were designed to house an led rope light that would light the step below and illuminate the steps with distinctive blue led light. Unfortunately, just taping the inside of the steps is not sufficiently strong enough and the step set I have cut the door out of has already started to come apart as a result of moving it around the shed each time it was in the way of the next job I was doing at the time. So plan B is to remove the overhang, de-core the step tread edge and back fill before rounding them and glassing outside. This will then make them strong enough and they can be glassed into the boat once all of the outboard well work is done.

stb steps rope light flange removal sbd steps edge decore

stb steps flange removed edges decored backfilled

As I mentioned in the previous post, the multi tool is fantastic for de-coring. So a jigsaw cut to remove most of the material, a run over with a grinder to remove the rest and to remove the fairing bog for the next tapes to go glass on glass and to be buried beneath the bog height already in place (much easier to re fair) and the de-core back fill and I am ready to shape the edges round and glass the outside of the starboard steps. The port steps are a bit trickier in that the doorway is already cut out and ideally I would want to re-attach it somehow to get the door and steps fair to each other in their new profile/shape. At the moment I cant even get the door back into the opening because the door is currently slightly bigger having had the edges de-cored and filled.

rear steps with door roughly in place

Next week Terry is coming over and we are going to raise the boat about a meter. At the sterns at least. We need to do this in order to get the rudders into the shaft tubes and bearings. Once they are in we can lower it most of the way back down again. I need them in so that the steering can be hooked up and made to work properly before I glass the rear steps in. I am also waiting on the outboard transom car bearings……yes……same company. They are cheap but S>>>>L>>>>O>>>>W! I gave them the job when they finally gave me back the rudder bearings, some 4 months ago. I hope to have them next week so I can get the outboard raising and lowering mechanism working either just before or just after (might need the steps in for this part as the top sheaves may need to be anchored to the underside of the top step). The other job needing to be done in the well before close up is the halyard entry exit points and mechanism.

For those that dont know, my sail halyards (foresails/spinnaker if used and mainsail) come down the inside of the masts, into the mast posts and exit inside the boat and are led aft through a series of copper pipes to the last bulkhead where they exit the interior. I had intended they travel up the inside of that bulkhead then out near the deck but that added a complex series of turn blocks. But exiting at their current height that they travel through the hulls at is a little too close to the waterline for there to be holes through the bulkhead into a very wet (flooded) outboard well. So in order to get these rope lines around the 90 degree bend through the bulkhead and up to the deck I have settled on gently curve bent copper pipes (with flared ends either end) that will be glued through the bulkhead. This takes the opening to a meter above waterline, inside a covered well, and with ropes in the pipes, the likelihood of water ingress through those pipes is minimal. If for any reason the ropes are removed from them, a stopper can be placed in the top of the pipes to seal them off. Should work ok. I am a bit worried about the friction that the curve might cause but really, the ropes are only for raising and lowering sails, so the loads should not be too great.

So all of these functional constructs should start to come together in the next couple of weeks and then the rear steps can finally go in. I cant wait for the day I start entering the boat via the steps instead of climbing through the bath well that I currently do. Then the bath and can finally go in!

One last pic for the post, just because I like the convergence of the curves created when I trimmed the second step riser to the hull side.

second step inside hull edge trimmed

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