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Perhaps it was the cancer operation or, as my daughter suggested, just plain old mid life crisis, but sometime around the middle of 2015 Deb and I made the decision to relocate from Alice Springs to Devonport and build a 12 metre catamaran.

So whatever the reason (and there is a reason for everything) we write this blog to share a little of our journey with our friends, old and new and our rather large extended family.

Its by no means a unique story, as the boat we chose to build was designed specifically for amateur builders, and many have gone before us. It is however, a major project and rather daunting for two Centralians from the red centre of Australia.

So please join us.

Pete and Deb Imms

PS: whats in a name?

Selah is ancient Hebrew. So ancient in fact that its literal meaning has been lost in the midsts of time. I love that. It is most commonly used in the Book of Psalms seen in both the Torah and the Bible and is believed to encourage the reader to “Pause and reflect”.

Bridgedeck lifted and fitted

May 27, 2017Leave a comment

Building a boat is a series of milestones. Some, such as turn-over day, bring about a sizemic change in the working environment. This week we lifted and fitted the lower bridgedeck and once again our world has changed.

It took us two days to prepare for the lift. First we jacked it up for a dry fit and to rehearse the final lift. While it was up we scribed the positions of the frames, and made a minor adjustment to the fore-aft alignment of the hulls. We also removed the scafold from beneath and pushed our trailer below frame five. We used a hydraulic scissor-lift positioned on the trailer, to lift the deck. This worked excellently, and the trailer provided a safe zone for Peter to work, in case the whole lot came down. We estimated the weight of the deck to be around 150 kilos, so every manoever was carefully discussed to ensure that neither of us was ever at risk. The forward and aft ends were held up by support struts on bearers.

The primary consideration was ensuring the final lift would happen as quickly as possible. It was our biggest glue lay-up to date, around 24 metres in total, and once we activated the glue, we had 40 minutes to butter the joints and screw everything into place, before it went off. We also drilled all the screw holes and pre-loaded them with the 200 screws, ready to go.

Lift day was scheduled for 10am on Wednesday, and Russell and Jody kindly offered to help. We mixed four pots of epoxy, thickened with West System 403 filler, and set about laying it out. This is a critical structural lay-up and we did not skimp, applying it thick enough to ensure plenty of excess ooze, a visual confirmation of full glue coverage.

All went smoothly and 30 minutes later the job was done. Pete and Deb then spent the next hour cleaning up the excess glue and re-purposing it, filling screw holes and filleting the frames. We then took ourselves to the local bakery for a celebratory pie and coffee, before returning to tidy up the work site and disassemble the support scaffolding that was no longer needed. We left the supports in for 48 hours as the glue set.

In the following two days, Deb finished up fiberglassing the external face of frame nine, that is exposed to occasional wind blown rain from the NE. Pete started cutting out the internal frames that are no longer needed, and preparing for fitting the flooring. The plans do not specify the height of the floor as there is a certain amount of leeway for personal preferences. We opted for maximum head room, so set it as low as we could, while still ensuring a single level along the main accomodation cabins.

Lifting the deck for dry fit. The trailer provided a safety zone for Pete, who can be seen working underneath, pumping the hydraulic lift.

Lifted for dry-fit. The bridge-deck is the final step in aligning the hulls. As it is built perfectly square, any fore-aft difference will become apparent, and adjustments can be made prior to fixing off.

Prepping the glue surface on frame five.

Russ and Jo, invaluable help with the big job.

Russ had this hydraulic lift in the workshop. Worked a treat lifting the deck.

Port sleeping cabin.

Starboard hull with non-structural frames cut away. This is the galley area.

Supports were removed on Friday and the deck didn’t fall down. Success!

Deb fibreglassed the external face of frame nine…

…then began prepping frame three for a layer of glass.

Saloon and cockpit. Port outboard well can be seen lower left. This will be covered with a hinged cockpit seat.

View from below.

Surprise visit and stern steps completed

May 20, 2017Leave a comment

Its been a busy couple of weeks since our last post. The highlight being a surprise visit from our youngest daughter Haley, who flew down from Alice for a week. A great mothers day for Deb. We took a few days off the build to visit Pete’s parents in Hobart, but not before co-opting Haley for some boat work fiberglassing the starboard steps. It was her first real look at the boat, and she was excited, imagining days together on the reef. She has done a couple of charters with us in the Whitsunday’s, on a Seawind 1160, so was easily able to visualise the layout of the cabins and living spaces. Alas, after a precious few days she had to head home and it was a melancholy mum and dad who returned to the work site. But Selah is already showing signs of being a demanding family member, and we threw ourselves into our work, meeting her needs.

The stern steps are now complete, sealed and weather tight. The top steps are fitted but will not be glued down until we have completed the steering and targa bar. This is will be much later in the build, so in the mean time they will be held in place with temporary screws and protected with thick plastic as they will be in constant use as the primary access to the hulls.

Ventilation ports were installed in frame 10, allowing us to vent the void beneath the swim platforms on hot days.

Pete was looking forward to getting on with the next major step, lifting and gluing the bridge deck in place, when he realised he needed to scarf some long lengths for the fore-beam and Webb locker supports first. These are over 5 meters long, and the bridge deck currently provides a handy 7 meter long work bench for such assemblies.

Deb finished up waterproofing the steering compartment, and Pete cut the rudder shaft and post to length. We ordered some aluminium tiller heads, from Vetus Maxwell and dry fit them to check measurements.

Vent port between the rear voids. The stainless pad-eye is for a lanyard for the lid. Access will be gained through a deck-plate in the deck above.

More confined work for Deb as she filleted the sub bulkhead into place.

Extra coats of epoxy were applied prior to closing up.

Rudder post re-enforcing.

Haley put to work with mum.

Glassing the steering compartment.

Applying epoxy and filler to create a fillet. This strengthens and waterproof’s the join and provides a curve for the fiberglass.

The fore-beam is a box section, 150mm square. Here Pete rips the stock prior to scarfing the lengths.

Forebeam stock ready for scarfing.

Pete uses a routing jig to machine the scarfing joins.

Rudder post trimmed to length and tiller head dry fit, to check for fit.

The joggle-stick method is a simple and ingenious way to fit panels into irregular spaces. First the corners are scribed onto a piece of scrap template using the joggle stick.

The template now contains all the information required for an accurate cut.

The information is transferred to the stock to create the outline for cutting …

… which, if all goes well should fit with minimal gaps.

Stern Steps and frosty mornings

May 6, 2017May 12, 20171 Comment

Well we are into full winter mode down here in Tassy. Thermals and beanies are back on as we rise to 3 degree temperatures on some mornings. Actually we welcome the frosty ones as they generally precede a clear sunny day. Good follow up rain after last years wet winter, has kept the countryside fresh and green and the colours are spectacular. If you are considering a winter holiday destination, Tassy is the place to come. The locals are predicting a mild one; here’s hoping they are right!

Work on Selah is progressing at steady pace as we are now tackling detailed woodworking and structural fibreglass jobs.

Deb has been kept busy re-enforcing the rudder post/hull joins, and the hull bilges above the keels. The plans call for 8 layers of 200g glass surrounding the rudder posts where they enter the hull. She cut 24 x 100mm wide, 300 long strips, laying them along the hull and up the post, in a wagon wheel pattern, building up the layers until it was about 1cm thick at the base of the rudder post. She did it in one sitting on each side to maximise the chemical bonding between the layers. It took around two hours each side, working in a confined space (see photo) as Pete fussed around supplying resin and coffee as requested.

After that she lay two layers of 200g in the bilges between frames 3 to 6 as per the plans. The bilges are the internal spaces under the cabin sole (floor). Unlike most boats, Selah’s designer specifies that the cabin soles are sealed in place, effectively creating a second hull bottom. If, by misadventure, the hull is pierced below the cabin sole water is contained between the hull frames and the sole. If above, they act as a series of buoyancy tanks. In addition to the bow and stern voids, she is effectively unsinkable in all but the most extreme circumstances. This has been tested by modelling, which indicated the boat can still be sailed after a hull compromise.

While this was going on, Peter got stuck into assembling the stern steps areas. This also incorporates compartments for the tiller head & steering components. The plans give overall dimensions, but not specific framing details, so there was a lot of thinking time. Decisions about the steering had to be made. There are three options for wheel steering, mechanical push/pull, hydraulic cylinders or cables and pulleys. A fourth option is tiller steering. Some owners use both wheel and tillers. We took a trip to Tamar Marine in Launceston to investigate and have decided upon push/pull. Either way, provision must be made for an emergency tiller, so construction of at least one tiller is the to-do-list.

There is a lot going on with these steps; multiple angles and weird shapes, water proof access hatches, provision for the steering equipment, targa bar, plus mounting points for the back-stays. Its probably the most technical wood working to date. A lot of thought has also gone into the best way to provide for access to the voids, once they are closed up. We have decided upon a combination of stainless flush-deck plates on the decks, and plastic inspection ports in the bulkheads that can be opened on hot days at anchor to ventilate the voids and enable visual checks for leaks etc.

This boat is keeping us young … Deb spent two hours in this confined space, fibreglassing the rudder post to the hulls.

She did such a neat job its hard to see in the photo, but the overlapping layers can be seen radiating out from the post. There is about 1cm thickness at the base.

More confined spaces: two layers of 200g above the keel . Knee pads helped with this job.

We are building up a collection of templates. These are used for best fit, prior to cutting expensive marine grade plywood. It also helps to make the most use of offcuts. Once the pattern is made, we simply offer the pattern up to our stock of off-cuts to find a piece that fits.

The internal bulkhead was made using the joggle stick method, in conjunction with 3mm MDF templates.

The laser level is used on a daily basis to project lines and check for level.

The steps have a 1cm “fall” to shed water. Pete also made things a bit trickier by building a slight camber. Nothing is straight and there are angles all over the place. The steering compartment can be seen here, beneath the second step. This will be self draining and will house the tiller head, push/pull mechanics, connecting rod and self steering. The shaft and post are yet to be cut to fit. There is a hatch built into the step for access.

Pete is thoroughly enjoying this part of the build. The curved panel is the base of the targa bar, that will ultimately extend to support the cockpit roof, solar panels and tender.

Frame 5 and 9 completed

April 21, 20174 Comments

Building a boat, especially one the scale of Selah is a fascinating endeavour. Prior to turning over day, the work flow was primarily in one direction. Now there are a number of ways we can choose to go, and we find ourselves having to consciously remain focused on one job at time. It’s easy to get distracted.

Frame five is now completed, apart from some minor finishing off jobs. There was a surprising amount of time taken to complete it. Although relatively simple, it is a large double skinned fabrication, and requires some big glue lay-ups. Also there is some fiddly detail work blocking around the doorways. Pete did not trust his jigsaw to cut an even curve in the doorways, so he made a template to guide the router.

Frame nine is also completed, as far as we can go at this stage. If we so wished, we could glue the bridge-deck into position, but have decided to complete the stern steps first. Without them access would be restricted once the bridge-deck is fitted.

The stern swim platforms are completed and have been fiberglassed for weather protection. Deb has filleted the rudder voids immediately forward of the platforms. As well as strengthening this load bearing area, the fillets prevent water pooling in any of the knooks and cranies around the butt joints and keelson timbers, guiding it to the lowest point where it can be mopped up through inspection ports. These areas receive three thick coats of epoxy resin, prior to closing up.

The rudder posts/ hull joins have received a thick epoxy fillet, in preparation of 8 layers of fiberglassing re-enforcing, and fitting of a sub bulkhead. After that the rear steps can be constructed over the top.

Frame five ready for the second skin.

Door fame router jig..

Clamped in place, a router was used to trim the three thicknesses that are laminated to make up the bulkhead.

Second skin receiving its epoxy coating prior to fitting in place.

Frame five second skin glued up.

Can never have too many clamps.

Frame nine laminated in place. A second skin is glued on when the cockpit is constructed.

Laying up the fiberglass on the port platform.

Panel detail, frame five.

The rudder void has been strengthened with epoxy fillets. Next job is 8 layers of fiberglass, and a sub bulkhead fitted just aft of the rudder post.

Beams continued

April 8, 2017April 8, 20172 Comments

Autumn is well and truly upon us here in Tas. The days are becoming shorter and there is a chill in the air in the mornings. So far, however the settled conditions we have experienced for the last couple of months have continued, with light variable winds from the NE on most days. We were unaffected by cyclone Debbie this far south, but our thoughts were with the people of QLD and northern NSW. Extreme weather events seem to be more frequent these days.

This week we have pushed on with joining the hulls together, by focusing on frames three five and nine. These are scarfed together then offered up to their corresponding frames built into the hulls. They ensure the hulls are vertical and correctly spaced apart and are the final check that the hulls are set up properly. We were relieved they slotted into place perfectly.

Initially there are three main beams that connect the hulls. Later in the build three additional beams or bulkheads are constructed for varying purposes, so ultimately there are six spans that cross the hulls. In addition the upper deck and lower bridge-deck combine to lock the entire structure together, making a very rigid boat.

The assemblies we are constructing at this point are critical load bearing structures, so we are taking our time and making frequent calls to the designer with any queries we may have along the way. Each beam is constructed differently depending upon its load, or to reduce the impact on internal accommodation spaces. Modern catamaran design has evolved to the point where these heavy structural elements are incorporated into the walls of the cabins and are not apparent to the casual observer. It’s also why, if considering purchasing a second-hand cat, you should be wary of modified or “custom” builds that have strayed from the original design.

Frame three glued off.

Glulam beam atop Frame 3 completed. This is constructed of four 42 x 18 profiles laminated into a curve.

Gluing up the first of the glulam laminations.

Hulls set up in final positions, ready for gluing off. The bridge-deck Deb is standing on is lifted to join the bottom of the frames.

Joining the hulls

April 1, 2017April 1, 2017Leave a comment

This week we have been working towards joining the hulls. First we leveled the hulls fore/aft and vertically, using the laser level as a guide. Once leveled off, we used a small hand winch and a snatch strap around the keel to slide the hulls forward and backwards as required to bring them into alignment.

This turned out to be a lengthy process, and at times frustrating. For a while every small adjustment would knock out another. The critical adjustment was to ensure the bridge deck aperture was square and plum and correct to a few millimeters, not easy to do over such a long length. eventually the monster bridge deck will be jacked up and slotted into that space. Once we hit upon the idea of using a couple of spacer beams that enabled us to fine tune the hulls for level, while at the same time maintain the bridge deck gap, it came together quickly. The laser level was used to double-check waterline levels, and we were thrilled that they were within a few millimeters bow to stern. Selah is one straight boat.

Other job completed this week was sheeting the stern steps / swim platforms. While most of the upper decks are sheeted in 9mm ply, we were advised to sheet the steps in 12mm, as they are subject to higher loads . We need to conserve our stocks of 12mm so we laminated 9mm with 6mm for a total thickness of 15mm. Combined with the slight deck curve Pete decided to build in, the result was a very stiff deck. So pleased are we, we have decided to laminate the remainder of the steps in the same fashion. Before closing up, Deb saturated the internal void with three thick coats of epoxy, plus filled or filleted all the internal joins to ensure any water ingress will run down to the lowest part of the space. A flush mounted deck plate will be installed to allow access to mop up any moisture that may form.

Meanwhile, Deb has completed waterproofing the under-floor of the shower, wet room. The shower grey water will be pumped from there into a holding tank.

Pete has also been scarfing the wide 190mm profile boards that make up the cross beams, that we have begun installing.

These beams are double skinned truss members that join the two hulls, and in the case of frame 5, take the compression loads of the mast, plus form bulkhead dividers between various living spaces.

Hulls aligned, we began assembling the main beams.

Laminating the lower spar of the aft beam.

Winching the hulls into alignment.

Gluing up the starboard swim platform.

Port platform ready to be trimmed for fiberglassing.

Deb waterproofing the shower under-floor.

All done.

Scarfing jig.

Aft decks and a bit of R&R

March 25, 2017March 26, 2017Leave a comment

After a couple of big weeks we treated ourselves to a day off. We have had a season of glorious, settled weather with mostly light NE winds, sunny days and very little rain. Port Sorell is a beautiful spot and we love to take walks along the foreshore tracks. On Monday we headed to Hawley Beach, with fond memories of our daughters wedding there last October.

Then it was back to work.

We have broken with orthodoxy, as usually the first job after turnover is to join the hulls together. Instead we decided to get straight onto weatherproofing the stern steps as they are open to wind-blown rain from the east. We are well and truly over messing around with tarps every night! Also these will be the primary access into the hulls as we move building operations inside.

So we had a couple of small but historic moments. Deb became the first to officially set foot “inside” the boat, as she filleted the internal seams in the aft void. Also we purchased and fitted our first bit of hardware. Weirdly, of all things, it was our swim ladder, as it is incorporated into the starboard stern step. We have also decided to fit mooring cleats, so backing pads have been fabricated and will be glued in place prior to screwing down the deck panels. Later on two small stainless steel flush mount inspection ports will be fitted on the deck to give access to bolt on the cleats and laddder, plus a 6″ plastic inspection port will be fitted on the bulkhed to allow internal ventilation into the ajoining space. Thats boats: and why the darn things take so long to build. A lot of thought for just one meter of length!

Meanwhile Deb spent a lot of time grinding down random screws points that had penetrated through, mostly at the but joins.

Now that the hulls are right side up we have started making some important decisions. Firstly we decided that the port hull will be the master cabin, and the starboard hull for guests. We could then allocate the shower room, so Deb began preparing for fiberglassing the shower sump. She also prepared for some internal structural fiberglassing above the keels as called for in the plans.

A small but historic moment. Deb fillets internal seams, before the void space is sheeted over.

Measuring up the boarding ladder.

Starboard stringers and bearers fabricated and glued into place.

Swim ladder recess

Dry-fit port deck

Dry-fit starboard deck

Prepping for keel re-enforcing.

Roll over day happens

March 19, 2017March 19, 20172 Comments

At 10 am yesterday (Sat) around 20 people turned up to help us turn the hulls & bridge deck over. We were grateful that so many turned out to help us. A mixture of interested locals, acquaintances, friends and relatives.

It was a three stage process. Firstly the bridgedeck, which was built upside down, was carried out and flipped over. Then the formwork that supported the bridge deck was lifted out to make space. We then had room to roll the hulls and manoeuvred them into position onto the concrete pads we had prepared a year ago. These pads are 2.4m x 300mm wide and were poured as accurately as possible to ensure the hulls were level with each other. They were incorporated into the strongback that supported the hulls during construction. This was necessary, in our instance, as we are building in an outdoor site on uneven ground. When building in a shed the keels can sit straight onto the concrete floor with packers to account for any unevenness of the floor.

Some have asked us about our decision to build outdoors. In an ideal world, we would have loved to be in a warm shed, but in the end, one has to grasp the opportunities that present themselves and just go for it. We have been very blessed to have the space that has been made available to us, with the kind generosity of Deb’s brother and sister-in-law for the building space, and Deb’s parents for somewhere to live. In many respects this is a family project for without the support of our family, we would not have been able to make it happen.

We braced the hulls with temporary supports, and then moved the formwork and bridgedeck back into position. This will then enable the two of us to jack the bridge deck up the remaining 300mm to secure to the cross beams.

The whole operation took a bit over an hour, slightly longer than we expected, but quite acceptable given the scale of things.

Refreshments were prepared and quite a number stayed around, enjoying the sunny day and company.

Pete and Deb spent the remainder of the afternoon, tidying up the site, weather proofing with tarps and generally acquainting ourselves to our new reality. It was a somewhat surreal experience for us as we considered our new surroundings. This is the wonder of boat building as once again we switch gears. More woodworking, and detailed carpentry. Less fiberglass, Qcell, sanding and painting …at least for now.

First the bridge deck was lifted out to make space.

Starboard hull goes over.

The rudders were fitted before the hulls were lifted upright.

The formwork lifted back in place …

ready to receive the inverted bridge deck.

Those bow decks are about 2.4 meters from the ground. We fitted temporary decks against wind-blown rain. Winter is around the corner with its wild westerlies.

The bridge deck will eventually be offered up to span the hulls.

The concrete pads we poured in preparation for this day, a year ago.

Bridgedeck complete

March 17, 20172 Comments

The lower bridgedeck is complete and ready to be rolled over. This beast taught us a few thing along the way.

Big and unwieldy, we underestimated how long it would take us to build. It had to be finished in time for roll-over day so the pressure was on. The last detail sanding was completed by smoko today. Pete then spent the remainder of the day unscrewing the hulls from the building frames, and making preparations for rolling the hulls tomorrow. Deb tidied up the site and organised catering for the volunteers.

Job done, a moment of satisfaction.

We halved the width of the 1m wide roll, which fitted perfectly, running up the sides of the bearers. Resin was applied with squeegee’s, the fastest way to wet out cloth when horizontal.

We then used 150mm fiberglass tape over the bearers and used rollers to wet out. This method avoids the problem of air pockets forming along the fillets, and was significantly faster than trying to massage wet cloth over multiple bearers.

After fiberglassing Qcell was applied and sanded smooth.

Gearing up for roll-over

March 12, 2017March 12, 20172 Comments

Well we have made the date and sent out the invites…

Rollover invite web version

Next Saturday will be a major milestone for us as we roll the hulls.

We should be able to make the deadline. The bridgedeck bearers have been affixed and we are currently sanding and cleaning up in preparation for fiberglassing, applying QCell and fairing.

As all this is happening, a lot of thought is going into the best method to roll the hulls. Pete has made calls to gather info from others and we feel reasonably confident about the process. The challenge for our particular site is the roughness of the ground. We will not be rolling onto a smooth concrete floor, so will have to make provision to protect the topsides we have so painstakingly faired smooth.

As well as rolling the hulls, and while we have a captive volunteer team, we will also be turning the bridgedeck and placing at the optimal position for the two of us to offer it up to the yet to be built cross beams, in a few weeks. In the meantime it will function as a sort of giant work-platform to stand on while we construct the cross beams.

Deb on the sander again. Cleaning up for fiberglassing.

Gluing on the bearers. First the base was pre-resined and smothered in epoxy glue…

…then flipped over and screwed in place. After drying a double fillet was applied along the entire length. This effectively doubles the glue surface area, and is astoundingly strong.

The various butt and scarfing joints were liberally glued with epoxy resin mixed with West System 403 filler.

Pre-resining the butt joint. With structural joins we do a “wet” bond. First the timber is coated with a layer of raw resin which penetrates the wood fibers, then while still wet, we apply the glue mix and screw or clamp the assembly together. As the resin chemically bonds it “welds” the wood together. The resin continues to cure for months.

	Viki Moore on Stern Steps and frosty mo…
	selahcat on Frame 5 and 9 completed
	beav222 on Frame 5 and 9 completed
	selahcat on Frame 5 and 9 completed
	svtakeiteasy on Frame 5 and 9 completed

	Viki Moore on Stern Steps and frosty mo…
	selahcat on Frame 5 and 9 completed
	beav222 on Frame 5 and 9 completed
	selahcat on Frame 5 and 9 completed
	svtakeiteasy on Frame 5 and 9 completed