Seaducer Build - words & pics by Andy
Details of the build can also be found on the
At the end of last year, I had my new hull delivered - a Seaducer 90-100 SD3. This was custom made for me by Jerry with the Gecko Green metal flake deck, with white undersides. I decided it was so impressive that I had to order the 40 boat too. Both hulls are full carbon fibre layup and vacuum bagged. This one is the newest boat designed by Jerry, measuring 45" long by 11" beam. This boat currently holds the mono speed record at 98mph, Seaducer boats have all sorts of records to their name, with various national title wins in the USA over the years.
Power is provided by the new CMB 91 M-Line, which chucks out 7 horsepower at nearly 30k rpm. Prop initially started as an Octura x462 for running in, then a 465 and hopefully stepping up to a x467 when it’s fully run in. Radio is Jeti, with a Savox SB-2292SG on steering, a Savox SV-1273TG on throttle and a Hitec HS-430BH on mixture, all powered by a Hacker 2000mah 7.4v lipo.
Construction started by assembling the glassfibre fuel tank tray, which just involves screwing and epoxying in some eyelets to secure cable ties to hold the tanks in place. Tanks are both Sullivan Slant types, with a 24ox main and 4oz header tank. Pipe pressure will feed into the main tank, which delivers fuel to the header to maintain a constant and consistent fuel supply to the motor. When this was all done, it was tacked into the hull with two-ton epoxy, which was strengthened further when it cured.
With this boat I purchased Jerry's own Seaducer hardware set, which is beautifully machined and includes the strut, rudder, drop mounts for the engine and a pipe mount. Steve (our webmaster and engineering guy) was kind enough to drill the mounts for me so I could mount the engine.
Next job - put it in the sink...
Most commonly done with cat hulls but I decided to do it with this, ‘pouring the tips’ involves standing the boat on end and pouring resin into the nose, in this case 10ml of West Systems laminating resin. This helps to ensure that in the event of a collision the force will be transfer down the hull and be dissipated, rather than just breaking the nose off. Because resin gets warm and cracks when setting in large volumes, it’s best to leave it to cure in the sink or a bucket.
With the engine mounted, I got it into the correct position in the boat (17 inches from tip of glowplug to the inside of the transom board, with a 5" length of 1/4" brass tube in the motor’s coupling, with the end of the brass touching the bottom of the boat for the correct angle). This was then marked for drilling, having checked that the engine starter belt has got enough room to slip out when the engine has started. The drop mounts allow you to get the flywheel almost touching the bottom of the boat, so it's important to make sure you can get the belt in and out. The whole lot is secured in with M5 bolts, with penny washers outside the rails. It is important to seal the wood so any water ingress won't decay the rails over time, so I just mix and poke in 5-minute epoxy whenever I drill holes through the wood.
With this done, I moved on to the transom hardware. I started by masking taping the whole transom, then drawing reference lines of where everything needs to work from. I started by drilling the 1/2" free flood / drain hole around the shaft exit. From there I lined up the strut and rudder, marked and drilled for each.
My only one complaint about the Seaducer hardware pack is that the screws aren't really the highest quality, so I replaced all of it with new. Jerry's machined hardware is second to none, it's of excellent quality and the material used is very high grade. What interested me about the strut in particular is that it has a 3-degree offset machined into the leg, to counter prop effects on the boat. Clever tricks - and why everyone says that if you don't use the Seaducer hardware the boat will never run right...
Lastly for the transom hardware is the pipe mount. The kit mount wouldn’t work with the pipes I intended on using as it’s designed for the unsilenced pipes they use in the US. No bother as Prestwich Models do a 50mm pipe mount that will hold my pipe and fit onto Jerry's mount. The rudder was cut down to height, using a 24" ruler along the bottom of the hull. I marked the point where the rudder blade is in line with the hull, then a square line 3 3/4" down the blade from that point to cut the blade to.
I've gone for a total deviation on the instructions in the radio box as I despise the use of wood on glassfibre in radio boxes. It never lasts and every time I’ve seen it done, things eventually peel away. I've gone for all ally mounts bolted through the bottom of the box, again with epoxied screws for water tightness. The throttle is top left of the picture, rudder bottom left and mixture bottom right. The 2000mah 7.4v Li-Po went to the top right, with the receiver on the rear wall of the box. To the right of the mixture servo I placed an Ian's Boats waterproof switch.
I then fitted the pipe pressure filter / cooler, this is a unit from Answer RC that will help to reduce the amount of detritus that will find its way from the pipe into the tanks. It came with its own clip mount that is threaded underneath for M3, so I drilled and tapped the rail M3, then epoxied in a length of threaded brass bar.
Unfortunately this is where I stopped photographing the build, which can also be found at:
The build concluded by glassing in the stuffing tube for the flexi shaft using glass tape and west Systems resin, and linking the servos to their respective connections using M3 stainless rod, tapped on either end and using ball joints throughout. Below are some photos of the completed boat.
MODEL BOAT CLUB