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searunner-25-trimaran-restoration-continues-7The restoration of the Searunner 25 trimaran in Minnesota continues. And see here also. I received the following detailed info and pics from sailor John Ebert, who is really going the extra mile to restore this classic tri.

If you’re someone who loves “technical information” then you’re going to love this post! It’s important to note, however, that what John shares below isn’t techie for “techies’ sake” … it’s very practical.

IMO, John’s info is going to give a lot of sailors some food for thought as they work on their boats.

Anyone interested in this boat can also download Jim Brown’s classic, Searunner Construction Manual (from the 1970s), in PDF, on this page at OutRigMedia.

We can hardly wait to see this Searunner 25 in the water next sailing season :-)


Refurbing My Searunner 25 Trimaran
by John Ebert

searunner-25-trimaran-restoration-continues-1I carefully sanded the entire hull and the vertical upper deck sides and underneath, leaving the topside horizontal decking and trim for next year.

I put 3 coats of Pettit Hydrocoat Anti-Fouling ‘Blue’ below the waterline and this took 2 quarts, all done by 6 inch roller. I did the same for the amas but used red instead just to see if I liked better or not. I like the blue better.

I also roller painted Pettit EZ-Poxy Polyurethane Semi-Gloss White above the waterline on amas and hull, and this took 1 gallon. I nearly had to buy a quart to finish, but got lucky.

searunner-25-trimaran-restoration-continues-2I painted the top deck sides-only for this season, and the amas top decks with Pettit EZ-Poxy Sandstone Gloss, and I liked how smooth it rolled on and flattened down to nice finish that I think next time I will use gloss on all the hulls above the waterline. Getting a consistent finis with the semi-gloss was more work and precision rolling than I liked. Maybe I’ll buy a spray gun instead, that would have to surely be a sweet outcome, and faster too.

We removed the motor mount which had been on the starboard aft wall (dangerous and weak) and moved it to the transom, testing clearances and positioning carefully before-hand. We wanted to reinforce the aft without cutting any wood. Our tests of filling a clear plastic thin wall cavity with high density expanding foam revealed significant increases in structural reinforcement, so I went ahead and did light ‘tap tests’ on the transom to listen for where the hollows and framing were, and determined the motor mount location from that as well.

searunner-25-trimaran-restoration-continues-3From the exterior I drilled 8 holes in the transom (yikes!) and ran 5/16″ carriage bolts through to the interior. Because the transom is a curved plane, not all bolts could be the same length, and it was a very close result but my careful study of it all resulted in all bolt threads being accessible from the interior.

I torqued very little force on the bolts now holding the motor mount in position, and drilled one more hold in the interior wall only of the transom. To the walls and floor I taped up painters drop-cloth plastic, inserted the foam tube and counted off 5 seconds and stopped. Our prior tests, captured on video so we could review the test, indicated we would need 5 seconds and no more of injection.

searunner-25-trimaran-restoration-continues-4The foam expanded and did not spill out anywhere except the injection hole, surrounding the carriage bolts and their threads as planned. I let it setup for two days and then was able to extract the bolts using a light tapping on the interior thread ends using a wood block and 2 lb hammer, and removed the motor mount and all carriage bolts.

Using a counter-sink drill bit, I beveled the transom holes lightly and applied small rings of butyl rubber to act as water-seal ‘O’ rings and remounted all the hardware and did a final torque-down of it all. Tap tests and pull tests indicate we completed a successful transom mount motor mount installation. I hung a 3.5 horse 4 cycle extended shaft motor on it and it was stable and firm as hoped. We are very pleased with our adventurous result!

searunner-25-trimaran-restoration-continues-5We identified a few dangerous patch jobs on ama punctures by previous skippers, cleaned them out, and epoxy resin with hardenner with backing boards were fitted in as they should have been done. I feel so much safer, what a problem if one of those ama patches had failed and sprung a leak!

Since my last communication with you, we thought long and hard about our methods and equipment used for deploying the amas by one person and have made improvements in the process. Next year I will make a demonstration video of it all in action. Until then I’ll leave all that under-wraps as I still have one more variation in the process to explore.

searunner-25-trimaran-restoration-continues-6I installed some lengths of PVC pipe in the interior to act as raceways for wiring, where before it was stick-on pads and cinch ties (ugly!). I’m not finished with that yet.

I include some pictures of my interior ships Lithium Iron Phosphate battery (LiFePO4) The ‘Fe’ means Ferrous, as in ‘Iron.’ Also is included the balance charger that has several charge profiles available in case one wants to use other types of battery chemistry.

boat-batteriesOn first blush, buying a 20 amp hour battery for $170 might seem contrary to buying deep cycle lead acid chemistry because of shipping from China, including a $30 hazardous handling fee (a ruling from Congress that is a bit uninformed about the safety of LiFePO4 versus LiPOs that burn up in iPhones etcetera) A second look however reveals LiFePO4 is the more cost efficient, safe, and usage efficient solution.

There is no battery acid to gassing or spilling risk, and the LiFePO4 will attain over 2000 charge cycles with a useful depth of discharge of up to 80% drawdown, whereas lead acid will be challenged to attain 300 cycles with a useful drawdown of only about 20 to 25% before reducing the life cycles possible. Though initially cheaper, lead acid batteries are the technology of the past.

boat-batteries-setupAsk Elon Musk why his cars use lithium battery technology if more information is needed, the same factors are superior in sailboats as well. Readers can submit questions if they want to know more about this setup. I intend to power the DP6 OcDay battery charger with solar panels later, I managed to get it to power up on a 30 watt panel in strong sun, so its do-able, I just need more appropriate solar panels for the final install.

To minimize amp hour demands on this ‘small’ battery, I have converted all my ships lights, including mast and running lights to power efficient L.E.D.s and this battery should still have spare juice in it even after running all lights all night, but lead acid would have died long ago. If I were to install electric motor in the boat, it would use the same approach, just more and slightly different batts weighted for higher average current draw rates.

charger-to-boat-battery-interfaceI again re-wired the central power distribution panel (not happy with my first work) and began putting some interior lights and more efficient and clean routing wires into their raceways.

Finally, I also purchased the Raymarine ‘WiFish’ product for real-time navigation safety using the ‘chirp’ technology and ‘down-vision’ for actually imaging the contour of the seabed below and installed it in the boat. WiFish interfaces to the transducer and then sends the application data out over WIFi to my Android 7 inch tablet!

dp6-battery-chargerI took the unit out in Leech lake for a sea trial in my 16 foot fishing boat and it did a great job of reassuring me I was in safe waters, and also it revealed current maps of the area are too inaccurate, that I could actually approach land structures more closely or to back-off using downvision and depth readouts.

I bought the WiFish because I already had $200 invested in my tablet, and getting the ‘add-on’ hardware and software for a sale price of $149 this summer was a great choice. It’s currently $199.

dp6-battery-charger-2If I were to get another tablet, say a 10″ or more, what a display that would make! If I had not had a tablet, then I would have purchased their DragonFly 4PRO, 5PRO, or 7PRO. When I use the WiFish, I can record the journey and upload it to Navionics as a ‘community’ update of actual depth contours that others can then use.

In addition, I encountered a navigation hazard of a 12″ to 16″ tree floating in the lake with one end above water and the other end dragging 9 feet below on the seabed. I alerted local authorities but also upload the hazard to Navionics so other mariners would see it on their Raymarine gear electronic charts.

boat-battery-pack-infoThis is the product, I love it because it removes most stress and fear of being in treacherous waters, and offers manual or auto route planning, recording of actual track taken, distance and time between waypoints, water temperature readout, weather and tides, etc: http://www.raymarine.com/view/?id=11201

(Be sure to click on the images on this page to enlarge them).