Alan Stewart

We buy klingspor sheets for the shop and we like them.

Cool, I've watched many of their videos (SV Seeker). Looks like they got her to sit on her lines ok. Was worried about her for a bit when they launched she was pretty low in the stern. https://www.youtube.com/@SVSeeker/videos

Below, copied from this google docs. https://docs.google.com/document/d/14d9ZdooVy53R75y2mquZRJl8XymKDjYJaVbmyjAJ-is/edit?usp=sharing Centerboard Modifications to the 17 and 20 Mark 3 designs. Jan 2023 Note that if you are purchasing a kit or plans today, none of this is relevant to you as you have the most up to date version. If you have a Core sound 20mk3 or 17mk3 prior to the hull number below then you might consider this modification. Shortly after painting and relaunching Graham’s 17mk3 ‘Carlita’ in late 2016, Graham posted a thread called ‘Carlita goes under the knife’ where he detailed lengthening his centerboard after feeling that he could improve her upwind performance with a longer centerboard. This was just in time for the Everglades Challenge in 2017. This change was then added to the 17mk3 kit and plans in early 2017 (longer trunk and centerboard) for all hulls after hull #12. Then shortly after this a major overhaul of the entire design was completed around April 2018 which included Hull #15 and boats afterward. The overhaul included raising the cabin slightly, redesigning the trunk to move the centerboard further forward and other improvements to the kit. For the Core Sound 20 Mark 3, the centerboard location and length was updated for hull #21 and all hulls afterward. You can easily identify the difference in either model if you are still unsure as the original centerboard location was such that no part of the centerboard or trunk extended forward of the companionway bulkhead. This was done to keep the board out of the cabin. We found however that the boat had a touch of lee helm though we originally thought the mizzen location (being further aft than previous Core Sound designs) would account for this. This was especially evident with the 17mk3 due to its shorter waterline. Interestingly the Core Sound 20 Mark 3 does not seem to exhibit lee helm and we’ve yet to have the opportunity to sail the original and relocated board 20mk3 back to back. (perhaps at the next messabout) in order to see the effect. Perhaps after that it will be more clear if the 20mk3 would benefit from the modification. Ok, how do I do it? For those interested in making the modification to an existing boat, a very helpful video explaining the process (specific to the 17mk3) should be watched here. Pictures of Graham’s original modification which he did just before his trip around the Delmarva Peninsula can be seen here. The modification for the 20mk3 is done in the same way Don Silsbe completed the third known modification of an existing 17mk3 board and trunk on hull #6. (#2 and #6 also have the modification) Here is a link to his thread with good step by step shots of the process starting from the removal of the existing king post. We’ve created full size printable templates (seen below, each comes in 4 sheets of letter size paper) to use for the modification. See below to download the files for the 17 or 20 mk3 and be sure to read a few additional notes below. 17 mk3 Modification Dimensions and Files: Download Here 20 mk3 Modification Dimensions and Files: Download Here Do I have to extend both the trunk and the board? Yes, if you do the trunk, you should also extend the board. Extending the board: To extend the centerboard itself we are recommending doing this from the top of the board by adding a “crescent” shaped piece (shown below) to the top of the board and fiberglassing it on. This preserves the majority of the shaped board and means that redoing the lead tip is not necessary. Some of the existing board will need shaping into a foil shape as it will now be below the hull when rotated down. Also note that some additional uphaul purchase may be needed since the board’s lead tip has additional leverage on the uphaul line. The current centerboard rigging diagrams can be viewed here. 17mk3 rigging diagram and 20mk3 centerboard rigging diagram. Below shows the extent of the difference on the 17 mark 3. With the extended trunk and board there will be a slightly larger gap behind the board in the trunk but probably not enough to worry about doing anything about. Below shows the extent of the difference on the 20 mark 3. Pictured below the lengthened centerboard in the original trunk with the trunk extension. Note that with the 20mk3 there will be a gap of approximately 7” behind the lengthened centerboard when it is rotated into the original trunk. We recommend cutting a block of blue insulation foam that will slide up into this space and form a “filler” that can be glassed over and painted. Dow Blue foam is epoxy safe and the primary reason for doing this is to reduce the amount of water turbulence in the trunk which slows the boat down.

For anyone thinking about moving their boards forward on the 17 and 20mk3's here is the definitive guide with templates. I'll create a new thread for this topic. https://docs.google.com/document/d/14d9ZdooVy53R75y2mquZRJl8XymKDjYJaVbmyjAJ-is/edit?usp=sharing

Stew and Aphers, Thank you both for posting your comments! We went back to check the numbers and geometry on the S11N as we always do and in the process you helped me discover that we STILL have an error in the S11N templates and the kit with the aft seat. Aphers comment clued me into it. It's something I fixed nearly 2 years ago in the plans but the templates for some reason did not receive the update so I'm now drafting a correction email to the affected builders and hope to "save" some of them. To answer your question about the nesting bulkhead location, you have it in the correct place. As was noted, the bow sits well above the top of the transom so there will be ample space for it fore and aft in the stern half of the boat as you can see below. Depending on how far forward you taper out the keel strip it will sit roughly as shown. Just make sure your nesting bulkhead is "planar" i.e. flat in all directions when you put a straight edge across it especially athwartships. There is more than enough "wiggle room" for an 1/8" deviation from the plans in it's placement so consider it perfect. In the case of the stern seating parts as mentioned above, use the dimensions shown in the cut sheet located in the plans for the stern seat tops, sides and fronts. These dimensions are correct. The seat top in the templates is too wide at the front end and does result in an interference with the bow half (much to my embarrassment). It's ironic since we "updated" the Spindrift designs to 3d models and added a lot of detail to the plans including the shapes of these aft seat parts only to have this happen. The original plans only included their location in the stern of the boat and the builder is meant to frame them in and pattern the pieces to the hull as built as Aphers did. A wise move but hopefully going forward this will be put to rest. T

My Dad really loved this thing when we had Dawn Patrol our Core Sound 20. When not going fast enough for the venturi bailer to suck and water got in the boat either by rain or spray you just reach down and flip the switch. Put the hose in the cb trunk. The d cell batteries lasted a year or so. We found it to be very reliable. We always made sure the oring seal was clean and lightly coated in lanolin. I think a good choice for least effort and not wanting to cut the boat. Another advantage is it can go in a kayak or anywhere else in the boat you need to dewater while you do something else. Attwood 4140-4 WaterBuster® Portable Pump, Submersible, Battery Powered, 200 GPH, 42-Inch Hose, 5 ¼-Inch Diameter https://a.co/d/jaRUdba

Jay's video from above.

Hey Jay, I couldn't get your video to play but happy to see you on here and rest assured any issues you come across we will be happy to help resolve with you. I think it is a fair critique that we should have a bit more info on the build sequence for Marissa as she's become very popular in the last 5 years or so with over 100 plans sold now and she is too good a boat for first time builders to be scared off from taking her on. We will work on that. In the mean time we are so happy to have you here! -Alan

Yes for sure just as good if the thickness of epoxy is equal. The problem is that it's hard to know if the thickness is even throughout without kind of overdoing it in spots. Multiple thin coats ensures a good even thickness everywhere but some of us get impatient. Thickness of epoxy is the most important thing for a good barrier coat to protect the wood from moisture. One other way to achieve a consistent thickness barrier coat is to just glass the wood even if not needed for strength a layer of say 6oz cloth over plywood necessitates a certain amount of epoxy to fill the weave and therefore ensures a good barrier coat. Glassing the ply as a means to an end (getting a decent coat of epoxy on the surface) is just another trick that sometimes makes sense to use.

I haven't tried those grey ones yet but with a plastic core they probably hold up longer than the foam ones for sure but you can get a pretty smooth finish with the yellow ones. For coating flat parts on a table however I've started just using a wide chip brush and doing a "flood coat" pretty thick and just brushing it out as smooth as I can. Wouldn't do that if i was going for extreme weight savings but it's a one and done method. If you can still see the wood fibers, pour on some more! I also sand the wood if I'm going to do that with 220 grit to keep the fuzzy grain rise to a minimum.

We also use the wooster ones at the shop. (These). We like to buy the 7" ones and cut them in half on the bandsaw for use on a 3" roller cage. https://bandbyachtdesigns.com/wooster-brush-r730-7-tiz-foam-roller-cover-1-8-inch-nap-2-pack-7-inch/ two 7" rollers for $2.90 gives you four 3.5" rollers for about $0.75 each They are about 1/8" foam over cardboard and usually last through about 2-3 epoxy batches before the foam starts to get all floppy and then we just toss.

Yeah do it! I got a dji mavic mini as a Christmas present. A very impressive machine. Graham also has the larger mavic pro.

Come one come all! Sign up is now live on the B&B website. Let us know you're coming! For all the info (click here) or just go straight to the signup form. And we're planning to go back to our Friday night buffet dinner at Little Italy for which you can now get your tickets. I compiled some picture albums from past years. Check out here. I have a feeling we are going to be a really great Messabout this year. Here is some drone video from last year.