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Feb 14, 2018, 02:54 PM
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Enterprise Build 2018


I've decided that 2 wasn't enough so I chose Enterprise. I've been intrigued by Enterprise for the past couple of years since building Rainbow. I like her lines and with a shorter water line then Rainbow and a greater allowable sail area, it will be interesting how well she performs as a scale model. I just received the laser cut frames from Rick Shusha (The Modelers Workshop). Feel free to ask questions as the build progresses.
After studying the J's from "The Book", I saw that several of them (8) sported keel center boards. I figured there must have been a reason the designers incorporated it in their designs and since none of them are around to pick their brains, I decided that this might be an interesting exercise. Worst case scenario, it flops and I extract the whole thing and repair it. It's only wood and fiberglass. I've repaired worse on big boats so....... I built a few mock-ups to study the dynamics of the whole idea. When I built a scale model and saw that the concept was doable, I decided to bite the bullet and try. Now that most of the questions have been answered, mechanics, materials, waterproofing etc. The base material is brass and I have a thin layer of lead to help with the weight.
The trunk is constructed from leftover 1/8" plywood from the laser cut frames that has been glassed with a composite carbon fiber/kevlar cloth so the inside of the trunk is durable and waterproof.I proceeded and am now back on track planking for Stowe's J Day. I have added several pictures showing the progress.
I have finished the planking, trimmed off the center board trunk and cut out the space for the rudder brass shoe. I've removed her from the tee rail, placed her in a working cradle so I can coat the inside of the planking with a thinned down West System. I do this before sanding the exterior as it gives the planking a more unified resistance to the pressure of sanding. I will put her back on the tee rail for sanding. After sanding, I will fair the hull and finish sand before applying the 5.7 oz. carbon fiber cloth and West System epoxy.
Sanding and fairing done. Carbon fiber cloth and first coat of resin. The next step is sanding, inspect for areas that may need a little fairing, fairing the rudder to the keel, building the brass rudder shoe and apply another coat of resin. Then, on to the inner workings and deck structure.
I created the rudder post fairing by using an old section of mast that matches up to the thickness of the leading edge of the rudder.
Enterprise is officially off the tee rail/construction table and in her construction cradle. I've spent a couple of days cutting out every other bulkhead and installing some of the blocking needed for the sheeting system, Jib rack, possible jib traveler and main traveler and main hatch framing. I have also installed a fairlead for and adjustable back stay. The purpose of removing excessive bulkheads is to allow for better lead placement, to eliminate some excess weight. I was able to remove over 2 lbs. That may not sound like much in a J but if that weight is relocated to a lower point in the boat, ie. lead, it can help in the righting moment and stability. Some of that weight is removed from the bow and stern and moved amidships. I will be finishing work on the bulkheads and cleaning up the interior so I can make some molds for casting lead ballast. Then systems boards and working out the mechanics of the keel center board.

The deck framing is complete. I've been working on the tubing for the center board cables. Trying to get the right feed angle to maximize strength and clearance took some time but I think I've got it solved. Had to remember to keep the terminus above the waterline. I decided to use linear actuators for the center board and back stay. I have also installed a jib twitcher servo (may not need it). I wanted to have the option of forcing the jib to wing out and act more like a spinnaker if needed. Again, we'll see. When I built Rainbow, I planned on worst case scenario and put the structure in for any servo scenario I could think of. I ended up using about half. The way I figure, you have one chance to address these ideas when you are building so why not. Hopefully by the end of this week, I should have a good start on planking. That's when you, as a builder, really get excited. You see the light at the end of the tunnel, and hopefully, it's not a train.
Final 2 servos are in. I decided to go with a direct drive for the rudder. Should be a simpler set up then dealing with linkages. In the new photos you will also see that I have added a main traveler servo.
With all the interior items set up and in place, it'd time to proceed with the deck. First layer of the deck is a 3/32" balsa infill to bring the surface even with the sheer flange. Before laying the layer down, I completely coated the underside with West system as a sealant and bonding to the frame members. This was then taped and weighted down and allowed to cure. This layer was then sanded to eliminate any irregularities. Next, the surface was again coated with West system and a 1/16" layer of plywood was applied taped and weighted to cure. After curing, I cut out the hatch openings and prepared to start the planking process. Planking has begun. First, laying out the hatch trim pieces and then the initial plank at the sheer. From here, it's just 1/16"x3/16"x24" Mahogany planking and black construction paper (to simulate calking). At some point this week, I will also start fabricating her Sitka Spruce mast. Pictures should tell the rest.
Progress made today. May be able to finish it up by the end of the week.
This past weekend, I finish up planking and the initial sanding. The next stage is to seal the grain with some Mahogany Interstain. That will be sanded and then I'll finish with several coats of Spar Urethane. I have also reassemble my mast gluing/clamping jig. While the deck dries, I'll start fabricating the mast. I think the weather will finally break for us next week. That means a possible float in my test tank and start configuring the lead ballast, waterline etc.
Interstain completed and first 2 coats of Spar Urethane. Onto the mast. I ripped down some Sita Spruce and then halved it on the band saw. I ran it through the router table to make a channel for the sail luff slugs and a larger one for the Carbon fiber core tube. The tube adds some stiffness to the spruce and serves as a chase for halyards. The halves were coated with West System and clamped.
Last edited by spinnaker225; Apr 22, 2020 at 04:44 PM. Reason: updated
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Mar 13, 2018, 07:00 PM
rshousha
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Wow, your speed of construction is just amazing. And the boat looks wonderful. Your stern is awesome; these boats had such grace; such style!
Mar 22, 2018, 01:29 AM
Registered User
Fantastic job, I have looked at all of the build photos with great interest as I am teetering on the edge of a commitment to build a large J class model.
I currently have two 40" long J's one Bermudan to which I have added Huon Pine planked deck and the other Nottingham gaff rigged one both with Grp hulls. I have also just finished the deck planking on an EC 12. I am interested to know what timber and plank size you used cover your hull frames.
Also what other J models have you built and do you have any comments as to their relative model performance?
I am also impressed with your immaculately tidy work shop, it reminds me that mine could do with a bit of discipline instead of the current chaos.
Mar 22, 2018, 05:46 AM
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Thread OP
Thanks for the note and compliments. Below my Enterprise build blog are 2 others that I did a while back, at the same time. Rainbow was another plank on frame and Endeavour was from a fiberglass hull from Chuck Luscomb. I used 3/8" x 5/32" Bass wood on both Enterprise and Rainbow. That dimension seems to work well with the bending that has to be done for the contours of the hull. I'm about the post some more pics. as I have the boat off the the building table and am addressing the interior, control board layout and prep for decking.
Mar 30, 2018, 01:31 AM
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I am still following your build with great interest, the removal of alternate frames having turned the hull over is presumably for lightness with now great strength been added by the epoxy/carbon fibre exterior and thinned down epoxy interior, question how do you thin West System epoxy?, I have been using this product for several years but have only got it thinned by applying it with a spatula and scraping the excess off (not practical for the hull interior) I am contemplating using WRCedar for planking assuming coating will add sufficient strength. Another question I have been told that the 1/16 scale J needs only 14" plus of water to sail in, is this correct ? my Tippecanoe T37 needs about 11" and that is fine for my local river mouth.
Please keep posting as you have at least one extremely interested viewer.
I have looked for your earlier posts on other J's that you have built but so far have unable to find them
Mar 30, 2018, 04:52 AM
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Thread OP
Yes, the removal of every other bulkhead was for weight reduction but it serves another purpose. When I get to the keel area, it allows me to get more weight concentrated down low which is important dealing with the righting moment. One thing a stick built model has compared to a fiberglass molded model is that weight distributed too evenly spread throughout the hull instead of down low at the lowest part of the keel. On Rainbow, one of my earlier builds, I actually cut the bottom 2" off the hull, cast a mold of it, poured solid lead, and reassembled. This makes for a heavier "bare hull but I think the trade off helped. It gives the boat 13lbs. of weight down at the lowest point.
Regarding the thinning, I use and have good luck with denatured alcohol. It looks milky when you mix it, but dries clear. I use the alcohol instead of lacquer thinner of acetone because it does speed up the drying as much.
The J's draw about 14".
You should be able to scroll down my building blog page and find both Endeavour and Rainbow builds. Check back, I'll be posting some more progress notes and photos by the end of the day.
Thanks.
Oct 02, 2018, 11:58 AM
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TsunamiTsling's Avatar
Your work is quite fabulous. I have been thinking of building a J for a long time. My brother is Sailing Junkie.
Oct 02, 2018, 02:58 PM
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Enterprise Build


Building is half the fun for me. I've built 2 from scratch, Rainbow and Enterprise, and 1 from a fiberglass hull I purchased from "Sailing Junkie". Rainbow was used as a plug this past year to make a mold. I hope to lay-up a Rainbow this winter and also restore the original by the spring.
Oct 04, 2018, 01:38 PM
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TsunamiTsling's Avatar
Quote:
Originally Posted by spinnaker225
Building is half the fun for me. I've built 2 from scratch, Rainbow and Enterprise, and 1 from a fiberglass hull I purchased from "Sailing Junkie". Rainbow was used as a plug this past year to make a mold. I hope to lay-up a Rainbow this winter and also restore the original by the spring.
Rainbow was another great build. who made the plug? Chuck? I was looking at Endeavor's interior. interesting. You have 5 servos plus the 380? Rudder, Twitcher and 2 travelers and a backstay?
Oct 04, 2018, 02:17 PM
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Thread OP

Enterprise Build


After I finished Rainbow and sailed her at J Day a couple of years ago, I decided to use her as the plug. I sanded her down and coated the hull with duratec primer and then sanded that coating and waxed her. Now that I have the mold made, I'm going to restore her back to a finished J. Regarding Endeavour, the # of servos I had originally planned on was reduced. Now she has a 380, Jib trim, main traveler, rudder and back stay. Enterprise is now the challenging project as far as servos go. She a 380, jib trim, main traveler, back stay, boom vang, and 2 retractable keel center boards, and a rudder. One of my challenges is power monitoring and usage. Anyway, I have the winter to solve issues.
Last edited by spinnaker225; Oct 04, 2018 at 05:39 PM.
May 07, 2020, 11:14 AM
rshousha
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Very curious to know how the mast turned out. Any new?


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