Well, my bench has been clear for a couple of weeks. I did some tidying up, then thought about what my next project should be. I did a trade with my buddy Larry, came out with a few kits and some fittings and such. One of the kits is a little all wood boat named the Mini Jupiter from KNK models out of Japan. From the looks of the box, and the young lady modelling the boats on the back of the box, I’d say this kit is from the early eighties. A quick web search shows the kit being listed from a website in Japan, I’m worndering if they’re re-kitting it. No other mention of the kit except for the odd older build log, one guy says his kit dated from the late seventies.
KNK mad 3 or 4 different sizes of this boat, this one, at around 17 inches long, is the smallest. It sits right between my Graupner SAR and my little Deans Pibber in length. I intend to run a 28mm outrunner of around 1300-1500 kv and a 2 cell lipo for power.
So far, I’m building it pretty stock, with a few exceptions. The stuffing box and shaft will be replaced, as the shaft is simply a piece of what looks to be 2.3 or 2.5 mm wire, and the prop is glued on. I’m using a Fineline 4mm shaft and tube, which is coming in my semi monthly care packet from Cornwall.
The kit is pretty straightforward, you builds up a keel, add bulkheads, stringers, and supports then sheet it.the bottom sheeting gets a little tough near the bow, due to the pinched(?) bow then as you go further aft the bottom flattens out to a shallow v. On mistake I’ve made so far is I glued the front chine support in upside down, had to cut the glue joints and fix it, but I got it handled. The bottom of the hull is planked with 3 narrow thin plywood sheets that overlap each other, giving the hull bottom strakes all the way aft. The side sheeting is one piece of the same thin plywood.
I’m almost ready for the decking, before I do that I need to trim the excess sheeting at the gunwale, then I’m going to paint the inside with some epoxy finishing resin befor I sheet the deck. What you see in the pics is about 7 hours of work.
Cash

Hi y’all. Got some more done today. I brushed the interior of the hull with 20 minute finishing epoxy. I then did the decking, and started the cabin. The cabin builds up pretty quickly, although there are a couple of crossmembers that the plans and instructions contradict each other...might be a typo. Anyway, she’s coming along. This will be the first all wood boat I’ve built, I want to get a decent finish on her, so I’m thinking using sanding sealer, then go ahead and primer her, then paint. My thinking is the sealer will fill the grain well, and a light coat of primer will help show any irregularities that I need to address before painting begins. If any of y’all have any tips on this subject I’m all ears. I’m thinking either acrylic from my airbrush or Tamiya rattle can lacquer.
Cash

Had a little time this evening, got the cabin mostly finished. As I was looking over my work, I noticed something on that was mentioned in a thread somewhere...the rear deck does not go all the way forward. In other words, if the boat is left stock, and you have the cabin sealed up tight, it won’t make a bit of difference as any water that splashes onto that rear deck will find its way forward into the hull. Now, this boat has quite a bit of freeboard, but still....anyway, I need to add the rub rails and strakes, and I’ll add a fwd bulkhead to keep her watertight. Maybe this boat was optionally fitted with a glow or Diesel engine. There’s windows for the 2 windscreens, but no mention or material for the side windows. Might be I’m on to something, cooling air would come thru the windows and exit over the rear deck.
Yep, gotta address that..
Cash

Hi y’all, I’ll keep this short as it’s almost time for bed, and I work tomorrow..ugh.
Anyway, got the rub rails and strakes installed and the cabin is “ purt near” finished, she needs a good sanding, then it’s sanding sealer and primer time...
Cash

The past week or so I’ve spent priming and painting the Jupiter. I really wish my finishing skills would improve, seems like it’s 2 steps forward, and either 1 or 3 steps back, depending on my patience or lack thereof. I started painting with a rattle can enamel, sure enough it just didn’t coat worth a darn, so I sanded her down and used my cheap Harbor Freight airbrush and some Createx and Testors acrylic paint. Turned out okay, I’ve done better but I’ve done worse as well. After I touched up a few mistakes I glazed the windows. Now, I have to plan the radio/motor install and do some fiddly bits like rails and some details. Not goingto do much, if any interior work as she’s pretty small. Might add a seat and a wheel..maybe not, I’ll see how she goes.
Cash

Quick update. I have the motor mounted and the rudder and servo installed. The motor is a 1300 kv 28mm outrunner, she’ll be running on 2 lipos. The rudder servo is an older nib Hitec HS80, mounted with adapters so I could mount it close to the rudder, and use a wire with z bends for the pushrod. Any mechanical trim changes needed will be at the rudder horn. The motor mount is bass and thin ply sandwiched together, with ply supports and epoxied into the hull. I used a Caldercraft fine line 4mm shaft and stuffing box. Radioactive sells a slightly less expensive unit, but it has nylon bushings vs the brass or oillite units in the Caldercraft unit, and I just don’t know how long the nylon bushings will last.
So, I’m waiting on my esc, and I need to add a ply floor in the aft section for battery mounting, that will give me several inches to fine tune the boats balance.
I guess it’s time for fiddly bits!
Cash

Hi y’all. Added a bit of detail to the Jupiter, not a lot. Wheel, throttle and instruments and a few railings. I decided to get her in the water before I do much more, and she really looks good! That is, until her trim changes due to taking on water. This is the first lapstrake hull I’ve ever built, and I’m thinking part of a glue joint didn’t take. I was being very careful as to not have any residual glue on the bottom of the hull, I might have been too sparing in places. No matter, I’ll find the leaks, take care of that and then give her a proper maiden, then finish her up.
Cash

I’m off the remainder of the week, so today I decided to fix the leak on the Jupiter. I found the culprit, sealed that, then ran thin ca along the hull plate edges, and spread thin epoxy inside near the suspected area just in case. I then took her to my church’s test pond, and ran her pretty hard. After about 30 minutes of running, I took on maybe a scant tablespoon of water, and I honestly think part of that was spray getting under the cabin.
This boat is unreal. It handles almost as good as her big sister. My buddy Larry has one, and it handles well. This one does as well. It gets on plane very easily and stays there, no matter what the operator does, even though I spun her once.
Once we came home, I did some paint touch up and added a couple of details. I also added magnets to help hold the cabin in place. I made up a bulkhead that accepts a dowel I built into the cabin, like the locating down on a model airplane wing. I took one of the metal cleats and installed it just aft of the cabin, thus not allowing it to slip back, while the magnets add another layer of security.
I really enjoyed this boat, she will vie with my SAR as my “always bring” boat. She’s a keeper!!

Thanks everybody for the kind words and encouragement. I really appreciate it.
There’s 2 other sizes of this boat, 650 mm and 900+ mm, and there’s a company called Ayard in Japan that’s supposedly selling this kit again. Now, I have more projects than I can shake a stick at, but...if the roughly 27 inch boat is available, and can get here before Christmas...I might have to talk to the Commodore.😁
Be safe y’all
Cash