Filling in between the ribs. My plan was to use featherlite to fill in between the ribs but I'm starting to consider the concrete sealer that seems to be used by some. Any opinions? Boats scale weight is 40lb so I have some weight to spare, and it'll be down low in the Hull. I cant think of any serious downsides unless it has durability issues over time. My plan is to put the hull at an angle and do individual pours between each set of ribs, blending it perfectly from the bottom edge of the penetrable window to the top of the keel water channel in the hull. Recesses will be made with blocks of wood coated in saran wrap, painters tape, etc as dummies for batteries, electronics, etc. The way I see it, I have 3 real options and 1 I've already tossed out but might have merit. Option 1 is continue as planned, fill the rib areas with featherlite. Cons are I guess price and I'm not entirely sure of the featherlites adhesive properties, so removal in the future could be difficult. Option 2 is to use a 2 part expanding foam system, like the urethane foam they use on 1:1 boats. Biggest downside I can think of is it could be extremely buoyant depending on the density of the foam...but then again I could be wrong? Should be the easiest to remove of all the options. Option 3 is the self-leveling polyurethane based concrete sealer. I've heard horror stories of how difficult it is to remove and that it can be "heavy", but in a 40lb boat I'm not sure if I should be worried. Option 4 is easily the worst of the options in my opinion, but that is to fill the whole bottom of the boat with resin. Expensive, and good luck getting it out. Unless certain resins are easier to remove? No idea.
well, old school tradional says to use wood (usually balsa) and glass over it. Your option 1 looks interesting. I've used in the past balsa chunks to provide the bulk of the fill and then gone over them with a mix of resin & microballoons to gapfill & level. The featherlight sounds like it's a very similar product to that. I did end up needing to place a layer of glass over the the epoxy resin/ microballoon mixture. I had problems with the cracking over time in one ship with the resin mixture without the glass. The glass adds a nice bit of support and also makes for a stronger support surface for all of the gear that goes in. Option 2 - I used on my rookie cruiser way back in the day. Big mess, don't recommend it in general. I did use it again in the bow/stern of my old Wisconsin where I basically built large plywood boxes that defined the major waterchanneling in the ends, glassed them to the hull and then used foam to infill. That worked ok as the plywood provided containment, but again, those were very large volumes. Option 3 - weight is likely not that big of an issue. I might still steer clear of it in favor of one of the other options. I've a Lutzow where the original owner used the sealer. Works fine, weight is fine with lithium batteries. Only issue is that I do have trouble with gluing internal bits to it. E6000 has worked the best, but even that seems to work loose over the course of an event. Option 4 - $$$ and heavy as you mentioned. I'd expect it might be prone to stress cracking as well over time (changing weather, etc) without some glass to support.
So small update, I made a prop template cut for 2.25" props (in reality the props I ordered are 55mm, so 2.25" gives me a small margin) and drilled for shafts. I am running 4mm stainless shafts inside of .050 wall 3/8" OD stainless tubing for stuffing tubes. These things are excessively beefy compared to the 9/32 brass I had used on Dunkerque. I followed @SteveT44 's Atlanta build and used red loctite to secure the bushings into the shafts, time will tell if I succeeded or if I'll have to redo that. (Thankfully the epoxy+filler white mess you see will be covered up by whatever I use to fill those ribs in. Trying to keep this build nice but my giant gorilla hands cause problems when trying to delicately pour fluids through two ribs with the boat on it's side.) I experimented with the self-leveling concrete sealer ( https://www.lowes.com/pd/Sika-29-oz-Gray-Self-Leveling-Sealant/999977080 ) and poured the 3 middle most rib voids on the starboard side. I used masking tape to create walls so the sealer wouldn't flow out into neighboring compartments and I angled the hull so it would create a smooth run from the bottom of the penetrable window right down into the keel water channel area. It's been sitting for about 8 hours now and has shown no signs of hardening, so I'll post an update with pictures when it finally sets up. (if ever). By doing the middle 3 sections with the sealer on both sides at least I've kept the weight concentrated towards the middle for turning performance and I can use lighter substances in the remaining areas.
The concrete sealer takes about 3-4 days to be well set at about 1/4” depth. Deeper and probably about 5 days. It will get there though.
Well the concrete sealer has at least formed a skin. It is like Nickelodeon slime consistency right now. Very minor update. I am updating the 3d model for Jean Bart with what I've learned building this one. The rear subdeck has been extended aft, on this hull the cutout in the subdeck is much larger than the actual deck hatch, so the fore part of the deck floats with no support, only support on the sides. I'm going to fix this by epoxying in a support piece, but it shouldn't have been this way to start with. Easily rectified in the design process, should make it nicer for any other builders who try and build it based off my files. Also, some more pics: @Kevin P. already leaked this pic, which is from my Facebook. Always love the first shot of the superstructure sitting on the deck. Still lots more to do... Deck magnets in. I realized I showed pics of the subdeck magnets but not the deck. It's pretty self explanatory. I might need to add more magnets to the large front/center deck hatches...we will see. This pic shows the 2nd iteration of planning the pumps/motor locations. You can see the drawn out "Pump A/Pump B" from version 1. After talking it over with @Kevin P. I have two options for my dual-pump setup: a fore/aft pump setup...one directly between the motor cans and the second one directly in front of the battery area. Or my original, a port/starboard arrangement makes my OCD happy but I'm not confident it would be optimal. Any input, audience? This was my original port/starboard plan...or something like it. Brown areas being filled in with foam/sealer/etc. I still think the fore/aft pump setup could work...just not sure. And I'll need to commit soon.
Another minor update. Did some more work in the garage today, building stainless steel tight bore barrels for guns and working on the prop shafts. I ordered some SRA #71 liquid flux for soldering the stainless steel parts of this boat, which has so far worked great. The guns I've known my whole time in the hobby have been the foster breech style, with a sleeve on the breech end of the barrel, so that is what I am building for my first set of DIY cannons. I am using 1/4" OD .035" wall tight-tolerance SS tubing for the gun barrels, with 5/16 .028" wall tubing for the sleeves. I have nothing more complex than a power drill and a table mounted belt sander to clean up/true things, so I'd like to think they came out halfway decent considering. To bring the stainless shine back to life post-soldering and sanding down the high spots, I chuck the barrels in my porter cable cordless drill and run them against some 220 grit sandpaper, which was the finest grit I had available. Then, I wrap them in a dish scrubbing pad and run them with the drill again, to polish them up. Unnecessary, but what the heck. Picture time: I am waiting on pexuniverse to ship me out the 1/4" compression elbows I ordered for the breech assemblies and then for the drill press to arrive, at which point gun assembly will really take off. I already started making magazines for the 9 guns I need to build this season as well. I also did some soldering on the prop shafts. So as any who've seen Dunkerque know, I have a serious love/hate relationship with gearboxes and especially with any sort of shaft-reducing bushings to adapt gears to smaller shafts. Well, I guess I'm a glutton for punishment because I ordered M4 threaded props which dictated my use of 4mm prop shafts. Turns out, there aren't a whole lot of widely available 4mm 32p gears like there are for 1/8 and 5mm. So, armed with McMaster and my new stainless steel soldering ability, I ordered some 5mm OD .5MM wall thickness tubing and made my own sleeves for the shafts to fit the widely available 5mm gears. Now the motors and shafts will use the same bore for gears. It creates one complication, which is that you need to pull the shaft up into the boat if you have to remove it for any reason. Annoying yes, but I'll live with it. And once all that was done I decided to start tossing stuff in the boat to see what the internal layout was going to look like. Traditionally I put the bottle in the nose of the boat, and I may still, but I want to try and leave maximum room for the 4 cannons/solenoids/expansion tanks that will need to live in that area. I also thought if I could concentrate as much of the weight as possible in the middle area of the boat, it may turn slightly better as it tries to pivot around its center of mass. The bottle is a placeholder, I plan on running a 12oz or 9oz tank in this boat but right now only have 5oz and 3.5oz tanks. With 4 batteries in there I will have 32AH @ 11.1v, hopefully plenty. That's all for today. Should have more updates as parts/supplies arrive over the next few days.
I'm building my new boat's pump systems in almost the exact same configuration, right down to the forcing cone in the center. the schematic looks okay to me. I originally thought about putting one forward, but water sloshing around while at speed would not be conducive and that forward pump would be intermittent. But there might be a way to do it. I've just never heard or seen a good solution, doesn't mean there isn't one.
Also, we're on the same track for moving the bottle to the core of the boat. here's a shot of how I did it in TX. and, if I can get them to load, a few shots of what I have going on in the Bow. Bow for me is the electronics and solenoids. if you need pics of the jerry-rigged battery and bottle cradle I have, just ask. I am going to be using these as the design template for the integral system I build for Idaho. I'll be using the ribs themselves to make the cradle. it's going to be tedious to build, but the results will be delightful.
Only had a little bit of time in the shop today, so spent it working on the prop shafts some more and motor mounts. Needed to modify the Traxxas gearbox aluminum plates with slots at the bottom center to allow the prop shafts to come up and out through the inside of the boat, since the motor mounts will be pretty permanently attached to the hull. Threaded the 4mm rod for the M4 props, need to get some M4 nuts to use as locknuts against the props to keep them from sliding off. The whole drive gear + propshaft + locknut +prop needs to go together shish kabob style and needs to go together correctly the first time, so I'm test fitting everything 10 times. If I ever really need to pull these shafts out, I'm probably going to bore out the bushings and props to 5mm and just call it a day. But we're trying it this way for now. Anyway, picture time. Here are the props in what is roughly their final resting places. The small space behind the prop is for the jam nuts which I'll need to run out to Home Depot and grab. Need to get some bar stock to make struts, not sure if I want to do brass or aluminum. Also, general disclaimer: I haven't done much work cleaning up the hull post-glassing, as I've been waiting to make all the messes that will be made and then clean it all up vs doing it 5 times. That process will probably happen this coming week once the rudder shaft is in and there will be no more major modifications to the hull. That was my main concern with a front/rear pump arrangement, was that under power the water would rush out of the forward pump and it would suck air for a bit. I'm still on the fence with the port/stb or front/rear pump. I'm going to keep playing with the layout until I absolutely have to pick one and then at that point whatever I end up doing will be done and I'll live with it. All of the electronic components like ESC's I try to keep as close as possible to their task to limit wire run, so if I run the bottle in the middle of the ship the bow will be 90% empty. I could stuff the firing boards up there, but that's about it. Maybe hide the test switches for the guns up there too, not sure yet. Still very fluid in terms of overall interior layout, item locations will start to solidify as they get attached to the boat haha.
Update: Building has trumped typing, as @Kevin P. says. I was invited to tag along to a battle in Georgia in 7 days, and I have been down for the last 2 days due to illness. I have kept Dunkerque in her end of season 2018 condition...which isn't saying much. Before I would take her out again, she'd need the soldered prop shaft adapters, all new cannons, and her Co2 plumbing redone (leaks). So I figured if I'm going to build 4 new cannons and do all that plumbing for Dunkerque, I might as well just do it for Jean Bart and try to take it. Updates will be light, pictures will be lacking, but hopefully I'll be able to dump a bunch of pictures and update material in a week or so.
So here is the post-georgia update. I was unable to get Jean Bart finished in time and realized that was going to be the outcome about 3 days before the trip. Honestly, it let me relax and not stress about having the boat ready. I had a great time anyway, at the helm of Steve Andrew's veteran USS North Carolina. Driving an NC again gave me a good preview for carrying around/launching/managing a boat as big as Jean Bart. Here are some pics of the progress made since the last picture dump: Internal layout, you can see the BC gun test boards on that rear deck shelf. Planning on that being their home. Will mean a bit more wiring running fore/aft to get to the solenoids for the dual sidemounts, but if I can keep the wiring clean it'll be a good install. Rudder throw/prop coverage test. The left side prop is not installed for this pic, but is 100% covered by the rudder in a turn. This boat will never turn "great" but I'm hoping I can at least get it to turn "okay". Blurry rudder chain shot. I should've built a slot into my rudder servo mount to adjust tension on the chain...lesson for next time. The butt end of this boat is relatively narrow/shallow, made it interesting fitting the rudder servo hence the distance between it and the rudder post. Motors mounted, bottle sitting in its location. Port side internal armor not glued up yet, but cut and in the boat. Starboard side is done. Superstructure mounted, BB's for weight to allow glue to set up. I love/hate E6000 sometimes... Superstructure 95% done. Missing a small stern section and a small section that connects the front citadel with the funnel. Need to clean up some stringyness from painting in the cold. Should've waited for the garage to warm up more, thankful it didnt come out super fuzzy. Have had that happen to 40k miniatures...was a massive mess. There was a small platform off the armored trunk up front, have already filled in that hole with bondo but didnt take another pic. Anyhow, that's it for now. Waiting on solenoids to show up and then it'll be gun mounting time. Need to start laying out the electrical and plumbing. Will probably bring the superstructure inside to my 40k model painting area and give it some detail touch up.
Looks good, my advice on test switches is to move them closer to the guns, one of my regrets on Missouri. I had a plan to move them up but decided a bit too much work for the time I allotted. It can probably be done cleanly but all the wires going there and back make up a decent pasta dish quickly, doesn’t look like you are too committed at this point. The overall height needed also surprised me with wires on the bottom, more than I anticipated
I would drill a drain hole in the bottom of those micro-shorting-switches. When they get full of H2O they will short without any external indications. Makes for interesting forensic exam.
That's solid feedback, thanks Kevin. I can build out a small board to hold them towards the bow. I guess running 1 gun worth of wiring to the nose (stern gun) would be more efficient than running 4 guns worth of wiring to the stern. I'll have to check that out, I hadn't heard of anyone having issues using them but a small drain hole couldn't hurt.
Turret hold down system is installed in barbettes. Used what I had on hand, didn't like the idea of matching magnets in the barbettes because I wanted to be able to adjust the turrets if I ever changed the gun setup and the barbettes are glued in place so you can't swivel the whole turret+barb. I think it came out well. Also experimenting with my phone's automatic GIF function:
