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General Discussion about the Great Alaskan / Bow thruster install
« on: March 13, 2023, 01:59:57 PM »
I am going to be installing a bow thruster at some time in the near future, and was reviewing the images in Grady300's build thread of the cad drawings that Brian did for his install. I put my crash chamber bulkhead too far forward to use the measurements in the drawings, so, I have a couple questions around it.

Is there a hangup putting the tube further toward the bow? I believe there is a minimum width of the bottom of the tube, so as long as that requirement is met, and the minimum depth of the tube is also met under the waterline, is there any other reason that the tube needs to be located further aft as in the drawings?

If the tube is far enough forward such that the back of the tube becomes a perpendicular face toward the direction of the boat traveling, is there any reason to reenforce that back edge and round it off so that the water would flow off toward the outside of the tube?

I am attaching the drawings from Grady's build thread for reference.

General Discussion about the Great Alaskan / Hull Numbers
« on: September 28, 2021, 01:03:42 PM »
What are people going to be doing for hull id numbers? Paint? Decal letters? Something else?

Anyone have any advice here? I was assuming to put the rear bunks under the stringers but that seems awfully narrow for stability's sake. Now I am thinking maybe a few inches from the inside of the chine on both sides, or maybe half way between the stringers and the chines. The front bunks seem like they can maybe be directly under the stringers, so unless I am missing something there that's where I intend to put them.

Also, how do I get this thing from the jig onto the trailer? Back the trailer up to the front of the boat and start cranking with the hand crank on the front of the trailer? Crack a beer first or later? Should I have my wife "hold my beer"? So many questions... :P

Brian (or anyone else who wants to chime in) - I am trying to build in some chambers to hopefully make my boat have the tendency to roll upright in the event of a capsize. I am pretty sure it's been discussed here but not sure where, something to the point that adding buoyancy under the aft shelves would help avert the full upside down unrecoverable scenario. Approximately how much displacement would help in this? I am building a euro transom similar to grady300's, and have the triangular spaces to both sides open (under and behind the shelves all the way aft), but not sure if they are big enough. I could probably get creative if they were anywhere close to adequate. Any feedback about this? Very rough guess is those spaces are about 3000 cu in each, could be made somewhat bigger, and I should be able to seal them to be air tight.

General Discussion about the Great Alaskan / Pool noodles
« on: April 18, 2021, 06:09:53 PM »
I found jumbo pool noodles at walmart in San Clemente while I was down there this weekend for $2.97/noodle (ignore the skinny little blue one in the front, it was the outlier). They are way thicker walled than the ones I purchased last year at target for around the same price, so load up now if you are entertaining using noodles for floatation foam (assuming they are available in your area)...

As I was putting in hours on the project today I was sort of reflecting on my journey to this point, and what I have learned between then and now. I thought it might be kind of useful to make a thread of builders tips or advice that would help people just getting started to gain some insight into things that may or may not be obvious or mentioned elsewhere. So maybe if you have some, put your top 3 here to help your former self hit the ground running...

1. Glass whole panels with 50" cloth, not sub assemblies.
It's way easier to glass a whole panel, fair it, and then cut to shape than it is to glass a sub assembly after it's built (shelves for example). For those who don't want to get addicted to peel ply you can also make a thin fairing compound and trowel it on to fill the weave to save yourself from having to do a bunch of coats to fill it. It's a bit more work than using peel ply but it works well. Bonus points for using a rubber spreader or shower squeegie to put the glue on... Using glassed and faired panels saves a lot of effort down the road with a bit of fore planning and patience.

2. Get a $10 amazon scale to weigh resin/hardener that weighs in 1/10th grams.
I am still using the first $10 scale I started with, and it works great. Here is a link to it (currently unavailable but for example and specs) Make sure the scale has a high capacity (that one works with 3000 gram capacity). I overloaded my first one and wasted a pretty large cup of resin and hardener when I bottomed it out. When you measure by weight make sure that you use the ratio by mass, not volume (ebond is 100/43 resin/hardener by mass). With a scale you can measure as small or large a batch as you want so you can really dial in how much glue you mix and use. With resin and hardener in bottles it's a breeze to get a cup of glue measured accurately and mixed.

3. Fair things before you glass or tape them.
If you glass over fillets that have a bunch of bumps you are going to have bubbles. Same with panels. Either tape fillets when they are still wet or get something that works to sand an area like that, for instance I bought a belt sander that is killer to smooth out fillets that are already cured but not taped

General Discussion about the Great Alaskan / Bilge pump considerations
« on: January 07, 2021, 10:18:11 AM »
What are people planning on doing for bilge pumps? I am thinking a smaller one in the lowest spot in my bilge and then a much higher capacity one a little higher, both on float switches and both dumping into my little drywell... Anyone given thought to this and care to elaborate? My thinking with my initial plan is to work the smaller pump for all but the biggest emergencies and then have the bigger one waiting there for serious duty if it ever comes to that. I am curious what flow rates and brands people are considering as well.

General Discussion about the Great Alaskan / Under cockpit sole plumbing
« on: October 26, 2020, 04:48:13 PM »
Question for those more knowledgeable than me - is it safe to use PVC to plumb a discharge from a bait tank under the cockpit sole to the transom (above the waterline)? I want to do so but I am worried about it cracking or aging, etc, and filling the bilge with water when I am offshore. I can't seem to find any real information about it on the interwebs so I thought I would throw it out there here and see what people think.


I have been reading Nigel Calder's book Boat Owner's Mechanical and Electrical manual, and have learned quite frankly more about lead acid batteries than I could have ever imagined. I have also done some things with lithium ion cells, such as building a 12s5p battery from scratch for an electric skateboard that I am very fond of, but that has made me realize how dangerous lithium ion could be on a boat (I used to commute with it on the train and would wince when I thought about what would happen if the cells decided to catch on fire, and really can't imagine something like that on a boat). I have been reading up a bit on lithium iron phosphate for house batteries, and from what I can tell it's much safer than li-ion. The only drawback I can see is really price, which from what I have been seeing isn't that much steeper than a quality AGM lead acid battery. The benefits are that you get 80% or so usable capacity, you save at least 50% of the weight per watt, you get 5-10x more cycles, you charge much faster, you don't have to worry about PSoC, etc. What's the rub? Calder says the tech isn't there yet, but perhaps it's moving fast enough that since his last revision it wasn't. But paying $3kish for 300 usable amps in li-iron phosphate vs $2kish for that in lead acid seems like a no brainer to me. Anyone have any thoughts about lithium iron phosphate power, or experience with it? Or any recommendations about quality from one vendor to another?

I feel like I have seen this discussed here, but I wanted to talk a bit about transom weight. As it stands I am thinking I want to have a single high power yamaha (f250 or f300), which weighs about 560 lbs. I am intrigued though by running twins for the helm master digital controls, which allows the engines to maneuver the boat with a joystick as well as a lot of other benefits, namely redundancy. Since I will likely throw a kicker on the back as well for redundancy if I run a single, that ups my transom weight into the 700lbs range, throw a bracket on there and it's in the 800lb range. Digital yamaha outboards start at the inline 4 cylinder f150, which weighs a whopping 490 lbs. So, is a thousand pounds hanging off the transom unrealistic? Or can I balance out the weight and not worry about my transom getting snapped off like a lever? It's expensive and I am not sure I can justify the cost, but I would like to at least know what's a realistic option before I make the investment.

General Discussion about the Great Alaskan / Okoume core voids
« on: August 07, 2020, 09:26:16 PM »
I have been doing my build with largely hydrotek and aquatek and some fir plys (marine fir & MDO, etc). I bought some okoume to do the roof for the weight savings, and a lot of it has voids in the cores. I don't think I have ever seen a core void in hydrotek or aquatek, the former being bs1088, not the later. Those of you using joubert okoume, do you guys see core voids? Do your okoume sheets come with any stamps or identifying marks like the hydrotek and aquatek sheets do? The guys I buy this from seem legit, but my stack always seems to be mangled by a forklift or otherwise just not in the best of shape, and this okoume has no identifying marks on it (maybe because it's optional to finish bright?). Anyways, feedback appreciated. Gracias.

General Discussion about the Great Alaskan / Seakeeper Gyro Stabilizer
« on: March 03, 2020, 01:16:48 PM »
Seakeeper released a new smaller version of their gyro stabilizer, and while it's definitely a wish list item for me, I would like to build in the ability to install one at some later time. Motion sickness runs in the fam, me included, so for the best chance at my family enjoying trips out to the channel islands and out on the ocean in general it's probably something I should consider. The new Seakeeper 1 is made for boats 23 - 30ft, and it is pretty freaking expensive ($15k), however it would be good to know if it's doable and if so what I need to strengthen so it doesn't tear the boat apart. I was talking with their west coast rep who said that 'I should use caution, especially with plywood boats' because of the forces a seakeeper exerts. Their installation video shows it only glued to the cockpit sole. I am envisioning tying it into the stringers behind the fuel cell or just forward of the transom, maybe building a reinforced box frame between the stringers using LVL or similar. Are forces applied to the stringers in this way over and beyond what they are capable of handling in a GA? Can I use additional reinforcement to shore that up if so? Would installation closer to the transom be preferable to the center of the boat where there is less lateral support for the stringers? I could see the stringer - hull seam getting cracked after being stressed wave after wave although maybe it's strong enough, especially with a light boat. It seems that maybe reducing roll also could compromise safety too if waves were too big... Any thoughts?

General Discussion about the Great Alaskan / Glassing the sheer decks
« on: December 31, 2019, 10:11:56 AM »
I can't seem to find where the instructions are for glassing the sheer decking in the manual. I want to glass and final coat both sides of the plywood I use before I use it to cut and fit the decks. Should I not do that? The manual does specifically say to glass them later, but I am having trouble finding that later point.

General Discussion about the Great Alaskan / In-hull transducers
« on: August 12, 2019, 12:57:14 PM »
I read in rbob's build thread a bit ago where Brian mentioned that you could make a fiberglass layup and replace part of the hull to be able to use an in-hull style transducer. I would love to go this route, but am questioning a couple aspects of it.

First is that it needs to be bubble free. I have access to a vacuum chamber so I could likely make a bubble-free fiberglass plug without too much trouble, but adhering it into the hull has me wondering how I would keep it bubble free. For instance, if I had an 18 mm thick plug that I dropped into a precut hole in the bottom assembly, I assume I would have to glass over it, which would introduce bubbles. Do I need the ability to vacuum bag right on the boat hull? Maybe I can make the plug bigger than the area the transducer will be transmitting through and then just glass around the edges leaving the center only the originally vacuum-chamber bubble free material? Once I have the plug in place can I coat the outside of it as normal with something such as graphite impregnated epoxy? How bubble free does it have to be?

Hi all,

I have recently started building a GA. I live in southern California, and am lucky enough to have a pretty decent spot to build a boat. My city (Orange) is somewhat a bunch of sticklers about things though, to the point where they made me build a 6 foot fence to make a shop yard if I was going to be building anything in my driveway. I am pretty sure they won't let me build a temporary shelter for a project like this (some people might think it's an eyesore?), so that said what am I going to run into if I do a lot of this build outside? The temperature is pretty mild, there is direct sunlight though, and some things concern me like condensation on things like the jig or pieces of wood that I have yet to encapsulate. I know many people who contribute here build in enclosed shops in the pac nw (I am from a portland suburb so it's definitely a stark contrast to the weather we receive here). My weather very rarely gets below freezing and we get very little rain. It's typically sunny and 70.

I guess the long and short of it is what things should I be aware of / trying to prevent when I am building outside? Is moisture in the air going to be of concern? Can I cover my project in a tied down tarp when I am not working on it to sufficiently protect it from the elements? I can build a lot of the sub-assemblies in my shop but it's only 25x25 so I don't quite have the room in there. Any ideas/advise would be extremely welcome.



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