28 GA in Pagosa Springs colorado

[Djeffrey]

Todd I found a new,used windlass on craigslist this summer while I was in Washington. As far as a hatch the answer is yes, just need to decide if I want it outside or inside the birth.

[Djeffrey]

Brian, I am looking for help in placing my fuel tank. I am having an 8 foot single belly talk built out of aluminum. Boat is right at 28 ft with rear platform. All my bulkheads are very close to your drawings. I am putting a 26 gallon water tank in the belly in front of the fuel tank (216 pounds of water) 200 hp engine. Fuel tank will be 128 gallons max. I think that all the work I did on the back added about 100-150 pounds to the back. Not sure what else you need?

[Djeffrey]

Working on an access hatch for the swim platform. To cheap to pay 3-4 hundred on an aluminum hatch. Think this will work. Don’t need to get in it a lot, just to mount the engine

[Dan Boccia]

I'm curious how you decided on the 200 hp engine? For my GA28, the rpms are around 3600 for the ~ 22 knot cruise the boat was designed for, and still comfortable at around 4200 rpm up to about 28 knots, past which the engine still performs well but starts sucking a lot of fuel - and that's on a brand new Suzuki 250. I have to believe the 200 would be awfully wound up at 22 - 28 knots and you wouldn't have much speed on top of that without really straining the engine, and might not have much reserve for a heavy load.

Anyway, this is just a curiosity for me - what your final boat weight will be (which depends on how you build/outfit it) and how you plan to use it drive the choice to some extent.

Also, on your fuel tank, a bit of advice - my rear fuel tank will not take on fuel at full flow from the pump - I have to go painfully slow filling it, or it burps up gas through the vent. I have the problem traced back to the vent tap being only 2" from the fill tap.....which is the only difference from my other, nearly identical tank. The lesson is to be sure your vent tap on the tank is at least 4" and preferably more from the fill tap.

Have fun, it's looking good!

[Todd j]

DAN, Can you expand on why the distance between the two makes such a difference when it comes to filling?

[Djeffrey]

Dan, I chose a 200 hp strictly from what Brian is saying on the forum, that combined with the fact that I am not a fast boater. May want to revisit that subject. Thank you for the fuel tank suggestion but I am a little unclear what you mean when you say 4 inch vent, can you post a pic or explain further. Thanks again

[Brian.Dixon]

1) Vent ... for belly tanks, I do prefer and suggest having the vent on the same end as the filler ... but yeah, filling belly tanks is more difficult and on the water, more difficult to run empty without gulping air.  For the fill-up, find a gas station where you can have the boat on an uphill slope that keeps the fill end higher than the other end.  Belly tanks are nice in that they utilized under-deck space that might otherwise be underutilized, but every 'solution' has upsides and downsides.

2) 200 hp or    There's a guy in Oregon running only 140 hp on a 26-footer and finds it to be entirely adequate, but he said it 'grunts on hard turns'.  I know someone running a 300 hp motor that's too heavy on the stern and still has throttle left over when he reaches 44 knots and picks up some porpoising (no trim tabs).  I think that definitely, the 200-250 hp range is the happy range, with 175 hp being a practical lower limit and 275 hp being a maximum that won't buy you much as compared to a 250 hp.  The typical rule is 25# per horsepower or so for satisfying power.  If your typical on the water displacement is a day-tripper 4500#, then that says the 175 hp is likely fine for you.  If you have a more typical displacement of say 5800#, then a 225 hp would be very satisfactory, and a 200  hp perfectly adequate.  If you run extra-heavy at over 8000# ... say 8500# on a larger GA, then you better aim for the 250-300 window if you can get the weight onto the transom (see the construction manuals for guidance and choose your motor by weight - including bracket weight - short brackets weigh a lot less).   Personally, if I had a 28-foot day tripper built for fishing more than luxury living, then I'd be perfectly happy with the 200 hp motor and be OK with it being worked hard if or when I loaded her up to be a lot heavier, say for a long camping trip in SE Alaska.  It'd be a fair trade-off.

Brian

[Djeffrey]

Thanks Brian, not sure if you saw my post on tank placement. Was looking for the center of gravity? Can you chime in on that? Thanks dennis

[Brian.Dixon]

Thanks Brian, not sure if you saw my post on tank placement. Was looking for the center of gravity? Can you chime in on that? Thanks dennis

Maybe I am guilty of shallow reading ....

CG on a 26-footer is about 9' forward of the transom and it moves forward a few inches for each 2' of boat longer than that.  Close 'nuf.  If you look at the plans for a stock boat, e.g. not an extra short or extra long house, you more or less want to balance your fuel weight fore and aft of the aft pilot house bulkhead.  Look at the construction profile drawing ... the two belly tanks shown (dashed lines under deck) straddle that point.  What is 'optimal' varies with what else you put on the boat, and in which order you burn fuel etc ... but like I said, close enough is close enough.

Brian

[Dan Boccia]

On my attached fuel tank drawings, you'll see with a bit of study that the horizontal distance (centerline to centerline) between the 5/8" vent and 1 1/2" fill is only 2" on the aft tank. On the forward tank, that distance is greater (it's not called out, but ended up being about 4-5"). I have zero problems filling the forward tank, and have to fill the aft tank VERY slow. I think the aft vent/fill distance is too little, such that the "spray" of gas entering the tank is intercepted by the air venting out of the tank, and thus if I fill too fast I get fuel froth coming out the vent.

If I was to do this again, I would put them 12" apart just to be sure. It would have been easy to do!

Regarding the engine sizing, I found this online calculator to be quite helpful and with the hindsight I have, surprisingly accurate:

https://btb.fishing/boat-horsepower-calculator/

I wanted to run a 200hp engine, but adding up all the various weights of *everything* that was likely to be on the boat, it wouldn't let me It kept pushing me to a 250, and thank goodness it did. I think a 200 would be fine for a stripped down fishing boat that you're only going out for the day or short overnight in. But my boat is weighted down with additional systems, gear, etc. for staying out for a week and being halfway comfortable. But if you stay out a bit late fishing, land a bunch of heavy fish, and the weather kicks up a 4-5 ft+ sea and it starts getting dark.....do you want the 200 or the 250 then?? Your answer may validly still be the 200, it's just that you have to ask the questions and go through the scenarios to honestly determine what your use will be.

[Todd j]

Sorry for the hijack,  but does the flange that overhangs they sides support the weight of the tank on the stringers keeping the tank off the bottom of the hull?

[Djeffrey]

Thanks Brian and thank you Dan. Dan can I ask how much your boat weighs

[Dan Boccia]

I'd say my boat weighs 4900 - 5000 lb with the anchor system, etc. but no movable parts like pot puller/davit, etc. The local concrete pre-mix outfit allows me to weigh it for free pretty much any time they're open, so if you have one close to you that may be an option for you. It's nice to really know what weight you're at. Drive your trailer across it before you load the boat onto it first so you can subtract that weight off of it, if you can.

And yes, the flanges support the weight of the tank on the stringers, such that the tank side walls have about 3/4" of space between them and the stringers, and the bottom is at least 1" above the bottom of the boat. Works perfectly. Be sure to bed the ENTIRE flange area with sealant so no moisture can be entrained between the stringer and the flange....otherwise pit corrosion most definitely will occur and you might have a loose tank in a few years.

[Todd j]

Very good.  Thx

[Djeffrey]

Hard cut to make. Cutting the door in was a little nerve racking, I was worrried about added spring back on my curved transom but ended up with none.  Very happy with how the back is turning out. Still working on both ends of boat and a little in the middle as well