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Messages - Brian.Dixon

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1
Day three on the water. Raised the motor 2 inches, gained 500 RPM, way more then expected. Up to 5500 RPMs and happy with that at 7000 feet elevation. Last week I felt like the the back of the boat was pulling down, it was. I was getting water in through my scuppers when I would turn. Today no water in the scuppers. 37 MPH. More then I need most of the time.

Yup ... all boats are a teeter totter around the center of gravity.  Trim the bow up and the stern goes down and vice versa.  If the motor is too deep in the water, then you've got an undesired trimming up of the bow ... Note that when a boat is on plane, the center of gravity is above the waterline (around 9" to 12" in a Great Alaskan).  In an ideal world, you'd have the line of thrust (prop) at the same height as the center of gravity, but that's impossible when on plane.  The deeper the motor, the more leverage the motor has on boat trim.  The higher you can run the motor, the better ... as long as you are getting cooling water pick-up in all conditions and operations (hard turns) and your prop is not cavitating (including jamming the throttle on slow speed hard turns - aka 'evasive maneuvers' when you need that thrust!).

Brian


2

Thanks for the link!  I shared it on FB...

Brian


3

You already know about making sure there's no residual amine blush before adding more epoxy, so I won't mention that ... but you know, subsequent coats of epoxy just need to have the shine removed from the previous coat (unless the prior coat is newer than 36 hours old, plus or minus).   You can take the shine off, without removing epoxy that you want to keep, by just lightly scraping ridges, specks/bugs, bumps off first then put your random orbital on top of a green scrubbie and 'sand' the epoxy.  The random orbital sander does a great job of scrubbing epoxy with a green scrubbie ... takes the shine right off without actually sanding.  Folks not using peel ply may have more of a weave pattern left that needs to be filled, so sanding helps ... green scrubbies alone may require more fill coats to get it all smooth (MY opinion is that the only smooth, shiny, faired surfaces should be those between the waterline and sheer, the exterior faces of side panels, and maybe the roof of the cuddy ... all else is OK to see a fiberglass pattern on).

Brian



4

Good plan. Use that 3rd coat.  It's not that much material is removed by scraping and sanding, noting that you should lightly sand even after using peel ply, but more about the thickness of the epoxy resin itself.  I doubt you'd end up with any too-thin regions after glassing, especially with peel ply, but for the cost and effort, why not?  Pilothouse roofs end up storing stuff ... fish nets and gear, rafts, etc ... it's a good area to protect with glass, epoxy, paint...

Brian



5

Looks great from here!

"Waterproof" is 1 properly-saturated layer of fiberglass plus 2 'fill' coats, or 3-4 coats of epoxy on bare plywood (3 coats is marginal and I think, not reliably waterproof on softwoods).  You'll know by looking at it ... smooth and glossy is a good sign, anything dull or inconsistent in shine and smoothness isn't.

Brian


6

I like the approach of starting too high then working down.  Unfortunately, it's common in Alaska to hear the suggestion that the cav plate should be 3/4" under water or so.  But that's typical for a work boat, not so much a sport boat.  The Great Alaskan is light enough, regardless of what you use it for, to justify more of a sport boat tuning of the motor height.  The risk of cavitation occuring on a hard hole shot is low, so why not?  You'll get better efficiency, and I suspect we'll hear from Dan on, with the cav plate higher ... less drag AND the line of thrust being higher on a planing hull makes it more efficient.

bd


7
Great minds think alike ... plans sales have picked up as a result of the virus :)   Others must have more free time now, so why not build a boat?  Afterall, if you go bankrupt and lose the house, it's nice to know the Great Alaskan has room for  a galley, head, and queen-size bed in the cuddy!  You can always live in it instead of the house, right?  :D :D :D


9
FORUM REGISTRATIONS TEMPORARILY DISABLED - Here's how to register!

We're getting 40-50 false registrations per day, all of which contain porn links.  Until I get the time to install better registration filters (the built-in ones clearly aren't working) ... you can register via our main website contact page:

  Glacier Boats of Alaska - Contact Us to Register Here

Send me your email address and preferred user name, and I'll email you a temporary password - which you should change once you log in to the forums.

Sorry for the inconvenience.  I'll update here when I turn registration back on....

Brian


10

That's great, Randy ... You're getting very dialed in and that's very positive.  I know that your build process and the boat are going to be fantastic ... Keep that SE Alaska trip as your carrot on a stick and keep at it.  The SE Alaska trip is very much worth your effort, and how better to do it than camping in a big 28-foot Great Alaskan?  There are more 28-foot Great Alaskans than any other size ... for good reason.  It's really an ideal boat.

Brian


11

You'll put sand on the sheer decks and f'w'd too, right?  Any thoughts on handrails?  Will you service the anchor via the Cuddy hatch or go around the side of the house?

12

I think you nailed it ... that's a perfect spot to drain the water off.  Add a little diverter on the roof to direct the water to the side ... And the mock-up of the 'curb' or 'visor' looks great too :D


13

Looks like you're making GREAT progress!   ;D ;D ;D Did you really mean 180 gallons ... or is it 108?  Where does the f'w'd end of the tank start and where's the aft end end?  It's best to keep the fuel CG near the aft pilothouse bulkhead if you can.  If you've got it forward of that, it may be a good idea to offset it by locating batteries at the transom and/or moving the CG of the outboard further back with a jack plate or motor bracket.  I can do the math if I know the size of your tank for sure, boat length (28 ft), and a measurement of where the f'w'd and aft ends of your tank is ... measured from either bow or stern as long as I know which.

14
I'd mock it up, stand back and take a look at different ideas.  Note that there's nothing at all wrong with putting strips of wood on top of the house roof to guide water to where you want it to drain, or to have a drain hole through the side curbing ... it looks and works fine.  I believe it's very important to have water drain onto an area with no windows ... water on a window wrecks visibility, encourages eventual leaks into the boat past the window, and means you can't open the window for a little ventilation on a rainy day.  The same concepts apply to diverters on the sheer deck to force water over the side instead of into the cockpit or even the dry well (splashwell).

Brian

15

Your grabrails really turned out nice ... the template and router did a great job (in your hands :) ) ...


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