Messages

2776

General Discussion about the Great Alaskan / Re: yet another build option??

« on: February 25, 2010, 06:13:36 PM »

Thanks for that one on the stringers. All the other stuff I think wouldn't affect the strength of the boat but I was worried that the stringer thing would.
It is not what I intend to do anyway, I will look into the cost of transporting two full stringers from my home up to the build site. I just wanted to know that it was possible and if I have to then I will certainly do it the way you outline.

Many thanks

Haha ...shipping costs for long LVL beams is the main reason that I hear this question.  I should put something in the FAQ about it... (note to self)

Brian

2777

General Discussion about the Great Alaskan / Re: Hull thickness

« on: February 23, 2010, 10:36:37 AM »

To add additional strength could I made whole hull from 4 layers of 1/5" (sides 2 layers) ply and between each layer put one thin layer of kevlar. Why to construct like that, first I will made thin 1/5" complete hull and then add additional layers but kevlar will cover all parts of hull together bottom, chine, side. And will be better then vacuum bagging couse I will screw layers until epoxy cure and then remove screws.

What you think about that ?

I check temperature data in my area, it never falls below 5 C (41 F), so there is no hazard of delamination.

My first thought was "overkill" since the boat is very strong as-is, and you don't need all that kevlar in order to prevent puncturing.  I think that by the time you were finished layering all those layers on, that you'd be tired of all the work and all those screw holes that had to be fixed each time.  Try my methods and I think you'll like them.  If you want increased puncture resistance, add a second layer of 10-oz woven glass cloth to the outside bottom panels and a single 5-oz layer of kevlar on the interior face of the bottom panels ...while they are still flat, e.g. pre-assembly, and you shouldn't have difficulty.

Brian

2778

General Discussion about the Great Alaskan / Re: Hull thickness

« on: February 23, 2010, 10:31:37 AM »

Bow is made of two layers couse of easier bending or there is some other reasons ?

Absolutely.  Bending 3/4" plywood over the bow would be very difficult while bending 3/8" plywood over the bow is easy.

Brian

2779

General Discussion about the Great Alaskan / Re: yet another build option??

« on: February 23, 2010, 10:30:48 AM »

I see what you mean about the sides bending a bit but that is surely only because they are sort of hanging there on their own with not a lot to stiffen them up or fix them. If they were attched to bulkheads I would have thought they wouldn't flex much at all. I could even tack them on, mark them, trim them and then rehang??

It's not that things vary a lot, but your molds for carrying the sheer shelves may be slightly different from somebody else's (width, height), the shelves may not bend exactly the same, the bottom panel assembly may not be exactly the same height above the jig when you put the sides on, etcetera.  You won't have much boat-to-boat variation, but may find differences around 1/4" here and there, maybe more for some.  Yes, you could build the bulkheads in advance but may have to trim them to fit (kind of a pain ...big bulky pieces to trial fit) or fill gaps larger than you'd prefer to fill (with epoxy.)  So far, those that have started on the boat report tight fits however, gaps no larger than 1/8" as things go together.

Brian

2780

General Discussion about the Great Alaskan / Re: yet another build option??

« on: February 23, 2010, 10:26:43 AM »

If you're going to build stringers up from shorter pieces, I'd rather see you join them with a long diagonal joint, e.g. diagonal from top to bottom of stringer, that spans 6+ feet fore/aft, then glass it well.  Cut the joint with a saw, but do not sand it, then pre-wet with unthickened epoxy and glue it up on a flat surface (using a straight edge to guarantee a straight beam).  Use epoxy thickened made from about 20% glass fiber, 20% silica, 60% wood flour.

Brian

2781

General Discussion about the Great Alaskan / Re: yet another build option??

« on: February 23, 2010, 10:18:40 AM »

This is sort of how you build anyway.  There are under-deck bulkheads that go in first, then everything is decked over, then the bulkheads that you mention are added from the deck up.  The construction manual describes how to fit the bulkheads to the boat, e.g. how to take dimensions and get them cut out.  Since the sheer structure and side panel plywood will always bend slightly differently for each build, it's best to fit the bulkheads to the boat after it is flipped.

Brian

2782

General Discussion about the Great Alaskan / Re: Hull thickness

« on: February 16, 2010, 10:09:17 PM »

Bottom panels and chine flats are 3/4" thick, the bow area being formed from two layers of 3/8" ply.  The bottom only needs to be 5/8" thick, but it's hard to find 5/8" plywood, so I rounded up to 3/4" instead.  The weight difference is minimal.

Side panels are made from 3/8" thick plywood.

Transom thickness is 2-1/4" thick in the motor mount area and 2" thick below the motor mount area.  For the stern drive option where the transom does not have an outboard cutout, the entire transom is 2" thick.

Brian

2783

General Discussion about the Great Alaskan / Re: Bow thruster

« on: February 14, 2010, 01:17:03 AM »

Hello again ...I'd be happy to plug your info into my CG model and get back to you.  Give me a couple of weeks or so since we are now in the midst of moving into a new house and I'm also in the midst of changing my CG spreadsheet into US Navy format, reorganized around systems and components the way the navy does it, etcetera.  I'm only about 25% done in the spreadsheet switchover, so it'll be a little bit...

BTW, Nothing wrong with your pilot house and roof idea....

Thx,
Brian

2784

Board Help / Re: Missing topics

« on: February 12, 2010, 11:42:18 PM »

Should be fixed now.

Thanks,
Brian

2785

General Discussion about the Great Alaskan / Re: Bow thruster

« on: February 12, 2010, 11:39:56 PM »

This boat is not a deep-V type of boat and it's light weight.  It doesn't sit deep enough in the water to allow a bow thruster, but it's hull form and weight will allow easy maneuvering at the dock anyway, so you don't need one.

As far as where to put something like a generator, the first answer is "where it is well ventilated!".  The second answer is "Give me a general layout and I will plug it into the CG analysis and will help you fine tune your boat for best trim".  I'll help any builder of a GA perform layout analysis for weight and balance so the boat's CG remains in an appropriate envelope and so that the boat trims out properly.  As you progress, ideas will change along the way, but I am happy to work with you on it... repeatedly, and especially for the heavier items (appliances, fuel storage, water storage, powering options).

Brian

2786

Board Help / Re: Missing topics

« on: February 12, 2010, 11:35:25 PM »

Well yes, u hide whole thread ... and please can  move closed transome topic to more appropriate

P.S. G.A. FAQ is hidden, probably forgot to add rights for users

Hidden?  Wow!  I thought I just turned off the ability to post!  I'll have to look into that!  Thanks for the heads up!  It of course works for me (admin access) so I never knew...

Brian

2787

Board Help / Re: Missing topics

« on: February 12, 2010, 12:24:20 PM »

I think that something missing G.A. FAQ

Can you expand on that?  I turned off the ability to post to the FAQ board since I prefer seeing discussions taking place in the general (or other) boards.  When I see a topic that looks like a good one for the FAQ, I will move it over manually.  Other than that, is there something else wrong with the FAQ board?

Thx,
Brian

2788

Great Alaskan FAQ / How the FAQ board works... and why you can't post here! (Sticky)

« on: February 11, 2010, 10:35:27 PM »

NOTE: In most forums, if all boards are left open then general discussion ends up being split between the 'FAQ' type board and the general discussion board.  In OUR forum however, I have disabled the ability to post in the FAQ board in order for people to stick with the general discussion board instead.  As typical questions in that (or other) boards show up, I will individually move them here to be a part of the FAQ board.  Thanks!

Brian

2789

Boat Building Materials / Re: Epoxy

« on: February 11, 2010, 10:28:56 PM »

Thank you for you honest answer, I contacted company and my domestic provider and they have one new marine epoxy Megapoxy HX no solvent just right one and also price is very good.

Do yourself a favor and buy a quart (mixed) or so and try fiberglassing a bit of wood with it, and do the same with a known standard such as System Three, WEST, MAS, or RAKA etcetera to compare to.  That'll tell you right away whether the new stuff will be easy to use or not.  Just for your information, I started out in this world using WEST but switched to System Three and never looked back.  But now, I'm switching to AeroMarine since a buddy in the business can supply it to me and it works very well ...a bit thin, so you might find yourself putting on an extra fill coat, but on the other hand, it saves time when wetting out fiberglass so you can work fast.  The other epoxies in the list are known good, but I have not personally used them.

Brian

2790

Boat Building Materials / Re: Epoxy

« on: February 11, 2010, 01:15:15 AM »

Also in my area i found http://www.megapoxy.com/?p=627 at very good price they have liquid and gel variant.

Again, I'm sorry that I'm not familiar with MegaPoxy.  I will say however that you can use any epoxy that is a) designed for marine use, b) non-shrinking, and c) is designed to wet-out fiberglass well.  RAKA, System Three, WEST, MAS, Progressive Polymer's Basic No-Blush, AeroMarine, etcetera are all good choices.  If you find something similar, then fine, it'll work.  Just make sure that it is designed for marine use (waterproof) and is non-shrinking (some contain solvents... you want zero solvents).  Compare the viscosity of the MegaPoxy with these others, and make sure the product meets the other requirements that I just specified, and you'll be fine.

Brian