Author Topic: 13 Bananas New Jersey Kodiak  (Read 405 times)

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Brian.Dixon

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Re: 13 Bananas New Jersey Kodiak
« Reply #15 on: April 14, 2021, 06:31:31 AM »

Well ... you're officially on the naughty list now!  That's 4 feet beyond recommended and I also don't recommend the 'lift out of the water' style (aka Armstrong) brackets.  It'll be interesting to see how the boat turns out.  Make sure you build heavy.  (You been drinking with Dave again?)  :D  Love the moaning chair ... hope you don't need it!

LOL.  Dave was one of the (aka Armstrong) bracket yes votes.  Theory is this is a 31' 6" boat on plane with the bracket out of the water.  We'll see if there are any ill effects.  I'm not worried about the chines walking...  only porpoising.    I believe your design wouldn't porpoise until the low 40's at 31' 6".  (Even if it would!)  I'm hoping for the best, but always have the moaning chair for backup.

--dave

The advantage of the Armstrong type bracket is that it allows the water to rise behind the boat, which in turn lets you run the prop higher, which in turn means the line of thrust is closer to vertical center of gravity ... which is always above the water in a planing boat on plane.  The more you can line up the prop's line of thrust with the VCG, the more efficient the boat will run.  The only downside is that without hull support under or just ahead of the motor, your CG *will* move aft versus the waterline ... this can be an issue with lighter weight boats ... and comparatively, the Great Alaskan is lightweight compared to commercially-built equivalents.  You're on the right track using those heavy and taller-than-required stringers (they're a beast!), but the note of caution is to NOT build too light.  Building heavier will help balance out the weight of the motors behind the boat... As Dave has suggested in the past, float the boat with motors on it and then use buckets or bags of sand in the boat to 'model' how the boat will trim when finished.  Try your best on this.  Your 34-footer should trim about 1-1/2 inches high at the bow versus the stern if the CG is in the 'window'.

Brian


The Great Alaskan - Professional performance - Easy to build! - https://www.glacierboats.com  ><((((> .`.><((((> .`.><((((> .`.><((((>

cj8mule

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Re: 13 Bananas New Jersey Kodiak
« Reply #16 on: April 28, 2021, 08:06:45 PM »

Well ... you're officially on the naughty list now!  That's 4 feet beyond recommended and I also don't recommend the 'lift out of the water' style (aka Armstrong) brackets.  It'll be interesting to see how the boat turns out.  Make sure you build heavy.  (You been drinking with Dave again?)  :D  Love the moaning chair ... hope you don't need it!

LOL.  Dave was one of the (aka Armstrong) bracket yes votes.  Theory is this is a 31' 6" boat on plane with the bracket out of the water.  We'll see if there are any ill effects.  I'm not worried about the chines walking...  only porpoising.    I believe your design wouldn't porpoise until the low 40's at 31' 6".  (Even if it would!)  I'm hoping for the best, but always have the moaning chair for backup.

--dave

The advantage of the Armstrong type bracket is that it allows the water to rise behind the boat, which in turn lets you run the prop higher, which in turn means the line of thrust is closer to vertical center of gravity ... which is always above the water in a planing boat on plane.  The more you can line up the prop's line of thrust with the VCG, the more efficient the boat will run.  The only downside is that without hull support under or just ahead of the motor, your CG *will* move aft versus the waterline ... this can be an issue with lighter weight boats ... and comparatively, the Great Alaskan is lightweight compared to commercially-built equivalents.  You're on the right track using those heavy and taller-than-required stringers (they're a beast!), but the note of caution is to NOT build too light.  Building heavier will help balance out the weight of the motors behind the boat... As Dave has suggested in the past, float the boat with motors on it and then use buckets or bags of sand in the boat to 'model' how the boat will trim when finished.  Try your best on this.  Your 34-footer should trim about 1-1/2 inches high at the bow versus the stern if the CG is in the 'window'.

Brian

Thanks for that sound advice Brian!

cj8mule

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Re: 13 Bananas New Jersey Kodiak
« Reply #17 on: April 28, 2021, 08:18:09 PM »
Getting a little bit of work done






A word of caution from those who would choose to build with fir MDO.  It's a great product, but it will not make the bend for  the 3/8" bottom panels.  Since other types of 3/8" marine ply was unavailable to me, I made it work with 3 layers of 1/4" fir.  I can only assume the thin paper they use on the mdo keeps it from making the bend.  I'm pretty sure it'll make the bend at the bow for the sides, but a definite no go for the fairbody. 

I was looking for some pictures of the failure, but can't find any. 

Anyway,  back on track!  We'll be putting the jig together this weekend.

--dave

Djeffrey

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Re: 13 Bananas New Jersey Kodiak
« Reply #18 on: May 02, 2021, 03:25:19 PM »
Looks great.

Scott L

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Re: 13 Bananas New Jersey Kodiak
« Reply #19 on: May 02, 2021, 08:08:39 PM »
Looks like every thing fit together great and the glass work is first class. Are building the Kodiak or the Great Alaskan?