New unproven design question

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Cbavor
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New unproven design question

#1

Post by Cbavor »

Hi I'm new here . My first post . I've been reading a lot . Lots of great info here .
I'm a welder fabricator in CT been working in the marine industry my whole life . I've been wanting to build an alum. boat for a long time . I've worked on and modified and fixed many . I think an aluminum boat is def. the way to go ...
I'd like to build a trailerable cruiser around 28' x 9 feet or so . Not the usual west coat looking craft . I found a design by a designer in Maryland I really like . More old shcool east coast looking I think . I don't know . Any way . This design has not yet been built by anyone ,except for a tank test model that I know of .
So my question is how do I know this is a proven design and will work and handle well ? I've been on a few boats that look great but handle and ride very badly . I certainly don't want that . It will be used for mainly coastal cruising near shore . I' live on Long Island sound .
I thought for a while I might try and design one myself . But I'd rather be boating than designing and building the whole thing myself . I also thought since I'm by myself I'd try and have the hull built and finish the rest . Still a large job , I don't have a huge fat wallet though This boat is called , " sunset channel 24 " cruiser By Cerny yacht design . the designer said he could easily stretch it to 28 ' and said he thought when designing it it should be longer ..
Any thoughts, experience ideas and wisdom appreciated . Thanks
Cbavor ...
welderbob
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Re: New unproven design question

#2

Post by welderbob »

with all of the money and work that is required to build a custom boat , why would you want to be the first one to build a new design. There are lots of designs on there website, but no pictures of real built aluminum boats.

welderbob
ReelSong
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Re: New unproven design question

#3

Post by ReelSong »

Lots of great designers out there, many on this site. Id chose to build design by a proven designer with lots of experience . I'm on my 5th build and happy to say the first four ran and handled flawlessly and I'm sure the one I'm building now will be the best one yet. I'd look at designs by Cope, Specmar, MBK, Ctmd most of there stock plans are proven, why be the Ginnie pig ? It's a lot of money.
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Re: New unproven design question

#4

Post by welderbob »

Talk to Bill Lincoln At Response Marine, he is just north of you in Massachusetts. I'm also close by on Long Island. Happy to talk to you anytime.
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kmorin
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Re: New unproven design question

#5

Post by kmorin »

cbavor, we can make some general statements about the design you're discussing that are reliable given the online images and that site's info.
First this is not a (classic) planing craft by design- so she shouldn't be compared to one. The 4k lb displacment and the 40hp engine make her a 'cruiser' intended to be slower than the typical NW power boat of this class with twin 250HP four strokes delivering 50Plus MPH and using about 100.00$ and hour in fuel.

This boat is designed to deliver speeds under 20 mph likely 12-16 and to cost less to operate, and it not a deep V, high speed hull. She is a classic design originated in the era of the early 1900's when engines were not in the same horse to wt ratio of today. She's great for inland waters, coastal cruising in good weather and weekending with a small crew.

Your discussion of 'ride' is a bit too subjective (no conditions are given- speed, weather, sea-state, crew, seating, and all that ) for me make much of the statement about "ride"- I can't correlate it to this boat. (but)) If you get this boat, it will run flat, not pitched up by the bow, not leaping waves and it will give a very nice smooth ride because it will go slow! Fast is harder to give a 'smooth' ride- slow, well not so much, sharp bow, narrow topsides plus slow is smooth!

Her plumb bow means she will not lift over a swell and will part the swell so the water will come over her foredeck in a blow with a course into the wind and waves. Fine for inland 'chop' and little 2-4' waves, not for offshore weather.

The boat is a long proven design and has a long very distinguished history in your neck of the woods- made in wood. It's called a commuter. The hulls buttock lines are very conservative, little different that I can see from the Ditchburn yachts on the Canadian Lakes, somewhat like the 1920's commuter yachts that ran into the (NY)City from estates on the Rivers a little North?

The build is kind of extravagant in welded aluminum which is most economical for its light wt. in boats where all up speed in a high priority. At the middle displacement and low speed, she's not taking great advantage of her materials in regard speed and horsepower. That is why I describe her as extravagant in welded aluminum, the original Hp/Wt ratio insures she cannot take full advantage of her reduced displacement.

Work-wise, she's a very conservative hull form therefore the effort to form her is minimal compared to some other high speed welded boats with more drastic plate/panel contortions. The hull will be 15-20% of her (total) effort where the interior and accommodations will be 50% or more of her build effort.

Painting her to yacht standards will cost almost as much as the materials of the entire hull and paint prep costs will depend on your skill in fabrication of a hull with as many relatively flat planes; like the plumb, flat (and wet) tops ides forward. With almost no visible tumble home in her after topsides sections, she will be a bear to keep fair or require a 'brown bears' wt.' in fairing compound before painting!

I agree stretch her to 28' if you're going to build in welded aluminum the cheapest thing in the build is long sheets! Look at the BlueJacket http://bluejacketboats.com/boats/ - admittedly not identical but the bottoms are 'cousins' and so you can rely that this design is fully functional.

Now... if you decided to post some more exact requirements like speed, sea state, endurance, crew, provisions and so on... well then we could get to cases and be more useful instead of making somewhat generic statements about the pictures on a web page?

Having the metal work done is very realistic if there are cut files already available? IF you have to finance the cut files!!! you may find sticker shock for that cost. I'd consider the metal work roughly 1/5th her cost maybe less if you're not finishing her to a 'Bristol yacht' and perhaps more if you have her faired and painted before she was finished?

If I were looking at this project, as a designer and builder, I'd consider two things to change her a bit for the build.

#1 I'd ask the designer what it would cost to have her panels made more convex? A bulge/outward curve/convex surface will remain very significantly more fair when the transverse framing is welded to those exterior panels- extremely reducing the cost to fair with filler and painting.
#2 I'd consider a small inboard just aft the cabin to provide both hydraulics and cabin/potable water heating with and HE. The very low horse power proposed for the hull lends itself to the relatively low cost inboard diesels which can be encapsulated in what are called 'generator pods' to control sound transmission inside the boat. These 'clam shell' sound dampened enclosures would allow an inboard installation to provide the waste (heat) energy to the accommodations spaces that cannot easily be obtained from an outboard installation.

The all-up cost of a shaft and rudder instead of an outboard is likely more expensive but the class of boat is much higher and in keeping with your overall 'look and feel' of this 1920's cruiser than hanging a Japanese outboard on the stern for all to see!

I think the boat's designers have enough experience that this is not a risk to build- or to have built.

Cheers,
Kevin Morin
Kenai, AK
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Re: New unproven design question

#6

Post by ReelSong »

Kevin, not to sound like a butt kissing idiot, but you are amazing , I'd Love to sit in the shop and just pick your brain for about 10 years, I've been around off shore boats for about 40 years , been a mechanical cantractor for 31 years and a boat builder for only the last 7 or 8 years, but I'm consistently amazed at your knowledge of sea going crafts, welding practices and boat building in general. and more amazed at your willingness to share. What I wouldnt give to be a young apprentice under you for about 10 years if I had them . Thank you again for being a part of this site and boat building in general.
kmorin
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Re: New unproven design question

#7

Post by kmorin »

ReelSong, thanks for the kind words, somewhat of a red face here.

Cheers,
Kevin Morin
Kenai, AK
kmorin
Cbavor
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Re: New unproven design question

#8

Post by Cbavor »

Thank you so much for all the replies and thoughts . All great info . I am not stuck on that particular design or designer . I just liked the look and style . I'm drawn to a north east lobster style than a northwest looking boat that's all . I know it would be difficult to build a lobster boat out of alum. Do to all the compound shapes . But something to that look . I like the plumb bow . I know that doesn't lend for going over waves but through them without good flair .
I saw another design I liked by albatross marine designs . This was a pro boat builder design challenge winner by Albert Nazarov. I tried emailing them for more info but no luck .
If you guys know of any other designs or designers For sort of what I'm looking for that would be appreciated too .
I want a certain form but also a good function . ... A good cruiser. Economical Trailer able , good space for.a couple for weekend , up to a couple weeks at a time just needs to be simple . I don't want to fair or paint I'd like to stick with an outboard . Most cruising ill do is on Long Island sound . short chop 1 to 3 feet I'd say. I'd like to be able to cruise at 20 kits or so as seas allow . I'd like to do the great loop a bit at a time . Some day .
Thanks again .
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kmorin
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Re: New unproven design question

#9

Post by kmorin »

Cbavor,
We're into some terminology to keep our discussion alive, otherwise we'll be aground on the shoals of misunderstood words - I think this happens between the coasts more than it should with the internet but I'll make a stab at my version of clarification.
Cbavor wrote:I know that doesn't lend for going over waves but through them without good flair

The Carolina Skiff or sports fisher has a hull that curves in two directions at one time, this compound surface is called flair. But a sheet metal/plate metal boat that uses the material without roll forming or English Wheeling to stretch the original material does not provide a compound curvature (Flair) at the bow; instead is can be leaned out from the keel in a conic shape (developable not compound) and that is referred to as flam. Flam is not as sculptural or visually appealing and unless you have the hull built by the Gravois (not sure how many of them there are- or what companies they've populated? and my greatest respect for those fine looking hulls) in LA; forget flair and being to discuss flam.
http://www.usedboatyard.com/used-boat/2 ... na--157689, notice the bow is curled outward while the topsides are curved toward the bow stem; I consider this flair not flam and its more than a little effort to add to an aluminum boat!

I think there's a post here on this shape and terminology?

Next, the following words are not exact enough to hold an effective internet conversation. "Good", " efficient", "Economical", "simple form" "good function" are all relative terms so they may mean something to you that those same word may not mean to other readers?

Let me give you an example? here is a boat from Alaska: 28'LOA x 10'BOA X 4' sides, 2 x 300 HP Four Stroke O/B; Speed 54mph WOT; sleeps 6 (family or good friends), gets 1.23 mi/gallon cruise @ 35mph & 22-26gal/hr. Now in Alaska, this may be a good cruising speed (35mph), and an efficient burn for the boat (25gal/hr?) , and comfortable for 6 for the week's fishing. It's definitely economical (if you work on the North Slope earning $165,000 annually) and only have a few weekends a year to be on the water? Some people who want to go slower, with a smaller boat may say this 130$ an hour boat is not efficient so it's not "good"? Terms can be relative.

Do you see how the terms can be difficult to discuss in a nationally read Forum? What is much more constructive to holding a discussion where others offer advice (or opinion or share experience) is to state the relative terms in more exact terms; say numbers? For example,
" I need a top speed of X MPH using 10 hp"
Or
"I want a boat that displaces less than 1, 2, 10 thousand pounds." details in numbers are better than generalized terms.
" The LOA must be 20', 30' 40' " By giving fixed definite numbers for every single item on the design list (and making a table for your own use of these factors) you can then begin to compare different designs' features to your list of criteria.

Design methods:
IF a person is not a marine designer then the next best method is to 'cut and paste'. This begins with a SOR or Statement of Requirements sometimes called the design narrative. That is a tough document to make if you're just doing your first boat. Then, after your SOR; make an image collection of ALLLLLL of the countless boats out there, online, and show what you like in that boat. "This is the sheer line I want!"; "Here is the cabin profile I want to use." so by clipping pics and annotating them you can come up with your design's 'features'. In the end you take the rough ideas to a designer or begin drawing?

If in the process you find one boat that is "IT" - your dream boat, then that's simple; buy it or build her. In the meantime if you're shopping for designs and considering a build you'll wander for years if you don't begin to make design decisions in the Design Helix. I think there's a post here on that? The decision making of marine design is complex but based on a simple idea.

You make the biggest decisions first, and go around the circle of your boat's features every time you make a new decision, and only move up to more complex design decisions (smaller more detailed) when you've solved the more fundamental decisions, allowing you to move onward and upward. However, if any decision changes or implies change to the fundamental decisions below and foundational to the upper details, you'll have to go back down... revisit all the fundamentals and adjust them to the new implications!

I will let you know: this is not something ANYONE who designs learns in a single boat or in a single turn around the design helix.

To get others' input, you'll have to get pretty exact or we'll all be using relative terms, so our replies may mean something to us they don't mean to you (!) and they won't be much help if we're not talking the same meanings of words? What do you mean in numbers for the relative terms you're using? What is good, or efficient, or " good function" ????

The post of the modern commuter shape shown in the last post for example, is not a lobster boat profile as commonly used to describe the pot and trap fishing boats of the East Coast, at least as I've seen them shown? http://youngbrothersboats.com/ this link is to 'Down East lobster boats' as I use the term? How are you using that term?

Hope we can offer some help once we're talking the same boating terms language?

Cheers,
Kevin Morin
Kenai, AK
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Re: New unproven design question

#10

Post by goatram »

As a first time builder myself I had the help and assistance of a few people in the industry. If I had to do it over again I would go with a builder to weld out the basic hull.ready for rigging. Reason is you will have way less issues of how things fit and work together. Mistakes are made by the novice. Some that require assistance in redesign or work arounds. Welding aluminum is not steel and the learning curve is long to get pretty and functional welds. The cost of welding supplies, aluminum, forming, rigging components, along with everything else will cost you twice what it will cost someone in the business. Yes you will save some money but it will cost you.

welderbob is someone to get to know. He is offering to talk. Kevin is helping as well in the design and understanding terms. I am fortunate to have Bruce and his Son Brandon of Coldwater Boats about 12 miles from me. I also have a friend that can lay down a weld bead beautifully. Learned his art welding at Munson Boats; 35 miles north of me. A willing and hungry young man that fits in odd places.
Jim aka Tigger climbing out of a offshore bracket of a 26' boat
Jim aka Tigger climbing out of a offshore bracket of a 26' boat
To use Kevin's term: glad you made the choice not to use "pain-t".
My Glen-L designed Norwestern designed boat. Modified by me. Proud of her. She was finished in my shop. The Basic hull was purchased partially finished. Tre Build thread his here and on BD Outdoors.
My Glen-L designed Norwestern designed boat. Modified by me. Proud of her. She was finished in my shop. The Basic hull was purchased partially finished. Tre Build thread his here and on BD Outdoors.
I do like to fabrication things and I am always looking for my next project/mod. Just remember that if you begin; it will take you many days of 12 hours in the shop building your Mistress. Your wife will hate her in time. I am a graduate of the University of Hard Knocks. With a Masters in R&D. Enjoy your Journey. and Welcome to AAB :thumbsup:
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ReelSong
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Re: New unproven design question

#11

Post by ReelSong »

I say if you feel confident in you welding abilities, and your willing to do and re do a few things then pic a proven design or designer and go for it. There's no better
Way to learn something then to do it . With the information available through sites like this and others, anything is possible if you have the aptitude. One must be willing to be honest with his self and abilities. I am a mechanical contractor by trade, but have always enjoyed fabricating and creating. The boat pictured below was my very first build and I'm still very proud of it and happy to say it is in operation after five years as a charter boat in Alaska .I've since built five others and am currently building b the 36 foot Cope Patrol shown on this site on a build thread. If your up to it, then go for it and enjoy the time spent, also enjoy the special feeling you'll get the first time you bonk a fish in your self created machine. There's definitely something to be said for fishing in a craft you know every single piece of.
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