Cheapest cost to self-design & self-build a 45ft sailboat

Polyurethane foam is flammable, yes. There are nonflammable foams available, for example http://www.avantigrout.com/images/stories/products/Product_Guide.pdf - their AV-280 Hydrofoam or AV-290 both have ~ 2000% expansion ratio. Here is AV-202 with only 600% expansion:


Here is AV-280


Also here is a video of a team putting a boat together in 3 days using aluminum and bending sheets together
- the trick is to design it right in the first place.

 

That's only a bare hull, which by far isn't a boat yet, as was already said in post #20, and also in the bottom citation there.

 

It says . . . ‘‘ New construction method ’’ . . . ‘‘ No one has done this before ’’ . . . and more snake oil . . .

Check 1981 patent US4282617A and the 5 drawings there, which are also to be seen in this PDF of the patent.

Also the type of dart cutouts in the video and the hull shape look as bad as an old Brent Swain design, which can be much improved.

And the wooden building jigs in the video aren't needed at all for the shown origami boat building method.

↓ Brent Swain long ago but after 1981 at the built of Sailing Vessel MOM

‘‘ Brent has developed a unique construction method that is called "origami" as the hull is "pulled" into shape. ’’

Also snake oil, see the above linked 1981 patent . .



I do like however the Origami YAGO Project which is different in many details . . .

-

 

Ideas are free, only execution matters.

 

True in this case, the idea has become free after the patent expired.

Not true, it also matters when saying anything it's the truth, like e.g. about ‘‘ New construction method ’’ and ‘‘ No one has done this before ’’ and also the building time of the bare hull being presented as total boat building time is far from providing the truth, so that matters too in terms of reliability of the source.

 

A CNC aluminum 49 pax ferry 42' long with triple Bravo II out drives and a bow ramp took 1800 m-h of very experienced builders running 15 m-h / CIGRT. Most professional small builders run more like 35 - 45 m - h / CIGRT. An amateur working alone would probably be twice that at least.

 

CIGRT?

 

Must be some Baltimore acronym that has "time" in it

 

Even Google does not know about it.

 

cubic feet in gross tonnage?

Best I could google.

Estimate Man Hours to build a yacht...... https://www.boatdesign.net/threads/estimate-man-hours-to-build-a-yacht.25530/page-2

 

From the context in which CIGRT was mentioned I'm thinking about a typo, maybe CICRT was meant, which means Cost to Income Ratio (also CIR), and is a term that comes from the banking and accountancy industry...

↓ How to Calculate a Cost-to-Income Ratio

‘‘ In accounting, the cost-to-income ratio measures the cost of running a business compared to its operating income. The lower the cost-to-income ratio is, the more profitable the company should be. It's a useful metric for gauging the efficiency of the operation. . . . . . . . . . . ’’

↓ Definition of cost:income ratio

‘‘ the cost:income ratio (or efficiency ratio) measures operating costs as a percentage of operating income. The ratio, which will vary across the bank, should be as low as possible (but not so low that it compromises customer service). Banks hope to reduce their cost income ratio as the business grows thanks to economies of scale. The idea is that additional revenue from existing or new customers has a relatively low cost associated with it and so is increasingly profitable. This is sometimes described as 'positive jaws' between income and expense growth - ie income grows faster than expenses, creating bigger profits. ’’

 

Pretty sure the cube is
LxBxD, length beam depth and the grt is gross tonnage.

We'll need to wait and hear back.

 

Compensated gross tonnage.

 

From the given context I'm still thinking something financial like operating expenses to gross income ratio, so the G could stand for gross, but can't fit that into the acronym right now, so agree we have to wait for CDBarry for the answer . .

 

http://www.oecd.org/industry/ind/37655301.pdf

Gross Tonnage is a Measure of a Ship's Volume, Not its Weight https://www.thoughtco.com/what-is-gross-tonnage-2292983

Googles, not expertise.