new but ambitious

In my many years working as a naval architect, I have never seen a single person design a boat. I've always seen a team of professionals from various specialties, working together with a common goal.
On several occasions my clients, shipyards, have proposed to me a design generated by a draftsman, which was nothing more than a good user of a graphic design program, in order to carried out the technical and construction project from that very nice sketch.
In this forum we have seen many people who, having made ​​a pretty picture with Rhino or FreeShip, proposes that we say what we think about his boat. That is neither a boat nor anything but us, instead of telling him to stop "playing with boats", we advise that, in our opinion, can be improved for the "boat".
Now we have a gentleman who says he wants to design a boat, with the help of a naval architect, and seems that we want to convince him that it is nonsense. In my opinion, that's what always is made to project a boat. It also seems that pipergsm know what the cob is, he knows tha ship´s stability exits, etc. and he tells us that, if something does not know, he is willing to learn. I see that we can do nothing but encourage him.
In the five years that lasted my career, I studied more than 40 subjects. Only mathematics and especially physics (2 subjects) are used to design a hull (not talking about the entire project). No need, then, imo, that pipergsm study for 4 or 5 years.
So, go on with your illusion, and enjoy "designing" boats.
Greetings everyone.

 

I've sat here for a little while trying to decide if I should post this. I don't like to "rain on peoples parades" to coin a phrase. I like to encourage people rather than dash their hopes. Going back to your first couple of posts pipergsm, I just have to ask the following:

I still can't fathom how you have determined that you can build a 30 footer with a 300hp diesel that cruises at 26 knots, can cross hundreds of miles of open water (safely, I presume) and weighs only 6,000 lbs - for how much? $15,000.00?

Dreams are great but reality intrudes on us all.

 

missinginaction, I very much agree with you and I share your doubts, but I hope pipergsm to be able, if well advised, to realize their folly (if any) and thus to modify his initial project. Recall that the design process can be likened to a spiral to be closer and closer to its correct final at every turn. If in the end, what can be done is not what pipergsm needs, sure he does not endeavor to build.
At least, this is what I advise pipergsm to have in mind.

 

The numbers are off.

Some years ago I built a rugged marine ply ,epoxy , eglass 19 ft skiff. At advantageous material prices it cost 11,000 dollars. This was a simple skiff with a bench seat, an internal 12 gallon tank , one battery , a set of running lights ....fit out for a twist grip outboard .

the materials cost for a simple, rugged 25 footer ... with its interior furniture, decks and systems will cost three or four times this

 

to all:
I do realize I could be way of with the cost estimates and will not be disappointed if they appear to be much higher.
My estimates are based on the price information I found for the "essential" construction material and equipment.
For example:
I intend to use dark red meranti for all scantlings, and it's weight shoud be 710 kg/cubic meter.
If my preliminary calculations are correct, I'd need little more than 1 cubic meter.
In the UK, 1 M3, cut to size, would cost me about $2.000, but here in Thailand things are definitely cheaper than in the UK, so I guestimate 1.500$ for 1 M3.
On the internet, I found used inboard diesel engines (150 HP) for $2.000, and I calculated a budget of $6.000 for the engine (maybe I'll buy a gas engine, not sure yet).
I think I should find something for that amount (maybe not entirely what I want, we'll see).
Having seen some prices for marine plywood (9mm), fiberglass and local epoxy-prices, the total of my preliminary price calculations ends up around $10.000.
However, there are a few essentials for which I haven't found any prices yet and I also suspect there are a few essentials I'm simply not thinking about at the moment!
I've only just started my project-research and I'll have to adapt all my calculations as I go on and discover ALL the things that are needed!
Maybe some of you could tell me which essentials or prices I'm probably not taking into account? I'd be grateful!
I definitely do agree with TANSL: I do realize there's a strong possibility I'll have to revise/modify my original project, and if necessary I will certainly do so!
For now however, I have "my dream" and I'm just trying to get reality as close as possible to that dream!
Future will show just how close I can fit reality to my dream!

 

The OP would be better off considering building a fast displacement cat with twin outboards, you have a stable platform that can make good miles in relative comfort, the security of twin engines, no vibration and diesel smell, and not depending on some second-hand junk that has probably been worked to within an inch of its life. Here's an example:

http://www.boatdesign.net/forums/boat-design/skoota-28-36-power-cat-47480.html

 

I mostly agree with Michael. Commodity prices are not much different anywhere in the world.

Your cost might not be 4 times as much, but it will be twice as much.

And this is great advice as well:

 

Mr. Efficiency + El Guero,

more than likely you are right about the cost, but I do wonder what I'm forgetting or miscalculating to make the difference so big???
Can anyone give me some hints here?
What I think I need (basic stuff, the
timber, plywood, screws, fiberglass, epoxy, paint, engine, fuel tank, shaft/propeller, speed/fuel gauge (cost??), steering gear (cost???), communication system (cost???), furniture (limited and I make it myself), generator.
Unless the 3 "cost-unknown" items cost +10.000$ and the fiberglass/epoxy appears to be 10 x more than what I think I need, I really don't see what I'm forgetting to make the difference so big.
Please help me out here!

 

That skoota design looks nice indeed, but is it seaworthy? The video seems to be made on a lake.
To be honest, I was contemplating a catamaran at first, but it seems a little more complex to build and the models I found in Plywood were rather small (I like space!).
Also: would it be possible to make it a little bigger and faster?
Difficult to see/estimate the inside space, but it seems rather limited to me.

 

Just found a Glen-L design that looks very much like the one I have in mind.
36' Sorrento, sedan cabin cruiser.
I just don't need the bedrooms and stuff and also would like to change the cabin/cockpit style.
Maybe I can contact them to customize that design??
Does anyone have experience with that?

 

All your calculations are way off...

4L of resin to cover a 39' boat? No way, you are talking a couple of hundred gallons at least...

Things may be cheaper in Tailand, but $15,000... if it were that cheap, builders would be breaking down doors to have hulls built there and shipping where ever to be finished out...

A 39' plywood boat - oh here we go with the "Flying Hawaiian" again...

And from all the articles I have read, from designers that have a lot more experience then I do do, it is NEVER simply a case of taking a small boat design and simply stretching it out to the size you want... and you admit to not having ANY design experience what so ever...

I just find it hard to believe someone with NO experience in boat design can take a free plan he downloaded off the internet, redesign it so it's 39' long, build it out of fiberglass covered plywood, put a 300HP engine in it, build it for $15,000 or less and have it cruise at 26knots...

You certainly have BIG dreams... but I honestly doubt you can make this one happen the way you see it in your minds eye...

You are already starting off badly, you have a naval architect giving you advice, and you're ignoring him...

Good luck with your white whale...

 

I don't see any mention of tools in your calculation. You don't need the best quality but you will need at least the following.

1. Table Saw
2. Compound miter saw
3. Circular saw
4. Screw gun (you'll probably need 2 as you'll probably wear one out)
5. Descent 1/2" drill
6. Good quality router
7. Router table
8. Epoxy application supplies (protective gear, rollers, disposable brushes, mixing supplies, containers)
7. Saw blades (they wear out so you'll need more than 1 or 2, or you'll need to have them sharpened)
8. Drill bits (twist, forstner)
9. Router bits
10. Sanders. Belt and random orbital
and my favorite but most expensive tool.......

A good bench top or stationary planer!

There's lots more, but let's stop at the top ten that I can think of.

Oh, let's not forget things like carpenters clamps. They're not that expensive but you'll quickly realize that you never seem to have enough of them. The cost adds up.

You'll need some sort of structure to protect the boat from the elements while you construct it. You'll probably have to rent a spot or build some sort of structure. Even tarps and a frame will work if done thoughtfully. This costs money too.

You'll need a place to store supplies and keep those tools I mentioned. Can't leave them outside. Weather will ruin them and people steal things. I'm lucky to have an old SUV that fits everything. Some people buy trailers. It all costs money.

If you are really determined to do this, keep in mind that it is a long process. I thought I'd be done with my boat in a year or two. It's now been 5 years and I'm still not finished. You might be happy on the open sea with a partially finished boat but most women will not be gleeful in this situation. If you value your family do everything you can to balance your family and your boat building. I see boat clubs and yards filled with lonely boat obsessed men who's family have long ago moved on. You have to be obsessed with boats to embark on the long journey of building one, especially a backyard build. Please don't allow that obsession to cloud your better judgement. Leap if you must, just look carefully before you do.

And if your wife gets pregnant.......well, let's not even think about that for now, OK?

 

david 78212
I didn't say 4L was enough for the boat, just mentioned the quantity/price
Hundreds of gallons for covering the plywood hull with fiberglass?
Surely you're confusing with the amounts needed to create an entire fiberglass hull.

I'm definitely NOT ignoring the remarks, ideas and advise of more knowledgeable people!
I'm just trying to find out how closely I can approach my dream in reality (I do know the difference between the 2, believe me).
I'm sorry if "voicing my thoughts and ideas" create the impression I'm ignoring more experienced people.

At the other hand: reading your remarks, makes me feel like you either did not read everything I've written before, or seriously underestimate my will to learn and my intelligence.

I realize I'm chasing a wild dream and that, more than likely, I will not be able to realize it "the way I see it at this moment".
But as I've said (or tried to) before: I will change my ideas, plans and designs as I continue to learn and gain more knowledge, hopefully with the help of all of you!

So please, stop the insinuations about "how stupid I am", and let's focus on answering each other's questions, so that we all can learn and try to realize our dreams!

 

One more thing and then I'm done.

If you want to build or restore something as large and complex as a boat I really believe that you have to do it because building the boat is an enjoyable process for you, in and of itself.

If I were to fall off my boat tomorrow and break my neck in the yard, I think that my wife would say "he died doing something he really enjoyed doing." She would be right. I'll certainly enjoy using my boat but if for some reason I never could I'm still happy that I restored her.

 

Missinginaction,
I've checked prices of most tools I need, and they add up to $300 - $400
How much do they cost at you place?
I'm not familiar with all technical terms in English, so excuse me if my next questions seem stupid:
what's the difference between a drill and a screwgun? I usually do these things with 1 and the same tool.
Next English terms are also unknown to me:
compound miter saw, router, bench top/stationary planer.
Can you describe them for me?
about protection for the boat as I work: I'll think about it, but I honestly believe this can be limited to some waterproof cover, due to the climate and place where I live.
November through April is so called "winter" here, with day temperatures most of the time over 25 Celsius and almost no rain. By the time rainy season starts, all the wood should long be made waterproof.

Thanks for the advise! I'll definitely not allow the obsession to take the upper hand!
As a matter of fact, my wife is already pregnant, and since she's 39 (I'm 40), it will probably be the last time! Baby is due early December, so he'l be almost 1 when (if) I start the construction.