Building my first boat.

Hi everybody,

This is my first post of hopefully what will be many to come. As is the tradition of boat building forums, I come forward with a humble request. I wish to build a small powerboat of aluminum. It must be impeller driven, preferably with a small block V8 powerplant, wet stack exhaust. I've been talking around with some people that know about boats (mainly my father), but nobody that I know really can tell me much about actually designing and building my boat. My father is a machinist/millwright by trade, so he is pretty good with AutoCAD.

However, my problem is this: I have not the slightest clue about where to get started. I would like to pick up some reading on the manual, but the libraries around here only carry books on how to "Carve your own canoe" and "Piece together a kayak." I'm not looking to make anything beautifully handcrafted and wooden here (although I do take pride in all my work). I was planning on welding an aluminum hull that had a relatively shallow draft and then go from there.

So, to get to the point: Can anybody recommend a good book for me to pick up and read? I need to learn basic Hull Design (unless somebody already has a good hull plan they would be willing to part with!) as well as any other crucial parts of design. I can handle the wiring no problem (have restored several old cars and custom built a wiring harness for them) and the welding will be provided for by my father who was 30+ years of experience (TIG, MIG/MAG, arc, Heli-Arc, pretty much anything.)

If any of you kind folk can provide a newbie with some advice on where to get started, it would be much appreciated. Thanks in advance!

--ihallenius

 

ihallenius,

High-Speed Waveless Boat is the right choice, it can save 50% energy, and increase 15% living space. Waveless Boat is more easy to construct that without complicated curve hull. It can run at high speed in the river.

Don't forget to give a picture here after complete.

 

From learning from books (with all sort of parameters..)to build your own boat you must have some time on your hands.

I suggest you find stock plans and go from there modifying (within reason) interior arrangement. You would find yourself saving a tremendous amount of time and headache.

 

my advice (and what I intend to do)

get a bare hull made professionally and then finish/fitout yourself

 

your first boat

you can email me, I have thirty years building alloy boats
go http://www.carlsondesign.com/
scroll down to frree designs, you can design you own boat from a big start list
it is not a cad programme , but you can print out offsets of each and every plate, in other words it'll develope the plate for you,(no compound)
I.m at present writing a book on practical alloy yachtbuilding, but its too much for what you need, I can help you with the structure, scantlings for free, sound like a jet boat? river? bars. shingle? what is your use? frinstance you can go very heavy plate with little of no frames. from Carlson you can make temp bulkheads, cut from any old crap, build a jig, and lay your cut plates over and tack up.
cheers Stu

 

oh I,m not Carlson by the way, thats the way it reads sorry!!

 

Why doesn't some young designer who is looking for his first design/build project step up and submit a design? I don't have the time or money to be able to offer a free design, but I'd be willing to mentor an up-and-coming.

 

Maybe I can use him

i have so much software and no talent for it, give me his name and I will call him, I spent/wasted so much time with MAXSURF and got nowhere, their tutes are poor, compared with say solidworks, that I gave up

 

maybe just sketch it with pencil and paper and then get a pro to put it into the computer

 

where to start

ihallenius, the first step is an HONEST statement of the design's intent. 90% of new builder/owners won't/can't/don't make HONEST statements of design scope.

This means you can't use a line like,

"my boat will weigh next to nothing run on 1 gallon of fuel for a 100 miles traveled and run in a shallow river at 38 knots and the open ocean for 3400 nautical mile range- Oh! and trailerable behind my little subaru."

If you can't state simply and EXACTLY what you want to accomplish- you cant' get there from here.

You have to qualify the functions of the design in order of priority. What water, what load, what speed and what general purpose. If you can't realistically limit the boat to a definite design statement YOU not only can't design it- no one can- not even the best and most imaginative designer.

The closer to a true, not imaginatively fantastic, desription you can define the more rapidly you can accomplish a design. The biggest limit I've found to realistic design statements, in a few hundred welded aluminum boats, is the owner's ability to agree to reality!

If you will simply list the functions and look at other boats that offer as many of them as you can find in one other design, you have begun to realistically design the boat you want.

Dave Gerr is a boat designer and Naval Architect and author of the first book you should buy- THE NATURE OF BOATS (D. Gerr) will help you get some feel for overall floating objects which feature propulsion systems. Once you've spent time, say four times cover to cover with your calculator; you and your Dad should give it a go on a smaller outboard powered skiff (forget a V-8 for your first boat) of someone else's proven design. Then, if you are still talking to each other, you'd have enough real world experience to take on some sled with a V-8.

By the way 'impellers' are propellers in a duct- like an axial flow "jet" pump; and EXPOSED rotating appendages use to force the boat forward or reverse are called PROPELLERs on boats with shafts, outdrives or even outboard engines.

There is no book on the market anywhere for small welded aluminum boats design and construction. Of the few welded aluminum boat building related books all focus on larger (30+) and almost all sail boats not planing power boats. Some of the information is useful but most of it is generalities that will not help your inquiry.

Remember that an internet search for "welded aluminum boats" will show you people's work, ideas, and solutions from others that are already doing what you're discussing.

I began in 1976 with similar interests, questions, and a vaguely similar goal and had to make "millions" - no countless - mistakes figuring out what you're proposing to learn. If you can't state the length without changing, the water without moving from lake to ocean; if you can't focus on realistic propulsion (buy a Honda to start you'll have your hands full with the hull); if you can't focus on EXACTLY what you are really going to do with this boat- you will not fulfill your goal of building.

On the other hand if you can focus, define what you're trying to build and what you'll do with it- then you can find something out there that is close. From close its not far to your version.


Cheers,
kmorin

 

Planning a boat.....

Hi ihallenius

I think you need to start with the basic of boat building before you rush into something that will put you way over your head.
Buy a Canal "narrow" boat magazine, as many have articles in them showing how they are built.
...And you really cant get more basic than a Canal boat!
place some 2m x 3m x 12mm steel plates down flat on the boat yard floor, butt weld them end to end, cut out the bow and stern shapes, weld some angle-iron frames vertically all around the edge about 0.5m apart, weld some 3m x 0.75m plates around the frames, butt weld the ends of the plates then weld all around the sides and the base, and voila, there's your basic Narrow boat hull ready for topsides and fitting out!...Couple of days work tops if your a quick welder!
Now once you know how to build a narrow boat try to find a magazine with an article on building a steel sailing boat, not a dingy though a largish one, say about 30', and possibly multi-chine to add a little complexity.
Once you have learned all the relevent info you will be in a much better position to work out how hard it would be to build a boat.
Note that both the both the examples above were steel boats. Steel in the cheapest, easiest and safest material to built a boat from and with proper design considerations it need not be much heavier than a boat with an aluminuim or fibre-glass hull.
You must also consider that welded aluminium is soft aluminium, and cracks can easily occur at high stress areas in the hull anywhere where the aluminium has been welded. Therefore a welded aluminium hull needs far more care in its design than a fibre-glass or steel hulled boat.
You also cannot just plug in an old arc welder and start to weld aluminium, you need an expensive Tig welder and an expensive and plentifull supply of large bottles of pure Argon gas, then you need lots and lots of practice to even get close to getting good weld as its no where near as easy as welding Steel.
In case this has put you off welding an aluminium boat togther lets consider the only viable alternative: riveting, which is even more time consuming and labour intensive!
And dont forget that aluminium can cost 5 times more (Or even more!) than steel, so not only would an aluminium hull take longer to build it may also end up costing you a fortune!
Then you also have to take elecrolytic decomposition into account. Put an unpainted aluminium hulled boat close to a steel one in brackish water and your aluminium hull will literally start to desolve in front of your eyes!...OK. I'm exagerating the effect, but proper hull protection is essential none the less.
With steel you just weld a couple of magnesium anodes under the hull, for fresh water, and even unpainted it wont rust hardly at all. (Zinc anodes for salt water)

I am also planning to build a boat, a fast planing hulled motor cruiser, but for the reasons above it will be made of steel!

Regards

Aquatek

 

aquatec, you know very little, you do not write from experience, just by a few bits gleaned from here and there
I ran an alloy building yard for 20 years
We never had any troubles whatsover
people do not build 50million dollar superyachts in al al, just to see their investment disappear in a clowd of magnesium oxide
Now behave and stick to what you know, whatever this may be
cheers

 

50 million dollar super yachts hull are well protected they are never bare aluminium!

Regards

Aquatek

 

I have to say something...sorry Aquatek.

First off tig welding is swell, but MOST welded aluminum hulls in fact are mig or pulse-mig welded, though, yes argon gas is used for the shield gas. Welded aluminum is soft aluminum, but so is welded steel. Generally, aluminum is not a heat treatable alloy (some serieses are heat treatable, but not the ones we are concerned with here), and is hardened slightly by the process of rolling it into sheets. Aluminum generally gets it's mechanical properties from the alloying (here I go again "generally"). In fairness it fatigues readily and stress risers do occur at the heat affected zone boundaries and cracking CAN occur there. Actually, If it occurrs anywhere it will be in that area, and that's good! If it doesn't crack there, the hull probably won't crack anywhere else. Using the proper amount of "heat" and the right thickness of material, plus a skilled welder, will assure that you boat will last a lifetime. The issue with aluminum is to keep the flexing to a minimum. No flex, no cracking. Large numbers of boats throughout north america (particularly the pacific northwerst) have been built using a mig "wire feeder" proper structure and a decent amount of skill.

Most aluminum fishing boats are not painted and we're talking fifity feet or larger.
$50 million dollar megayachts are well painted because blotchy, foggy, stained, unfaired, bare aluminum on a huge hull obviously looks godaweful. Bare aluminum boats are protected in much the same way as steel hulls are, using zincs. Parking you aluminum boat next to a steel hull will potentially eat up the other guy's zincs faster, but to be a real corrosion cell, there needs to be a hard connection between the boats, they must touch in some way. This usually happens at marinas weher both boats are plugged into a shore power system that is not properly grounded, and somebody is shortcircuiting to the hull or rudder or prop shaft (thus a complete circuit between the boats). I'm conducting a corrosion test right now to see how long it takes a couple pennies to breach 5/32 5052 plate.

 

welded aluminum

Aquatek, you're a bit off base old son, welded aluminum boats aren't quite the tender frail craft you've made them out.

I have to weigh in here, agreeing with the other NW N.American continentals here, many of your remarks are inaccurate and without basis in fact.

On the other hand those narrow boats are lots of fun and a wonderul solution to turning a 300 year old set of ditches,with water in them, littered about the country side; into a recreational facility. I hired a 70'er that was barely an arms' breadth for the one of the 'ring ' tours in the Midlands -I think(?) The entire island was so small and crowded I could barely keep one village from another-so my impression isn't lucid from the shock of so many people. Anyway, narrowboats are totally fun and a great metal boat but the poster on this thread wouldn't do well trying to substitute his planing sled for a steel bath tub with a Winebago in it!

Most unfortunately they'd everyone-and-all be a death trap in a sea swell in the Pacific Northwest and so there's a bit of apples-and-mangoes discussion going on. I think they both grow on trees but past that we're not discussing the post by ihallenius.

Our young, soon to be skipper, is looking for advice on a high speed boat with 330+ hp in a 20' hull. My wife would step off the bow of the narrow boat (during out tour of the Midlands near Birmingham) and walk AWAY from it on the tow path- as she'd go to the next village to shop. The original request was for info about a light weight boat with a V-8 engine (!) and as we motored along at 2-3 knts there along side of the canal a mile or so ahead would be my lovely 1st mate waiting patiently for the barge I was piloting to arrive!

I'm not sure you have a clear picture of what is being discussed- do you? And if you do- please don't malign bare aluminum boats as they are durable, strong and much more economical than you've made out. In fact there are a number of narrow boat makers now working in the 'miracle metal'; ring them up, compare prices and see why they've chosen aluminIum over steel.

Cheers,
kmorin