building a steel boat

[fishnducks]

ok , so this is still abrain sceme.

i want to build an 18' tiller boat for hunting, fishing , breaking ice for no aparent reason.

no tworried about thickness or design so much yet, more concerned about how one would get a boat titled they built, and also can an idividual get one single boat coast guard certified? cuz i for one dont want to go out in my own death trap let alone someone else.

my plan so far is to copy a crestliner or lund hull but make it deeper or taller maybe becasue the steel im assuming is going to sit lower.

thanks for the help, and i am going to consult a naval engineer grad before i build anything.


tony
in the mitten state

 

[Bob_VT]

Re: building a steel boat

You do not have to get a homebuilt certified (only if produced for the public resale).

You will have to assign it a hull number or the regitering authority will issue one.

How much ice do you think you will break? I doubt you will be able to propel through anything over an inch.

Most icebreaking hulls are actually double hull so...... maybe you want to build over an existing hull.

AND the amount of power required will be BIG!

 

[fishnducks]

Re: building a steel boat

no the ice thing was more of a joke. but thanks for the hull # info.

Can you get a home built cert or you just maek sure if can float enough yourself?

tony

 

[Bob_VT]

Re: building a steel boat

http://files.dnr.state.mn.us/education_safety/safety/boatwater/backyardboatbuilders.pdf

same rules for all States

 

[erikgreen]

Re: building a steel boat

The problem with steel (or any boat material, really) is that it lends itself well to a certain size of boat.

If you make a hull out of steel light enough so that you can get good performance with a standard boat motor for an 18 footer (say a 100hp outboard) then the steel will be so thin that it'll corrode holes through or puncture at the least chance, like when you toss your cooler in from the dock.

If you make the steel thick enough to avoid puncture and the supporting steel strong enough to keep everything together, you get a lot of weight. The hull will last forever, but you won't go fast. Think displacement hull.

To give you an example: My friend has a 30 foot trojan with twin inboards and twin 100 gal fuel tanks. Fully loaded without passengers its weight is about 9000 lbs. The twin 316 Chryslers get it on plane and it almost does 30 mph.

A 31 foot steel hull Chris-Craft roamer with about the same interior space weighs about 17,000 lbs, and unless you put an immense motor in it, is a displacement hull that does about 7-9 knots max.

If you want an 18 foot boat that goes faster than about 5 knots, your choices are either fiberglass or aluminum, or possibly wood. If you build it of steel, you'd better use a different hull design than a standard 18 foot fiberglass boat.

If you want to break ice you need not only a heavy hull but one with a big motor... icebreakers work by riding up onto the ice and their weight crushing it. Not only will a standard 18 foot boat have the wrong bow shape, it won't be heavy enough to break through ice more than about 4-5 inches. If you must use a small craft to break ice, build a hovercraft.

Erik

 

[Kiwifisher]

Re: building a steel boat

Erik has hit the nail on right head with regards to issues that crop up with building a hull with different material than it was designed for. Just to add to what he has said, if you build a planing hull that will only ever be used as a displacement due to weight/power issues, your fuel consumption will be way over the top. It would be more prudent to then build a hull that was originally designed as an efficient displacement hull.

Fortunately for you, there are thousands of well designed boat plans out there as a net search would indicate. For a 18' boat, I would give a wooden boat some consideration. If you look at this thread, http://forums.iboats.com/showthread.php?t=306152 the poster did an excellent job. These Hartley designed boats were built from the '60's here in New Zealand and there are still thousands of them around, just proving that well built wooden boats do last.

Good luck and when u start your project, please post on here! I'd love to follow the progress on this one.