considering starting a part time boat building business

Ah, "... INFLATABLES,... ARE EXCEPTED FROM ALL REQUIREMENTS
EXCEPT FOR THE HULL IDENTIFICATION NUMBERS."

So I can strap my 70 on a tractor intertube and the USCG is cool with it

 

Yes you can, but...........
There is an ABYC and ISO standard for horsepower on inflatables and they are regulated by Canada and the European Union. So you can sell them here but not anywhere else. And if they prove to be unsafe with all that horsepower the Coast Guard can declare that it may "contain a defect which has been identified,
in any communication to such person by the Secretary or the
manufacturer of that vessel, equipment or component, as creating
a substantial risk of personal injury to the public" Chapter 4307 United States Code Subpart 4307 a(I)(A)(ii)

and make you recall all of them and put a smaller horsepower rating on the boat, which will really piss off all of your customers, who have all bought big herky outboards, and who now have to sell them (used of course at 50% of their value) and buy a new engine at the lower horsepower.

So it's best to stick with the ABYC standard even though it's voluntary.

Of course a tractor innertube is not a boat (as defined by Federal regulation), so sure, why not.

 

The USCG standards for HP rating are ridiculous in many smaller craft. I have several designs under 25' that are intentionally well under the recommended maximum, under USCG guidelines. This is just prudent design work and responsible engineering.

 

Hey PAR, how you doing. Haven't chatted in a long time

 

I've got a 3 month old 60' x 30' fabric building and about 50 gallons of System Three epoxy up for sale if you want to dig right in.

My boat build project failed due to the need for too much labor using the method I was using and building a 45' cat.

Farmtek building is being sold for 1/2 of what I paid for it 3 months ago. Comes with spare roof!

System Three Epoxy is being sold for $35/gal or $1000 for all the epoxy and hardener I have - NOTE: This is LESS than half of what it costs to buy.

PM me if interested.

 

Thanks Cat, that sounds like a fair deal, but now isn't the time for me. Maybe once I start selling some, but I expect you'll have sold by then.


Ike and PAR, I don't want to give the impression that I'm looking to make overpowered, unsafe watercraft. Just trying to understand the rules better. When the guidelines were created weren't outboards rated at the crank, and aren't they rated at the prop now? That would lead to overpowering a bit...

I will put in foam for level flotation, even though I'm not a big fan of foam. I'd rather have watertight compartments that can be inspected and dried out, but it looks like the USCG doesn't care for them if they are integral to the hull, which is the obvious way to make them. So I'm tentatively thinking of having the minimum amount of foam necessary for USCG reqs, preferably above waterline, and air compartments for extra safety.

 

When the hp formulas were created it was the fifties. And they were actually created by the boating industry and then borrowed by the USCG in the 70's. Yes they are a bit arcane. Europe uses a performance test, it's a barrier or collision avoidance test. However the USCG and ABYC ran a series of tests in 2003 and 2004 using the ISO rules and many of the smaller boats (jon boats in particular) were overated by ISO standards, so they stuck with the formulas. At least the formulas give a level playing field because everyone has to use them. For larger boats 20 feet and up ABYC prefers a maneuvering test, which has been around since the 60's.

Back in the 80's I was in charge of a project to determine a new formula by instrumenting boats with accelerometers that measured side forces in a hard turn, to see if we could correlate horsepower to lateral acceleration. Big failure. The results drawn on a graph looked like a shotgun blast. But the tests were fun. Mercury Marine loaned us their racing facility at Oshcosh Wi, and all the boats and engines. What a kick racing around the buoys. Too bad nothing came of it. But it only cost the taxpayer a few thousand for travel and expenses, and for the instruments. Everything else was gratis from Mercury.


You certainly don't have to use foam. You can use air chambers. Foam is used because it is convenient. It has it's drawbacks. If you build a boat rated for more than 2 hp then it has to be able to float level with the two largest airchambers punctured. So you split them up and make a lot of small airchambers. I have seen this done and it works well. I have also seen people use everything from ping pong balls to plastic bottles. One manufacturer used pool noodles. Be creative. Remember, it is a performance standard, not a technical standard. All the boat has to do is be able to pass the test.

And, the law does not require you actually test it. But what the hell, the USCG will do it for free, and if it fails, tell you how to fix it.

 

Doesn't it say that the air chambers cannot be "integral to the hull?"

 

Yes. Integral tanks are not allowed. The exception is manually propelled or 2hp or less boats. On boats with airchambers I have seen such things as
Tanks fitted under seats with several partitons in the tank.
Integral chambers with an inflatable bladder inside.
Integral chambers with plastic milk bottles inside.

So on. Again be creative.

 

Srimes you'll need a design, one where the details can pass muster. There are plenty to choose from, though most of the low cost ones will be dated and possibly non-compliant in some regards.

Hay, Peter, it's been I while. Glad to see you're still kicking up spray.

 

Yeah, I know...

In keeping with the small-simple-cheap theme, I'd like to design it myself. At least mostly, anyways. I'm sure I'll need advise in some areas, especially laminate schedule. Proving that the design works is another reason to build a prototype instead of starting with a plug.

I wouldn't try to design a yacht, but I know I can build a jon boat. "Any hillbilly can build a jon boat." I'm thinking of something a bit more evolved than the ubiquitous flat-bottoms and mod-v's, but not too far off. Sort of a mod-v tunnel hull in fiberglass instead of aluminum. The ******* child of a jon boat and a thundercat. I'll post a sketch when I get a chance to make one, I've been pretty busy lately.


p.s. Someone posted neutral feedback (didn't know you could do that) saying "send me a picture of the boat if you build one." But you didn't sign it so I don't know who you are. I'll post pics here if there's something to post. Send me a PM if you want me to let you know when I do.

 

I did a little materials pricing, and must admit I'm surprised by the cost of glass cloth. 10 oz cloth is almost 3x the cost of 24 oz woven roving/mat combo. Haven't looked up csm, but I'm guessing that's even cheaper. Straight roving is even cheaper, too bad I can't lay that down. Guess that's what chopper guns are for.

I'm going to order "The Elements of Boat Strength," by Dave Gerr, to figure out how thick the hull needs to be. My initial guesstimates for the little catamaran skiff were coming out heavier and more expensive than I wanted, so if the calculations don't come out lighter I'll choose a simpler boat. I'm thinking a jon boat built to paddle. It would be a much more stable alternative to sportsman canoes.

 

All of Dave Geer's laminate schedules will come out heavier then necessary. Not overly so, but a significant about, certainly enough to consider reduction. Of course, this assumes you've calculated loads and incorporated this into the schedule.

 

Have you built any thing yet .... hope you did not give up. I have been working my plan to build inshore bay boats. I have don't what has been suggested here. paid cash for everything, building, molds, equipment, etc.... Hopefully in the next month I'll produce that first boat to test. If anyone could recommend a naval architect that I could review my build plan with I would appreciate it.

Thanks

 

Boat building as a hobby business.. Here's a thought. First.... Divorce the wife and kiss your kids goodbye. sell the house, buy yourself a van and get rid of the BMW. Prepare for a life of sorrow and heartache. If you havn't got a problem with alcohol you will have after about 10 months so don't worry there. And then your hair falls out. All joking aside. I was in a somewhat similar position a long time ago. I had a good business and liked boats. I bought some moulds and starting building. After a year the boats were selling so well I sold my other business. To this day I wish I had kept that business. Its not an easy business to be in. Its fickle and there are lots that can go wrong. But I love it. Must go now. I have to pick the kids up. Its my weekend.....