Mini tug mold cost estimation

[Simonas]

avoiding anything more than a slight chop would be mandatory.

Looks like small chop, but handles well..

 

[Skyak]

We've drifted quite heavily from the topic. Let's get back to it.
So looking at the drawing is it possible to make a mold for such a tug?

Simonas,
this tug design is for stitch and glue ply. It is what we call 'developable surfaces' -all the surfaces are sections of cones and can be made by bending a flat material. The way to lower the build hours is to make a flexible mold -a thin sheet of material that can be bent into the different cone surfaces you need, does not stick to epoxy, and has a surface quality you want in the final product. With this flexible mold, jigs, and templates you will be able to produce about as effectively as full female molds without the huge investment up front. The biggest risk is investment with un-proven demand -this technique minimizes that risk. As a bonus, the tooling is flexible, so you could use some of it to make different boat models (the difference between tooling and equipment). If customers don't like wood, the technique also works with appropriate cores and vacuum infusion.

 

[SamSam]

Will Berkeley Engineering give you permission to build their boat? They might not want it mass produced, but if they did they would want royalties. If you did not want to pay fees and royalties, they might resort to legal remedies.

Do you know what sort of regulations you will have to deal with?

I'd make one and see if you even like it. It looks like a very bad ride in any sort of waves. It's 'cute' and 'interesting' but whether people will pay any money to buy one is a large gamble.

Two part molds aren't too difficult to make, and you could use a finished boat as the plug for the mold.

All the questions you asked are way too vague, the answers would take so long that a person might as well write a book. Maybe dozens of books.
You need to start narrowing down the universe of possibilities by describing your mechanical abilities (have you ever built anything) and your resources such as time, money, tools, build site, access to materials etc.

 

[Simonas]

Thank You all for the answers, I have decided to build one during the winter, and then I will go from there. If I like the design, maybe I will do mold, if I don't I will choose another design, because I'm interested to do it.

On the side, I'm also building Devlin's Polliwog, maybe I will use IT as a plug and make a test mold.?

 

[SamSam]

That would be easy to make a 1 piece mold from a finished boat like that. Again though, there are the legal and ethical challenges to copying a designers boat.

As far as making molds, shapes like the first boat, with negative drafts and strakes etc, are more difficult to make the molds and to make the boats that come out of the molds. Even then, that whale tail part might have to be made separately and then somehow attached to the boat.

If sales of 20 boats a year for the whole country are correct, depending on the economics of the country, it seems there could be a much larger market for boats.

 

[Simonas]

That would be easy to make a 1 piece mold from a finished boat like that. Again though, there are the legal and ethical challenges to copying a designers boat.

As far as making molds, shapes like the first boat, with negative drafts and strakes etc, are more difficult to make the molds and to make the boats that come out of the molds. Even then, that whale tail part might have to be made separately and then somehow attached to the boat.

If sales of 20 boats a year for the whole country are correct, depending on the economics of the country, it seems there could be a much larger market for boats.

Legal challenges I think could be solved very easily. I would honestly pay royalty for every boat I'm building. I don't even have to say which type of construction I'm using. (mold, or plywood)

I think that there should be a market, although it's 2mil population. It's mostly dead, because nobody is working to introduce boating to potential customers. Family boating is barely starting to take place, usually it's fishing with some drunk friends. And that will not change in soon future, because two main dealers in country are also fisherman type personalities.

SO, I think, that this type of boat (fun, small, easy to: own, maintain, trailer, store) will at least spark someone's interest, who has never even thought about boating before. AND, that's an easy start for me as boatbuilder.

 

[PAR]

That hull can't have a single piece mold. The reverse curves at the aft end of the topsides, will require the mold to be at least two pieces. This particular set of shapes isn't well suited (again) for a GRP female mold process.

 

[Mr Efficiency]

No doubt the original design posted simply is not a moulding proposition, even without the "fan-tail".

 

[Simonas]

Getting a bit back to my main idea to build 5 pieces and use it for rent. Is there any way to speed up the process, than without mold?

 

[Mr Efficiency]

It could be built from Aluminium, but not by neophytes.

 

[Simonas]

It could be built from Aluminium, but not by neophytes.

I like aluminium in aircraft kits, but not in boats.

 

[Mr Efficiency]

With some modifications, it could be done in GRP, with the split-line half-way up the topsides. But not a small task, and not really economic for a small production. And you may rise the ire of the owner of the design. Seeing it needs quite a bit of tweaking, a similar, but still different boat may solve that issue.

 

[SamSam]

It can be done fairly easily. I would split the mold vertically down the center line, the spray rail and fan tail not part of the mold but attached separately. The laminate schedule and structural elements would have to be figured out, unless the designer has already done that.

Being part of the EU, I would guess there would be a boatload of regulations to comply with, since your plan is a commercial venture concerning passengers and /or sales to the public. Maybe plywood wouldn't be allowed, I don't know. Maybe flotation tests, possibly inspections before, during and after construction. Liability insurance here can be monumental. You can easily lose everything you own, here, if you lose a liability case in court. Or even if you win, you could go broke paying a lawyer to defend you.

But yeah, the boat could be easily and quickly made if you have a plan and money and facilities and materials and tools and competent workers. And a market would help to possibly make it profitable.

 

[Skyak]

Getting a bit back to my main idea to build 5 pieces and use it for rent. Is there any way to speed up the process, than without mold?

Yes! I told you how in post #17. If you can make a valuable boat out of conic surfaces, thank God, because the cost of low volume production is much lower. Read post 17 again.

You might not understand because the Mini Tug design you picked specifies thick hardware store plywood that will be too difficult to bend. The answer is to use thinner, high quality marine ply. Coating non-marine plywood with epoxy and glass is like rapping a turd in gold foil -worse because the epoxy and glass can't be recovered. Non-marine ply will be much harder to build with and will rot disturbingly quickly.

About designer permission; This design from BE is not what I would consider high quality. Even amateurs around here are capable of better. If BE does not treat you well I suggest you solicit proposals. The other thing to consider is support. You asked early on where you get info about molding (I said material supplier). If you had asked where you get info, advice, and support about boat performance, boat building, and the business I would have said from your designer. You can ask here for opinions, but you should trust the designer you pay to help you decide. If you are serious about going into boat building professionally, choose a quality designer that will support you. It will be the best investment you make in this biz.

Boat designer reputation is about equal to builder reputation in establishing brand quality and resale value of a boat. If I check with a designer about one of his boats and he tells me it's not an authorized copy I know the builder is not to be trusted.

 

[Simonas]

Seeing it needs quite a bit of tweaking, a similar, but still different boat may solve that issue.

Do You have any idea what kind of design that could be?