Can You Build a Fiberglass Hull From Scratch

luckyinkentucky

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A buddy of mine who works at a local body shop brought up an interesting topic tonight that no one knew the answer to. Is it feasible for an every day 'Joe' like you and I to make a mold, spray it with a release agent, and mold a fiberglass hull in our own back yard?

I've seen it done on small alcohol powered 'toy' boats, but can it be done with the real deal?

Of course I realize there would be a lot of finishing such as sanding and gel coat afterwards, but could it be done?
 

Solittle

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Re: Can You Build a Fiberglass Hull From Scratch

Of course - - just need a bucket full of time and money. Build a plug, then a mold and pop um out.

Well - - there is a tad more to it - - you might do a bit of research on how the manufacturers do it to get an idea on what is involved.
 

KnottyBuoyz

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Re: Can You Build a Fiberglass Hull From Scratch

If you're in the hotbed of boatbuilding in the SE or NE US there are places you can rent molds to build your own boats. Otherwise one-off boats are usually strip planked or cold molded by stitch & glue ply construction.

There's big bucks tied up in molds they're expensive to produce and maintain and are meant for mass production.
 

fishingdan

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Re: Can You Build a Fiberglass Hull From Scratch

Yes you can, but you need to build a boat hull first so that you can make a mold of it. Why would you want to do this? I'm all for learning, but is that the best approach for your end goal (not sure what that is from your post)? Molds are produced for mass production. There is no reason to build a mold.

If you want to build a boat, try it this way:

http://www.bateau.com/

It is great fun and the results are outstanding.
 

luckyinkentucky

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Re: Can You Build a Fiberglass Hull From Scratch

It was basically just out of a pure curiosity thing. :)

But now .... I'm wondering what it would cost to build an offshore fisher type for overnight trips up and down the river. Could one be built for a lot less than, let's say, a Crownline or other mass produced Cabin cruiser?
 

Barnacle_Bill

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Re: Can You Build a Fiberglass Hull From Scratch

There are a lot of stripped down hulls out there of all sizes. Wouldn't you be better off to start with something like that?
 

180shabah

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Re: Can You Build a Fiberglass Hull From Scratch

DonS just gave you a great site. once you are through browsing the plans, there is a TON of information there for the builder, also some very well written books on the subject. I don't have the site available, but if you google Bruce Roberts i'm sure it will turn up. He is a world renowned designer of larger yachts, I think the smallest thing he has is about 28 feet and they go up to well over 100feet.

As for the feasability of developing a mold.......
for a single boat, it just aint worth it. It is a very very expensive process and unless you intend to use it to build many many boats it is a waste.

building a one-off hull using a foam or plywood core fully encased in fiberglass can result in a boat that is both lighter and stronger than a comparable mass produced boat. It just takes alot more man hours to complete.

My wife and I are tossing around several plans from different designers right now. We know we want something classic, it must have a cabin, it must be trailerable. We still have many other decisions to make - cuddy, enclosed salon, single helm, flying bridge, displacement or planing hull, the list goes on....

If you are serious about this, get a plan set for something small like a canoe or kayak and see of you have the patience or even the desire to build a larger craft.

COST??? It really all depends on materials and finish.

One of the boats we are considering is a modified "downeast cruiser" We estimated the completed hull to cost $15-20000, another 25k in running gear(diesel), plus another 8-10k to fit out puts us at 48-55K ready to party. it should easily survey for 2-3 times that amount but we will have a solid 4-5 years worth of sweat equity in it. This same boat could be built for $15-20,000 less, with gas power, Little if any teak, no mahigony in the cabin, or on deck, etc.....However, the final value would suffer greatly to the point that it would probably be worth little more than the material cost.

Get clickin' and start dreamin'
 

Mark42

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Re: Can You Build a Fiberglass Hull From Scratch

But now .... I'm wondering what it would cost to build an offshore fisher type for overnight trips up and down the river. Could one be built for a lot less than, let's say, a Crownline or other mass produced Cabin cruiser?

I looked into building a boat from scratch extensively. I found the least expensive way to build a 17' to 19' off shore capable boat is by 'stitch and glue'. Not many plans out there for boats over 17' in s&G construction.

Bottom line is it will run you about 15K for a basic hull, finished, plus another $8 -$15 K for the outboard or I/O setup of your choice.

If you really want to build a boat, get a junker with a good hull, completely gut the boat and build what you want. It will save you $10k easy.
 

luckyinkentucky

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Re: Can You Build a Fiberglass Hull From Scratch

I looked through the free want ads yesterday, and I'm going to look at an old Coast Guard boat with a 33' hull this morning. The guy said he's had it stored in his barn for 5 years, and it has been stripped,but the hull is sound. He wants me to 'make him an offer', but did say he got it for free. :) The only thing is finding something to tow a 33' boat. Guess I'd figure that into the cost of the package. Although, I could just have someone tow it to the lake for me and wet slip it for the summer. Right?
 

Mark42

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Re: Can You Build a Fiberglass Hull From Scratch

Make him a resonable offer. Especially if it has a working trailer for a 33'boat. The trailer is worth $500 easy.

BTW, to repower a 33' boat, you are talking some serious horsepower. At minimum a 350 I/O, preferably twin V8's. Or if its setup for outboards, it will need two 200 or better outboards.

Just be aware it will cost a lot more to power that boat than you will spend on a rebuild. On top of the 10-20K it will cost in power, figure burning about 20 to 40 gallons an hour at top speed. At about $4.00 gallon at a marina, it could cost up to $120 for a one hour trip.
 

180shabah

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Re: Can You Build a Fiberglass Hull From Scratch

Not many plans out there for boats over 17' in s&G construction.

All of the Devlin plans are S&G, with boats from 8-45 feet. One of the boats were are considering is his Czarinna 30'. Not real fast, but very, very fuel thrifty.

Here are Glen-L's S&G plans - Only go up to 20' though

Luckyinkentucky - I don't know exactly what you are looking for, but here are a few fishing boats that you may be interested in:

Vee Gull
WildCat E-X-T Sport
Barracuda
Cuddy Sport Walk Around
Carolina Sportfish - 25
Carolina Sportfish - 25 - Walkaround
Seachaser
 

KnottyBuoyz

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Re: Can You Build a Fiberglass Hull From Scratch

I looked through the free want ads yesterday, and I'm going to look at an old Coast Guard boat with a 33' hull this morning. The guy said he's had it stored in his barn for 5 years, and it has been stripped,but the hull is sound. He wants me to 'make him an offer', but did say he got it for free. :) The only thing is finding something to tow a 33' boat. Guess I'd figure that into the cost of the package. Although, I could just have someone tow it to the lake for me and wet slip it for the summer. Right?
I work for the Cdn Coast Guard and when we get done with small boats they're pretty much TOAST! Maybe our US counterparts are much easier going on their equipment! *lol*
 

jedimaster

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Re: Can You Build a Fiberglass Hull From Scratch

What about taking an existing hull, flipping it over and and making a mould from it?
 

flashback

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Re: Can You Build a Fiberglass Hull From Scratch

What some folks do is make a male plug (instead of female). you get a bunch of styrofoam blocks and glue them together and carve them into the shape you want then glass over them..It's a lot of work fairing the hull, but when it's done, it will work just fine..
 

Bondo

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Re: Can You Build a Fiberglass Hull From Scratch

What about taking an existing hull, flipping it over and and making a mould from it?

Ayuh,.........

That's called Splashing a hull.........

It's been going on since fiberglass boats have been around.......

Usually,......
It's done as a Manufacturing Mold,....... Not a 1 off project.......

The Cost of the Mold would Equal the cost of the Hull.........Or More..........
So,......
I guess you could Double your costs for the boat of your Dreams,.......
Or,......
Just go Buy it..........:rolleyes:
 

fishingdan

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Re: Can You Build a Fiberglass Hull From Scratch

I looked into building a boat from scratch extensively. I found the least expensive way to build a 17' to 19' off shore capable boat is by 'stitch and glue'. Not many plans out there for boats over 17' in s&G construction.

Bottom line is it will run you about 15K for a basic hull, finished, plus another $8 -$15 K for the outboard or I/O setup of your choice.

If you really want to build a boat, get a junker with a good hull, completely gut the boat and build what you want. It will save you $10k easy.

Have you seen the S&G composite boats at www.bateau.com ??? They have boats up to 28' now and 30+ is on the way.

In general, your numbers are a little high for the 17 - 19' class of boat you mentioned. One could use all high-end hardware and reach that number, but there is a quality middle point that is at least 1/3 less than that. If one is careful and shops around, one can build it for much less without compromising quality.

I have done both. Built from plans as well as rebuilds from the hull up. I'll never do the hull up approach again. You spend too much time undoing poor engineering or sloppy craftsman ship that is usually covered up and not visible. There are too many advantages to modern S&G composite designs.
 

wire2

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Re: Can You Build a Fiberglass Hull From Scratch

Of course I realize there would be a lot of finishing such as sanding and gel coat afterwards, ...

There shouldn't be.
Gelcoat is the first layer sprayed into a mold, followed by fibreglass & catalysed resin.
And the mold is typically like glass, so there's no sanding involved.
 

KnottyBuoyz

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Re: Can You Build a Fiberglass Hull From Scratch

Have you seen the S&G composite boats at www.bateau.com ??? They have boats up to 28' now and 30+ is on the way.
We're building the TW28 from Bateau. Stretching it 30" for a total of 30.5'. Keeping the same beam.

I've estimated a low cost (if bought everything wholesale) of $45K and a high (if bought everything retail) of $70K all in Cdn dollars. We want a nicely finished boat but probably not yacht quality. Just something reasonable to live on for the summer.

http://209.217.103.164/kbii/summary.htm
 
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