Foam Block To Bass Boat... can this be done?

[Curious]

Hello

I have a wacky idea, some time, space, and a little cash; plus a buddy that just bough a really nice bass boat. See I want a really nice boat like this too, but I'm broke and or cheap, you'll have to ask my wife... :rolleyes:

I'm thinking I can measure and trace every inch of my friends boat and can carve a duplicate of the hull from one full piece of foam creating a core for a FG bass boat of my own. Hull and top side front and rear decks, plus cockpit along with carving out all of the storage nocks and crannies. Then also carving in small recesses the length of the keel, shear line, and in a cross hatch on the transom. Possibly also some following the line that battens would run.

Once the core is carved starting to lay up glass using the keel, shear line, transom and batten recesses in the foam to form thicker members in place of stations (could be way off on the usage of that term), then doing a final allover application to encapsulate the hull bottom, sides, deck and cockpit with the foam in place.

And assuming this can be done…

Question time:

Is this sufficient strength for a boat of 16ft with 50 to 60 hp?
Is this limited to closed cell foam construction only; is it possible to use other foam types?
Could joined pieces of foam be used or is a sold piece preferred, and what would be the best bonding agent to use to build up from multiple pieces?
Could A / B mixture expanding foam be used?
If carving an A / B foam mixture plug as opposed to solid stock, should the weight be 2# or 8#, is there a denser product?
What types or weights of glass tape, mat, or woven roving would be used to get the best results?


I know these might sound like the oddest questions but I would really love to know if I can do this. I’ve been dying for a boat like this all my life but the dog would get braces before my other half would let me pop for one at a dealer new or used. This way I’m just being eclectic and might sneak it past her until it comes time to build or buy a trailer and go fishing! :D

[gonzo]

The design is intelectual property. As such, you need permission from the desingner or owner to legally build a copy. What you are talking about is like suggesting rustling in cow country.

[Curious]

Intellectual property considerations aside, is the method of a unified foam core sound?

Will FG laid up in channel in the foam prior to mat covering serve as a keel, or provide strength in a shear line or transom?

[PAR]

I other words you're willing to take your chances with the designer or fellow followers to risk stealing his work, not to mention the work of the manufacture, sales team, marketing folks and legal staff.

The cost of building this hull in the fashion you have outlined will surly cost much more then buying a copy of the bare hull you are interested in.

DO us a favor and price out the cost of a few dozen gallons of resin, fabric to build out the lay-up to the desired thickness, lumber and other materials to construct this dream of yours.

You'll find the cost of doing it yourself will far over reach the purchase of a beater in need of an engine and some electric (all of which you'll need to install in your version of someone else's work)

Clearly, by the basic questions you've asked you haven't a clue as to what you're doing. Maybe you've played with some Bondo on you car or something, but you are not going to build cheaper then you could acquire in the used boat market. A very skilled builder, like myself would be hard pressed to compete with the mass-produced sea of boats out there. You, frankly haven't a chance.

Check out the back of the paper (it's in the classified section) and find a boat that needs some love and money tossed at it. They're everywhere and quite cheap. Don't steal someone else's effort and hard work. You'll soon learn about cold showers and twenty dollar bills you'll also get your fill of 'glassing 'till your heart's content, trust me . . .

[Curious]

I hope it was not assumed when I said "Intellectual property considerations aside" that this was a dismissal on my part of all consideration for the designer. It took me about 3 seconds to say "oh yeah, that’s right", and decide that a set of plans was in order. I have found many plans for Garvey or Jon boat designs that will suit me just fine... it is not the hull shape but rather the detail in outfitting that impresses me with the bass style of boat.

I have been reading everything I can get my hands on with regards to FG and foam core which lead me to the above idea. It would seem that the strength of a foam sandwich hull is due in part to the joining of the out and inner layers of FG meeting and forming a bond through the stem and keel of the hull; barring that joining of inner and outer layers in a foam core i was hoping a suitable amount of FG build up would suffice.

I have spent many hour reading the classifieds looking for a boat like a bass fisher but in the area I'm in they are rare and expensive when found. I am able to get very good prices on resin and FG however which is why I was thinking build, I also have access to large amounts and varieties of foam ergo the idea of a foam core.

[PAR]

You'll not find a cheapo boat in the paper, it's just not cost effective to advertise a $500 or less boat in need of engine or other major work. You'll find them at the back of boat repair shops, marinas and in backyards (maybe next door) The owner has lost interest, health as gone south, gotten too old or plan just doesn't want the bother of the thing anymore. The shops and yards will have a bill on them for storage/repairs and the boat can usually be had for the bill which is usually quite easy to get lowered. They want it out of there to make room for paying customers.

I picked up a 30 year old 18' bow rider with 140 HP I/O for $500 a year ago and it was easy to fix the fouled fuel delivery, buff the topsides to a nice luster, replace the ignition parts, oil, filters, fuel, impeller, hoses and clamps. The electrical needed some attention, but was running within a day. The trailer needed bearings and a tire, got a coat of paint and a new hitch. I sold her a few months later after I had my fill of blasting around the local lakes with it at over 40 knots. She still needed a bimini, had no electronics other then gages and the ArmorAll on the seats did a nice job of selling her for $3,000.

You have to do some leg work. Get to know the folks at these places, buy them coffee and maybe they'll give you a call when they hear of a beater up for sale or a fellow yard owner/worker bitches about another dead beat owner he's had to fill a lien on. Donuts before 9 in the morning will get you wonders in a boat yard . . .

[bobber]

im with PAR on this. the cost of building a boat like this is not cheap. You prices the mat and resin, but did you also take into account things such as laying up tools, gelcoat (with the method you refer to, you would need flow coat), wood for stringers and bulkheads, else your not going to last long out there. Its a bit more than just carving a foam core and fiberglassing over it. although the foam core layup is a method that does work if done right.
Also, method your talking about will look pretty awful unless you spend a fair few quality time hours sanding it down. Its very hard, and almost impossible to lay glass mat smooth, any one who claims they can do it outside of a mold is either lying, or has some amazing talents.

Dont get me wrong, i understand your situation. ive been in it, and its often tempting to look at the whole idea of building one yourself as a good idea. but trust me, it may look good on paper, but add to that all the fitting out required, engine, seats, decks, consoles, controls, electrics, everything else required, it mounts up to huge sums of money, and likely the wife will be beating you with a frying pan harder than if you went out and just bought one.
If its something you really want to do, to prove to yourself more than anything, then go for it, (but research your methods, and practice on much smaller scale first), but if its just to have a boat, then go with the buying a used one idea and restore it, it works out much cheaper and often much better.
HOWEVER, dont rip off hulls. Im a boat builder, and ive had one of my RIBs ripped off before, and its not nice. Spend a lot of time designing and building these boats, and its not fair to just go along and copy it. If your going to do it, either purchase the designs legitly, or design your own.
not that you would rip off someones hull of course ;)

[guest]

I'm with you all the way on the cheap boat project! Also, I do not think that copying a shape amounts to "ripping someone off" if you are building for your own personal use and are not using stolen plans. Anyway, I am working on a similar cheap boat project, I am planning on using foam insulation board to build a 15 foot Garvey hull, designed myself using "Hulls" software, (available free on the web) but closely resembling some shapes I found in the Glen-L catalog. The Glen-L approach is to use plywood and fibreglass the seams, I intend to build the whole thing out of foam and will wrap the whole in fibreglass cloth. Power will come from a jet ski drive (hunting for ugly but running jet ski in the method suggested by "par"!) mounted into the hull (see jetjon.com for some really cool ideas). I have a roll of really light weight glass I got at a hobby store auction, it is really too light for a boat, but I am hoping that many layers of thin stuff will be as strong as a few layers of thicker stuff. I like your idea of whittling a boat out of foam and wrapping it in glass even if it won't work, I am always on the lookout for cheap construction methods and materials. Once they put the word "marine" on the label, the price triples! Good luck!

[Ol' man]

cheap boat project
>>Very bad place to start.

Also, I do not think that copying a shape amounts to "ripping someone off" if you are building for your own personal use and are not using stolen plans.
>>Then don't think. It is a illegal as stealing music or movies on the Net. The design belongs to someone else.

Once they put the word "marine" on the label, the price triples!
>>Marine materials have been tested to insure they can withstand the wet environment in which they have to work. They are also required to resist gasoline and oils without dissolving or failing.

I am planning on using foam insulation board.
>>This stuff is designed to insulate, not provide structure or support.

approach is to use plywood and fibreglass the seams, I intend to build the whole thing out of foam and will wrap the whole in fibreglass cloth.
>>Plywood's properties are established and it is able to take the stresses of what you hope to achieve. Construction insulation makes no such guarantee.

Power will come from a jet ski drive, mounted into the hull.

I have a roll of really light weight glass I got at a hobby store auction, it is really too light for a boat, but I am hoping that many layers of thin stuff will be as strong as a few layers of thicker stuff.
>>The thicker stuff is made to be used to carry people safely. The stuff you bought is made for models? Any you HOPE it will work? What will you do if it doesn't - like if you are in the center of a lake?


Don't get me wrong, I love innovation, but this plan sounds downright suicidal. You want to make a boat from foam that is not designed to be glassed or used as a structural member. The cloth you want to use is not as strong and harder to get the air out of and you want to power it with a hi-torque package that will transfer much twisting force to the edges of the hole you want to afix it to.

I get shudders when I think of you bouncing through the chop in mid-lake when there is a loud crack. The foam was dissolved by the gasoline that leaked down the screws that you used to hold the power unit in place and it has torn free, opening a gaping hole in the hull. Suddenly, you find yourself neck deep and hoping that the construction insulation has enough bouyancy to keep you afloat, while you try to stay warm.

As the others said, but a used boat to play with and add your jet ski to that. It may mean you have to save a bit longer, but it's safer.

[lakerunner]

You have been given some great advise I think you should take it . There is a good reason that these new bass boats have a nice pricetag. And I can guarantee you will not save a dime if you are natured the way you saybuiling it your self. I can give you an example,
I replaced a transom on an 1988 model 18' w/150 hp popular Brand of bass boat.
Given the year and use of the boat it was a nice and well taken care
of boat. Except for what you could not see. It cost me $1200.00 to fix MYSELF.
I have experience and let me tell you I did not pay myself for labor.
Building and renovating new and old boats alike it not for the Weak of Heart.
or a light wallet. These are Toys unless you earn a living Bass fishing and then I probably would not be writing this if you do. If you can afford $200.00 a month you can end up owning a damn nice bass boat. Maybe not like the one your fishing partner has but hey ........ If you want to fish go fish ..... Or marry your buddy ...Trust me
I've been told to do That. Good luck

[PAR]

Actually, you can save quite a bit of money building your own boat, but there are several kickers. The designs you'll save money on aren't the designs you'll typical see out on the puddle you fish each weekend. They will have a dated hull form and styling, but will likely provide the same amount of enjoyment the new, flash in the pan designs do. A real do-it-yourselfer can save over 50% compared to the cost of similar bought new.

This is rarely the case, because you can't buy materials and equipment needed for the build in the volumes necessary and therefore have to pay a much higher price compared to the production builders. They buy thousands of yards of cloth, hundreds of gallons of resin and get great pricing as a result. You'll likely pay retail. They have engines built to their specs, you'll go down to the local marine store and get hacked by a salesman. They have equipment and processes specifically designed for the production of boats, you'll be picking bugs and leaves out of the freshly cured goo you applied yesterday, with hopes the rain would hold off for just one more day.

This all adds time, energy and cost to the project, but if well planned you still can save a lot. The typical bass boat is very application specific design, developed (read, research and development department) over countless meetings and design team sessions. To find a similar design to the latest (read, copyright protected) flats rocket with a 250 HP Black Max hanging on her stern, on the open market is unlikely.

Copying a design is strictly against the law, an most who design take great offence, screw the copying is flattery crap, I'll take a chainsaw to the boat and a bat the head of the fool who steals my work. It can take years to develop a design into something that can be built and safely relied on to carry about it's business. Is stealing your wife basically saying "I like your selection in women" . . .

Building a Garvey style hull isn't copyright infringement. The type has been around long enough to become a breed unto itself, bearing no designer royalties. The Garvey is a good flats boat, but will get it's transom blown off by the pocket rocket bass boats available currently by production manufactures.

If you want to layup a dozen extra layers of thin glass, because you got a deal on some, then go for it, but it will be heavier and require much more effort. Marine materials cost more for a reason, they must stand in an environment that is nasty to most things. Those materials must keep people from mixing with the unnatural state we're floating on. Marine plywood is a good example. Take two pieces of 1/4" ply, one Lauan from the LowesDepot and the other from Boulter Plywood with an APA 1-95 stamp on it. At first glance the marine ply has 5 layers, each about the same thickness, the Lauan has 3 layers and the inner is much thicker then the paper thin outer layers. The Lauan will delaminate from it's plys very quickly if left out on the back step in the rain, the APA1-95 will not, a reasonably important feature in a panel that may be required to keep the wet stuff outside the boat always on the outside. Lauan can't be made to work well in a marine environment, unless it's dry sailed, which basically means it's sealed well enough that the little exposure to moisture it does get will do little harm. Sure the Lauan is 10 bucks a sheet and the stuff from Boulter is a bunch more, but you get what you pay for generally. No amount of epoxy or other coating will make it a better deal then the same treatment on quality marine ply.

I've been running a test on a piece of MDO (also carries the APA 1-95 marine grade) It's lived in a 5 gallon bucket for coming up on two years now. It has a broken edge and sawn edges, no coatings of any kind and been soaking in fresh water 90% of the time. It receives direct Florida sun for several hours each day, has dried out and been wetted repeatedly, has dog spit all over it (my 4 dogs drink out of it cause it has the cool green slime water, rather then the fresh clean stuff I provide for them) My dogs have fought over it, having tug of war contests with it. It has been subjected to the worst kind of treatment, unlike what even the most uncaring person would do to their boat. It has faded a bit (the resin face) from UV, but isn't delaminating. Because it's Doug. fur, the grain has raised, but not a structural problem and typical for Doug. fur. The are no signs of rot, not even in the teeth marks, though something clearly is growing on it. Eventually, the marine growth will break down this slice of lumber product, but currently, if a skiff had been made of this panel and not painted or coated, it would stiff be serviceable. Try that with your non-marine grade good deal (so you thought) materials . . .

Do yourself a favor and buy a cheap set of plans from Glen-L, you will not find less expensive unless free. The design will be tested and when you pack the kids and wife aboard she has a real good chance of not flopping over on her side and drowning someone you love. Save the backyard engineering for figuring out how to weld the cracked motor mount in your Chevy without having to remove the engine and leave the structure and material analyses and engineering to the folks with the education and experience. Fiberglass and the coring products sometimes used inside are highly engineered materials. Trying to second guess, without the background necessary for complete understanding of the concepts and principles, is fools work.