Boats without a wood core?

flipbro

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I thinking of buying a bigger boat than I have know. Possibly 25 to 27 ' just wondering what manufacturers didnt yous wood as a core material in the 80s if any and also are these bigger boats full of foam aswell?
 
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In the '80s? None that I know of. Look at a Marinette if it is that big of an issue to you. Generally boats that size don't have flotation foam if that's what you mean.
 

Texasmark

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I know that in the smaller boats the wood core if used, was balsa. I know the Kingfisher brand for one used it. It's purpose was to separate 2 layers of fiberglass and make a sandwich out of it to increase strength while keeping weight down. You can google the specs on balsa's qualities.

On foam, BIA (Boating Industry Association) certification requires some kind of flotation mechanism for boats. Two popular foams were used due to light weight vs volume: One was blown in and was open cell meaning it could absorb water. This was the easiest to apply as you just drill a hole in a hatch and shoot it in. It expanded, filling the hole and you have your flotation. The other was Styrofoam, the white stuff like in coffee cups, which is closed cell and doesn't absorb water. It comes in sheets hot wire sawed from huge blocks.

That's what I know about it. HTH,
Mark
 

NSBCraig

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Nobody didn't use wood in many ways in 80's boats. Balsa core, stringers, bulkheads, stiffeners, transoms... and unless your just looking at a foam filled boat (whaler etc) your not going to find many with any floatation foam. It takes alot of foam to float a big boat.
 

flipbro

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I guess what I want to avoid is rotten strngers or transom ive completly restored to 20'ers and dont care to try a 25 lol. I know as a rule that no flotation foam under 20' and ive heard storys of foam filled stringers
 

25thmustang

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I don't know of any non wood cored boats. I had a 1987 Cruisers Inc that claimed to have floatation foam. I honestly never found it (bilges didn't have any) however it was touted as being able to float if swamped. With that said she had a wood cored hull (balsa cored sides to the chine) and stringers. Your looking at a big older boat for floatation foam and no wood.
 

tpenfield

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Boats that are built according to ABYC standards will have flotation up to 26 feet. USCG requirements are only to 20 feet. 1980-1990's will almost certainly have a wood structure and decking. It is not until you get into the later 1990's and 2000's that some manufacturers started eliminating or reducing wood in the structure. Manufacturers are fairly vague about the exact materials used in the core of the boats. Most of the published documentation is about the stuff you can see versus the stuff you cannot.
 

Texasmark

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Nobody didn't use wood in many ways in 80's boats. Balsa core, stringers, bulkheads, stiffeners, transoms... and unless your just looking at a foam filled boat (whaler etc) your not going to find many with any floatation foam. It takes alot of foam to float a big boat.

Somewhere down the line BIA certification required flotation material sufficient to float the boat upright. I remember when that was incorporated because bass boats in particular....like the Ranger I was running, all of a sudden lost a lot of storage space near the transom converted to foam to support the 200 hp engine, 3ea 27 size batteries, a 30 gallon livewell, 30 gallons of gas and all the rest of things that added weight. That was in the 1989 time frame as that was the model year of that particular boat.

Back in the day, Forrest Wood, owner of Ranger Boats had a commercial where he cut huge blocks of the boat away, sides, hull, interior and all, on one of his bass boats to show you how much foam he puts in his boats and even with chunks cut out of the sides and all it floated high in the water.

The commercial was informative, but with the sides cut away, you couldn't fill the boat with water which would have made a difference in it wanting to flip, sink or not. The only way something will float is if it's volume vs weight is lighter than the same volume of water that it displaces. The higher the volume vs weight, the higher it will sit in the water....aka a cork on a fishing line.

If equal it will remain suspended (jerk baits that were popular a dozen years or so ago) and if heavier it will sink (your fishing sinker). That's how you determine the weight of large objects. Put them in a tub rim full of water, and measure the weight of the water that comes out. The purpose of the foam is to substitute foam for the water that would otherwise occupy the interior of the boat and tilt the equation in favor of floating.

Course the definition of floating is not necessarily having the freeboard you had prior to the incident. The gunwale could be even with the surface of the body of water and still be considered floating.

I think I remembered all that correctly. Been awhile!

My 2c,
Mark
 
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undone

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There has never been a time where open cell foam was used, kind of defeats the purpose of using it for floatation.
 

Texasmark

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There has never been a time where open cell foam was used, kind of defeats the purpose of using it for floatation.

Well you may be right. I just googled the subjects and I guess I was wrong on classifying the cell structure, not on the performance. I did see that the sprayed in could absorb water which makes my point and when you cut through it you have open bubbles. My thoughts on closed cell were styrofoam cups you use to hold coffee where the foam is made of individual pellets. But upon googleing, I find many types and uses and strengths and all that of Urethane and Polyurethane resins. It did say that the closed cell did require more material which meant more cost and weight and that could have been an initiative for boat builders to use what appeared to be one, a low density closed cell to go along with their non treated whitewood stringers!

My Starcraft 18' aluminum Holiday had what I called closed cell foam sheets under the floor. It was not contained, just lying in the bilge. I restored the boat when it was about 20 years old and reused the foam as it was intact and had not absorbed any measurable if any water.

Sorry for any disinformation.

Mark
 

Scott Danforth

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I know my '88 Cruisers Rogue has flotation foam. it is also uses balsa core in areas, has plywood laminate stringers, bulkheads and transom.

I also know that the Carvers are the same type of construction, as well as many searays.

from a few posts on iboats, wellcraft and crownline also have plywood laminate stringers.

I know that chris crafts of the past decade use engineered stringers (no wood). it is actually a stringer tub that is bonded into the main hull tub.

since the issue is that you do not want to do a restoration, I would simply look for a well cared for boat. They are out there.
 
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