Is foam neccessary

[Boataudio]

Hi I am in the process of replacing the floor and stringers in my 17.5 foot Larson Silverline. I have read the threads about foam. My question: Is the foam neccessay? I realize it is there for flotation but is that the only purpose? Is it structural in any way?
Thanks

 

[Bondo]

Re: Is foam neccessary

Ayuh,... That's a Loaded question.... I don't know the hull....

Generally speakin',...
A Stringered,+ Bulkheaded hull get's it's strength from them.... Not foam...

A molded hull using glass,+ foam,.... No wood, No stringers...
Ya, probably All it's strength is from the foam...


Btw,....
"Re: Is foam neccessary ?",....
Drainage is what is Necessary,.... Regradless What you decide...

 

[Bob_VT]

Re: Is foam neccessary

Welcome to iboats.

Wow that's a loaded question for a first post! There is a requirement for flotation from the USCG and information can be found here http://files.dnr.state.mn.us/educati...atbuilders.pdf

Just FYI the larson uses the foam for flotation. we have a pretty good policy here ..... we hate shortcuts that could endanger you or your future passengers..... I would highly recommend you follow the USCG guidelines for the flotation for safety.

The boat you have has a floor? Hmmm post a few photos since you are doing the "floor and stringers" how is the condition of the deck and transom?

 

[stylesabu]

Re: Is foam neccessary

I'm re doing the deck on my 16' sylvan(aluminum) and the foam does add regidity to the frame. the back have is water logged so i removed it. I'm planning on replacing it. I'm debating between sheets and spray in 2 part. Hers a couple of pics.

 

[BobsGlasstream]

Re: Is foam neccessary

I think I'm just going to follow this one. :redface:
It should be very interesting. To say the least.
Bob

 

[metriccrescentwrench]

Re: Is foam neccessary

Even if, technically, a boat's stringers support the deck you can't argue with the fact that foam under the deck will add rigidity.

Regardless, as bondo said, be sure to account for proper drainage. I replaced the transom, stringers, and part of the deck in a 1981 fish-n-ski this summer, every bit of foam was bone dry because water had a path to the bilge without being able to get to the foam. (I just wish the previous owners had taken a little care to keep water out of the transom !!!)

 

[HVAC Cruiser]

Re: Is foam neccessary

Regardless of all the debates here with regard to foam, I spent the measly 200 or so in material and poured in the replacement 2 part foam. What bob said is right even if he is teasing you about replacing your floor, hehehe (just kidding bob )

When I was at that point with my boat I actually found an earlier post from bob with the link to the coast guard boat builders handbook which I downloaded and followed with regard to foam.

Look at it this way, it will add some rigidity to your Deck, if you fill it right, and if for some reason it gets swamped the 200 in foam is a lot cheaper than retrieving it from the ocean floor.
Aside from that there are safety issues, in the event something does happen, you and your passengers can hold on to the boat while waiting for the coast guard to fish you out of the water, its easier for them to spot a boat than people with life jackets.

Just my 2 cents

 

[Bob_VT]

Re: Is foam neccessary

Regardless of all the debates here with regard to foam, I spent the measly 200 or so in material and poured in the replacement 2 part foam. What bob said is right even if he is teasing you about replacing your floor, hehehe (just kidding bob )

Let's see..... Marine Park/Flatbush Ave in Brooklyn...... then Hauppauge...... then Franklin Square...... then the Army for 20 yrs! Now you know where the teasing comes from!

 

[HVAC Cruiser]

Re: Is foam neccessary

Let's see..... Marine Park/Flatbush Ave in Brooklyn...... then Hauppauge...... then Franklin Square...... then the Army for 20 yrs! Now you know where the teasing comes from!

Lol - Marine Park/Flatbush Ave- My old neck of the woods, I watched my friends 33' Chris Craft sink to the bottom over there, got rammed while docked at the Canarsie Peir . No flotation foam . These days I'm a stones throw from Hauppauge in Neseconset