refoaming the hull after the new floor or leaving it open
 

im having my boat sent out to have the floor redone, it is way over my head with the stringers rotted out and alot of other nonsense i neither have the time or patience for. Now the friend of mine is doing the work who happens to own a small boat shop, he suggest not putting foam back in because all it does is ad in the rotting of the stringers because the hull never breaths. i can see this b/c the boat was sunk 5 years before i bought it and the wood or foam never fully dried under the floor. I know the coast guard kinda frowns on this and there wouldnt be alot of hope getting the boat back if the hull ever because compromised but isnt that what insurance is for?? IDK if there is another option. If this boat were going into the ocean or inter coastal waterway i would be more inclined to doing it. This is only gonna be a lake/river cruiser....

any suggestions?

Re: refoaming the hull after the new floor or leaving it open
 

If you make a significant modification to a boat and that modification leads to some sort of accident or becomes a contributing factor in an incident and it becomes apparent to an insurance company that you've done this, you run the risk of having your insurance claim denied for not advising them of a Material Change of Risk. Its your money though and your call.

Re: refoaming the hull after the new floor or leaving it open
 

Mikey covered the insurance part. Now from a structural point. The foam does more than just provide flotation. Some parts of the hull use a sprayed in foam, other parts use a 2 part poured in place foam. It is a structural part of the hull meant to work with the stringers and bulkheads. It absorbs a lot of vibration and sound. It makes the hull more rigid(it handles and rides better). The bonus is it keeps you boat from totally sinking. It is your call, I am just trying to provide you with some more information from a different angle:)
Happy Boating
Dan

Re: refoaming the hull after the new floor or leaving it open
 

my spider man scenes tell me you are both right. i have read in some other places people used foam blocks and cut them to size. i found a manufacture that makes foam blocks for dock floats however they do not recommend using them under the floor. my goal with this is being able to leave a 1/2 gap off the stringers and was going to leave and opening under the dash in the cuddy to put a fan to at the end of the season i could dry this boat out from head to toe or in this case from bow to stern. not so much a cost issue this boat has become an open checkbook job and its more of a quest then a hobby to get it done, but along the way doing things as smart as possible.

Re: refoaming the hull after the new floor or leaving it open
 

Wanna use that "open checkbook" on my boat? :D

Re: refoaming the hull after the new floor or leaving it open
 

one boat is more then enough!! if i win the mega millions ill get back with you:yes_grin:

Re: refoaming the hull after the new floor or leaving it open
 

Foam blocks are used for floatation in some instances, but there again they are not structural because they are not "bonded" to the hull and stringers/bulkheads. Generally, poured in place foam bonds slightly and expands to fill voids and uses more of a compression force to add stiffness to the boat. The basic way to install it is to complete the new boat skeleton, encapsulating or at least coating every piece inside and out with resin, starting at the transom and going forward, drill 2 holes about 1" dia near the front of each chamber that willl hold foam. Elevate the front of the boat as high as feasible. Mix the foam a little at a time and fill each chamber. It expands fast and you [B]do not[B] want to overfill a chamber(it can blow the top of the chamber off)Do it a little at a time till each chamber is filled. If you don't want to fill each chamber completely u could pour with the boat flat, but that may be hard to control fill rate/quantity(lots of voids). Remember the foam is structural, meaning it helps to strengthen everything including the floor. Hope this helps.
Happy Boating
Dan :)

Re: refoaming the hull after the new floor or leaving it open
 

I dont know the exact layout of your hull etc but is it possible to place a tube for drainage before you refoam the hull?

Re: refoaming the hull after the new floor or leaving it open
 

there could be a place for a drain.. im looking at any possibility. thank you for all the possible options

Re: refoaming the hull after the new floor or leaving it open
 

What did you end up doing? I agree with your boat guy about the wood in the hull needing to breath.

After reading this thread and doing some inspections of the structure of my boat I'm very worried about the potential of rot on mine also. My ski locker is always wet and after peeling back the carpet around the floor cooler I see that all the wood under the floor is just bare treated wood. It was not covered with resin or anything else. When I open the rear fuel tank sender access panel I see the wood there was only painted and not very well. I planned on keeping this boat for a long time, but now I'm concerned.

My 77 Cobalt which I sold this year had zero rot and drained and dried out very quickly.

I'm thinking about this winter pulling up the carpet, drying the boat out very well, and coating the floor and inside the ski locker with either resin or possibly having it sprayed with Rhino Liner (you can get almost any color now) and then putting in a snap in carpet.

On the Mariah promotional video... They talk about the wood they used "simply will not rot" and that is not true... Any wood exposed to water constantly will eventuallly rot. Most people don't keep a boat for 20 years, but I'm not most people. These boats were sold with a lifetime hull warranty.... haha. I'm not impressed with the build of my boat at all... Fancy and pretty does not mean well built.