BYYB Forums

I have been reviewing plans for a build which includes adding foam floatation in some of the out of the way chambers.  I am skeptical of filling a chamber in a wooden boat with foam, because I can't believe that it won't promote rot.  I understand that there are two schools of thought concerning using pour in foam vs solid foam blocks.  Either one makes me nervous.  Has anyone used foam on their build, and has it been effective over time?  Right now I am in favor of sealing up the interior wood and leaving some provision to vent the area when not in use.  I have used liquid foam in the walls of my RV, but that is fiberglass and steel. 

If anyone has experience with in particular, pour in foam, I would appreciate your input.

Al

If you mean the foam in spray cans, I used some in the fore peak of the Vacationer. It expanded and stuck to the wood pretty well. It is an open space so I never gave rot a thought. For my Weekender I've been using empty water bottles in all the out of the way places but I may improve my boat with foam as you are contemplating. My boat was built rough and fast so I don't worry about rot or what happens to it. I have seen photos of Duckie and it is a beautiful boat so I can understand your concern.
Infact if my boat rotted away, I'd have a good excuse to build another one.

On my super skipjack I used 6 pool noodles behind each seat back 12 in total. Each one able to hold my 200 lbs. they worked well, easy to fit behind the seats, cheap too!

On Duckie I rely on water tight chambers that are heavily painted inside to forestall rot.  Each one has an inspection port or gasketed hatch that I leave open when I'm not sailing.  I figure that these will give me the maximum floatation for the available space.

The plan that I am reviewing is for Autumn Leaves.  It is a cheap download at $49, but not very explicit about how to get things done.  This plan calls for foam in some oddly shaped areas, which is what's causing me the heartburn.  I would like to take a swing at this boat because I have been thinking about canoe yawls for a while now, and this one promised a quick easy build.  Maybe not.  I spent a good bit of time trying to figure out how to hang the bilge boards in the area that they have, all the while trying to figure out how to keep the water out. 

There are some modifications that are important to me such as changing the main to a gaff rig and mounting the mast with a tabernacle.  Both of these mods will demand quite a bit of head scratching.  It boils down to wanting to make Autumn Leaves as handy, safe, and convenient as my weekender.  I won't spend a dime until I have satisfied myself that I can do just that.  Its funny how when I consider other boats I always hold them to the standard that Duckie set in my mind.  So far they all have fallen short in one important way or another.  That is why I have had such a hard time picking a build that will match or exceed weekender without being a weekender. 

Oh well.  So far it has been a lot of fun looking around.

Al

Buoyancy chambers and floatation needs to be ideally placed, which is typically on the hull sides and under the decks. You'd think placing it low would be ideal, but it's not. Pool noodles are a great way to get a lot of reserve floatation, without spending a bunch and they're easy to stuff into places too. I generally use chambers, rather than foam for this, as they're easier to live with, but some insist on foam, which if snugly positioned against wood, will eventually cause issues.

I placed 2" thick styrofoam sheets, cut to size and stacked horizontally in the bow of my Skipjack, in front of an additional bulkhead not listed in the plans.  (I found that it was impossible to reach forward past this point from behind the designed front bulkhead with it's trapezoidal holes.  So I made useful with flotation a space that would otherwise be wasted.)  This section is not sealed: It has a limber hole for draining at the bottom.

On the sides, instead of cubbyholes behind the seats these areas are filled with a combination of pour-in-place foam and leftover chunks of Styrofoam.  One S-1 kit and the leftover Styrofoam and a can or two of Great Stuff to fill in the blanks completely filled these compartments.  The front 18 inches behind the seats are separate compartments for stowage, accessible by 4" round inspection ports.

These side compartments are completely encapsulated inside and out and sealed.  It's unlikely that there will ever be water intrusion unless the boat is damaged, especially considering that the boat will live under cover on a trailer.  No water, no rot.  But time will tell.  I haven't quite finished the boat yet due to cold weather but definitely will launch this Spring.

The total flotation is distributed such that if the boat is ever swamped it should still float level and relatively stable, so that bailing will be more effective (less chance of being re-swamped.)  I supposed I could have just sealed the compartments and not used foam.  The boat would have been maybe 10 pounds or so lighter.  I guess my thinking at the time was that in the unlikely event that the seal failed, the foam would prevent the compartments from filling with water.  I think if I were to do it over again I'd make the bench seats and seat back straight instead of curved, and would install maybe three 6" inspection ports in the seat backs so that those compartments would double as storage as well as flotation.

Yeah, if I do this, I will go with chambers like I did on Duckie.  I watched a couple videos about installing poured in foam, and they really put me off.  I also saw a video of what failed foam looks like.  It might as well have been a sponge.  I seriously think that if I built a boat and it rotted out quickly, it would break my heart.  In the last seven years I have learned a lot about what can go wrong.  With that in mind, my next boat build will be carefully sealed if it is anything. 

When I restored my little motorhome, I used pink foam bricks that I cut out of a two inch thick sheet.  I mortared them in place with foam from a can like building a brick wall.  I did it this way because the walls of the camper were rounded much like a boat.  After the foam cooked off I cut it flush with a machete and paneled over it.  It is surprising how many uses you can put a machete to.  I didn't worry about rot in this case because it was fiberglass and steel. 

Al

WITH MY POOL NOODLES, THEY WERE CLOSED IN BEHIND THE SEAT BACKS BUT THERE WAS A OPEN SPACE UNDER THE SEAT ALONG THE FULL LENGTH, SO I HAD NO WORRIES OF WATER COLLECTING THERE

whoops no reason for the caps, haha

I just checked out Autumn Leaves. Nice boat but seems like a lot of work plus 600 lbs of lead. total weight is 1500 lbs...........almost double of the Vacationer ( and it has lots less room )  I have a hard time launching Vacationer so I figure Autumn Leaves would be more difficult. It says that Autumn Leaves can be a coastal cruiser. I don't know about that. I'm personally thinking of building another Weekender using better materials. Best boat for me......... light and easy to launch, wheel around the yard by hand plus no lost MPG's on longer trips.