Styrofoam floatation in 1985 Mac 25

[Seadoc]

Has anyone out there with a Mac 25 removed and/or replaced the styrofoam flotation blocks under the V-berth and at the stern? If so did you replace them and if so with what material. Or perhaps it's not needed at all. I had a Lancer 28 sloop which had no foam. If you did remove them...at least temporarily...how did you gain access to the spaces?
It seems to me that these spaces are a great way to keep a mold farm going.

Comments.

Thanks and fair winds.

BTW is there no icon for a good old Mac 25?

[kmclemore]

That Styrofoam is definitely needed - it provides valuable flotation in the event of a capsize, and without it I would consider the boat to be unsafe. I strongly advise against removing it. The pieces can be removed temporarily for cleaning, maintenance or replacement via the access covers.

[Seadoc]

My biggest question is how do I access the flotation spaces? On my Mac 25 the after portside space is blocked by a vertical piece of the liner while the starboard side has an opening about 15 in x 20 in. Most of the styrofoam blocks are much larger than those dimensions. The space under the V-berth is accessible only by two openings about 11 in x 15 in. Most of the blocks in this compartment appear to be much larger in size than these openings. Most likely the foam was placed before the liner and deck were added to the hull. I'm considering enlarging these access points, removing the foam for cleaning/evaluation, cleaning the spaces, and finally making new covers for the modified access spots.

I'm sure that there must be someone else who has faced this issue.

[TIMBOAT2]

I am planning to remove some foam from under the V berth to make room for a water tank. Plan to figure out how much weight the individual blocks hold and do the same with a "swim noodle" and put the correct amount back in. I am sure they will nest up a lot nicer than the blocks just crammed in there. That is my thought any way. Anyone know how much weight an cubic foot of foam can float?
Thanks,
Tim

[Tomfoolery]

The same weight as a cubic foot of water, minus the weight of the foam, which is almost negligible - 62.4 lb/ft^3. At least, that's the number I remember using constantly in thermodynamics and fluids classes, but sea water is a bit more dense.

[sailboatmike]

I have been lead to believe that its a very simple calculation, the buoyancy of anything is calculated by the amount of water it displaces less its own weight, foam is used because its own weight is very low giving a greater difference between the amount of water displaced and its own weight, hence more buoyancy, of course not all foams are created equal, some of the cheaper more open cell foams will start to absorb water much sooner than closed cell or more dense foams, thus increasing its weight and decreasing its buoyancy

Please correct me if Im wrong, always happy to learn new stuff or revise old learnings

[Seadoc]

Looks as if I'm not the only one confused by flotation calculations. If you'd like further clouding of the issue, have a read of the USCG Manual for Boat Builders.

Calculations aside has anyone removed the foam. If so was it a mold farm in the spaces?

[Orkia]

It will only be a mold farm if you have water infiltration. Mold takes moisture. The best way to solve the moisture problem is to find the water infiltration issue. I am not familiar with underneath the V birth in the 25, but in the 26S the foam is not on the bottom of the boat. If you do have foam on the bottom. Raise it up off the floor a few inches to let any water you have taken on pass underneath. Remove the water
with a sponge or wet vac often to stop accumulation and/or install a bilge pump.

[Herschel]

I keep my 26X in a slip in Central Florida year round. I have been surprised at how little mold is a problem in spite of our humidity. I am aboard the boat about every two weeks, air it out, wipe away any mold that I see developing (which isn't much very often), spray mold topside with a cleanser that contains some bleach designed to kill mold. I am very careful about not stowing cushions and other gear wet for very long. About once a year, I go over the interior pretty carefully looking for mold and wiping it away with the same cleanser. I keep the bilges bone dry. There are a lot of upgrades and mods we can spend our time on with these older boats; not sure if a "mold crusade" is where I would start. When I wanted to be overly confident of my buoyancy, I taped up four empty, heavy duty Styrofoam coolers and pushed them up under the cockpit to give me a little added margin of comfort. I am not the original owner, either, and the PO had done quite of bit of mods. I wasn't sure he had put all the foam back in. Just wanted to be safe. Good luck.