I am rebuilding my 1986 NACRA 5.8 and after opening the hulls I have found that there are loose foam blocks
inside both hulls. I guess they are there for emergency floatation. My 5.8 was a Florida rental and only has one inspection port per hull compared to the 1983 5.2 that had two ports per hull. Can anybody out there tell me if this type of Positive Floatation is really the right thing to do? Should I remove all the old nasty styrofoam and replace it with a better solution and wouldn't it be better to fiberglass the stuff to the insides of the hulls?
Thanks for any insight on the issue (Pete in Bellingham WA, USA)

why make extra work for yourself. if the foam blocks cannot get out the inspection ports they will do the job.

All Nacras only came with one inspection port per hull located aft of the rear beam, if there are more than one in each hull it could indicate that another was installed to have access to make a repair.

Hobies are the same way. The flotation blocks just sit inside the hull. As long as the blocks are not disintegrated or water-logged, just leave them be.

sm

pete,
i bought a used N5.8 that had two large clear plastic air bladders inside for extra flotation. the kind you might use to hold drinking water when camping. they were not filled with water of course, but just air. i always wondered if they were really large enough to do any good, if the hull filled with water would two of those bladders really support the hull. i came to the conclusion that they wouldn't, so i took them out.

how much foam do you have inside? would it be enough to do any good? does it shows signs that it has been wet in the past? whenever i've seen the foam inside a used hobie, it's disintegrated. (not picking on hobies here!)
j



Edited by arch on Apr 26, 2016 - 04:57 PM.

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Hi All,

Thanks for the feedback. I did pull out all of the foam I could reach.
It was a little nasty.
Might have been 1.5 to 2 cubic feet of the stuff. The air bladder concept seems interesting,
but the hull I opened has a lot of sharp objects in it due to sloppy f-glass work on the inside,
this stuff would pop a bladder, and trying to remove the stuff may lead to more interior hull damage.
I was also thinking about using air-filler boat bumpers or the like.
I like the concept of adding positive flotation (just-in-case)
but I would hate to add weight and possible noise makers when
returning to the water after flying a hull (clunk... thud... etc.)

I am open to anymore input if there is any out there...

Thanks again,

5.8 Pete on Lake Whatcom in Bellingham, WA

People have used pool noodles bundled together to replace the rotted foam blocks. Again, if the foam is OK, there's no reason to mess with it. It won't make any noise when flying a hull. The only time you'll notice it is if you flip the boat upside-down, you might hear it drop onto the deck.

sm

Thanks Dogboy.
Sounds like a good idea.
The form factor seems pretty good too to just fill the
middle cavity with the noodles...

-Pete in Bellingham

HULLFLYER

All Nacras only came with one inspection port per hull located aft of the rear beam, if there are more than one in each hull it could indicate that another was installed to have access to make a repair.

OR it could be just for more storage. this is very limited on a beach cat.


I would not mess with the foam any more. Unless it is waterlogged!
it was there as emergency buoyancy in case you sink/ swamp your hull (i now carry 2 part pool epoxy in my little on board tool box in case i rupture a hull or boardwell, again).

I think the water noodle is a decent idea if you bundle a bunch together with line and secure it inside the hull (if you break open a bow, you want them to not float away). they Will degrade and get waterlogged with time and humidity, so check them often. ymmv


as per the " f-glass work"...

These boats were built on tight budgets and slim margins.
sharp edges and excess glue etc happens with production built boats. and even in custom built boats

i am no pro but ...
after you lay up fiberglass, epoxy, gelcoat..., when it's cured, it's now full of razor sharp shards and fiberglass needles and razor sharp edges. I think it's part of the process and example of commercial fiberglass boat construction in the mid 1980's.

this boat seems to have held up 30 years so far...



Edited by MN3 on Apr 28, 2016 - 10:14 PM.

Allow me to make a suggestion. What if you contacted an insulation contractor in your area that does liquid injectable insulation They could stick the gun through the inspection hole and shoot certain amounts. Just need to remember the expansion size once fully cured. You don't want to blow or pop something off as it cures. The foam would adhere to the inside of the boat and also give some additional support to the hulls.

--
Forrest
I-20 USA-645
Hernando, Florida
"There's not enough rum in the drum"
--

MillCreek

Allow me to make a suggestion. What if you contacted an insulation contractor in your area that does liquid injectable insulation They could stick the gun through the inspection hole and shoot certain amounts.

This sounds like a really bad idea.

I doubt if expandable insulation foam is particularly light, and it will absorb water over time making it even heavier. Also it would end up filling up from the bottom of the hull creating a dam so that any water that gets into the hull forward of the foam dam impossible to remove.

--
Damon Linkous
1992 Hobie 18
Memphis, TN

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