Balsa core how afraid should I be?

shoker

Lieutenant
Joined
Nov 21, 2012
Posts
98
Likes
89
Any and all info, the good the bad and the ugly would be very much appreciated. I have been doing a lot of research and always reading posts on here about different building techniques and what I should be aware of when looking at a boat. What specifically should I be looking for as far as water intrusion on a balsa hull? Should deletions around through hulls and transducers be noticeable? I am leery of a wood hull after reading some horror stories. Again any info would be a great help.
Thanks
 

F/V First Team

Admiral
Joined
Jan 10, 2012
Posts
6,146
Likes
2,481
Location
Narnia
Website
www.otisenterprisesmarine.com
Boat Make
Northern Bay 36 - Modified
Any transitions from a cored hull laminate to a solid glass one should be quite noticeable. If there is no seam or buildup where these hull penetrations go, well I'd be quite leery of that.

Done right, and used properly, cored hulls are alright. It's when impacts occur that damage the exterior skin and allows moisture to work its way into the core material - be it balsa, foam, etc. From here there are a number of things that can happen, most often it rots the balsa core. But even in PVC core the water can get in there, freeze (in colder climates), expand and then allow more water to come in next time the boat is put into service, which then freezes and expands again, keeping the wonderful cycle going. Rotten balsa also makes this happen since more and more water can get between the skins and start pushing.

Can it be fixed? Absolutely. Is it a hassle? Absolutely. Can you do it yourself? Absolutely.

I would much rather have a cored hull over a glass-over-wood hull and put up with some bits and pieces of spotty core material. That is if a solid glass hull was unavailable. Those are my favorite. Nice and straight forward.

I hope this has answered more questions than it created. If not, let me know where to expand on explanations.
 

Toolate

Admiral
Joined
Aug 6, 2013
Posts
6,379
Likes
2,298
Location
Southwestern CT
First Name
Ben
Boat Make
1998 36' Sabre Express CAT 3116TA's, 2015 ROS Scotia 16 Etec 50
I have heard that they are quieter in a pounding sea with less vibration?

Fixed a bit of it in the past and it really is easy if you can fiberglass. Check with moisture meter- all over.
 

CEShawn

Vice Admiral
Joined
Sep 21, 2011
Posts
3,325
Likes
1,224
Location
Cape Cod, MA
Boat Make
Downeastless
I do not think I will buy another hull that does not have a core. Correct me if I am wrong but just the freaking hull sweating issue, the rigidity and swear it was quieter. Sure you can take care of the sweating with the carpet pads etc, but just seems like a pain. The hull can be strengthed with a proper v-berth. I know I just lay in the bunk at 7 knots running out and I watch the side move, feel it against my back and then with going down to high 50 degree water then 74 and back seeing the moisture issue.

Next boat will be cored, miss it from my others and did not mind dealing with it.
 

Toolate

Admiral
Joined
Aug 6, 2013
Posts
6,379
Likes
2,298
Location
Southwestern CT
First Name
Ben
Boat Make
1998 36' Sabre Express CAT 3116TA's, 2015 ROS Scotia 16 Etec 50
You ventilating with something special or just leaving hatches open? I mean a solar fan thing or something like that. Had one of them on every boat and it makes a huge difference.

I would think a hull would sweat more in a compartment like under a v berth where it stays a little cooler for longer too. Not sure how you ventilate that.
 

CEShawn

Vice Admiral
Joined
Sep 21, 2011
Posts
3,325
Likes
1,224
Location
Cape Cod, MA
Boat Make
Downeastless
See this is something I need to understand... Wondering too, does it come from me just laying against the hull and the water being 55F on the other side? Idea's on more ventillation? Some of those Vetus mushrooms?

What was I thinking about when people talked about glueing carpet with special backing to the hull to prevent this? Thanks for your help...
 

F/V First Team

Admiral
Joined
Jan 10, 2012
Posts
6,146
Likes
2,481
Location
Narnia
Website
www.otisenterprisesmarine.com
Boat Make
Northern Bay 36 - Modified
The majority of sweating issues, at least the ones I encounter from other people, are below the deck. Where that engine space gets super-heated from the engine being run and then cools off since that part of the boat is in water and excess trapped moisture in the compartment adheres to the surface of the interior skin of the hull. If you design the boat so that air moves evenly below deck you wont have pockets of stagnant, moisture-rich air to leave droplets.

Think of it like a cold glass of lemonade (pink if that's what you prefer) outside on a hot humid day.

I don't have anything special up forward and that area doesn't sweat, but then again it doesn't get a heavy amount of moisture-rich air up there either.
 

Toolate

Admiral
Joined
Aug 6, 2013
Posts
6,379
Likes
2,298
Location
Southwestern CT
First Name
Ben
Boat Make
1998 36' Sabre Express CAT 3116TA's, 2015 ROS Scotia 16 Etec 50
Good point- was dreaming the other day about a solar powered bilge blower that could just be on at all times- very low cfm but some anyway. WOuld help everything on a boat- keep bilge dryer and def help with sweating. Just dreaming.
 

CEShawn

Vice Admiral
Joined
Sep 21, 2011
Posts
3,325
Likes
1,224
Location
Cape Cod, MA
Boat Make
Downeastless
I do really like that disc heater for $50 from West Marine, I use that except when out on the water as its 120vac. Really makes a difference...
 

hntrss

Rear Admiral
Joined
Feb 17, 2012
Posts
1,064
Likes
447
Location
Oceanside NY
Boat Make
31 Duffy
th
I had one of these in the escape hatch on my 35rp. Moisture was very rarely an issue, unless it was foggy/rainy. In normal conditions it worked perfectly. My hull never flexed either. She too was solid glass. Nicro solar powered vent. Never leaked a drop.
 

jawz

Lieutenant Commander
Joined
Sep 3, 2011
Posts
149
Likes
52
Location
cape may nj
Boat Make
23 sea craft - 31 bertram
those vents are an excellent idea - provided the space you're attempting to ventilate is somewhat open...meaning: that parker - the fuel cell area,it's sealed,and foam filled-water will find it's way in through that deck plate - inexperienced people will believe that deck plate is waterproof - experienced people know otherwise...



coring:

balsa coring,it's not a problem if it's sealed - but,that's the problem right there...through hulls - ANY through hull that core needs to be removed at least a few inches beyond the largest portion of the through hull - this area should be filled with an epoxy mix - key word there is "epoxy"...if the area is too large,build that area out with alternating layers of matting and cloth to build to required thickness...

composite coring can be a problem too,if not sealed properly...
 

shoker

Lieutenant
Joined
Nov 21, 2012
Posts
98
Likes
89
Thank you guys for all the great info, I love the knowledge on here.
 

jawz

Lieutenant Commander
Joined
Sep 3, 2011
Posts
149
Likes
52
Location
cape may nj
Boat Make
23 sea craft - 31 bertram
The fuel tank area on my boat has clear opening where the fuel lines and wires pass over bulkheads into the bilge plus area around the sides where the vent an fill lines pass through, plenty of area for air to move.

Since I installed that vent, the small standing water that collects in the bilge evaporates after a few days, so I would say a win win over just letting the deck plate leak.


the picture - that's the fuel cell area on a parker...note the foam on both side of the stringers ?? the deck sits on those stringers...the aft bulkhead is indeed cut,to allow fuel lines to pass - the bulkhead's plywood,the hole isn't sealed,it's drilled through with a small hole saw - no chafe protection either...
that fuel cell area,it's sealed,meaning,if water leaks through either one of the deck plates on the deck,that water remains in that area - deck plates leak...take note of that picture - the "grey areas" - that's foam,which was supporting the tanks,and the grey,is the cheap enamel paint the tank manufacture uses on the tank's surface...
that's water,water that's leaked in the area through the deck plates - the foam that was surrounding the tank,it's been removed to allow removal of the tank - that foam was completely waterlogged...the boat,it's was sitting on land for approx. 5yrs,before I began repairing the structural problems - dry rotted stringers,dry rotted decking,dry rotted bulkheads,you get the picture here,yes ??

will ventilation help ?? it can't hurt...but,will it dry the entire area ?? you tell me ;) that's basically a sealed area,not much of an air flow is gonna take place in there,and,as far as the bilge is concerned,only opening is a hole approx. 1- 1 1/4" diameter,that connects the bilge to the tank cell area...

this is the third parker I've cut apart to perform major structural repairs to - everyone,has had similar poor construction techniques used by the factory - including the use of iron nails holding unprotected plywood together...
I believe you follow my business facebook page,yes ?? you've seen the pictures,and I believe you made a few comments on them,yes ??

sorry for the side track here guys...

539287_10151137423709690_1182593870_n.jpg
 
Top Bottom