26m during winter on the lake... Danger with through hull?

[kurz]

Hi
When the boat hibernates in the water and freezes over the lake. Is there a problem with the through hull on the ?
Actually, I think it should not get a problem. Because there's no valve. In this way, no valve can burst when freezing. But the ice simply presses itself inwards or outwards the tube.
Am I right about that?

Anyway, I've never had any problems with it for the last five years. Even with frozen lake.
But I have to worry a little bit...

thanks for inputs - kurz

[Catigale]

All the stock through hulls are above the water line, do hard to see how could be damaged

[kurz]

All the stock through hulls are above the water line, do hard to see how could be damaged

The stock through hull from my is in the water. Not too much, for sure enough to be in the water 100%. I did not change anything.

[BOAT]

You guys remember that electric valve I put on the ballast vent? Well, I plan on putting something on the thru hull too. I want to be able to throw a switch and slam that valve shut. A big - brass - heavy - BALL valve. And I want a handle on it too so I can open and close it manually too.

Just yesterday i was surfing the web looking for a good marine electric thru hull ball valve - if you guys already have knowledge or experience please advise me. Otherwise all I have to go by are the old Naval specs in my old library on Naval Architecture and Electric Boat Builders.

kurz brings up only one of the many problems I have about the thru hull in the back of the boat - water getting in that plastic loop between the motor well and the thru hull and freezing and bursting the hose is just one of them. There is also:

A leak in the hose
A hose coming off

And my all time most hated - trying to get back there to repair it in a emergency. It's just too dang hard to work back there. And I need to put in a holding tank so that means I will be pumping out my grey water UNDER PRESSURE out that thru hull when my sump system is all installed. I don't trust those fittings to hold up under pressure so if I am going to replace all the hoses anyways why not put in a valve I can close and also prevent 99% of all the other issues that could happen?

The other issue I have is CALIFORNIA! There are a lot of places now where they will give you a ticket if they see ANYTHING coming out of your thru hull fittings. (The Peoples Republic of California is getting so bad that the only people I talk to anymore that understand me are Russians, Iranians, and other peoples living under a communist, fascist, or dictatorial regime). So I need to take steps to protect myself from the authorities.

[Highlander]

U can always plug it from the outside with an emg. Plug made from a wooden dowl. I do that every spring then fill the motor well with water & then check for leaks inside the rear bilges usually leave it filled for a couple of days then recheck the inside bilges again
But it would not be hard to plug it pernamently then install a new one above the water level mine is about 1" below the water line with ballast tank full
J

[paula_ke]

Hi Highlander! I tried to find another way to contact you. I have a question regarding your double axle spec. It indicates a 'V Bend". I ordered one up form Six Roblees but they were questioning that. If you have a moment, could you contact me? (my email should work on the board.)

Paula

[Highlander]

Hi Paula
I received ur E/M & as I said I'll gladly help u out when I get back home

J

[yukonbob]

You guys remember that electric valve I put on the ballast vent? Well, I plan on putting something on the thru hull too. I want to be able to throw a switch and slam that valve shut. A big - brass - heavy - BALL valve. And I want a handle on it too so I can open and close it manually too.

Just yesterday i was surfing the web looking for a good marine electric thru hull ball valve - if you guys already have knowledge or experience please advise me...

Groco makes an electric ball valve. Groco’s are generally the gold standard and having bought ten complete sets I can say they are solid and it’s a shame they’re going to be hidden.

[Russ]

I'd be less worried about the thru-hull that is technically above the water line freezing. Mine is underwater when the boat is full (ballast, people), but well above when light.

What I'd be afraid of is ice damage to the hull. Do you have a bubbler system?

U can always plug it from the outside with an emg. Plug made from a wooden dowl. I do that every spring then fill the motor well with water & then check for leaks inside the rear bilges usually leave it filled for a couple of days then recheck the inside bilges again
But it would not be hard to plug it pernamently then install a new one above the water level mine is about 1" below the water line with ballast tank full
J

This one looks cool.

[BOAT]

Yeah, those are all nice an' all but really - the whole aft thru hull is not really up to Naval Specs according to my old books.


Dad's old Naval Specs book says there is supposed to be a vented loop:



And a cammed anti back flow pump for pumping the holding tank is also nice if there is any possibility of sea water filling up the holding tank:



But AT THE LEAST there should always be these vented loops on all thru hull fittings:



The Groco electric valve units are great but I can't find one for less than 1800 dollars for a 3/4 inch electric and I think that's not warranted since I got my 1-1/4 inch for only 188.00 dollars that I have on the bow vent. I know how to add a handle to the unit I used on the bow vent so I think I will use one of those in 3/4 inch.

The way they did the thru hull from the factory is wrong according to the drawings in my dad's old Navy books - that's all I have to go on.

[yukonbob]

Yeah, those are all nice an' all but really - the whole aft thru hull is not really up to Naval Specs according to my old books.


Dad's old Naval Specs book says there is supposed to be a vented loop:



And a cammed anti back flow pump for pumping the holding tank is also nice if there is any possibility of sea water filling up the holding tank:



But AT THE LEAST there should always be these vented loops on all thru hull fittings:



The Groco electric valve units are great but I can't find one for less than 1800 dollars for a 3/4 inch electric and I think that's not warranted since I got my 1-1/4 inch for only 188.00 dollars that I have on the bow vent. I know how to add a handle to the unit I used on the bow vent so I think I will use one of those in 3/4 inch.

The way they did the thru hull from the factory is wrong according to the drawings in my dad's old Navy books - that's all I have to go on.

I said they were awesome, not cheap!
I think you’d be hard pressed to get a proper vented loop at the transom or that doesn’t interfere with the steering, but a good quality check valve will suffice.

[BOAT]

check valve? what is "check valve"?

[Russ]

Vented loop works if you are pumping. The Mac drain is gravity fed. And with that it sometimes has issues. My sink won't drain well on the trailer if on a hill.

[yukonbob]

check valve? what is "check valve"?

Let’s water out but not back in. Pretty common for fuel, water drains etc. Low operating psi (think gravity fed drain) to open any back pressur closes. Many different styles and pressure ratings and many materials.

[kurz]

BOAT, I don't think you are right with your illustration and that ALL THROUGH HULLS have to be vented.
Your illustration says that when the tube inside end in the boat is deeper than the through hull the system has to be ventet. Becouse water can travel from the higher level to the deeper, there you have a danger. But as long the tub ends inside the boat 1meter higher in the sink - nothing can happen. What is proved by the thousends of macs....


Also we never read about a problem with a frozen through hull with the Macs. Also there maybe a reason that it has to work in stock style. I'm shure Roger was tinking about the sistem.

Many problems you can bring in the system with a valve, as it sometimes not so simple to get all the water out. --> freezing --> damage.

But still I'm worring about it...