10 minute "no mod" ballast tank vent mod

[mastreb]

There's a classic Mac mod I've been considering for years wherein the ballast vent is run to the anchor locker so you no longer have to plug and unplug the vent hole. The problem with it is that it removes the vacuum pressure that helps to keep ballast in the boat, as the gate valve is not a 100% seal. But getting up under the forward v-berth every time you launch and retrieve is a hassle, so I've wanted to do it but I'm also pretty lazy and I wanted to preserve the ability to plug the vent. But going up to the anchor locker is no easier than going up to the V-berth.

So it finally occurred to me that I could just run the vent hole back to the transom. This mod took about ten minutes to install and doesn't involve any real modification to the boat, it preserves the plug-ability of the vent (including the original plug) and takes it back to the transom right next to the gate valve, so you can easily open and close both the tank and the vent at the same time.

After installing, I tested the vent hole as I dumped ballast at a steep launch ramp. Sure enough, plugging the ballast reduced the firehose pressure down to an thin and insconsistent gurgle as air bubbled into the tank, and opening it restored the gusher. You could feel with your hand the strong intake and outtake pressure when the tank filled and vented.

Finally, there's no more "tank smell" in the cabin when the tank fills at all.

I wrote it up in the mod section here: http://www.macgregorsailors.com/modt/in ... ?view=1884

[kurz]

looks cool. I'm shure, next year you will go on puting the plug 1meter higher, and also a remote for the big valve, so you do not have to go down to the motor...

The only problem I see when you do not have the original plug in the v-berth: You cannot unplug it and CONTROL how much water in the ballast tank is. But this would be easy to install, just by drilling a second hole

[raycarlson]

Why would you want to adjust amount of water in ballst tank??? It should either be full or empty,only two choices.......

[seahouse]

A really good one Matt! I'll be "stealing" that one , thanks for posting it.

I might be inclined to put a (ball, or similar) valve at the transom, to avoid having to deal with the plug.

It's probably worth pointing out to future adopters of this mod that too much suction when draining ballast when the temps are high and the tubing soft might tend to collapse the tubing, particularly if there are any kinks along its route. So the careful choice of tubing material (and thicker-wall) is noteworthy to prevent slow draining under certain conditions.

-Brian.

[Azzarac]

Chameleon has a similar system for the front vent, however our vent is run up the bow with reinforced vinyl tubing and controlled with a ball valve.


It is then vented from the starboard side:


Fair Winds,
Capt. Azzarac
Chameleon
Follow Chameleon's travels at: http://svchameleon.weebly.com/

[mastreb]

looks cool. I'm shure, next year you will go on puting the plug 1meter higher, and also a remote for the big valve, so you do not have to go down to the motor...

The only problem I see when you do not have the original plug in the v-berth: You cannot unplug it and CONTROL how much water in the ballast tank is. But this would be easy to install, just by drilling a second hole

Yeah, once I'm better at drilling holes in the boat I'll move it up. And I've already got the tank valve extension remote handled from another Valterra gate valve, so you called that

[Crikey]

Doesn't anybody do 12v stuff anymore? The RV world is full of it.

[BOAT]

A 12 volt solenoid valve for the bow vent, and as for the transom gate I do already have a 12 volt operated gate on the holding tank in the little Sprinter motorhome I use to tow 'boat'.

I really think a 12 volt gate valve on the transom is overkill thought. A solenoid in the bow would make some sense, but Mathews MOD is SO easy breezy I must admit it's pure genius.

I will be doing that mod immediately Matt!

By the way, there is a hole already on the other side of the well in the same place as the steering plunger on the opposite side. You think i could use that for the hose?

I'm also sending you a PM about beer this week.

[Berber Boy]

The problem with it is that it removes the vacuum pressure that helps to keep ballast in the boat, as the gate valve is not a 100% seal.

I have the mod with the breather tube going up to the anchor locker drainage pipe and have never noticed any loss of ballast. Is this common overtime and how do you check on it? Timing the outflow seems to vary with the degree of slope on the ramp so not a very reliable measure. I do use a plumbers vegetable based grease on the rubber gasket about twice a year that seems to keep it in good condition.

Dave

[mastreb]

The problem with it is that it removes the vacuum pressure that helps to keep ballast in the boat, as the gate valve is not a 100% seal.

I have the mod with the breather tube going up to the anchor locker drainage pipe and have never noticed any loss of ballast. Is this common overtime and how do you check on it? Timing the outflow seems to vary with the degree of slope on the ramp so not a very reliable measure. I do use a plumbers vegetable based grease on the rubber gasket about twice a year that seems to keep it in good condition.

Dave

You probably have no appreciable loss of ballast. I really don't know how much the vacuum pressure is important to keeping ballast in, but I was warned by the factory (Mike Inmon) that it was important when I mentioned the anchor-locker ballast vent mod. Much of their advice is based on maximum safety for liability reasons. Like everyone, I've sailed with the ballast plug out and spilled a few gallons of ballast water into my bilge. Doesn't seem to affect much if the gate valve is working correctly.

Probably the vacuum plug is just a good backup for eventual bad seals on the ballast gate valve.

[mastreb]

By the way, there is a hole already on the other side of the well in the same place as the steering plunger on the opposite side. You think i could use that for the hose?

I have no such hole, so I can't say. If it'll accomodate a 3/4" hose, I suppose it would work although you'll have to go underneath the steering bars and loop back up. I kind of like going through the cableway because this hose serves to "fill it up" so it won't accept as much splashed water into the bilge.

Matt

[BOAT]

Crap, I can't find a 3/4 by 3/4 that is a Barbette. They give me 5/8OD by 3/4 IN MIP - That would take a 3/4 OD x 5/8 ID hose and I think that is too small. (Crap! )

Matt, where did you get the stuff? I will go shopping at the same place cuz my home depot and lowes does not seem to have the right stuff.

[Crikey]

It's one thing dealing with the venting and confinement of spillage, but aren't we really talking about the speed of the whole operation?
Doing some recent work I was following this thread, and got to wondering about the space that is the subject of our concern.

On my this appears to be a pretty wide and deep chasm. Lots of room to slosh about!

What if you took two of these:

and mounted them symmetrically? Would it halve the drain and fill rates? Not all have outboards large enough to plane - would it better enable draining at low speeds?
I was thinking in the context of a pair of solenoid operated Valterra's, where I could see the open/closed status on the pedestal, and not have to worry about neglecting one or the other.
R.

[Berber Boy]

Thanks Mastreb. That makes sense. Our increasingly litigious societies (Oz is following the US in this) means companies sometimes go over the top in their risk management of corporate liability. 'CYA' Rules the day!

Dave

The problem with it is that it removes the vacuum pressure that helps to keep ballast in the boat, as the gate valve is not a 100% seal.

I have the mod with the breather tube going up to the anchor locker drainage pipe and have never noticed any loss of ballast. Is this common overtime and how do you check on it? Timing the outflow seems to vary with the degree of slope on the ramp so not a very reliable measure. I do use a plumbers vegetable based grease on the rubber gasket about twice a year that seems to keep it in good condition.

Dave

You probably have no appreciable loss of ballast. I really don't know how much the vacuum pressure is important to keeping ballast in, but I was warned by the factory (Mike Inmon) that it was important when I mentioned the anchor-locker ballast vent mod. Much of their advice is based on maximum safety for liability reasons. Like everyone, I've sailed with the ballast plug out and spilled a few gallons of ballast water into my bilge. Doesn't seem to affect much if the gate valve is working correctly.

Probably the vacuum plug is just a good backup for eventual bad seals on the ballast gate valve.

[mastreb]

Crap, I can't find a 3/4 by 3/4 that is a Barbette. They give me 5/8OD by 3/4 IN MIP - That would take a 3/4 OD x 5/8 ID hose and I think that is too small. (Crap! )

Matt, where did you get the stuff? I will go shopping at the same place cuz my home depot and lowes does not seem to have the right stuff.

West Marine