PDA

View Full Version : question about ballast?



mutau052
05-23-2010, 11:55 PM
I've been looking at buying a OBV with the gravity III ballast system. I really like to surf and will put a 750 in the glove box side rear immediately.

because it is almost double the size + the residual static weight why not just hit the switch twice to fill it up, that way when we want to board we can just hit it once and fill it to 400lbs. on each side.

Maybe this is just the engineer in me looking to make things easier, has anyone tried this?

mmandley
05-24-2010, 12:13 PM
The Engineer in your is correct in your rational thinking. The problem is some one else with there engineering idea rationalized this system.

When you hit the switch to fill a 400 bag, it doesn't shut off at 400. It really doesn't care what size bag is there because it runs for a predetermined time. Not a fill amount.

Time this predetermined time down to 400 and you can use your idea of hitting it twice.

mutau052
05-24-2010, 02:50 PM
The Engineer in your is correct in your rational thinking. The problem is some one else with there engineering idea rationalized this system.

When you hit the switch to fill a 400 bag, it doesn't shut off at 400. It really doesn't care what size bag is there because it runs for a predetermined time. Not a fill amount.

Time this predetermined time down to 400 and you can use your idea of hitting it twice.

I take that when it over fills it just vents to the outside of the boat? And at that point can you switch it off without draining it? So is the drain on a timer too?

cab13367
05-24-2010, 03:39 PM
I've been looking at buying a OBV with the gravity III ballast system. I really like to surf and will put a 750 in the glove box side rear immediately.

because it is almost double the size + the residual static weight why not just hit the switch twice to fill it up, that way when we want to board we can just hit it once and fill it to 400lbs. on each side.

Maybe this is just the engineer in me looking to make things easier, has anyone tried this?

I don't see why this wouldn't work if you have the timing down to where it shuts off just about as the 400 fills.

Do the new systems have a vent line? I guess they would almost have to to prevent bags from exploding (or fittings from popping off, more likely). I know they fill and empty using the same pump and thru hull.

mutau052
05-25-2010, 10:29 AM
So do the 09 and newer outback v's have vent lines from the ballast to outside the hull? On the rear bags?

mmandley
05-25-2010, 11:29 AM
I take that when it over fills it just vents to the outside of the boat? And at that point can you switch it off without draining it? So is the drain on a timer too?

The 08s all have a aerator pump stock and then holds the pressure till the bag is full. Then it allows water to pass by it and leak out the drain fitting. This tells you the bag is full.

As for the new boats i haven't looked at there ballast systems to see exactly how it works and differs.