1,100 lb bag question

[DOCDRS]

I'd like to see the comparisons too. I wish somebody had photos of the 750 vs. the 1100 in the LSV. I would think you'd have to add more weight up front to really improve it. Stacking that much in the corner would make it taller but a little more up front should lengthen it too. At least I know that Daze and Cab will get it dialed in for me and I just have to copy them.

I have 750 as well as 1100, but it will not be till April that a pic will be taken........ For some reason every one likes to sit on the starbord side of the boat and they get ticked when ever I ask them to move to the port side , so I only need the 750 on that side???? plus they are usu only 100 lb girls and not much good for ballast......... Are you asking me to move because you think I am fat?.......boy some people are just too sensitive.

[bergermaister]

Surely you guys have seen this sticker...



I migrated from a 400 in the rear and 750 in the belly to a 750 in the rear and 400 in the belly to 750 in the belly and 1100 in the rear. Yes, the 1100 is much steeper and you definitely need to add weight to the front to get some length. A lot of times I"m out with only a few people or a handful of kids so I don't have the option of telling people where to plant their butts.

I wish I had some photos to show the comparison of this migration but we were too busy having a good time. I did post some photos on the forum (gone now) of the 1100 the first time out with it as I was shocked at the difference in size of the wave.

By next summer I'm hoping/planning to have an 1100 on each rear side, a 750 in the belly, an additional 750 on top of the basement, and two 400's on the side or to throw around with a bunch of Tsunamis filling and draining. Will be doing a lot of experimenting in search of the perfect wave...

[you da man]

I totally disagree with this idea, and you are kidding yourself if you think this is true. JMO nothing personal. Yes it would if the bag actually had some substance to it like a rigid container but it does NOT! The pressure of water is directly proportional to the height or column of water. no matter how you place the bag is totally irrelevant to the pressure exerted on your engine divider wall. This is plain simple physics! The greatest pressure will be at the bottom hinges and a reinforcing metal angle piece should be added between the 2 hinges as well as longer screws....at some point you may even want to thru drill your hinge screws thru your engine walls and thru bolt them as again this is where the most pressure will be.

When my boat is leaned over, the sac is not sitting level. You can try it with a loosely filled water balloon. Fill it, sit it on a flat surface and tilt that surface 10-15 degrees and see how the balloon deforms.

[DOCDRS]

When my boat is leaned over, the sac is not sitting level

I totally agree less with boat listing, but the height of water in the area directly above the hinge is what determines the force( in all directions ) at the hinge or along the floor / engine wall. there is no reduction due to an apparent leaning of the bag. Yes the more the boat leans the less the force, but when compare a 400 lb bag to an 1100 bag the force exerted on the vall at the area of the hinge and thus the entire area of the wall is 66% greater. That is assuming that the bag is not overfilled at all.
The pressure at the hinge area is .577 lbs per square inch vs .866. Less (but still proportional) to any listing of the boat. If there is any expansion of the bag upwards , due to excessive filling then the force will be great increased depending on the pressure that the filling pump can exert. I think this is where one can increase the force imensely on the engine wall.

Plus this force will be increased if a cork is used to prevent bag emptying , or if the discharge/vent line is on the opposite side of the boat.

so if we take a 36x24 engine wall the amount of force is equivalent to about 378 lbs sitting on it 1100 lb sac , vs 166 lbs for the 400lb sac. A considerable difference!!!.....but that is level a 10 degree list would result in 10% less weight.... roughly

the bag deforms but that has nothing to do with water pressure and pressures exerted

[you da man]

My only real concern is the 1100 sloshing on rollers so that's why I need to re-enforce. I'll probably do it over the winter.

[you da man]

I totally agree less with boat listing, but the height of water in the area directly above the hinge is what determines the force( in all directions ) at the hinge or along the floor / engine wall. there is no reduction due to an apparent leaning of the bag. Yes the more the boat leans the less the force, but when compare a 400 lb bag to an 1100 bag the force exerted on the vall at the area of the hinge and thus the entire area of the wall is 66% greater. That is assuming that the bag is not overfilled at all.
The pressure at the hinge area is .577 lbs per square inch vs .866. Less (but still proportional) to any listing of the boat. If there is any expansion of the bag upwards , due to excessive filling then the force will be great increased depending on the pressure that the filling pump can exert. I think this is where one can increase the force imensely on the engine wall.

Plus this force will be increased if a cork is used to prevent bag emptying , or if the discharge/vent line is on the opposite side of the boat.

so if we take a 36x24 engine wall the amount of force is equivalent to about 378 lbs sitting on it 1100 lb sac , vs 166 lbs for the 400lb sac. A considerable difference!!!.....but that is level a 10 degree list would result in 10% less weight.... roughly

the bag deforms but that has nothing to do with water pressure and pressures exerted

Quite the physics lesson.

[DOCDRS]

My only real concern is the 1100 sloshing on rollers so that's why I need to re-enforce. I'll probably do it over the winter.

wow I never even thought of that, going from a + 15 degree list to a -15 degree list would increase the weight on the board another 30 % over the already 50 %.....wow.......but i was using a level starting point

so in reality, using a 15 + to 15- list then it would be 15% on top of the 24 inch height so another 3.6 inches or 27.6/12x.433x36x1.8=64.5 lbs more on the wall, or a true 442 lbs at -15 vs 321 lbs on it at a +15 degree list which are realistic numbers. if you wanted to know


Oh did I tell you i love physics....but more importantly numbers

[dusty2221]

So basically, reinforce....lol. Just to be safe. I like the KISS method.

[moombadaze]

wow I never even thought of that, going from a + 15 degree list to a -15 degree list would increase the weight on the board another 30 % over the already 50 %.....wow.......but i was using a level starting point

so in reality, using a 15 + to 15- list then it would be 15% on top of the 24 inch height so another 3.6 inches or 27.6/12x.433x36x1.8=64.5 lbs more on the wall, or a true 442 lbs at -15 vs 321 lbs on it at a +15 degree list which are realistic numbers. if you wanted to know


Oh did I tell you i love physics....but more importantly numbers

um, what did you say? oh I get it now--the wave is steeper/larger, the panel needs reinforced