I need course buoys with the inflation port at the bottom

[Mastercrafter]

As the title says, looking for round buoys (boat guides and turn balls) with the air inlet as close to the bottom attachment point as possible.

 

Working on a submersible course idea. I read that Polyform buoys had this, but I ordered one and it’s basically centered on the side. Any thoughts?

[PatM]

I don't know what your idea involves with submersing the course, but keep in mind that buoys will still float deflated.

[Mastercrafter]

@PatM Yup, with any air, they float. Totally vacuumed out, they're about neutral but do sink.

 

I'm planning on a 1lb weight 3-4' below the buoy on elastic, to keep everything pulled down. We don't have enough depth for a sinker course so I'm trying to come up with the next best thing.

[Andre]

All the bouys i ever bought had all the inflation port on the side...

[BraceMaker]

Years back I posted a concept where you would basically build buoys like a jellyfish. They would be fully open on the bottom and have a small port on the top to bleed off air. Under water would be something like a 5 gallon bucket with the bottom cut off, a rubber bladder would be stretched onto the bottom of that bucket to form the "ball"

 

Being a "jellyfish" when you pumped air into the bottom using something like a Gast rotary vane pump something capable of high volume at low pressure these would rise up to the surface where they would gently hiss air through the port in the top.

 

Once the pump shut down these would sink back down to the bottom. Properly engineered the item should be somewhat less than neutral bouyancy with the upper half floating better than the bottom half so they'd stay upright, and the air port would be sligthly into the bucket portion so it would always inflate.

 

Ideally this would be done on a portable so the air hose could be zip tied along the booms and mainline, with weights added every few feet along the air hose to offset the buoyancy.

 

Unlike wally these would always blow clear as any water would eventually be pushed out of the line and start bubbling. I would use some small check valve at each ball so that water didn't want to flood the air hose.

 

Final item is that since the item would have a fully soft top that if struck would blow the air out of the bottom these would work like bubble bouys for ankle safety.

[dave2ball]

@Mastercrafter check out Wally skier. I believe they have what you are looking for.

[BraceMaker]

@dave2ball I think he's envisioning running an airline to the ball itself.

 

The old accufloat system had these plastic chambers below the balls that basically were sinkable subbouys and would offset the floatation of a fully inflated turnball.

 

Wally took the idea and split the bladder and the ballast into 2 separate bags, an advantage because if say one ball was in 30' of water, and another in 10' you could hang the ballast bag 20' lower on the 30' side and then the whole course drops relatively level. Also wally uses flexible bladders for the floats so you can vacuum out the air and also this means you can also vacuum out the water that might leak in.

 

But none of these actually change the inflation of the ball itself which is usually molded with an inflation needle port. My guess is to do what he really wants to do the ball needs an inflation port more like a set of children's arm floats that can actually flow a volume of air. instead of a needle inflation hole.

[Mastercrafter]

Bracemaker, more or less.

 

The needle actually flows enough air, wont be instant but not really an issue. Biggest issue is getting the port near the bottom so the air like isn't sticking out the side.

[DavidN]

You could easily retrofit regular course buoys with bolt on valve stems.

Punch a small hole in the bottom of the ball, push the valve stem in, secure with rubber washer and nut from the outside, attach air hose.

As the pressure would be very low I don’t see any issues with popping out the stem when inflating. Just an idea …

 

 

[BraceMaker]

They sell replacement valves for balls. I just doubt that ski balls have enough body to hold one anywhere else on the ball.

 

I have this antique tool to install tire stems onto inner tube and its sort of a heat vulcanized but I don't think it would work on a ski ball either.

 

https://www.amazon.com/Inflation-Replacement-Valves-Removal-pumpuptheball/dp/B0793G6TW7/ref=mp_s_a_1_3?keywords=pumpuptheball&qid=1646786305&sr=8-3

[Mastercrafter]

It sounds like Wallys buoys have the filler right near the bottom. Going to order one and check it out.

[swbca]

@Mastercrafter Most of the standard skier balls have a thickened area around the rope connection loop. If you found a ball where that thickened area was large enough, it would probably durable enough to hold the valve.

 

Re the Wally buoy, they are designed to have pressure not much greater than atmosphere. This might play into your inflation system's controls. And it would reduce the amount of time to sink the course (less air). I assume you will have a larger trunk-line tube from shore to the opposite end of the course, so it doesn't offer resistance to the passive deflation process. Lance in Minnesota used 1/2" ID tubing from shore and down the center for inflating the 42' long bladders in each 2" aluminum tube holding the gates and skier ball. On his site its about 400' to the nearest green gate.

[BraceMaker]

Be interesting to get balls made with a reinforced hole to just shove them over a barbed fitting with a bit of soap.

 

That barb would be into a length of surgical hose and that would be your connection to the course instead of a rope to a hose to a clip.

[Mastercrafter]

I think physics is going to get me on this, in order to push air 5 feet underwater I need about 2.5 PSI, and I think that'll about explode a buoy once it pops up to the water's surface, much like a scuba diver's lungs exploding if they don't exhale coming up.

 

I'll continue the experiment but I'm not super optimistic.

[swbca]

@Mastercrafter Regarding the balls over-inflating at the top. Use a pre-charged pressure tank with the correct size and initial pressure to dissipate while the buoys are rising. Only use the compressor to pre-charge the tank. The tank can be calibrated to leave you with only .5 pounds of pressure when the ball reaches the surface, so it isn't over-inflated. Find a good pressure switch that is consistent enough to accurately fill to your specified pre-charge level.

 

Speaking relatively, its better if the pressure tank is small and pre-charged with a high pressure, so the course float speed is not too slow at the start, and to reduce the affect of temperature on air expansion in the tank when its terminal pressure in only about 1/2 pound (or whatever you need to inflate the ball to firm at the top.)

[skierjp]

Polyform boat lane buoys have the valve on the bottom. The cylinder ones not the round ones

[BraceMaker]

@Mastercrafter that was also part of the nature of my "jellyfish" buoy idea, because its a totally open system the air displaces the water and the system raises.

 

The "swim cap" of a turn ball acts like a goode bubble bouy saving your ankles if you peg the ball.

 

A small blow hole leaks the thing down so it doesn't take much air volume to sustain it just maybe a small pancake compressor or air pump like they use to aerate ponds and septic tanks.

 

 

Biggest thing is figuring out what to use as a swim cap that wouldn't need to be custom made.

 

 

[swbca]

@Mastercrafter When you get this figured out, I might do the same thing on the course I currently have installed with subbuoys, rather than completing the original plan that you have seen on paper. All the airlines could be at the bottom of the lake, safe from all the anchor lines and fishing lines used on our lake.

[BraceMaker]

Gosh thinking about this you could literally cut the U off the bottom of a turn ball, take like 1" PVC Pipe about 6" long, then you could glue a pipe cap onto one end of that PVC, Drill a hole into that.

 

Run your airline up to the bottom of the PVC (maybe use a barbed fitting on the PVC) take used popped or abused turn balls, cut off the base, put over the PVC, zip tie it.

 

Boom you have a bouy with a rigid component that's 1" PVC that burps out the bottom when it hits whatever rate of inflation. you could adjust how big the ball gets when inflated at X pressure by drilling more small holes in the PVC pipe.

 

Again ball gets some small pinhole leak to sink it eventually, then you figure out to get the amount of total pressure in the ball to inflate it to approximately the right diameter eventually requires you to drill 4 1/8" holes in the PVC as vents

 

 

[VONMAN]

@Mastercrafter is the set-up for Walled Lake? If is is I don't think between the weeds and the depth you will be fighting a losing battle.