camera rig buoyancy help, I'm 2.85lbs negative

[sentiens]

[FONT=tahoma, verdana, arial, times]Archemedes' principle states that an object immersed in a fluid is buoyed up by a force equal to the weight of the fluid displaced by the object. The weight of a fluid is equal to it it's density times it's volume times gravity.

That's just for fun I am looking for creative ways to neutralize my -2.85lbs. I have a recsea s100, tray, two ys01 strobes and 4, 5" arms for the strobes as well as two handles. Measured in a dunk tank with a digital travel scale the rig weighed -2.85lbs. I don't want to use the tubular arms because I would need four 10" arms to get even close to neutral and that is way more arm than I would like, plus they are expensive and Im already pretty deep with this rig.

I was thinking of strapping some expanding foam filled pvc pipes to the arms and tray - of course this will make it a bit more bulky. Another idea is to wrap the arms, strobes, and tray in neoprene but im not sure how much buoyancy this will give me plus it will compress at depth so will be less buoyant the deeper I go.

Anyone have experience with this or have suggestions?

Mine is similar to this but two strobs and sets of arms [/FONT]http://www.bluewaterphotostore.com/ultimate-recsea-s100-package[FONT=tahoma, verdana, arial, times]

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[3D diver]

I made floats using this stuff:

DIY Underwater Camera Floats & Strobe Arm Floats
DIVINYCELL FOAM PVC from Aircraft Spruce


see post 104 in my thread

http://www.scubaboard.com/forums/gopro-video/425784-my-gopro-3d-setup-11.html

 

[Gunrock]

In SoCal a lot of people were strapping plastic foam to the strobe arms to add buoyancy. I would like to do this myself. I still haven't quite got around to figuring out where you get the stuff from though.

Scuba Gear Related Tips - Kevin Lee's Photos

 

[muzikbiz22]

Stix Floats are your best bet. And your camera rig won't look like a junior high science project, as well.

 

[KeithG]

Q: do you want the rig to be neutral? Or you to be neutral?

You (including your rig) can be neutral by adding a little air to your bcd, or just filling your lungs. Problem solved. Your 2.8500 lbs can be offset very easily with air.

I have found that a slightly negative rig is easier to handle than a slightly positive one. Seems it is easier to point up than down?

 

[diversteve]

+1 for Stix floats. My buddy uses them to offset the weight of his heavy video light.

Or there's: View Pool Noodles Deals at Big Lots

 

[Interceptor121]

Start with a pack of 4 stix jumbo floats that takes away a good part if the weight
It is going to be difficult to for more on the arms without reducing flexibility but you should be left with less weight usually 1 pound negative is acceptable
If you put floats on the tray which is possible you need to make sure the bottom is still negative so that it does not flip
What I do is to put other floats on the focus light arm however the cold shoe of recsea housing is not to be trusted too much make sure it is secured
This would take around 1kg off your rig and should be sufficient

 

[danvolker]

[video=youtube_share;UaFNU6UkY9k]http://youtu.be/UaFNU6UkY9k[/video]
Start at 2:12 into this video, and you can see the PVC floats I made for Sandra.....Her Sea and Sea Housing for Canon 5d mark II and strobes was ridiculously heavy, and after several hundred dollars in Stix floats, we were pissed at the RIP OFF of the stix floats and the small amount of buoyancy they added--the camera was still just too heavy...with the large volume PVC I cut into custom lengths, we were able to make Sandra's camera DEAD NEUTRAL to the point you could let go of it in the water column, and it would stay put!
And the PVC pipes and glue for the end caps total price outlay at Home Depot was maybe $12 !!!! I don't remember exactly, but it was cheap..... And again...we went into this with a money is no object mind set---but the industry fails badly with this....

One other bonus, is that now I can white balance my videos on her floats

 

[tamas970]

Nice project, I'll try something similar. did you fill the tubes with something to support against pressure?

I was thinking, would a harder type Styrofoam do the job?

Start at 2:12 into this video, and you can see the PVC floats I made for Sandra.....Her Sea and Sea Housing for Canon 5d mark II and strobes was ridiculously heavy, and after several hundred dollars in Stix floats, we were pissed at the RIP OFF of the stix floats and the small amount of buoyancy they added--the camera was still just too heavy...with the large volume PVC I cut into custom lengths, we were able to make Sandra's camera DEAD NEUTRAL to the point you could let go of it in the water column, and it would stay put!
And the PVC pipes and glue for the end caps total price outlay at Home Depot was maybe $12 !!!! I don't remember exactly, but it was cheap..... And again...we went into this with a money is no object mind set---but the industry fails badly with this....

One other bonus, is that now I can white balance my videos on her floats

 

[dfx]

Q: do you want the rig to be neutral? Or you to be neutral?

You (including your rig) can be neutral by adding a little air to your bcd, or just filling your lungs. Problem solved. Your 2.8500 lbs can be offset very easily with air.

Or just by dropping 2-3 lbs in lead...