Heavy Housing

[ScubaDocER]

Question. Will the Ultralight Control System Buoyancy arms work with the Blue Fin Housing? The light controls are in the handles which I think goes through the arms to work. If I use these arms can I still control the lights through the handle?

 

[Teamcasa]

Dave...What is an ABS? And do you have a picture of what you did or can you describe it to me?

ABS (Acrylonitrile Butadiene Styrene) is the plastic pipe commonly used in sewer and drain situations. You can get all you want at any home improvement center.

I have two Nocturnal Lights SL50s. They are heavy (batteries inside), round and long so in order to make the whole rig closer to neutral, I added the tubes.

BTW, I made the mounts for the lights in order to make the rig as compact as possible.

 

[sassyalice]

What depth are they good for?

 

[mobula]

buy aluminium drinking bottles and fill them with PU foam if you need a floating device very soon. costs you a couple of dollars only.

 

[Teamcasa]

What depth are they good for?

I've had them to 130+, no problems.

 

[Wil]

My answer to a negatively buoyant video rig was much like Teamcasa's. I have the Amphibico housing with two GreenForce 250w HID and two of their FIII batteries. Mounting the batteries to a stainless plate with hose clamps, the entire rig weighs 45.9lbs (20.8kg) out of the water.

My solution was to use the ABS plastic pipe and attach it to the stainless plate with hose clamps. You'll need to calculate the buoyancy force needed to make it neutral in the water, then cut your tubes to the calculated length. It works great! I've had my camera system as deep as 165fsw. The ABS does fine. It's a bit lighter than the gray electrical conduit pipe, which works equally well. I also suggest that if you travel on the airlines, use the screw cap on one end and leave it open for TSA inspection. Bring lots of teflon tape to make a watertight seal once you assemble your rig.

In saltwater the camera is just slightly positive, which can be corrected with the weights provided with the housing.

Safe Diving,
Wil

 

[Video rookie]

buy aluminium drinking bottles and fill them with PU foam if you need a floating device very soon. costs you a couple of dollars only.

I can see where the bottles should work and be a quck fix, but I don't think the foam provides you any benefit, and actually adds weight which reduces the amount of gained buoyancy. This is just my guess, not knowing the compressive strength of the foam you are using.

The reason most of us are using plastic, or rigid foam covered with fiberglass, is that we want to displace a given amount of water with the least amount of weight. This provides the most buoyancy with the smallest float size.

 

[Teamcasa]

My answer to a negatively buoyant video rig was much like Teamcasa's. ...
I also suggest that if you travel on the airlines, use the screw cap on one end and leave it open for TSA inspection. Bring lots of teflon tape to make a watertight seal once you assemble your rig.

Excellent idea. I will have to make some new ones with caps!

 

[mobula]

You can use the bottles without foam. A friend of a friend had an implosion at 40 m So take care or try smaller bottles. Mount it with duck tape. This is just a quick and dirty solution and maybe it helps.
After a long search and some pressure tests I found a special hard foam for my Sony EX1 which is easily stable down to 90 m and weighs less than 100 g/L. Next week I will receive it and will build the floating device. The Fathom optics for my EX1 in Sealux needs 1400 g in the front.

 

[ScubaDocER]

Just an update:

I returned from Utila/Roatan a few days ago and the housing itself worked GREAT!!! Did about 21 dives and have an ungodly amount of video to sift through. The boat captain used 3 pieces of small PVC pipe with caps on the ends to help with the buoyancy. They measured and cut them on the boat!! Great guys. They tie wrapped the pieces to the bottom of the housing. I did not get a pic of the setup and had to disassemble it to get everything back in the suit case for the trip home. The setup was temporary and did well at shallow depths but was marginal at deeper depths (60'-100'). I assume that the compression of the air in the tubes at depth made it less effective. While this was not a perfect fix, it was certainly better than nothing. Apparently L&M is working to make a permanent flotation device a affix to the housing. I hope this arrives soon. Thank you everyone for your suggestions. I'll keep working on it until a permanent solution comes along.