On my trip to the Red Sea last year our DM was using a 7" metal tube for a shaker to get peoples attention. I have seen them available commercially, but thought I could make one fairly cheaply.
I started out with some 1/2" galvanized steel pipe about 3" long threaded at both ends. I got some Teflon plumbing tape and a couple of galvanized steel end caps. Before sealing it up with Vice-Grips, I put three old ball bearings inside of various sizes. I was fairly confident that it was water tight when assembled, but I went one step further as it would be going deep on occasion.
My last step was to take the assembled pipe and dip it into a liquid plastic. The same kind you use to coat tool handles etc. This hardened overnight and protected the outer surface of the steel. Plus, it gave it another layer of water tightness, protected the rest of my gear from metal abrasion and was a nice yellow colour to boot. After it was dry, I gave it a test shake and it made a nice 'shaka-shaka' sound. I was quite pleased with the results.
I took a stainless steel hose clamp and tightened it over a loop of thin rope so I could attach it to my BC. I was good to go... Total cost was about $9 CDN, not counting the liquid plastic which I bought for another project.
Took it diving and told my buddy I would try it when submerged. When we got to depth I took it in hand and rattled it... It was barely audible. If I had not known to listen I would have missed it. My buddy was 4 feet away and gave me a big shrug. Tried it when we got back to the surface and it sounded fine. For some reason when underwater it is very muted and all you can hear is a gentle high frequency 'tik' noise of the ball bearings hitting the end cap.
I thought it might be the plastic layer absorbing the noise, but on the surface it sounds fine. Any ideas? Am I missing something?
Picture enclosed of the completed item.
I started out with some 1/2" galvanized steel pipe about 3" long threaded at both ends. I got some Teflon plumbing tape and a couple of galvanized steel end caps. Before sealing it up with Vice-Grips, I put three old ball bearings inside of various sizes. I was fairly confident that it was water tight when assembled, but I went one step further as it would be going deep on occasion.
My last step was to take the assembled pipe and dip it into a liquid plastic. The same kind you use to coat tool handles etc. This hardened overnight and protected the outer surface of the steel. Plus, it gave it another layer of water tightness, protected the rest of my gear from metal abrasion and was a nice yellow colour to boot. After it was dry, I gave it a test shake and it made a nice 'shaka-shaka' sound. I was quite pleased with the results.
I took a stainless steel hose clamp and tightened it over a loop of thin rope so I could attach it to my BC. I was good to go... Total cost was about $9 CDN, not counting the liquid plastic which I bought for another project.
Took it diving and told my buddy I would try it when submerged. When we got to depth I took it in hand and rattled it... It was barely audible. If I had not known to listen I would have missed it. My buddy was 4 feet away and gave me a big shrug. Tried it when we got back to the surface and it sounded fine. For some reason when underwater it is very muted and all you can hear is a gentle high frequency 'tik' noise of the ball bearings hitting the end cap.
I thought it might be the plastic layer absorbing the noise, but on the surface it sounds fine. Any ideas? Am I missing something?
Picture enclosed of the completed item.
