Diy metal detector help

[freediver16]

Hello all.

I found this forum while searching for a metal detector for a specific task I have. I recently lost a 25hp outboard motor off the back of my boat. It now lies in 45 feet of water in a lake. I do not scuba dive and even if I did, visibility at that depth in this lake is like 2 feet. I took a gps reading with my phone a few minutes after the motor sank. It is worth it to me to build a metal detector that will find this motor if I can build it for under $300.

The coil in this thread made by stevemc :http://www.treasurenet.com/forums/shipwrecks/326005-boat-towed-pi-metal-detector-coil-what-issues-effectiveness-2.html is what made me think finding this motor may be possible. I'm thinking a 3 or 4' square coil at the end of a 40' cable towed around slowly in the area the motor sank should be able to locate it. The motor weights around 100lbs and is mostly aluminum.

I am into ham radio so I am familiar with basic electronics. Can anyone suggest at kit I could put together for the detector ? I see Surf PI 1.2 and barracuda mentioned. Something like those is what I was thinking may work. I have plenty of wires to make a coil with. I think if I get pointed in the right direction I should be able to figure this out.

Thanks

 

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[vpnavy]

Hello all...

1st - I noticed this was your very first post - so, Welcome Aboard from another resident of the great state of PA! Take a look at Sub-Forums: Pennsylvania for information (i.e., clubs, etc.) directly related to PA.

2nd - 73's -.- . ...-- .--

 

[Professor of Engineering]

IMHO: I would call a local metal detecting club or dive shop. I am sure someone would be able to help you. Building a metal detector may/is a fun project, but not practical for this situation. You will need a dedicated water machine with someone with detecting and dive experience.

Good Luck

 

[FreeBirdTim]

Magnet fishing. A strong magnet and a winch should do the trick. Motor probably weighs around 150 pounds. There are magnets that will lift that much weight out of the water.

 

[Charlie P. (NY)]

Trouble would be finding enough ferric metal on a modern outboard to get a magnet to hold onto. Plastic cowl, aluminum upper and lower unit. Aluminum prop. The mounting bracket may be steel; but that's likely aluminum & stainless (non-magnetic) fasteners throughout.

Cheaper to hire a diver or pull-in a favor.

Detectors can be built - but one that is submersible to that depth is specialized. "Waterproof" rating of IP67 is good to three feet deep for up to 30 minutes. 45 feet is fully submersible and

 

[Hawks88]

Welcome to tnet from Niagara Falls. Good luck with the motor.