Introduction: How to Waterproof a Metal Detector Control Box for the ACE 250 for Under $10

This is how I waterproofed the controls for my metal detector, which is an ACE 250 made by Garrett.

 I used to make underwater camera housings as a hobby and for several years manufactured and sold the NEMO 200 which had a depth rating of 200 feet.

 For shallow diving I liked to use the Lock and Lock  food storage containers You can see many of the housings I made in the past in my other YouTube videos.

    My criteria for the housing was it had to be absolutely foolproof, go to 10 feet, cost as little as possible and be built with the most common tools and little experience. I did not want to have to cut, solder or splice any wires or permanently alter the ACE 250 in any way.

 I think my design worked out well. The hard part is making the cable watertight as it passes into the water proof  housing . There are commercially available split cable seals but I could not find any that were small enough or cheap enough so I made my own out of wood discs and dowel.

  here is a list of my materials:

 1 Lock and Lock container size 1 liter 34 oz. 1.1 Qt.

3M5200  fast cure
glue gun
Super glue
 1/8 wood panel ply to make  2 split cable seals  attached with
4  machine screws    ( 8 total)  number 2-56 x 1/2 and 8 nuts and lock washers,
 and mounting board ( but I should have used plastic or metal and not wood for the mounting board)
attached with
1  number10-24 x 1"  brass machine screw and nut

 Neoprene to cover mounting board (optional)

  elastic or Theraband rubber to secure control box housing
2 pieces of 1/2" aluminum angle 3 inches long
attached with
2  number 10-24 x 1"  brass machine screws and nuts ( stainless will be better)
piece of round dowel cut from end of broom to make two  3/4 inch stems on cable seals

Butcher knife and cutting board and hammer to split wooden discs to make split cable seals and to split stems.

electric drill
  hole saw 1 1/4 in 32mm for making wood cable seals
5/8 spade bit for drilling 2 cable holes in container

 5/64 drill bit for machine screw holes in cable seals & container

1/4 wood drill bit for boring hole in round stock to make stems on cable seals

 A pre drilled hole in the detector handle will need to be reamed slightly to widen enough to accept brass bolt to attach the mounting board.

Once you cut out the cable seals, split them and attach them to the cables and glue them together with 3M5200 so the disc seams are separated and not aligned and you have a strong disk. Attach the disk to the container with bolts and nuts and use 3M5200 to make the permanent seal. The 3M5200 makes a wonderful gasket . The bolts make sure the seal does not separate from the polyethylene container which is a hard material to glue items to.

 I used a glue gun to attach the halves of the seals to each other and super glue to attach the stem and the stem halves.  The interior of the stem is then filled with 3M5200. I could have painted the wood and finished the cable seal construction at that point but  I added a large amount of the 3M5200 over the exterior of the cable seal and stem and over the interior where I added an additional cable seal.

 Be careful though, as I added so much 3M5200 to the interior there was almost not enough room for the Ace 250 control unit.

 I used a piece of 1/8 wood ply to make the mounting board. This is not a good idea. it is better to use a waterproof material. I covered the wood with neoprene and will be coating the edges to help keep the wood from deteriorating but it is only temporary, it is much better to use plastic or metal. The neoprene does a good job of keeping the housing from sliding around.

 I used elastic to secure the housing to the mounting board. A much better idea will be to use thick rubber Theraband material like that used in slingshots or dive applications. I used hot glue to attach the aluminum angle to the mounting board which will work well as long as the glue is never frozen as hot glue can separate at the joint if frozen and put under pressure, it would have been better to use small machine screws and nuts.
Always check your housing before committing your expensive detector to the water and continue to monitor wile using it. The most likely cause of failure will be operator error caused by dirt or sand on the seal.
 I will be waterproofing headphones and upload a video soon. Click on link to left to go to Ace 250 metal detector reviews on Amazon.

I have added a lot of Beach and underwater metal detecting videos to a playlist on my channel. You can see them here at

Thanks again. I hope to see your videos too and  I add more videos every week.
music by Holy Coast

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