Heres what an Excal coil looks like inside, hmmmm.......

[Bottomfeeder]

All this scare talk about salt water getting in the coil may be just that.....
I figured I had nothing to lose, since the detector was acting squirrely anyhow. I started cutting the loose seam off, one thing led to another, and I eventually cut the top off in pieces.
I had envisioned a bed of wiring laid out neatly. NO, to my surprise, there is an inner coil, sealed, inside the outer case. I found two openings, and figured the evil salt water somehow got in there, but I don't think thats the case here. Water may have penetrated as far as the two openings, but each is still tightly sealed with a black film, and no sign of any salt corrosion anywhere.
So, now, just as an experiment, I can reseat the coil into the coil cover, first refilling the coil cover with an epoxy, then totally sealing the top with more epoxy. like frosting a cake.
This should be interesting.

 

[bdahunter]

n/t

 

[VaBeachRon]

n/t

 

[Bottomfeeder]

looking down on the coil from the rear, (as if you were detecting).
There is an opening that the coil wire fits through,this is at 6 o'clock as you look down on it. there is a second opening at about 9 o'clock, and a third at between one and two o'clock. All of these seem to be sealed adequately inside. No visible corrosion anywhere.
My thought is to get some Loctite aquamarine epoxy, fill the bottom of the coil cover, and the bottom of the coil itself, then insert the coil into the cover. This will become a permanent bottom then.
After that is stable, I will then coat the top with a coat of epoxy to both seal the coil in, and, protect the surface.
Fingers crossed here!!

 

[Steve in PR]

Is it a cast piece of metal? Good pics but hard for me to tell.

 

[Sandpiper]

Looks like that may make for a heavy coil, then maybe not. Wonder if can fill with something like foam then epoxy?? Don't know.
Be careful with the expanding foam, had that stuff explode on me - not fun, but would have been great on Worlds funnyest video.

 

[Bottomfeeder]

I can't say what it is with any certainty. I epoxied the bottom of the coil, and the inside of the coil cover and put them back together. I'll let it set overnite, then tomorrow, I'll fill in the gaps on the top for a watertight piece. Then its slishy splash time.
It'll be fail or sail time. Fingers crossed!!

 

[Bottomfeeder]

n/t

 

[bdahunter]

n/t

 

[Beachcomber]

The gray film is the shielding. If saltwater gets to shielding the coil will false as you will have a conductive path from the electronics to the water. Here is a better pix of the internals of a Sov coil with the shielding removed. There is also a drain wire that wraps around the windings in the shielding material to maintain a good connection to the shielding material. When saltwater gets in it eventually corrodes that wire causing an intermittent connection to the shielding material. I have added 3 pix with the shielding material removed so that you can see the actual windings and preamp. The second photo shows a closeup of the preamp. The bare silver wire coming from the preamp acutally comes through the resin and used to wrap around the coil making the connection to the shielding but was removed during the sanding to remove the shielding so that you could see inside the coil. In the lower right corner of pix 3 you see the gray layer. That is the actual shielding material of the coil. If that comes in contact with the saltwater your coil will false.

[attachment 32443 Coil1.JPG]


[attachment 32444 Coil2.JPG]


[attachment 32445 Coil3.JPG]

HH

Beachcomber

 

[Beachcomber]

Don't know as it's kind of like a very hard rubber as you can peel it off the windings.

HH

Beachcomber

 

[Bottomfeeder]

Some people call it stubborn.

 

[Bottomfeeder]

If that is a shield of sorts, it appears to be in good shape, and no corrosion visible. If I make a waterproof seal over it, i should be okay (hopefully). if it does fail tho, I can fall back on a new coil. But I hope to put this back in service in the next couple of days.