Getting sand in the lower shaft can be a nightmare. I have tried a
number of things including taping with electrical tape to keep the
sand out but I always have the lower shaft frozen.
During my last trip (vacation), I installed a plug and brought a
metal shaft with me. Sure enough, when packing to come back home, I
couldn't get the lower shaft out. Since I had installed the plug, I
simply tapped the long bar and BANG, it was out.
So, we have made a few of these plugs by hand to sell or you can
make one yourself. The size made is for an Excalibur and many other
detector lower shafts, 3/4" OD with a 5/8" ID.
Note: This only works for straight shafts such as the Fisher CZ20
$15 if purchased with other
items, or $20 if purchased by its self including shipping to the