The Coil Cover Game - A Revew

I have watched this phenomenon for a very long time in the metal detecting hobby, and I still occasionally go off a cliff over it. My wife says "Let it be..." but I can't! Coil covers drive me crazy!!! Especially nowadays when they are pretty much akin to useless but are still recommended by those who theoretically are in the know; especially on social media (is there any other nowadays??) platforms.

Now I am sure there will be those who would strongly disagree with me, but that's because they have been subliminally subdued into accepting the logical-sounding argument that coil covers act as a needed barrier between the outer world and your EXPENSIVE and easily damaged coil! And that actually WAS the case many, many years ago! Back then, in the 1970's and 1980's, we used co-planar coils that looked like fat serving dishes, we slang-termed them "dinner plate coils" which were made of thin injection molded polyethylene or polypropylene. 

The skin was very thin and easily worn through, especially if you were beach hunting in areas that had a rocky, gravel- strewn beach, like England, California, Oregon or Washington. Very tough on coils bottoms! The plastic coil covers were really a necessity back then...which were also easy to wear through, and you'd go through at least one or two a year if you were a prolific hunter. But time moves on. Here is 2023 our technology has advanced as quickly as our society has declined, and today's coils are made of practically miraculous materials that renders the coil's physicality almost indestructible! 

The coil's electrical / electromagnetic infrastructure is imbedded in an epoxy resin matrix. This material is hard...very hard! Here are some of its properties: 

• High tensile strength ranging from 90 to 120 MPa
• High tensile modulus ranging from 3100 to 3800 MPa
• High glass transition temperatures (Tg) ranging from 150 to 220 °C
• High compression, resilience, flexion, and tensile strength
• High resistance to degradation over time

The tensile strength of epoxy runs from 90 to 120 Megapascals, which means a PSI factor (covert pressure) at its highest is over 17,000 pounds per square inch! And at the lowest end of the range, tensile strength is running around a little over 13,000 pounds per square inch! I ran my 11" coil on my Minelab E-Trac continuously on the beach, in parks, at construction sites and everywhere in between without a coil cover for 7-years with little to no wear on the coil. Here is a picture of the actual wear the epoxy resin incurred on the bottom of the coil.

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Unprotected 11" coil bottom after 7-years use in all environments

And of course, I'm talking every day intended use here. Thus, there is really very little need for a troublesome coil cover any more, and of course this is from my perspective, while you may disagree.

Now, my opinion of course, of the whys and wherefores of the continued recommendation for using them? Despite the fact they fill up with water, sand, things you don't wanna' know about, they become loose quickly, fall off, cause target falsing and are miserable to clean, as well as reinstall? Money, pure and simple. Cash on the barrelhead. Moola and mucho denero! A coil cover can cost you anywhere from $15 up to $40 and whoever thought of this is a bona fide genius! 

I was a plastics engineer for a number of years and I can tell you they cost almost nothing to make and are pure profit all the way! I don't begrudge anyone using one, and as a recent case in point over the last few years, something that really does not do anything and is a royal pain in the keister, yet makes certain folk feel safe, then so be it. Everyone has the freedom to choose, I'm just trying to point out the man standing behind the curtain. Cheers!