Before you can successfully recover a buried item, you must be able to pinpoint it with your metal detector. Many locations such as public parks and manicured lawns require careful metal detector recovery techniques. It is not acceptable or justifiable to take a full-size shovel into a public park or to dig a huge hole in a nice lawn. This method of recovery leaves a bad impression of our hobby and too often leads to restrictions and bans on metal detecting activities. A public park is not the woods so limit your digging tools to a small trowel and a flat-head screw driver.
Learning to pinpoint a buried object is an important skill to develop. The faster you are able to pinpoint and recover items, the more items you will be able to find in a given amount of time. Depending on your metal detector, pinpointing will generally be performed in one of three ways. Some metal detectors have a pinpoint button that causes the sound to get louder as you zero in on the buried item making for an easier pinpointing experience.
With a concentric coil, the coil is moved over the item in a side to side and then front to back motion forming a plus sign pattern. As the coil passes over the object in a side to side motion, watch for the coil location that provides the strongest audio signal. Once you have identified this spot, place the center of the coil over that spot and begin to move the coil forward and backward again listening for the loudest audio response. The object will be located under this spot.
With a DD metal detector coil, there is essentially a hot strip running down the center of the coil from front to back. To pinpoint with a double d coil, perform the side to side method as mentioned previously. Once the audio hotspot is located, there are two common ways to finish the pinpointing process that differ from a concentric coil as a forward and back motion is less effective on a DD coil.
The first way is to wiggle the coil side to side in small tight sweeps over the target as you slowly move the coil back towards you. When the audio response drops off, the item will be located off the front of the coil. Each coil performs this differently so you will have to practice to get an idea of where on the front of the coil the object is buried. A simpler method for beginners is to step to the side of the object so that you are facing ninety degrees from where you were previously then repeat the side to side motion. By doing this you are effectively completing the plus sign pattern without the forward and back motion.
For shallow targets, an electronic pinpointing device such as a Garrett Pro-pointer or Sunray metal detector probe can be used to quickly find the exact location of an object. These pinpointers are also helpful for locating items deeper in the ground once the hole has been opened up. They greatly speed up the recovery process and help minimize the need to break up the plug of grass.
When digging at the beach or in a plowed field, how you actually dig the hole is less important as you will not be disturbing vegetation. At a park or private lawn, it is important to dig a hole while protecting the grass as much as possible. For shallow targets it is often possible to use a flat screwdriver to pop the coin out of the ground without digging a hole. This is a preferred method of recovery when possible. To pop a coin, you will slowly push the tip of the tool into the ground until you find the coin. Then you carefully feel your way to the edge of the coin and slip the screwdriver tip under the coin and use the tool as a lever to pop the coin out of the ground.
Some detectorists argue that this method should not be used as it can damage a coin. If you are in an area with old collectable coins at shallow depths, then it is probably a good idea to dig a plug. If these are newer coins, then it does not really matter if it gets a scratch and many times they will not be scratched. As for jewelry, much of the jewelry that comes out of the lawn has been dinged by a lawnmower, deformed or scratched by abrasive soils and pebbles prior to recovering the target so this is not as serious issue and many times the popping action will not scratch the item.
If you must dig in the grass, then it is important to cut a plug that remains attached to the surrounding grass to help the grass recover and remain healthy. The easiest way to do this is to dig a plug in the shape of the letter “U” where the top of the plug is still connected to the ground. The plug can then be lifted out of the hole and folded back onto itself to be out of the way while you use a probe to locate the item in the hole.
If you must remove more soil from the ground, place the soil on an old towel or piece of drop cloth to prevent the loose dirt from making a mess in the surrounding grass. Once the item is recovered, it is easy to pour the dirt off of the drop cloth and back into the hole without making a mess. Any old piece of cloth will do so it is inexpensive and there really is no excuse for not using a drop cloth.
Once the dirt has been returned to the hole, the plug is moved to its original position and can be pounded back into place with your hand or foot to ensure that it stays put. If you do not secure the plug, then the grass will be more likely to dry out and die or it may be sucked up by a lawnmower, leaving an unsightly hole.
Learning to properly recover a target will lead to more finds and will help keep places open to metal detecting. Even if you are not digging in a lawn, always remember to fill in your holes.