Used/second hand drill rods are commonly used in wireline drilling processes. One of the biggest reasons for using these rods is due to the lower buying prices. Another common reason why miners use them is due to their availability during time-constrained operations. Although it's okay to use second hand drill rods, you should ensure that they meet proper safety conditions to avoid drill inconveniences.
Below, find some of the pertinent things you should check before buying or using them.
The threads always play a crucial part in wireline or diamond drills. They ensure proper attachment of the rods while in use. Worn threads will limit the level of this attachment making your rods prone to detachment. This can cause complications should your wireline string break while sunk below ground. Check the length of the pin threads to determine if they can still provide safe attachment. Also check to ensure that the threads are not stretched such that they can cause rods to slip off when attached.
Rust (internal and external)
Rust is a common risk for used drill rods. Rusted drill rods reduce the structural strength of the rods, making then increasingly susceptible to torsion and traction forces. Inspect second hand pipes carefully to ensure there is no rust. This should be done to the internal walls as well. Note that the internal walls are more prone to rust due to moisture. Light rust build up can be removed through blasting. However, rods with heavy rust build up should be avoided.
General body wear
Used wire line rods will often exhibit signs of wear due to their previous applications. The best way to quickly assess the wear of a drill rod is using the wear-indicator groove. This should let you know how much life a pipe has remaining. If a wear groove is not applicable, measure the pipe thickness to see what percentage remains. Dings and scratches should be expected. However, large scratches or marks should be measured to check their effect of the rod wall. Check the shoulders, too, for dents. Suspected cracks should be checked using magnetic tests.
Another important aspect that you should check on old drill rods is concentricity. This refers to the straightness of the pipes. Though some used pipes may look okay, their alignment may not. Pipes with poor concentricity values may bring about challenges when attaching to other pipes. They may also bring about additional stress to the drill string by creating friction with the walls of the drill hole. Concentricity tests will let you know if the pipes have any external offsets that you should worry about.
Safeguard your drill operations by only using secondhand wireline drill rods that meet acceptable safety standards.