V-Threads are a great way to rappel ice routes without having to leave gear if good fixed anchors don’t exist. They are strong, quick, and easy. With minimal practice, you can get it right first try every time.
I look for the best quality and thickest piece of ice I can find, and make sure it is well attached to its surrounding features and other ice. If needed, I will chip off the aerated, fractured, or sun affected layers to get to better ice. It helps if the feature you use is slightly convex, either horizontally or vertically, as this makes it easier to put the screws in at an angle to each other. V-threads can be oriented either vertically or horizontalIy, both have similar strength. I prefer the horizontal setup, as I can visualize the angles better that way.
I use the longest screw that I have, usually a 19cm, and start by placing that at an angle to the ice. Back that screw out and now measure one screw length from the first hole to find the location for the second hole. Placing the second screw is where it takes some practice. Visualize the angle needed so that the two holes meet at 90 degrees right at the deepest point. It can help to put a screw halfway in the first hole so that you can see the angle it is at. I get my eyes level with the screws which helps to see if everything is lined up correctly. Place the second screw, and look down the hole of the first to see if they connect. Sometimes, it is necessary to clean ice out of the holes, either by blowing through them, or using a v-thread tool to clear them out. If the holes barely concoct or are just off, you can rebore one of them by placing the screw and put pressure against it so that it goes in the direction needed.
Once the holes are connected, it’s time to thread the ropes and set up the rappel. Many people leave cord, but this isn’t necessary. We teach the Naked V-Thread at San Juan Mt Guides. This simplifies the process and leaves no tat to melt out in the spring. Make or buy a v-thread tool, and if you forget it, learn some of the tricks for making do without on. I always back up the rappel with a screw and loosely clipped quickdraw through the rope. Make sure the weight is on the v-thread, not the quickdraw. If I am the only one rappelling, I will bounce test the setup before heading down. Don’t forget to have the last person bring the back up screw with them. Very rarely, the rope will stick a bit in the holes and takes some extra pulling to break the freeze. Pull your ropes, you’re on your way down, and nothing was left but some holes in the ice!