I have got this annoying issue when bouldering: a sheared callus on the small finger:
I would like to tape this and continue climbing (with extra caution). I am not an expert in taping, and any tape I apply always gets crumpled up and quickly tears away.
How do I apply tape so it doesn't come off easily while I am bouldering?
Been there done that, I would just wrap a smaller width piece of climber's tape around the finger and then take extra care to smooth the end down as usually, that's where it starts to come unraveled.
I would make sure to try and get most of the tape around the middle piece of your finger in between the joints as otherwise when you bend your finger it will also start to make the tape come loose as well as making it harder to bend your finger.
I have found that the best way to handle calluses ripping off is prevention. Once one rips off, it is often painful to climb on even if you tape it properly. If you do need to tape, wrap tightly with a narrow piece of tape around the finger and make sure the loose ends are on the back of your finger.
For prevention, before climbing, check the skin on your hands for rough edges and small flaps of dead skin that are likely to rip off. You can use nail clippers to remove the flaps; cuticle cutters are better as it is easier to avoid cutting off healthy skin.
After you remove any flaps, sand any rough areas until they are smooth. You can use a nail file, sandpaper or a nail drill (i.e. an electric nail file made for use in cosmetics) for this.
It is important not to sand more than necessary as your calluses serve as padding for the structures inside your hands. This is especially true on overhanging jugs. I have gotten sore hands that forced me to take a few days off before from excessive sanding.
