Photos from Tim Banfield @timbanfield and article (used with permission) are from Sean Isaac. Sean is an ACMG (Association of Canadian Mountain Guides) certified Alpine guide, a former professional climber, and author of the “Ice Leader Field Handbook” and “How to Ice Climb” (2nd ed.) Follow @seanisaacguiding and @howtoiceclimb for more great tech tips.

From Sean:

“It’s shocking how fast ice screws can melt out on a warm (> 0 C) day especially when under tension in a top-rope context. Even on very cold days, direct solar affect at the critical angle of incidence will loosen ice screws quickly.

I’ve seen top-rope ice screw anchors melt out on -25 C days in January in 30 minutes due to the sun. If warm temperatures or solar exposure is anticipated then melt out should be a concern.

Using bolted or tree anchors is the obvious solution, but if an ice anchor is the only option then mitigate melt out by using V-threads instead of ice screws for one or all anchor points. The nylon cord/webbing does not conduct heat like metal screws so therefore do not melt out as rapidly.

It sometimes can take days for V-threads to melt out. The cord can then be retrieved at the end of the top rope session and a no-thread used to rappel.

Packing snow over the top of ice screws is not a recommended treatment since it does very little to negate melt out”

Some V-thread considerations:

• Threads should never be used as a single-point anchor. Make a second point as show here (screw or another thread), and equalize them.

• Threads should be made with a 21-22 cm screw.

• All angles are 60 degrees making an equilateral triangle that is as deep as it is wide.

• Aluminum screws make constructing V-threads easier due to their larger tube diameter.

• 7mm cord is the minimum recommended diameter. Not because of its strength but because of it’s surface area.

• Webbing makes a stronger thread than cord, due to its broad surface area spreading the load at the back of the V.

• Horizontal threads test at an average of 11kN in good quality ice.

• Vertical threads (A-threads) tests 3kN stronger because most of the force is on the upper hole, placing more total surface area in compression in a single vector.

• Remove cord from threads when possible to minimize plastic garbage in the mountains.

V-thread equalized with single screw.

Another option: use a pair of V threads. If you carry a cordelette that's open (a.k.a. untied), you can thread the end through ALL the holes and tie it off. #CraftyRopeTrick!