Would amsteel blue rope be appropriate for use in anchor building for climbing or mountaineering? I expect it's not very abrasion resistant so it wouldn't be good up against some rock or an edge. But could it be used in something like a T-slot or as a runner in space?
Amsteel blue is a dyneema cord that size-for-size is just as strong as steel cable. It'll hold. In terms of abrasion resistance, dyneema happens to be superior to nylon rope when it comes to wear and tear.
There are two factors to consider when using dyneema: It has a lower melting point than nylon (which means it's more prone to breaking when knots are tied in it); and, it doesn't hold knots as well. You're going to have to learn new knots to tie that will hold in dyneema cord.
It would work well enough as a throw away rap anchor if you can learn how to tie it, but I wouldn't suggest investing in it specifically for climbing.
Thanks, that's an important distinction to make between abrasion resistance and melting point. Even if the cord won't get cut on a rough surface, it can melt just as easily running over a smooth one. Follow up question though, climbing companies sell dyneema prussik cords, do they have issues with melting when used as a backup on rappel or such?– kag0Apr 2, 2018 at 4:46
Can you suggest any knots that are safe and tested with Dyneema? As far as I know, there are no reliable dyneema knots that won't shake out. Apr 2, 2018 at 15:56
Also, I've heard that Dyneema knots can melt from the heat of tightening under a shock load. Apr 2, 2018 at 16:10
1@Adonalsium I've never worked with dyneema cord myself, but I know that a triple fishermans is recommended for aramid lines. What knots to use for dyneema is still somewhat an area of exploration. I suggest the following forum if you'r interested in seeing some experimental knots being developed by the international guild of knot tyers: igkt.net/sm/index.php?topic=5935.0 Apr 3, 2018 at 17:06
2@Adonalsium I've heard triple fisherman's for sheathed dyneema, but for air core like amsteel splicing is far better.– kag0Apr 8, 2018 at 0:15