I currently use a 30' piece of 7mm cord for setting up my belay anchors. Alot of the times it is too long for what I need but when I need the length it is worth every penny. What is the best way to shorten it up when I dont need it so long? Clip another loop or two into the system? Use it doubled?
I do know how to tie a belay anchor with the rope I just prefer to use the cord.
30' is pretty long. I use 20' and set it up as an equallette and in this fashion I get a lot more out of it than the standard cordallette. When I need to be far away from it I just use the rope to extend out...
30 feet is a little long for a cordalette, but if you like it and want to carry that much cord it will be fine.
The easiest way to shorten the 30' cordalette would be to just tie an overhand knot at whatever length you want. Clip the now shorter cordalette as usual and let the now extra and not needed length just hang off the anchor.
An overhand knot is not as strong as the usually used double grapevine, but it is common practice among guides and climbers to tie their cordalette in this manner so as to easily untie it if they need a single long piece of cord material.
I use my cord open ended with a figure 8 on each end (15ft) . When the anchor set up requires me to shorten the length I simply clove hitch the cord to the proper length and leave it at that.
Considering the OP is from WI though he is most likely setting TR's at Devils I assume so 30' is perfect for your applications. Carrying shorter cords would then possibly require you to carry more than one and cluster your anchor set up.
Again, I think 20' of cord setup as an equallette is a great way to go. It's uses the cord length much more efficiently (even when using a 4 piece anchor) and equalizes a lot better. Hell sometimes I'm sure I can get away with only 14'-16' as I'm always tying it shorter.
It's not as hard/complicated as this guy makes it out to be either– this is the only video on youtube that shows it.
+1 for the equalette. I have mine tied on a 18-20' length of 7mm perlon. Very quick and easy to setup as long as you keep the limiter knots tied in the cord. Adjustments are made by simply loosening/tightening the cloves at each anchor point as necessary.
I use a 25 footer most of the time. It's bit long, but I like it. I usually just shorten w/ an overhand if required, but now that i'm thinking about it, i'm going to try this as it sounds easier: If it's too long, double back on one of your pieces so it's got 4 strands off it rather than 2, then tie your masterpoint.
Do not tie the cordalette into a loop. Once the pro is set run the cordalette through each piece bring the bite back the masterpoint. Once through all the pro and at the masterpoint tie a knot. If done correctly everything will be equalized, redundant and with no extension.
If the cordalette is not tied into a loop it is also easier to rig into an assending rig.