Rapping on previously placed, fuzzed-out threads?

Mostly an academic question & somewhat unlikely scenario: have heard mixed feelings about rapping on a previously placed, single thread (or even more in same or worse condition), even though well placed, geometry correct and good ice. The kicker: the thread is super fuzzy (like uber fuzzy) from a number of ropes being pulled. (Last year a discussion focused on whether anyone had experienced or heard of threads pulling out ice on rappels; I think the collective answer was "no"). When I've encountered such situations (e.g. several times at Cody & in Canada), esp. at night, super cold, tired, etc. & many rappels yet to go (esp. if overhung & I know that), I'll place an "A" thread (my preference) below the "V" with the top hole of the "A" below (how far depends on ice & other factors) the bottom of the "V" apex (but then you need to equalize the two). Since "A"s are stronger than "V"s and they place different directional stress on the ice, I think it's a good compromise. Since you have to pull your rope from below, if you run it through the "A" apex & then up & down the "V" apex, you might create a bit of a tangle when pulled. In an ideal world, you could run the top "A" thread (has to be placed just right) out the hole and thru the "V" apex and equalize the system there. Even better still would be to remove the super-fuzzed-out thread & place your own new one. Or just say "screw it, I'm outta here...a beer is more important...I'm glissading". My question isn't about "A's" v. "V's" (that's just how I often back up previously placed dicey rappels or sacrifice a screw in order to save time), rather, how do you feel about rapping on previously placed threads that don't look so good?

Maybe folks around here are kinder than elsewhere, but I mostly see cord in good condition. Another factor is that the threads, on the routes I've done that use them, tend not to get used so much that wear is a real problem. But at least once that I recall, I did come across a real fuzzy cord. or maybe it was webbing. It was clear by looking at it that it wasn't just fuzzed from ropes being pulled, it was a ratty-ass piece of mank that had seen a rough life elsewhere. So rather than fuzz it up any more, I simply put a biner on it. No biggie.

just duct tape the fray and use it. :)

Why didn't I think of that? Duct tape the 'biner to the ice, rope thru the 'biner and you're outta there.

I and others simply wonder how many rope pulls (disregard length to make the scenario easy) would it take to saw through (or dangerously weaken) 6 mill cord used as a "V" or "A" thread for rappelling. Would be easy enough to find out. My feeling is that it would take a fair amount of "sawing" when the ropes are pulled to markedly effect the cord strength). Interesting that no one has done that experiment.

I've noticed that super iced up, thick ropes look like they have more impact than ones that are not. That could have been a hallucination. (Maybe the newer skinnies when super iced up create more sheath & possibly core damage??

Several of us science & engineering types are interested in doing such tests. Lots of variable could be thrown in but if something strikes you that might be added to the test, let us know.

Warbonnet