Using vice grips to untie a stuck knot?

So I was at a gym recently at the front counter. Another gym member came up next to me and explained to the staff member that their knot was stuck. They asked for pliers. The gym staff member handed them vice grips. The member walked away with vice grips in hand to work on the rope. 

Is that safe to use vice grips on a stuck knot? 

Are pliers commonly used for stuck knots at gyms?

I indicated to the staffers that I did not think this was safe. Another staff member got involved and helped the member. I suspect the original staffer who handed out vice grips was only trying to be helpful for the stuck member and had the best intentions. (They are a wonderful staff )

 Vice grips produce far more force in a very narrow area than any gear I can think of. These produce far more force than pliers. If a the gym member were to pinch a narrow cross section of the rope (in the case of gripping part of knot) and twist I would think they could permanently damage the rope. I am skeptical that a manufacturer like Petzl or Black Diamond would approve of this practice, but maybe I am wrong? Thanks for any insight that folks might have.

Unless there was visible damage (sheath) to the rope, I wouldn't worry about it. I'd probably stick a screwdriver in between two strands to loosen it!

It might be kind of tough with a welded knot that happens to be close to your tie-in points, but a great way to deal with knots without damaging the sheath is to pound it with a rock (or hammer in you’re indoors) with medium pressure as your roll the knot back and forth. I definitely wouldn’t use anything that has the potential to tear/damage the sheath like pliers/vice grips. 

Isn't this exactly what a marlinspike is for?

John Pitcairn wrote:

Isn't this exactly what a marlinspike is for?

Scene at your local climbing gym: 

Customer: [walks up to front desk] hey, my partner's knot is stuck, what should we do? 

Staff member: here you go! [Hands them a marlinspike], jam that tip between the strands to work it loose.

Customer: okey dokey! [Skips off merrily]

In the distance: [horrifying scream] 

Customer: [shyly walks back to the counter] Ummm, I need some vice grips, that spike thing accidentally got stabbed through his genitals and it's too slippery to pull out with all the blood. Can I get some paper towels too?

Tony Lobay wrote:

So I was at a gym recently at the front counter. Another gym member came up next to me and explained to the staff member that their knot was stuck. They asked for pliers. The gym staff member handed them vice grips. The member walked away with vice grips in hand to work on the rope. 

Is that safe to use vice grips on a stuck knot? 

Are pliers commonly used for stuck knots at gyms?

I indicated to the staffers that I did not think this was safe. Another staff member got involved and helped the member. I suspect the original staffer who handed out vice grips was only trying to be helpful for the stuck member and had the best intentions. (They are a wonderful staff )

 Vice grips produce far more force in a very narrow area than any gear I can think of. These produce far more force than pliers. If a the gym member were to pinch a narrow cross section of the rope (in the case of gripping part of knot) and twist I would think they could permanently damage the rope. I am skeptical that a manufacturer like Petzl or Black Diamond would approve of this practice, but maybe I am wrong? Thanks for any insight that folks might have.

Vice grips aren't ideal. I have loosened hundreds of figure 8s with a screwdriver struck through the knot. Also helps to put the knot on a hard surface and hammer it loose. 

More importantly a rope that is easily getting the fig 8 stuck is at the end of it's life span. If a particular rope is getting stuck often, cut off the end or replace the rope.

John Pitcairn wrote:

Isn't this exactly what a marlinspike is for?

Yes except given the level of competence in a gym and diameter of the rope, it should be a very very rounded spike.

That said, having untied several stuck knots I would get it wet so to reduce the friction. I would not use pliers or vise grips because they are serrated which will cut fibers. What I have used is a screwdriver that for years has been use to pull weeds thus is very dull. 

Take off the harness first.

Having used ropes for rigging on trail building projects with heavy loads, one simple way is to put knot on hard surface, then step on it with shoe or boot and roll it back and forth. Works great on water knots on webbing too.

There's nobody here who worked at a gym where they handed out pliers when folks got stuck? That's not a thing, right?

A marlinspike seems like a better option. 

I'd roll the knot with my feet or a rock. Use a different knot if you're putting that much load on it. Isn't a figure 8 tightening a significant factor in fall absorption?

Let me just leave this here...

Matt Himmelstein wrote:

Let me just leave this here...

You like to tie in with a ‘biner?

Yeah. Except gym. Have to use 8 follow through. 

Also I never saw the knot or that. Just saw vice grips. 

Can't believe I'm the first.

YGD

Matt Himmelstein wrote:

Let me just leave this here...

How exactly do you tie this to a harness?

Stan Hampton wrote:

How exactly do you tie this to a harness?

You rethread it

https://www.mountainproject.com/photo/107476602/re-threaded-bowline-with-finish-knot

wivanoff wrote:

You rethread it

https://www.mountainproject.com/photo/107476602/re-threaded-bowline-with-finish-knot

Have you ever actually tried tying it?  Many climbers have trouble just tying a simple fig eight follow.  

Stan Hampton wrote:

Have you ever actually tried tying it?  Many climbers have trouble just tying a simple fig eight follow.  

Yes, absolutely. Start with a simple bowline and rethread the second loop.  I have no problem with it. I'm told it's a common tie in used in Germany

Stan Hampton wrote:

Have you ever actually tried tying it?  Many climbers have trouble just tying a simple fig eight follow.  

Then those probably shouldn't use it (or engage in an activity like climbing at all). While tying the knot is a bit more involved than a figure of eight, it's straightforward and just a matter of practice. Also it is much easier to untie after falling. There's a million videos on youtube how to do it if you search for 'doppelter bulin'.

Before I knew the better way to tie a figure 8 I had many difficult unties.....why is it we don't teach newbies the best figure 8 and just let them suffer?