Jump to content
  • Announcements

    • olyclimber

      WELCOME TO THE CASCADECLIMBERS.COM FORUMS   02/03/18

      We have upgraded to new forum software as of late last year, and it makes everything here so much better!  It is now much easier to do pretty much anything, including write Trip Reports, sell gear, schedule climbing related events, and more. There is a new reputation system that allows for positive contributors to be recognized,  it is possible to tag content with identifiers, drag and drop in images, and it is much easier to embed multimedia content from Youtube, Vimeo, and more.  In all, the site is much more user friendly, bug free, and feature rich!   Whether you're a new user or a grizzled cascadeclimbers.com veteran, we think you'll love the new forums. Enjoy!
Sign in to follow this  
corvallisclimb

rap knots

Recommended Posts

what knots do you use to join larger ropes with skinnier ones. I have a 10.8 and a 7 a have experimented with diffrent knots and dont know whats best. who knows?

Share this post


Link to post
Share on other sites

"Children's Cowboy Boots - Justin Youths Lace-up Boots - Black...Let your youngster loop, swoop and pull with a pair of Justin junior Lace-Rs. Durable enough to outlast the roughest buckaroo, these lacers are..."

 

Whats wrong with a double fishermans?

Share this post


Link to post
Share on other sites

I don't know if this is the best knot for your purpose, but one knot I have used is a square knot - backed up with double fisherman's on each of the tails. There may be stronger knots available, but this one has the advantage of being simple and using knots you already know, as well as the fact that you can untie it without too much struggle even after multiple rappels.

Share this post


Link to post
Share on other sites

last weekend I used a double fisherman's knot to join a 9.6 and an 8 for rappel and we lucked out, it worked.

I don't know why it wouldn't work with a 10.8 and a 7, try it at home.

back up each rope end with another double fisherman's knot.

the knots did pull fairly tight but that was good and not really much of a problem untying them.

Share this post


Link to post
Share on other sites
the knots did pull fairly tight but that was good and not really much of a problem untying them.

 

This is one advantage to Mattp's suggestion above. The double fisherman's back up keeps the knot secure and the square knot in the middle makes it very easy to untie the two ropes.

Share this post


Link to post
Share on other sites
If they are different diameters the most effective knot IMHO, is the double sheet bend:

 

http://www.iland.net/~jbritton/sheetbend.htm

 

He's planning on rapping with it. A sheet bend, double or not, employed as a rap knot would be suicide, IMHO.

 

WTF is wrong with a good ol' double fisherman's? confused.gif

I've been using it for over 20 years, I never back it up with extra frilly things on the tails, and I'm not dead. Werx 4 me.

Share this post


Link to post
Share on other sites

I will admit to having rapped off - multiple times - on a 10.5mm and a 7mm tag line using a very-well-dressed overhand. To keep this from possibly flipping down 12-18 inches of tail, I add a second very-well-dressed overhand as a stopper knot.

I know lots of people will protest this. But not once - NOT ONCE - has my knot flipped, or the 7mm cord "slipped".

Share this post


Link to post
Share on other sites

EDK w/foot long tails.

 

DF is a bitch to untie and hangs on shit.

Flemish bend (aka retraced 8s) has the same issues.

Square with honkin backups has the same issues.

A "flat 8", (which is like a EDK but using an 8 instead of overhand) is actually a dangerous knot as it will roll/invert on itself at relatively low forces.

Share this post


Link to post
Share on other sites

everyone seems to have their favorite knot, the overhand knot (aka edk) with long tails, and pulled tight (all knots should be cinched up tight or "dressed" to make sure they don't untie) is my favorite just cause it's less likely to snag on something when you pull the rope. double fisherman's works well too, just a real pain to untie after repeated rappels. just my two cents cantfocus.gif.

Share this post


Link to post
Share on other sites

Did a few raps sunday with a 10.2 and a 8.1, overhand knot worked fine. We did back it up with a second overhand knot.

Share this post


Link to post
Share on other sites

We've covered this before, but an "overhand" knot (I think it is actually a "double overhand" and it is also called a "water knot") is not the same thing as a "Euro Death Knot." An overhand knot has the tails sticking out opposite ends of the knot and is tied by making a single overhand, then following through with the other rope; the EDK has both tails sticking out the same side of the knot and is tied by taking two ropes and tying a single overhand on both strands.

 

Many of my friends, wary of rappelling on an EDK, are quite happy with the double overhand.

 

knots_EDK.jpg EDK

water3.gif Water Knot

Share this post


Link to post
Share on other sites

A water knot is not an overhand knot. An EDK IS an overhand knot. A water knot is a stupid choice for a knot to join two rap ropes together because it is best used for webbing rather than cord.

Share this post


Link to post
Share on other sites

Gary, that test data gets thrown around ever time this conversation is started. But the knot flipps at loads much higher than any rappel load will encounter - 1200 and 900 lbs in your two examples. And a second double-strand overhand knot (is that a better description Matt? I hate calling it an EDK) stops flipping.

Share this post


Link to post
Share on other sites

A square knot is not designed to be used with two different diameter ropes, whereas a sheet bend is. The sheet bend was originally used to attached a rope to the corner of a sail (make a bend in the sail, or sheet, and then bring the rope through and around it). I've never used either of these knots to rap off of, but the sheet bend would seem to make more sense if choosing between the two. Personally I use the EDK first, or a double fisherman's when attaching different diameter ropes.

Share this post


Link to post
Share on other sites

A sheet bend is not what is used to tie the sheets to the clew of the sail. The bowline is used for that. The sheet bend is used to join two sheets together.

 

Anyone who says differently is three sheets to the wind.

Share this post


Link to post
Share on other sites

Double sheet bends backed up with single fishermans on each tail have been used for joining highlines, etc so it can easily take the load of a rappel and unties very easily. I would not recommend it for that though because it is a gigantor knot. Usually it gets taped up so big pulleys can track over it. It is not "suicide" as someone suggested, but it is perhaps a little silly.

Share this post


Link to post
Share on other sites
Gary, that test data gets thrown around ever time this conversation is started...

 

Ah, I posted the data but not my opinion on it. My opinion agrees with yours, that an overhand on a 10mm rope and an 8mm rope, properly dressed/tightened, is plenty strong.

Share this post


Link to post
Share on other sites

Ahhh, and I didn't mean to imply that I thought you were being a stick-in-the-mud-Mountie...

Share this post


Link to post
Share on other sites
double-strand overhand knot (is that a better description Matt? I hate calling it an EDK)

 

when i took a mountaineering course, i was taught that this type of overhand knot was called a "flat" overhand.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

×