how to keep a knot from tightening too much when lifting something

Captain Dirty · May 9, 2020

downsizingnow48 said:
I did not notice the intent to tie knots in a strap. I've never done that, it is a real bad idea. Get a rope and use rope knots. Or use a strap and slings as they are meant to be used. Or a chain.

Fabric straps are designed to have the load evenly distributed across the width of the strap. Bunching the strap , for example by putting it on a hook or though a standard bow shackle, reduces the strength because the strain is greater on fewer strands. Knotting is even worse as the fibers are bent even more sharply.
The preferred shackle is one that allows the full width of the strap to bear on the pin or the (flattened] bow.

Sling shackles

Bow, piling, and chain shackles

sodamo · May 9, 2020

Do your straps have loops on the ends. Some of mine do and I have combined using a shackle. Other have sewn on hook, so I just hook together.
I didn’t know about knots weakening straps (thanks) but I did learn not to tie together without a dowl or something to keep from over tightening.

lamanated · May 9, 2020

thanks a strap was all we had, we needed to shorten it as we couldnt lift the piece to give it and extra wrap. down in the hole.

oosik · May 9, 2020

Slings or shackles for straps - bowline for rope.

/pine · May 9, 2020

FWIW...The newer type of straps and clips that lumber yards use can be reused and make great quick grab straps...it takes a minute to get the hang of manipulating the strap into the wire clips but once its there it can be easily cinched down on whatever needs lifting, pulling etc...the 1" wide straps are amazingly strong and can be cut to any length and reused...

Tractor Seabee · May 10, 2020

Shorten you strap by taking extra turns around the load if possible. With shackles (or clevis as the farmers and loggers say) allows you to double up. I use chains with grab hooks a lot when straps are too long. When I worked industrial construction we always had plenty of rigging equipment so work arounds were not necessary.

Ron

joefromga · May 10, 2020

A sheepshank is what you need to temporarily shorten a rope without having to untie either end and it doesn't bind and comes out easily. Very handy.

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Texasmark · May 10, 2020

RSR said:
Have you tried a bowline?

Ha! You took the answer right out from in front of me. Grin

I was in the Sea Explorer Scouts, BSA in my teen years and learned many knots...including the Masthead, which I can tie in about 30 seconds.

The Bowline is my favorite knot, which I can tie in about 3 seconds (lots of practice makes perfect)...and is my preferred knot for wanting to do heavy work and get the knot out when finished. It's also a non slip knot, will not slip, and does not pull up tight against the object to which attached. It is locked to itself, around the object to be tied....fitting loosely.
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Another good knot for tying baler twine is the Sheet Bend. It locks up tight and doesn't slip, but not made for a temporary fastener. It goes through sheaves of the (round) baler easily and is recommended for my JD rounder using plastic string.

Another (pulls up tight, doesn't usually stay loose like a Bowline) choice is something I thought of: Tie a regular half hitch, like you were going to tie a square knot but just the first half and rather than run both ends out of the knot, having a good length of the free end, loop it through the knot such that once the hitch is tied and pulled up tight, you could pull on the free end, thus pulling the loop through the knot thus causing it to untie. With adequate loop material, then do a couple of half hitches around the line to be secured to ensure that the looped hitch remains tied. The second hitches have no real stress on them and are easily untied and the loop can be easily pulled out as you have the free end available for "grasping and tugging".