How many times can i resewn same webbing

[alexey 6]

How many times rigger can resewn one piece of webbings - i.e. - how many times can you sew webbings at MLW (if you are trying to adjust it), or risers for example?

Sorry for bad English....

Lexa

[jas8472 0]

I'm no rigger but I was told you can adjust something like the MLW or major intergrated parts of the harness 1 time, most other things, risers, etc. can be changed for new.

[freefalle 0]

I believe the rule of hand is once, each time you resew webbing you increase the degradation factor of that webbing making it subject to failure.

[riggerrob 561]

You can sew a piece of webbing a maximum of three times according to Rigging Innovations' policy.

That means original manufacture and re-sizing (or repairing) it twice.
Clas 7 sewing machines use huge needles to pull thick cord (5 or 6) through the webbing.
Heavier webbings (Type 7 or Type 13) will keep their strength after more than three sewings, however lighter webbings (Type 8) look pretty ratty after upicking stitches the first time. That is why half the harness repairs/resizes done at factories involve new webbing.
The skill of the person unpicking a seam also makes a huge difference in how much damage is done to the webbing.

[linestretch 0]

to add to this, is it true that you should only sew paralell(?) to the load, and not perpendicular? Does this make sense? It's a structural thing with welding too, as to welding perpendicular to the load can cause a weak/break point. Anyone?

my pics & stuff!

[riggerrob 561]

You are correct.
Most 5-cord sewing is done parallel to the long axis of webbing.
However in a few places - like just below 3-rings - some manufacturers sew across the webbing. This protects the points of WW stitch patterns (i.e. 3-rings) and or prevents hardware from shifting so badly that it side-loads (i.e L-bar connector links).

[riggermick 6]

Quote

You are correct.
Most 5-cord sewing is done parallel to the long axis of webbing.
However in a few places - like just below 3-rings - some manufacturers sew across the webbing. This protects the points of WW stitch patterns (i.e. 3-rings) and or prevents hardware from shifting so badly that it side-loads (i.e L-bar connector links).

A "box" stitch is usually added across the top and sides of a four point stitch pattern at the three ring attachment point. this helps prevent the base ring from peeling and tearing through the four point stitch pattern during a head down opening. The use of a confluence wrap (wide webbing that wraps around the entire joint and is sewn in with the stitch pattern) greatly increases joint integrety and strength. If neither were present (as in the old days) a base ring could seperate the junction during a hard head down opening, causing the diagonal back strap to seperate from the harness and the wearer to drop out. Not so good.
As far as how many times webbing can be sewn, that's a judgement call as there is no maximum set by law, but three sounds prudent.

Mick.

[KevinMcGuire 0]

Storm Dunker presented some very interesting data at the last PIA symposium regarding webbing integrity. His tests focused on the various stitch patterns commonly used in skydiving for example, 3 point 4 point ect... each was tested to destruction using a heavy duty puller similar to the one used by the RWS.
I spoke to him privately after his presentation and he mentioned that he reused the same webbing multiple times for different tests. He also mentioned that he removed the stitching from the previous tests using a razor knife.
Heres the interesting part. Even though he used a razor knife to cut through the 5 cord thread and in doing so cut through unknown amounts of fibers of the webbing itself, he found that the stitching would still fail well before the webbing did.
I am not suggesting that we allow riggers in the field to abuse webbing in this way but to me, Storms findings indicate that webbing can endure far more abuse than some have suggested.
Clearly more testing on this matter is needed.

Having said all of that, lets not forget that failure to error on the side of caution gets people killed

[riggermick 6]

Quote

Quote

You are correct.
Most 5-cord sewing is done parallel to the long axis of webbing.
However in a few places - like just below 3-rings - some manufacturers sew across the webbing. This protects the points of WW stitch patterns (i.e. 3-rings) and or prevents hardware from shifting so badly that it side-loads (i.e L-bar connector links).

A "box" stitch is usually added across the top and sides of a four point stitch pattern at the three ring attachment point. this helps prevent the base ring from peeling and tearing through the four point stitch pattern during a head down opening. The use of a confluence wrap (wide webbing that wraps around the entire joint and is sewn in with the stitch pattern) greatly increases joint integrety and strength. If neither were present (as in the old days) a base ring could seperate the junction during a hard head down opening, causing the diagonal back strap to seperate from the harness and the wearer to drop out. Not so good.
As far as how many times webbing can be sewn, that's a judgement call as there is no maximum set by law, but three sounds prudent.

Mick.

Ah I've finally figured out my new scanner try this:

If the upload limit was more than 60kb I'd be able to show more of the drawing.

Mick.

[riggermick 6]

Quote

Quote

Quote

You are correct.
Most 5-cord sewing is done parallel to the long axis of webbing.
However in a few places - like just below 3-rings - some manufacturers sew across the webbing. This protects the points of WW stitch patterns (i.e. 3-rings) and or prevents hardware from shifting so badly that it side-loads (i.e L-bar connector links).

A "box" stitch is usually added across the top and sides of a four point stitch pattern at the three ring attachment point. this helps prevent the base ring from peeling and tearing through the four point stitch pattern during a head down opening. The use of a confluence wrap (wide webbing that wraps around the entire joint and is sewn in with the stitch pattern) greatly increases joint integrety and strength. If neither were present (as in the old days) a base ring could seperate the junction during a hard head down opening, causing the diagonal back strap to seperate from the harness and the wearer to drop out. Not so good.
As far as how many times webbing can be sewn, that's a judgement call as there is no maximum set by law, but three sounds prudent.

Mick.

Ah I've finally figured out my new scanner try this:

If the upload limit was more than 60kb I'd be able to show more of the drawing.


Um..........I forgot to describe what it is. A 4 point box stitch found on three ring attach points, sorry.

Mick.

Mick.