Here is a message from Brian Smith, owner of Powerline Sports, on the subject of line stretching.

I hope that this advice will prove useful. Giles.

Giles,



First you need to understand about stretch.

Normal braided line does not stretch so much as the braid is locked down when you “stretch” it like a Chinese finger trap. Spectra fiber itself has very little stretch, but there can be a substantial amount of mechanical stretch depending on the braid pattern and angle of the braid chosen by the line manufacturer.



Q-PowerLine has a linear core where all the strength is. When you “stretch” Q-PowerLine all you are really doing is improving the alignment of the already linear fibers.

If you stretch the line you should always have one end of the line terminated with the loop that you will be using and then pull the line with a load equal to a maximum 50% of it’s breaking strength, any more than this is will only increase the risk of breaking internal fibers and weakening the line without improving the stretch, this is actually true of all Spectra lines. If you do not use a loop and pull with a screwdriver you will probably start to break individual fibers since the diameter of the screwdriver is such that you put an unequal load on the different parts of the core. You will also probably not be stretching the line so much as pulling the sheath off the core when you wrap the line on a screwdriver.



You will normally get 1 to 1.5% of this type of stretch 12 to 18 inches on 100 feet.



Using a vehicle on an incline is fine if you wish, although I would not do that with line that is rated at 600 lbs (even though Q-Powerline is under-rated). As you can very easily break or damage the line.



How do you stretch lines properly?



1) Make a proper loop using a figure 8 knot on one end, http://www.powerline-sports.com/knots.html , either sleeved or unsleeved, depending on your preference.

2) Place this end on an immovable object (such as a hook in a tree)

3) Use a wooden dowel (minimum diameter 1 inch) and wrap the line 10 times around the dowel overlapping itself on each wrap. This will lock the line and the core, ensuring that you stretch the whole line and not just the outer sleeving.

4) Lean back, exerting approximately 300 lbs pressure with your legs, and pump the line about 10 times. You will feel the line give the first few times and then stop (the kinks are all out of the line) and the line is as stretched as it will get.



After flying a few times, check your line lengths and adjust them if necessary.



The only way you can actually take all of the stretch out of the lines is by flying them, as constant pressure does not work (the fibers just lock up on each other). The pumping mentioned above works fairly well but flying puts varying pressure on the lines repeatedly for a long time, taking all of the possible stretch out of the line, aligning the fibers, removing the kinks and tightening down the outer sleeving on the core to the maximum.



After that, all spectra fiber will have some “creep” (non-recoverable stretch) as the lines age. There is not way to engineer this out of the line as it is actually molecular creep and is a function of the material.

Keep your lines clean by rinsing them off occasionally with fresh water. Salt water does not attach Spectra fiber, but the dried salt and sand particles will act like small knifes, prematurely wearing the lines.

If you fly a lot, switching your lines end for end occasionally will balance out wear on the lines where they cross when flying.



Enjoy flying and feel free to contact us with any line questions you may have.



I hope this helps.



Regards,

Brian

Thanks Giles.

Brian has provided an updated version on line stretching. Giles

it, like a Chinese finger trap. Spectra fiber itself has very little stretch, but there can be a substantial amount of mechanical stretch depending on the braid pattern and angle of the braid chosen by the line manufacturer.

Q-PowerLine has a linear core where all the strength is. When you “stretch” Q-PowerLine all you are really doing is improving the alignment of the already linear fibers, and taking any kinks out of the line.

If you stretch the line you should always have one end of the line terminated with the loop that you will be using, and then pull the line with a load equal to a maximum 50% of it’s breaking strength, any more than this is will only increase the risk of breaking internal fibers and weakening the line without improving the stretch, this is actually true of all Spectra lines. If you do not use a loop and just wrap the line around a screwdriver and pull, you will probably start to break individual fibers in the line core, as the diameter of a screwdriver shaft is such that you put an unequal load on the different parts of the core. You will also probably not be stretching the line so much as pulling the sheath off the core when you wrap the line on a screwdriver.

You will normally get 1 to 1.5% of this type of stretch, or 12 to 18 inches on 100 feet.

Can I pull the line using a vehicle on an incline?

Use a vehicle on an incline if you wish, although I would not do that with line that is rated at 600 lbs (even though Q-Powerline is under-rated). As you can very easily break or damage the line, since you cannot control the amount of tension you are putting on the line accurately.

How do you stretch lines properly?

1) Make a proper loop using a figure 8 knot on one end, http://www.powerline-sports.com/knots.html , either sleeved or unsleeved, depending on your preference.
2) Place this end on an immovable object (such as a hook in a tree)
3) Use a wooden dowel (minimum diameter 1 inch) and wrap the line 10 times around the dowel overlapping itself on each wrap. This will lock the line and the core, ensuring that you stretch the whole line and not just the outer sleeving.
4) Lean back, exerting approximately 300 lbs pressure with your legs, and pump the line about 10 times. You will feel the line give the first few times and then stop (the kinks are all out of the line) and the line is as stretched as it will get.

After flying a few times, check your line lengths and adjust them if necessary.

The only way you can actually take all of the stretch out of the lines is by flying them, as constant pressure does not work (the fibers just lock up on each other). The pumping mentioned above works fairly well but flying puts varying pressure on the lines repeatedly for a long time, taking all of the possible stretch out of the line, aligning the fibers, removing the kinks and tightening down the outer sleeving on the core to the maximum.

After that, all spectra fiber will have some “creep” (non-recoverable stretch) as the lines age. There is not way to engineer this out of the line as it is actually molecular creep and is a function of the material.

Keep your lines clean by rinsing them off occasionally with fresh water. Salt water does not attach Spectra fiber, but the dried salt and sand particles will act like small knifes, prematurely wearing the lines.
If you fly a lot, switching your lines end for end occasionally will balance out wear on the lines where they cross when flying.

Enjoy flying and feel free to contact us with any line questions you may have.

I hope this helps.

Regards,
Brian

PowerLine Sports
4 Windbrook Crescent
Kanata, Ontario
K2M 1L4
Canada