Mainline tensioning in different temperatures

[Minnesota Tapper]

Almost done tying my mainline up to the high tensile wire. When I started wire tying my tubing project it was 40-50°. Using Chinese finger trap tensioners on each end and with a ratchet on one end on the mainlines I used common sense and put enough tension on the mainline to pull all the sags out. I got it pretty snug within reason. Nice tight straight lines. Now we are in the 20-30° range and the tubing is noticably stiffer and when I pull it tight the little waves dont come out nearly as good as when it was warmer. Being its colder now should I be stretching the mainline more before wire tying? At what temp should mainline not be put up? I dont want to end up with snaked mainlines when it gets warm.

[JoeJ]

I would suggest that your install temperature at 20*-30* is in the mid range of your temperature extremes. You could have lower temperatures to -30* and higher temperatures to 90*. So if I was installing mainline at 30*, I would be pulling the mainline through the tension grip by hand with a good tug and that is it. If you over tighten by cranking the ratchet too much, the main line shrinkage at -30* will pull any fitting in the line apart. I don't think that there is any temperature that you should not put up main line. Just use the the colder it is, the less tension on the mainline method.

Joe

[PCFarms]

I have thought about this problem before and I ran some calculations based on the material properties of the mainline and steel wire:
- 9 gauge wire is good for around 1000 lbs of force. If you install tight 25C and for forest goes down to -25C in the winter, the strain on the wire will increase by 30%. We have had failures of 9 gauge wire due to cold temps when we installed them in the summer.
- For this reason we have switched to High tensile 12 gauge wire. Because the yield strength is much higher, a 50C temperature fluctuation only increases the tension on the wire by 9%, reducing the chance of failure due to seasonal temperature changes.
- For mainline, there are three types, HDPE, MDPE and LDPE. (high, medium and low density polyethylene) Check what your manufacture uses. higher density is not as 'stretchy' and will fail sooner or even crack in cold temperatures under high tension. We have had failure of MDPE pipes around saddles - where the hole drilled is a larger diameter (what style of saddle are you using?). We now use only LDPE - this stuff stretches forever like a plastic bag. Also we use saddles that use small holes. DSD offers LDPE (I actually dont know if anyone else does) and they also have the hose clamp style saddle, which has a small hole on the mainline. We stretch the c*** out if it in the summer and have had no issues in the winter so far. For reference, I calculated that a 3/4" mainline would fail at 250 lbs, a 1" at 450 lbs, a 1 1/4" at 700 lbs and a 1 1/2" at 1000 lbs. Failure in this is case is stretching permanently, not actually tearing apart. So the tear force is much greater than even that. Temperature swings account for 16% of the strength.

[Minnesota Tapper]

I used 12.5 gauge high tensile wire. CDL blue HD 1" and 3/4" main tubing. This is my first install of this kind. Ive been tapping using all 3/16" until now. Heres what I did....
Marked elevation/slope and mapped out mainline route. I then unrolled all my mainlines out on the ground where they needed to be. I left them lay for about a month to let the memory "relax".
While the tubing was relaxing I Installed the ht wire straight from top anchor tree to bottom anchor tree. Pulled wire hand tight and then went back and side tied with 14 gauge side to side to take up all wire slack while getting slope set. With side tying the high tensile got TIGHT!
Attached tubing to the top tree with a tubing tensioner. Then I walked towards the bottom end loosely wire tying the tubing up to the wire every 10'. Making sure to put a longer piece of 14 gauge wire on the inside curve of every side tie. Tubing tensioner at the bottom tree and I pulled the tubing through it hard as I could by hand. I then went back and wire tied every 12" . Where i had initially tied the tubing up on the inside curves loosely with the longer piece of 14 gauge, I now pulled tubing into the curve by putting 4 fingers on the wire and using my thumb to pull the tubing into the curve while I wire tied with my other hand. After each curve was wire tied I removed the now loose piece of 14 gauge. Did this all the way to the bottom. some of the curves it ended up taking quite a bit of effort to pull the tubing into the curve with my thumb to tie it. In these spots id go down to the bottom and let out a little slack from the tensioner grip before I kept wire tying. I installed a wire ratchet on the lower tensioner grip incase I need to take up slack in the future but I didn't tighten them any when installing. Now I have all 3000 feet of tubing up and where it needs to be. I have 5 stainless y's to cut in and connect everything....thinking maybe it would be a good idea to wait until its below 0° to cut in the y's. Hopefully I did ok and dont have it too tight. Seems like everything maple related I end up figuring out how to do it properly about the time I'm done 😆

[PCFarms]

I would get a tool to join the mainlines on the SS y's. Look at the Pruno catalogue, there is item MAINLINE PULLER PLIERS and the MAINLINE CONNECTION PLIERS. These work great, I prefer the puller pliers and you can just pull them together with a ratchet strap.
In terms of pulling the mainlines tight, we run it as you did, and then pull it tight into the curves with the ratchet strap (they are your friend) and the put a dedicated side tie on the mainline itself.