12' XL Winter Haven on the way

[cmc4free]

Well I'm at a bit of a loss now...I left the tarp set up overnight and the poles straightened out a tad but are still way too tight with the tarp. I'm assuming a tarp stretches less in cold weather? It's almost as if I need a set of adjustable poles to allow for the changes in the tarps stretch....I guess this is the issue with going with the nylon type tarp that is known to have more stretch...

In general, due to thermal expansion, materials will contract under colder temperatures and expand under hotter temperatures. This goes for the poles as well as the plastic fibers that make up the fabric of the tarp. Theoretical expansion/contraction is pretty simple for basic shapes like a block, cylinder, tube... I wouldn't claim to have any real knowledge for how this affects materials with complex geometry like a fabric woven from extremely thin/long fibers. I would assume though that the overall width of the tarp pulled taut would measure less in winter temps and more in summer temps. Likewise, the poles will be a little shorter in winter than they would in summer, by small amounts - fractions of an inch.

So it may not be that the tarp stretches less when it's cold - it's technically a "smaller" tarp when it's outside in the cold vs. when it's at ambient indoor temperatures.

As a winter tarp, it probably makes the most sense for the pole length to be sized correctly for the tarp when both are at cold temperatures, say 0*F.

No real help here... just some random musings...

[SteveE]

I appreciate that insight...makes good sense to me!

[cmc4free]

For a DIY'er, it might be an interesting idea to make a pole mod with 2 sets of pockets for the pole ends. One an inch or so above the other. Insert pole ends in the upper pockets in spring/fall or in the lower pockets in winter.

[OneClick]

For a DIY'er, it might be an interesting idea to make a pole mod with 2 sets of pockets for the pole ends. One an inch or so above the other. Insert pole ends in the upper pockets in spring/fall or in the lower pockets in winter.

That would be great!! Just like a daisy chain suspension, pick what works best at that time.

[Othello]

For a DIY'er, it might be an interesting idea to make a pole mod with 2 sets of pockets for the pole ends. One an inch or so above the other. Insert pole ends in the upper pockets in spring/fall or in the lower pockets in winter.

This is a fantastic idea...and would be required for the center pole only, and then only on one side, yes? Adjust the tension, seasonally or otherwise, on the side poles by simply moving the tie-off point closer to/further from the center of the ridgeline.

In any event, IMHO, I'd prefer too loose (gap between the pole apex and ridgeline seam) to too tight (having the tarp excessively stretched and poles bent). Beyond that, minimization of fiddle factor would be a priority for me.

[SteveE]

Ya tight like this makes me nervous about damaging it...the problem is with having it too loose is that trough that gets created when the poles pull down on the ridgeline of the tarp....

[cmc4free]

This is a fantastic idea...and would be required for the center pole only, and then only on one side, yes? Adjust the tension, seasonally or otherwise, on the side poles by simply moving the tie-off point closer to/further from the center of the ridgeline.

Those suggestions seem correct to me.

My winter tarp is from UGQ and I now have center pole and end poles. The center pole has 2 lengths of shock cord with mitten hooks - each clips onto the split rings at the ends of the ridgeline. The end poles each have 1 length of shock cord with a mitten hook that clips onto the ridgeline split ring at their respective ends. (No intent to muddle up this thread in the SLD subforum, but any tarp internal poles could be modded to work this way, if desired). I do have a SLD Trail Haven with internal center pole, and that one just attaches to the tarp ridge seam via a pole clip, like you'd find on a dome tent. That doesn't offer the adjustability of the ribbon ties, like on OneClick's Winter Haven.

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[OneClick]

I just realized I never posted a clear pic of what was going on during my first trip. You can see the big gap on two of the poles. The third is about the same but out of frame in this shot. Other than looking sloppy, it puts way too much tension on the ribbons, so that's why I have them tied loose - just to keep them from falling completely to the side.

Looking at this, it's easy to think "just tighten or loosen the tarp, or ridgeline"..."stake further apart, or closer". Believe me, I tried everything and it didn't matter.

[Othello]

Yessir, I see your point, and why you needed longer pole sections. I must reissue my statement to say that ...I'd prefer a little too loose to way too tight...

That UGQ diagram for the end poles is exactly what I was thinking of, but it appears that the end poles in question may be even too short for that to work. They'd never hit the top of the tarp, and swing right through to the doors, perhaps!

[SteveE]

I wonder if attaching something like this to each tie out would allow some flexibility. I'm thinking the same idea but instead of a d ring on the end, maybe a few extra grommets. That way you could slide the pole end into a different hole depending on how tight or loose the tarp is at the time. It would be easy to adjust once the tarp was set up as well as if the tarp loosened you could just pull out the pole and put it in a hole closer to the tarp, thus making it taught again? I have that on my MEC winter tent and it allows me to keep the fly taught regardless of how much slack is in the fly...

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