So after making my tarp out of this stuff I figure I better do some testing on it since not very many people have tried to use it as a tarp. Maybe they're smarter then me :)
The things I wanted to find out were mainly were:
1) What is the best type of tie-out?
2) How much Tape is needed on the tie-outs?
3) What is the tensil strength of this material?
4) How does this material act in stress loading?
5) How strong is the double sided tape provided in the box?
Please note that I am not a scientist but rather a very curious frugal person. Nothing I did is very scientific but it is better to have "some" data then no data at all. And of course I took lots of pictures!
All test smaples were about 3" wide and 20 something inches long. I first started out using a tie-out that I have on my tarp that I made. It's basically the tape folded over itself with a hole thru it. The tape used was Gorilla Glue Tape.
This tie-out ripped with pretty minimal effort. It still took a good pull but I thought it would have done better. This is what it looked like after.
I then tried a plastic washer sandwiched between the tape. This was an idea given to me by another member here and I'm sure happy I tired it out. Sure enough the plastic washer that measures 3/4" diameter worked like a charm. So well in fact that I used it exclusively on every test here after simply because it wouldn't rip out.
Next I needed to know how much tape to use on the tie-outs. This is very important to know since the tape is the heaviest part of the tarp. I first started out with a 4" piece of tape folded over with a contact length of 1" on the tarp body. This allowed the other inch to be used to sandwich the washer. You can see this on the photo above. I then did the same thing but used a 5" length piece of tape folded over. I kept the same washer distance but now I had a 1.5" contact length on the tarp. Then I strung up my super scientific measuring tool to see which side would pull off first.
Sure the test area looks a little "elementary" but hey, it worked. In the photo it looks like the bag is touching the ground but it is actually about 2" from it. What I found out next surprised me. I started loading up the weights. First 5lbs then 10lbs then 15lbs then 20lbs etc... it finally failed at 35 lbs. And it was the material itself that broke. Both tie-outs held beautifuly. The material upon failure made a loud snapping noise that was pretty loud. The polycryo had sheared directly in a straight line across the middle of the sample. It should be noted that on every sample conducted the polycryo sheared off in the very middle. Not near the tie-out, but in the very middle. I found this pretty interesting. Upon further review I can tell you that when loaded the polycryo does stretch. Each sample stretched about 6" before failure. It should also be noted that I measured the distance each sample of polycryo slipped from the tape. And interesting also was that there was not any slipping of the material from the tape on any test.
So after that test I could conclude that both tie-outs were overkill for the material. I then tried the test with a different tie-out. This one is a 1" piece of tape that is 4" long with the washer with a contact length of 1" on the polycryo.
The test on this tie-out was only about 20lbs. I'm not a scientist (remember), but I think that it failed sooner due the concentrated stress it applied to the very center of the sample. Versus the previous samples that were done with 2" wide tape and were able to distibute the force thru alomst the entire sample width of 3".
Here is a photo of what the polycryo looks like under 30lbs of force.
After the foroce had been applied I removed the load to examine the material. Sure enough it stretched a little but it didn't show too much signs of deformation.
Next I wanted to see how the material did when I applied a single line of it's double sided tape that is included in the packaging on the sample under stress. I figured if it improves the strength then it could be useful to help out critical areas.
The test sample held about 40lbs and just like all the other tests it failed in the very center. Here's an after photo of the stressed piece.
The next test was to figure out which is stronger: The polycryo or the doubled sided tape. I made the same 4" tie-outs on the sample and applied force till failure. I cut the sample in half and then rejoined them with the tape. I then applied force till failure. I found out that the double sided tape has a stronger hold then the material. The polycryo sheared in half on one of the sections and the taped connection looked just like new without any slipping of the material on the tape.
I hope this series of tests shines some light on polycryo for everyone. I know it did for me. I guess what I can conclude is this. My original tarp used WAY TOO MUCH tape and the tie-outs aren't nearly as strong as they could be if I used washers. For all further polycryo shelters or anything I make with the material I think I'll "hem" the edges with the double sided tape as it showed it is stronger then without it. Also, I'm sure someone could use another type of tape to reduce weight but Gorialla Glue Tape is what I had laying around and from everyone at Home Depot they said it was the strongest they sell.
Now, Lets discuss!