DIY No-tape, No-sew Polycryo (some call it Polycro) Tarp

**ggreaves** · 08-04-2014, 20:03

Polycryo sheets are what you buy from the hardware store to insulate your windows in the winter if they're single pane. Its quite inexpensive, very clear and has amazing tensile strength. It's tough enough to make a good ground cloth and it's so light and compressible you won't even know you're carrying it.

There have been those that have tried with varying degrees of success to make tarps out of Polycryo. Most of the problems people have are not from the tarp material failing, but usually tie outs and ridge line attachment points break or come loose.

I decided to try to make a tarp that:

1. Was one piece. No taping of tarp sections together.
2. Was pointy along the ridge line. (I'll explain this in a minute.
3. Used no tape, grommets, sewing, reinforcements or anything at the tie out points

The sheets I was able to find all had max width of between 60" and 64". This would not be wide enough for a hex or winter tarp shape to be made with 1 sheet. Sheets would have to be taped or sewn together along the ridge line, introducing a potential point of failure. So the shape I settled on was an asymmetrical diamond shape (similar to the stock Hennessy tarp). The dimensions of the rectangle is 11'x5'4". The ridge line therefore is just over 12'.

I did use two sided tape to fold a "hem" around the tarp circumference. The tape peels off jus leaving the adhesive. The finished hem looks like this...

For tie outs I used sheet bend knots. They are easy to tie, easy to undo and hold very well. Here is a pic of the ridge line tie out and a side tie out...

Here are some pics of the completed tarp in the backyard.

And here it is all packed up. I haven't weighed it but it feels like nothing.

That's it. Takes about 1/2 hour to make. Costs about 13 bucks plus whatever tie out cord you use. It's all one piece and has no sewing, or taped together sections. If something will go wrong, it will be with the material itself. I will take it with me for the rest of the summer and report back on performance. For now, though I'll probably have another tarp in snake skins ready to deploy if something goes drastically wrong.

**geneaut** · 08-05-2014, 10:46

Impressive !

**RedStix** · 08-05-2014, 10:57

That is pretty neat. Please keep us posted with performance reports.

**Fancy Ramen** · 08-05-2014, 11:13

My only concern would be the durability of the material. Give us some updates as you use it more.

**ggreaves** · 08-05-2014, 18:56

Ok edges are all taut but it's a little saggy. I'm thinking about bringing the hair dryer outside. Somebody talk me out of it!

**Bushwhacker** · 08-05-2014, 20:01

It's almost as though you've reinvented cuben fiber, except made it accessible. Keep us updated with durability!

**ggreaves** · 08-05-2014, 20:39

if you search Polycro or Polycryo, in these forums, lightweight backpacking forums or on google, you'll see that lots of people have made these tarps. The only thing I'm doing differently is sacrificing aesthetics for function by using tie-outs that won't fail and keeping the integrity of the sheet intact by making the entire tarp from one sheet.

**Otter1** · 08-05-2014, 21:18

I REALLY like what you've done with the tie-outs! NEVER thought of that method! light, easy, and most important: it should last.

**ggreaves** · 08-06-2014, 07:01

Originally Posted by Funny Money

I REALLY like what you've done with the tie-outs! NEVER thought of that method! light, easy, and most important: it should last.

It does have its limitations, though. For a sheet bend to work, you have to be able to gather and make a loop of the fabric. Also, the fabric you're gathering should be an acute angle (< 90 degrees). If you look at the pattern for a winter tarp below, you'll see that the ridgeline angle is a reflex angle (> 180 degrees). To gather this fabric properly for the ridge line tie out would make a complete mess of the tarp, assuming the sheet bend would hold at all.

WinterDream-v2.jpg

A hex tarp would work because the ridge line would be easy to gather. However, to avoid any seams, I'd like to make it from one sheet of Polycryo and I haven't been able to find it wider than 64". For now, the asym tarp is the only pattern that fits the bill and it doesn't have great coverage. I'm trying to find a bulk supplier.

**Thumbs** · 08-11-2014, 07:15

A quick Amazon search turned up a 7x10' sheet. Might be OK for an asym of almost 11' ridgeline.

http://www.amazon.com/Duck-281065-In...productDetails