RBTR MEMBRANE silpoly tarp with doors on one side

**ksbcrocks** · 09-27-2015, 09:26

I didn't really need a new tarp, but I really wanted to try out this new fabric. I decided to build a tarp with doors on one side. I'll preface this by saying once I felt the fabric in my hands I got nervous about making this tarp. It's significantly thinner than the regular silpoly, and much much much stiffer than the membrane 66, which caught me off guard. This is probably due to the 2000mm HH rating

I started off with the diygearsupply.com winter tarp plans, but added a few inches to the ridgeline and removed one set of doors.

Since this fabric has a right and wrong side, I had to be careful with how I cut it. It's also pretty tough to tell the two sides apart. I decided cutting it the way in the following image resulted in the least amount of fabric waste.

So I laid out my fabric and got to marking and cutting. I decided against doing the catenary cuts so that saved a lot of time and frustration. I like using books to hold down the fabric while I do all of this stuff, and I just use the tape measure as my straight edge.

Let the sewing begin! First thing to do was to do a rolled hem around everything but the ridgeline. I was very impressed with the way this fabric handles in the machine. Making a very small rolled hem was a piece of cake, even along the bias.

For the ridgeline I did a flat felled/french seam hybrid, simply because I haven't used that on a tarp before. It's less fussy than a flat felled seam so I'll probably use this from now on. All that was left after that was to sew on all the tieouts! I don't use fabric reinforcement when I make my tarps. I just sew a 9 inch piece of grosgrain near the perimeter of the tarp folded over at the corner and sew my tieouts on to those.

This color is Dark Olive, and I like it a lot. When I first saw the fabric and was working on it insider the house it looked a lot greener than I was hoping for. Now that I have it hanging outside the dark brownish color I was wanting has appeared.

I might decide to add some panel pulls, but right now I don't think I need them. I can pitch the tarp pretty wide and still get good coverage by moving my hammock closer to the side with the doors.

This tarp has a much different sound to it than my silnylon tarps. It should be interesting in the rain. I'll report back with that information after I get it in some weather.

My scale isn't very precise, but it's showing that the tarp weighs about 13 ounces with guylines, which is the same as my smaller nylon hex without doors. I'm a happy guy.

**Lobstergrabber** · 09-27-2015, 10:05

Sharp looking tarp. Looked like some quality thread injecting as well.

Richard

**ripstopbytheroll** · 09-27-2015, 12:00

This is sweet. No cat cuts are definitely the way to go. Is this essentially a warbonnet style tie out?

Also we had some decently heavy overnight rain on Friday at fall sprawl and I used the Membrane tarp. My only comparison on sound is my hex made out of a material called soar coat that has a similar finish on the crisp side. I couldn't tell any difference in sound. I was actually happy to have rain so I could test it out.

**Eidson** · 09-27-2015, 12:33

Very nice! Appreciate the share.

let us know your thoughts after getting it out in the rain and"properly" tested.

**fletchisgreat** · 09-27-2015, 12:50

Nice, interesting no cat cuts

**ksbcrocks** · 09-27-2015, 13:42

Originally Posted by ripstopbytheroll

Is this essentially a warbonnet style tie out?

Yep, that's what I modeled it after originally. It's been a long time since I've seen a Warbonnet tie out and I know the way I do it has changed a bit though. I just thought of an idea to add a little bit more load disbursement since this fabric is thinner than what I'm used to. I'm going to try it out on one corner and see if it helps.

*update: idea added*

I've got rain coming tonight, so I'll sleep outside and give it its first real test. I haven't sealed the ridgeline, but hopefully the seam will keep the water out still.

**FJRpilot** · 09-27-2015, 15:44

I really like this, great job! I really like what you did with the tie outs. Going to try that on my next tarp. Thanks for sharing with us...

**LookinForArrows** · 09-27-2015, 16:32

Very nicely done!

**ksbcrocks** · 09-28-2015, 09:30

An update after a night in the rain.

I definitely need to seam seal the ridgeline. I got dripped on a little through the night. I'll have to order some stuff to do that since this stuff won't take the normal silicone mixtures.

In regard to the sound, I was expecting it to be much more "papery" but it's really not much different than anything else. It's still a nice sound to fall asleep too.

Another thing to note is that currently this fabric won't compress down as much as silnylon or silpoly. Maybe as the fabric breaks in it'll get better. It's not really bad, but this is how stiff it is:

An empty stuff sack with a cordlock will stand up by itself. Impressive!

I like the design change I made to the tieout reinforcement and will be adding the extra piece of grosgrain to the rest of the tarp.

Waking up this morning, the tarp looked exactly how it did when I went to sleep. I really like not having a loose tarp in the morning and having to worry about the now loose fabric getting blown in against the hammock.

My still early conclusion is that your next tarp should be made out of this stuff. It rocks.