Is grossgrain necessary for DIY rain fly edges?

[alexdickerson]

So I'm starting to make my first DIY tarp. I want to make an asym diamond fly out of PU coated ripstop. Some tutorials I'm reading over say that I should use grossgrain to line the edges. Is this necessary?

Thanks in advance

[SilvrSurfr]

Not necessary, but some think it provides a tighter pitch. I just made a silnylon tarp using Fronkey's tutorial and have grosgrain reinforcements on the corners/tie-outs only.

[alexdickerson]

My thought is that I'll do the same, reinforce the corners with it, but that the coated 1.9 will give it some extra strength as opposed to 1.1 sil. Weight is no concern.

[humer91]

I dont think it is necessary (didnt use it on mine) but it does give it a more "finished" look

[boulderv7]

Definitely not necessary, but it does look more finished. doing a rolled hem on a curve can be a bit tricky, depending on the depth of your curve. Either way works fine, I have done tarps done both ways. I always finish with grossgrain now because it is easier for me.
One thing to add, the grossgrain may soak up water, leaving you with a slightly heavier tarp after a good rain. I've never noticed the weight.

[alexdickerson]

What if I'm doing just a rectangular tarp with no cat cuts? Or is that not recommended?

[jwh123]

The only grosgrain I used to make my tarp were pieces about 8-10" long at each of the 6 corners to make the tie-out tabs on my 1.1 nylon tarp, which I then applied my own sil treatment to - it's a 12'x11' hex-cat tarp. The edges I just did my best at a rolled hem - and yes, they did partially unroll as they were sewn. And I used triangles of the same 1.1 nylon to reinforce the corners. I wasn't necessarily going for super lightweight, but I just didn't think there was a need for the heavier reinforcement and continuous grosgrain. I've only had this tarp out for less than a dozen nights, but it hasn't given me any problems.

Based on all the comments I see on this forum about reinforcements, grosgrain edges, and tie-outs relating to tarps, I keep getting the feeling I'm doing my tarp incorrectly if it isn't pitched as tight as a drumhead.

I feel like a slacker because I don't mind a bit of slack and ripples in my tarp!

HYOH!

[ripstopbytheroll]

Yeah not necessary, but looks more professional IMO and I'm a details guy. I actually feel like you can potentially get a tighter pitch without the grosgrain depending on how stretchy the silnylon is. On the other hand, the grosgrain provides extra reinforcement that will help for lighter/thinner/stretchier sil, especially on the cat curves. So you really have two things pulling you in opposite directions (no pun intended).

At the end of the day, I would use the grosgrain, but that's just me.

[boulderv7]

What if I'm doing just a rectangular tarp with no cat cuts? Or is that not recommended?

Either way again. If trying to save weight, skip the grosgrain. A rectangular tarp works just fine and you can use it for other things as well like cooking and going to the ground. They can be pitched in many more configurations.

[wgiles]

I made one silnylon tarp with grosgrain in the hems and one without. I like the grosgrain because it makes it easier for me to sew and looks better.