Sewing curves on ripstop? and other questions

[tight-wad]

Making a cat cut tarp. Marked and cut the fabric. Left room for a rolled hem. Sat at the sewing machine with all this in my lap. After many minutes, got up, grabbed some scrap, marked and cut a "training" piece, and began tinkering.

1 - How do you make ripstop cooperate on curves??? We have been fighting over this. Surely there's a better technique than brute force? Ha - brute force on 1.1 sil...

2 - A whole lot of fabric in the tips with a rolled seam on both sides. I'm going to muddle through and cut some darts, but is there a rule of thumb or some such about cutting out darts?

3 - I plan for a rolled seam. OK, roll em up boys and start sewing. But... I'm sewing from one side, and all the marks are on the other side... Hmm... How do I "see" what I'm doing? I spent too much time marking the curve on a template and transferring the template to the fabric to just wing it on the final step.

And - this fabric is too expensive to just waste in my blundering...

Thanks,

tight-wad

[warbonnetguy]

if you free style it, try just folding the raw edge once and stitch. then after that, go around again and do the second fold and stitch. since it's sil and curved, just try and stitch a couple of inches at a time, if you try and freehand a long stretch, the curve will become un-consistent.

washable glue stick from wm can also be a great help with sil, but with a 2 fold seam, water may never get in there to wash it out the gluestick.

lots and lots of straight pins can help too.

i think if you sew one fold at a time and do it in short (2-3") stretches, then stop the machine and fold another 2-3" and repeat, you should be ok, it is probably trying to sew 2 folds at once that is causing the most trouble.

sil can be a pain, but just take your time, and your results will show it.

[Schneiderlein]

Making a cat cut tarp. Marked and cut the fabric. Left room for a rolled hem. Sat at the sewing machine with all this in my lap. After many minutes, got up, grabbed some scrap, marked and cut a "training" piece, and began tinkering.

1 - How do you make ripstop cooperate on curves??? We have been fighting over this. Surely there's a better technique than brute force? Ha - brute force on 1.1 sil...

2 - A whole lot of fabric in the tips with a rolled seam on both sides. I'm going to muddle through and cut some darts, but is there a rule of thumb or some such about cutting out darts?

3 - I plan for a rolled seam. OK, roll em up boys and start sewing. But... I'm sewing from one side, and all the marks are on the other side... Hmm... How do I "see" what I'm doing? I spent too much time marking the curve on a template and transferring the template to the fabric to just wing it on the final step.

And - this fabric is too expensive to just waste in my blundering...

Thanks,

tight-wad

1. A rolled hem presser foot works well, and you can follow curves easily and make a consistent width seam, but it takes a little bit of practice, and may still mess up on the corners. That can be covered up with the tie-outs, though. The rolled hem feet I have seen make a pretty narrow seam (2-6mm range, I use 4mm) and are about $12-$20, so if you want a wide seam that's probably not an option for you. I find wide seams more difficult on curves and narrow seams impossible without a rolled hem foot or lots and lots of pinning and ironing (never done this on sil, not sure how well it would tolerate the ironing).

2. I am not sure if I understand you correctly. Are you talking about the corners? If your fabric comes together at the corners at an angle <<90 degrees, you can just cut off the tip at the point where the width is four times the width of your seams. Cut perpendicular to the bisector. When you do the second seam, you can tuck under the small piece of fabric that will protrude. The shape of a dart is quite complex if you want to make the two sides come together at a point, I just tried it on paper. It is also not symmetric, so you have to be very careful. Just cut it in a straight line and cover up any ugliness with the tie-out.

3. I don't mark rolled hems at all. Since your fabric edge already has the cat cut, just try to make an even seam as best as you can and you should be all set without need for additional marking.

Good luck and let us know how it turns out (photos)!

[Mule]

This is an excellent question. I had considerable trouble with my so-called battarp. I am anxiously awaiting enlightenment. I bought a MacCat from Brian that is flawless, but he binds the edges with narrow webbing. Mule

[stoikurt]

In my experience it's impossible to eliminate all puckering when trying to hem a cat curve or any type of curve for that matter. Unless the threads in the material move (like bias tape) or the material is very stretchy then the physics of it just don't allow for a perfectly smooth and flat seam; there will still be a little puckering. If you use a bias tape or gross grain ribbon over the seam you can cover up a lot of that. Otherwise, the narrower the seam then the less puckering you will get. But that's why you only do a few inches at a time or pin the heck out of it.

[tight-wad]

... do it in short (2-3") stretches, then stop the machine and fold another 2-3" and repeat, ...

2-3", over 11 feet x 2 + 10 feet x 2. Ouch, that hurts! Definitely not something you wait to do the night before a big trip! You did not say it, but I presume having your favorite beverage at your side makes it seem to go faster.

How on earth can the Jacks and Ed and others make any profit on these things after looking at the tedious labor costs?!?!?!

Thanks to everyone who replied. I was hoping that there was a magic bullet out there that would make this easy. Apparently not.

I'll post pix, but it may be a month from now given that I can only work on this hobby a limited amount of time And, I doubt that anyone will be impressed, its only going to be another cat cut tarp...

[stoikurt]

Even if you freehand the rolled hem and stitch 2-3 inches at a time you should still be able to hem the whole perimeter in a couple hours or less.

[Preacha Man]

I am in the same process now, I just finished cutting my cat tarp, but now have to roll hem it all. My wife wants me to just serge it. Is there anything wrong with that? It sure would be a lot easier, but would the rolled hem make it stronger? Anyway I have time, I do not need it for another couple of weeks.

[Just Jeff]

Yes, the rolled hem would make it stronger. I've never seen a tarp hem serged, even on cheap walmart tarps. That's gotta tell you something.

[Preacha Man]

Yes, the rolled hem would make it stronger. I've never seen a tarp hem serged, even on cheap walmart tarps. That's gotta tell you something.

Thanks JJ, I better get to work then.