To cat or not to cat, that is the question... (cat your tarp, that is)

[g0bez]

A question to anyone who has made their own hammock tarp (a la blackcat) -- considering this is my first sewing project with silnylon, does anyone have any advice/recommendations in terms of whether it is wise to make the cat cuts? or to stay rectangular? (or hex?)

It looks like there is quite a bit of fabric cut away from the blackcat -- does it provide adequate coverage in rain and/or wind?


I did buy some scrap material to practice on (cotton, so not even similar to sil, but was ~$0.80/yd) and test a shape, maybe between that and other people's input I can get it close to right on the first shot with the sil??


I realize there are a number of variables here (hammock length, ridge length, etc.)... just kinda nervous and looking for some advice... 12' ridgeline w/ 62-ish wide sil.

Thanks!

[angrysparrow]

The BlackCat (12' ridgeline) provides fantastic coverage. I've weathered many storms under mine.

The cat cuts make quite a difference in tautness of pitch. Well worth the effort.

[JerryW]

The cat-cuts really do help you get a tighter pitch. You probably don't need to make them as deep as the Blackcat instructions either. I made mine about 4" deep and they still work fine.

I also made the ground edge wider than was called for. I just wanted a little extra coverage.

That's the great part of DIY - you can try whatever you want.


Jerry

[g0bez]

The cat-cuts really do help you get a tighter pitch. You probably don't need to make them as deep as the Blackcat instructions either. I made mine about 4" deep and they still work fine.

I also made the ground edge wider than was called for. I just wanted a little extra coverage.

That's the great part of DIY - you can try whatever you want.


Jerry

Great points -- I'm thinking of making the cuts a little less deep. Did you use the calculator to get them right or adjust accordingly? Guess I'm still a little unsure about whether there is a certain magic to the exact angle of the curve....

[g0bez]

* a cat calculator that is (like the excel spreadsheet I've downloaded)

[thekalimist]

http://www.mathopenref.com/arcradius.html

[Knotty]

Getting the math right isn't all that critical. You can just flex a suitable item into an arc of the right depth, let's say 4" or 6" and mark the pattern onto the fabric.

[lonetracker]

i put cat cuts into a tarp i just made.i have only been sewing a little while.those curves were very hard ,to my limitted sewing skill to hem.(folded hem)maybe this is why some people use grosgrain ribbon for hemming there tarps?mine turned out well kind of good.did some ironing,taping stich pulling,resewing... maybe i just suck as a sewer
bill

[MondayHopscotch]

I finished my DIY sil tarp a while ago and skipped cat'ing the sides to keep it simple for my first piece of gear.

There is definitely slack in the tarp (nothing ridiculous, but there nonetheless), which didn't bother me, but i can definitely see a tighter pitch being desirable. I vote go for it if you trust your sewing/bs'ing abilities

One benefit of NOT doing the cat cuts the first time around is that if you are happy without them, great --- if you wish you had done them, you can always just go back and redo the edges.

[Ramblinrev]

A couple of sewing tips for doing cat cut hems. 1) use a shorter than normal stitch. Not tiny short unless you really want to spend a good chunk of time for each hem. The shorter the stitch the longer it takes to stitch each foot of length. _But_ the benefit is.. the shorter the stitch the easier it is to go around curves. So a short stitch is worth the additional time IMO. 2) Fold something into the hem when you get started. I use 3/8" twill tape. I would advise against gros grain for this because gros grain likes to go on straight. The weave makes it somewhat stiffer and so you may have to fight to get it around the curve. I know lots of people like using gros grain for binding the hem and I am not saying it is wrong to use. But I think it takes a more skillful or more patient stitcher. The benefits of rolling something inside the em is two fold (groan). It provides an extra bit of strength to the hem. Plus it acts as a guide to help keep the rolls in the hem consistent.