Flat-Felled Seam for BlackCat ridgeline

[macfly]

Hi y'all,

Have to confess I've been lurking these parts for a while now and am long overdue for posting! This place has become like the little devil (in-a-hammock) on my shoulder. At the beginning of the summer I thought I had it all with my new Hennessy Explorer Ultralight...well, now I'm sitting here in my mom's sewing room, knee deep in silnylon and binder clips, daydreaming about hanging with my ring buckle setup out in the Loess Hills this weekend . I'm not even gonna reveal how many Wal-Marts I've walked into in the last month!

Suffice it to say the hammock world has pretty much swept me right off of the ground and into asymmetrical bliss thanks to the friendly dialogue and valuable information on these forums and related websites. You gals and guys rock!!!

So my question is, I'm making a BlackCat tarp. I've made the caternary cuts and am now at the point where I need to sew a flat-felled seam on the ridgeline. I have the tarp halves lined up squarely on the ridgeline and secured with binder clips. I'm confused because according to everything I've read about how to do a flat-felled seam (here, for example), the bottom piece of fabric's seam allowance needs to be twice that of the top piece of fabric. However it seems like Blackbishop has made it pretty clear at the end of Step 1 and beginning of Step 2 that the two pieces of fabric need to be lined up squarely along the edges. Is there some kind of modified flat-felled seam that I'm unaware of that allows me to proceed from here without re-aligning and clipping/pinning the two tarp halves again?

Hope that makes sense, if not I am happy to try and clarify.

Adam

[thereisnospoon]

To the best of my knowledge, the only way to do a flat felled seam is to leave a double seam allowance on the bottom portion of the material and then open up the two halves and fold the longer seam allowance into the stitch line of the seam and stitch a second time.

You may be thinking of trying a French Seam. This might work okay, but the FF is better, IMHO. Just remeber you can't use an iron on SilNylon...

http://www.thru-hiker.com/workshop.asp?subcat=11&cid=16

A little hint iof you've never sewn a flat-felled seam before: DON"T GET IN A HURRY! If you want the seam to be neat, take your time and fold the material nicely, holding it tight with your right hand and pull slight tension on the material with your left hand as it feeds through the machine. Every time I get in a hurry tryig to do an FF seam it looks like crap.

Also, if your addiction gets bad enough, a nice walking foot helps feed the slippery materials we use in Hammock/tarp construction...

http://www.overstock.com/Home-Garden...3/product.html


Best of luck !

Spoon

[Nightwalker]

A flat-felled seam is just a french-fold seam lain over flat and sewn again. Try it on some scrap fabric first. Draw lines with dressmaker's chalk or a tailor's pencil.

It's not that hard, but practice helps a LOT!

P.S. I like pins better that clips, but you have to make sure that you seal the holes if they are in a weather situation. You were gonna seam-tape or -seal anyway, right?


Frank

Hi y'all,

Have to confess I've been lurking these parts for a while now and am long overdue for posting! This place has become like the little devil (in-a-hammock) on my shoulder. At the beginning of the summer I thought I had it all with my new Hennessy Explorer Ultralight...well, now I'm sitting here in my mom's sewing room, knee deep in silnylon and binder clips, daydreaming about hanging with my ring buckle setup out in the Loess Hills this weekend . I'm not even gonna reveal how many Wal-Marts I've walked into in the last month!

Suffice it to say the hammock world has pretty much swept me right off of the ground and into asymmetrical bliss thanks to the friendly dialogue and valuable information on these forums and related websites. You gals and guys rock!!!

So my question is, I'm making a BlackCat tarp. I've made the caternary cuts and am now at the point where I need to sew a flat-felled seam on the ridgeline. I have the tarp halves lined up squarely on the ridgeline and secured with binder clips. I'm confused because according to everything I've read about how to do a flat-felled seam (here, for example), the bottom piece of fabric's seam allowance needs to be twice that of the top piece of fabric. However it seems like Blackbishop has made it pretty clear at the end of Step 1 and beginning of Step 2 that the two pieces of fabric need to be lined up squarely along the edges. Is there some kind of modified flat-felled seam that I'm unaware of that allows me to proceed from here without re-aligning and clipping/pinning the two tarp halves again?

Hope that makes sense, if not I am happy to try and clarify.

Adam

[slowhike]

yep, pins will hold the slick sil better.
at first i was afraid of putting all those pin holes in the sil, but as some one pointed out, the sewing machine is putting multiple holes in the fabric.
when you seam seal it, they all get filled.
welcome to HF adam. ...tim

[lvleph]

Hi y'all,

Have to confess I've been lurking these parts for a while now and am long overdue for posting! This place has become like the little devil (in-a-hammock) on my shoulder. At the beginning of the summer I thought I had it all with my new Hennessy Explorer Ultralight...well, now I'm sitting here in my mom's sewing room, knee deep in silnylon and binder clips, daydreaming about hanging with my ring buckle setup out in the Loess Hills this weekend . I'm not even gonna reveal how many Wal-Marts I've walked into in the last month!

Suffice it to say the hammock world has pretty much swept me right off of the ground and into asymmetrical bliss thanks to the friendly dialogue and valuable information on these forums and related websites. You gals and guys rock!!!

So my question is, I'm making a BlackCat tarp. I've made the caternary cuts and am now at the point where I need to sew a flat-felled seam on the ridgeline. I have the tarp halves lined up squarely on the ridgeline and secured with binder clips. I'm confused because according to everything I've read about how to do a flat-felled seam (here, for example), the bottom piece of fabric's seam allowance needs to be twice that of the top piece of fabric. However it seems like Blackbishop has made it pretty clear at the end of Step 1 and beginning of Step 2 that the two pieces of fabric need to be lined up squarely along the edges. Is there some kind of modified flat-felled seam that I'm unaware of that allows me to proceed from here without re-aligning and clipping/pinning the two tarp halves again?

Hope that makes sense, if not I am happy to try and clarify.

Adam

Not to say that BB doesn't know what he is doing, but I didn't feel his explanation of a FF seam made sense. The way I do it and the way I have read it, was to line the top piece of fabric up so that it is 1/2" in from the edge of the bottom fabric (for 1/2" seam allowance). Then sew the top and bottom pieces together 1/2" from the edge of the top piece. This will result in a seam 1" in from the edge of the bottom piece. At this point you want to unfold the fabric, so that the two halves are side by side. The bottom we will say is now the right side. Fold the right side edge over the left (this is why it is longer), and then fold both together to the left. Sew along the left edge of the seam. Voila a flat felled seam.


EDIT: This is a better explanation and has pictures.

[Rapt]

A flat felled seam actually isn't the same as a french seam folded flat and stitched again although the french seam version is easier to sew possibly.

A flat felled seam actually wraps both fabrics around each other as shown here

It effectively hooks each fabric into the other making a seam where the tension is applied to the fabric via the fold rather than on the stitching. It also has the added effect of giving a neat finished seam with no exposed seam allowances.

When you aren't sure about sewing something it really helps to look at sewign specific material. There's tons of info out there, even if it is mostly aimed at women, its still the same techniques.

[T-Dubs]

The instructions I got on-line for a 'flat-felled' seam had me line up both raw edges (I used pins also) and sew a 3/4" seam. From there, I cut off +/- 3/8" on one of the edges, folded and stitched.

I mentioned in an earlier post the time frame for this step isn't real clear. For me, it was:
'Step one. Sew a flat-felled seam'
'Step two.... (so I'm thinking it's easy here)

Well, it took me about 3 hours of fussin' cussin' and sewing to get to that
2nd step. My wife called it a classic 'Stitch and *****'.

Take your time and apply a little outward tension on the silnyl material. Mine tended to wrinkle or bunch-up at the needle. I've got a few puckers in my earlier seams due to this. Once you get a feel for the material it isn't so bad.
I also had to adjust my thread tension on the thicker seam.

TWS

[Cannibal]

I'm just glad someone brought this up! When I was making my BlackCat I found two different websites showing how to make a "Flat Felled Seam". One showed it lined-up and the other showed the half inch bit. It caused much distress in my little mind. Maybe this thread will save someone else that aggravation.

[Rapt]

The classic sewing approach is to line it up with an extra wide allowance and then cut half of one of them away and wrap the other over it. This is hard with fabrics like silnylon that is slippery and fabrics that we can't iron and get to take a crease.

By showing the end result we're trying to get to its easier to see that there are other ways to get the same result. With fabrics that are hard to crease/fold easily and can't be pressed I often run an extra line of stitching to "hold" the crease. I find running the seam through once more in an easy seam mode is easier on me than trying to do too many things with a seam in one pass.

My usual method for a flat felled seam is to:

1) Sew the two pieces together (wrong or bottom sides together will put the seam on the top) with the offset seam allowance (rather than cutting it) to save fabric.

2)Then keeping the two layers in the same position roll/fold the longer allowance over the shorter one lining its edge up with the first line of stitching (like you were doing a single hem) and stitch that in place.

3)Open out the fabric flat along the seam as you want it in the finished product, and fold the hemmed seam allowance flat against the main fabric putting the exposed fabric edge "inside". Stitch this down. A second line of stitching is unnecessary, as you already have three in this hem.

As others have said it helps to keep things flat if you put a little tension on the fabric and the seam as it sews.

[slowhike]

another tip from ed speer was that he always removes the selvage.
he said that it is likely to be weaker.