Sewing experiment success!

[amethyst73]

So I have a piece of canvas which is now thoroughly decorated and is ready to turn into a bag.  I spent last night with some super-strong nylon thread, a couple of different kinds of 90/14 needles, and some canvas scraps to see what was going to work with regards to construction.  What I learned:

- I always like to at least give universal ballpoints a try.  Yup, even on wovens.  I know I'm prone enough to errors that I don't want to break any more cloth fibers than I have to.  However, the denim needle gave much better results: no puckering, didn't have to mess with the stitch length or anything to keep it happy.

- I have a couple of options for construction.  These bags are meant to be used, darnit, but I don't know how much I need to over-engineer them, esp. given that I'm using something pretty close to upholstery thread for them.  I could:

  - do a regular straight stitch for the seam,and then
      - do a serge-type overlock, which will work as reinforcement as much as it works as a seam finish
      - do a fake French seam: fold both edges of the seam inward, then sew along the outside, catching all 4 layers.  Disadvantage of this finish: not specificially a reinforced stitch.


 - do a reinforcing triple stitch for the seam, and then
     - either do a simple zigzag to overlock, which is not super-reinforcing
     - do the fake French seam as above.

I can't really do the fake French seam on both the top and the side without leaving a bit of edge that's going to be susceptible to fraying.  So probably I'm going to go with the simple single seam and do the serge-like overlock, even though that will use a lot of thread.

Note to self: The nylon thread, if left idle in the top of the machine, likes to kind of stick at first and can be a little hard to pull through.  As far as the stitches themselves go, the tension looks fine though.

Another note:  Knots: As I'd noticed in the embroidery session last weekend after the serious thread clog, there's something up with the knotting process.  It kind of feels like the bobbin end isn't long enough to get caught up properly for the knot making (though that may be due more to the stiffness of the nylon thread than anything else).  If I want a knot with this thread, I need to pull the bobbin thread up out of the hole first and hold some of the top thread.  This will be important for serging, which only has the knot option.  Regular seams can just use backstitching, which seems to lock the threads fine.  It will be interesting to try knots with just regular weight cotton and see what happens.  I'll be down in Sunnyvale sometime next week and had been planning to stop by Eddies to pick up some stuff anyway; I will ask about it then and perhaps schedule a service while I'm away on vacation in November.

Comments

[onyoukai.livejournal.com]

You could do flat-felled seams. That's the kind of seam used on jeans and heavy-duty pants. (I've had a number of pairs of cargo pants that use that form of construction.)

Another option is you can back the entire seam in twill tape and topstitch it from the outside through both seam allowances. This provides a lot of reinforcement. When the twill tape has been topstitched through, those two extra stitch lines take a lot of strain off of the actual seam and redistribute that strain over a larger area. The presence of the twill tape also prevents a lot of pulling that could weaken the seam. It's also a physical barrier that makes it a lot harder for external debris to get inside through the seam.

I can definitely vouch for the sturdiness of this method - I engineered it when a costume demanded a pleather codpiece/underwear thing, so I REALLY had to make sure there wasn't any strain on that item. I used double-fold bias tape instead of twill tape because I already had a ton of it on-hand, but twill tape would probably be even sturdier because it has zero stretch.

[amethyst73.livejournal.com]

You know, I thought about the possibility of doing flat felled seams. The only thing I'm worried about if I do either that or the twill tape trick (which sounds AWESOME, thank you!), is that the bag corners are going to be pretty close, cramped quarters and it may be fairly difficult to get in there with the machine. I do have the option of trying to sew sideways, which may make it more feasible.

I'll see how things look once I've done the initial seam in the Real Bag, and see how doable a second/third seam appears.

[onyoukai.livejournal.com]

Yeah, sometimes it takes careful planning to figure out tricks like that when corners and small spaces are involved. I know some work-arounds that I've done before, but being a visual person, if you post a photo of your bag-in-progress or an image of what the final product will look like, then I could offer possible suggestions on how to tackle it.

I made a small zippered purse for my mother once (the kind of thing that could be a coin purse, a pencil pouch, or makeup bag), and I ended up French seaming and topstitching the entire thing. The pattern was basically a rectangle, though it sounds like the bag you're making is more of a three-dimensional box shape. (I'm pretty sure it would be possible to French seam that kind of bag too, but I'd have to physically handle it to wrap my head around it.)

[amethyst73.livejournal.com]

That's the idea. I'll post a picture of the sort of bag that I'm modeling mine after, but a quick description:

Cloth is a long rectangle. Fold in half; the fold is one side of the bag. The bottom and the other side will be seamed. After that, the two bottom corners will be folded in a couple of inches each, and a seam will be sewn along the hypotenuse of each triangle, forcing the bag into a box shape. Ta-da!

(Clear as mud, right? I'll get pictures up later tonight or tomorrow, both of the cloth as it stands now, and of the bag I'm working off of.)

Pictures linked

[amethyst73.livejournal.com]

Okay, incoming links:

Outside of model bag (https://docs.google.com/file/d/0BxNqETF2SIQbUW4wUHBreDJjMGc/edit?usp=sharing). Note main seam along bottom and side.
Inside of model bag (https://docs.google.com/file/d/0BxNqETF2SIQbbzB2ZnZiV2dJVGs/edit?usp=sharing). You can kind of see the box effect that squaring the corners has given.
Bag turned inside out, with one squared corner (https://docs.google.com/file/d/0BxNqETF2SIQbMHR6Y3hlTEpwR1k/edit?usp=sharing) detailed.
Slightly different view of a squared-off corner (https://docs.google.com/file/d/0BxNqETF2SIQbbTlROHhOSHBUbzg/edit?usp=sharing).

Really, it's the fact that the seams will be in close-quarters 90° at the ends that makes me think that doing the tape trick or the felled seam will be difficult. I may just follow the model's lead and do the stitch-n-serge thing because it doesn't require getting into awkward corners, even if the finished product won't be quite so amazingly nice. :)

Re: Pictures linked

[onyoukai.livejournal.com]

OH okay, so it's this style of bag. Now that I can actually see it, I totally get how the corners work.

I'm pretty sure it would be possible to do the twill tape thing with it. You'd have to turn the bag inside out, and you should be able to use a single length of twill tape. You'd have to pin the twill tape in place on only one side seam, and then topstitch through it all from the outer side of the bag while the bag is inside out. When you get to the corners, you can stop - or even stop slightly before the corner. Tack your stitches, pull it out of the machine, then pin the twill tape along the bottom and resume the topstitching along the bottom. Stop when you're about to the other corner, pull it out again, and then do the final side. The way I'm seeing it is that you probably won't be sewing the twill tape down at that corner, but letting it gap slightly and only worry about the straight seams.

It doesn't really matter that you'd be leaving a slight gap in the tape at the corners, because you'll just be doing that perpendicular stitch so you can fold the corners to the inside anyway. The corners don't need the reinforcement of the twill tape. But if it bugged you and you really didn't like leaving the little gaps of the tape there, you could tack the twill tape to the fabric after the fact (like, if you're worried about little things being caught there and you wanted to close the gap).

The whole process of sewing something from the inside is kinda weird and awkward, but I've done it many times. I've even sewn tube-type shapes from the inside. You just have to take it slow so you can keep control, and every so often may have to stop sewing, rearrange the item under the presser foot, and then pick up where you left off.

Re: Pictures linked

[amethyst73.livejournal.com]

I ended up using the triple-strength seam and serge overlock, mostly because when I started playing with the seam with the idea of sewing in the twill tape, it was clear that it was going to take some serious fussing and being careful, and I just don't have time for that at the moment. Later iterations, I may; but I'm trying to turn out a couple of these bags before a November trip, and (having a full-time job, and other stuff I need to do most evenings), I only have weekends (not even full ones due to Other Stuff) for doing it.

But I finished it! And I'm going to assume that the person for whom it is meant is not going to be digging this far

The pictures are tiny, but you are allowed to see them:
Front of bag (https://lh5.googleusercontent.com/-XGoD1HnIto0/UmNhM50UgSI/AAAAAAAAEhE/tOqwplm5ImE/w240-h320-no/13+-+1)
Back of bag (https://lh3.googleusercontent.com/-fpnnUnkvXrE/UmNhMxZev_I/AAAAAAAAEhI/f1McF9VkiVc/w240-h320-no/13+-+2)

The Latin translates to the text in this piece of needlework (http://farm8.staticflickr.com/7453/8951373878_f4f00b4972_z.jpg&imgrefurl=http://www.cthulhu.com/2013/06/03/cthulhu-cross-stitch-sampler&h=640&w=538&sz=265&tbnid=LTdFrggb4MaBRM:&tbnh=95&tbnw=80&zoom=1&usg=__etcYIYL8QBM4uBHYNXH3nftHftw=&docid=bCD7Qalvt4uIhM&sa=X&ei=aPxlUvuWC4ToiAe404HIDw&ved=0CC0Q9QEwAA), because I saw a lot of that when I did a Google search for embroidery patterns with this character.

(I don't think the person who's going to be getting this bag as a gift is likely to be digging down this far in the comments, but that's the reason I'm hiding stuff behind links.)