The Sewing Place

Straight line bar tack vs traditional bar tack?

ozzo75

Straight line bar tack vs traditional bar tack?
« on: September 03, 2018, 05:15:07 AM »
Hello everyone, this will be my first post aside from the “introduce yourself” subforum. I’m not entirely sure where to ask this question, but I thought since I’ll hopfully one day be sewing and selling my work, maybe this would be the place to ask.

And I do apologize if this is something I shouldn’t be asking here. I’ve been trying to find the answer to this question all over the Internet but I can’t find it anywhere. Locally here in Taiwan I’ve asked sewing shops and our seemstress, but they just tell me “Don’t worry, it will be fine. Just do it the easiest way.” (They tend not to care about details here at times.  :( )

So my question...

Does anyone know if a straight line bar tack (two or three passes) is terribly inferior to a proper bar tack (criss-cross pattern) for load bearing purposes?

I’m trying to sew 1” nylon webbing with polyester thread, to be used for motorcycle luggage straps. I’ve mocked up a set that I’ve been using for the past couple months using only bar tacks (three tacks, two passes each) and they seem to be holding up fine to the amount of pulling I do to get them super tight.

But I worry for a product that people will (hopefully!) want to purchase, if this type of stitch is acceptable? From what I’ve seen in other straps made for this purpose, they use either bar tacks with the criss-cross pattern or a box-x. And the box-x is basically a straight line bar tack at the top and bottom of the box.

The problem is, I only have a Juki industrial straight line machine. It’s great actually. It sews through many layers of webbing like it’s nothing. But without the money to buy something more versatile, I’m stuck with what I have.

On a side note, I CAN do a box-x. I’ve been practicing every day. But I have questions about that as well. (Will leave it for another thread) And for quickness and simplicity sake, I’m hoping to do bar tacks if possible.

Lastly, I apologize if my terminology is off. I’m a guy with very little experience in sewing. The only connection I’ve had to sewing was an old high school “adult prep” class that taught me how to sew a button which proved quite useful over the years!

Thank you for any help and suggestions.


Efemera

Re: Straight line bar tack vs traditional bar tack?
« Reply #1 on: September 03, 2018, 09:25:17 AM »
The x box will spread the strain.. I’d stick to that even though it is more time consuming...I’d probably do it twice.

BrendaP

Re: Straight line bar tack vs traditional bar tack?
« Reply #2 on: September 03, 2018, 09:28:52 AM »
I can't see any reason why a three pass straight stitch bartack wouldn't be as strong as a single pass close zig-zag bartack.  In the commercial world it would be quicker to make a single pass with an appropriate machine set up as required and time costs money, but a straight one can be just as effective.

I will suggest making three passes rather than two because that means that there will be a continuous turn and two thread ends at either end of the bar tack rather than a turn at one end and four thread ends at the other.
Brenda.  My machines are: Caroline a Singer 201K-3 born 1940, Thirza a Featherweight 221K born 1949, Azilia a Singer 201K born 1957 and Vera, a Husqvarna 350 SewEasy about 20 years old. Also Bernina 1150 overlocker and Elna 444 Coverstitcher.
http://paternoster.orpheusweb.co.uk/

Surest1tch

Re: Straight line bar tack vs traditional bar tack?
« Reply #3 on: September 03, 2018, 11:28:58 AM »
Speaking as an ex-biker I would use a strong thread like button thread and go with a double stitched X in the box.

jesster

Re: Straight line bar tack vs traditional bar tack?
« Reply #4 on: September 03, 2018, 13:54:42 PM »
I only sew dog collars, leashes and use webbing for shopping bag straps, but I got interested in your question.  Google found THIS on the Wayback Machine.  It talks about extreme load testing for parachutes and sailing applications.  You have to scroll down about 2/3 of the way past knots and cording to find the  "sewing webbing" section.  It may be TMI, but perhaps it will help. 

mammafairy

Re: Straight line bar tack vs traditional bar tack?
« Reply #5 on: September 03, 2018, 20:33:05 PM »
I prefer a box X type finish, I feel it will be more robust.  But I think it will vary on the type of stresses involved

ozzo75

Re: Straight line bar tack vs traditional bar tack?
« Reply #6 on: September 04, 2018, 07:20:49 AM »
Thank you so much for all of your replies. I appreciate your thoughts and suggestions.

At this point I’m not sure which stitch I would like to go with. From what I’ve seen, most climbing gear and whatnot uses bar tacks - a heck of a lot of them. I thought I read somewhere that for bar tacks they tend to fail one at a time. So you would have a chance to remove the load before they all go. But with a box-x, once the first row snaps all the rest goes in turn.

Now I’m sure I’m overthinking it because the loads for what I’m doing won’t be anything near that of climbing gear. My only thought was how sometimes we would use these straps as a makeshift tow strap in a pinch. So I was hoping the straps themselves would break before the stitching.

So it seems it would technically be OK to use several straight line tacks if I go this route. As Brenda mentioned, maybe three passes instead of two.

One technique I’m curious about is a stitch on one of my straps I bought. 





It’s like an “E” but they didn’t sew completely from one tack to the next but moved on to the next tack without cutting the thread. Also the ends are unfinished. Is something like this ok in your eyes? I tend to care about minor details and this kind of bothers me.

Would you finish the thread ends by snipping them short and applying a bit of heat? I’ve been doing that with my practice stitches and they look to be ok. On another set that I own it looks like they used the heat method as well. I can’t find a thread ends anywhere in their work.

Ok, thanks again. I really appreciate it.

« Last Edit: September 04, 2018, 07:25:24 AM by ozzo75 »

ozzo75

Re: Straight line bar tack vs traditional bar tack?
« Reply #7 on: September 04, 2018, 07:23:27 AM »
I only sew dog collars, leashes and use webbing for shopping bag straps, but I got interested in your question.  Google found THIS on the Wayback Machine.  It talks about extreme load testing for parachutes and sailing applications.  You have to scroll down about 2/3 of the way past knots and cording to find the  "sewing webbing" section.  It may be TMI, but perhaps it will help.
Thank you jesster! I’m all about TMI!  :D I had to cut down my original post a lot because I was worried nobody would want to read that much!

You know, I’ve seen some of the pictures and illustrations from that article used in other websites. But there weren’t references to where they came from. Glad you could lead me to this. It was helpful!

ozzo75

Re: Straight line bar tack vs traditional bar tack?
« Reply #8 on: September 04, 2018, 07:33:42 AM »
And lastly, I want to ask about the box-x. From what I’ve gathered from a few forum posts elsewhere, people are doing a double pass tack at the top and bottom of the box and single passes with the sides and X. The straps I have look similar.

But what I’m unsure about is the “backstitch”. I’ve read that you *should* stitch a few stitches when you begin, and then go back to “close” the stitch. And then continue on with the box-x. Then at the end do the same thing so you’re not ending up at a corner.

This makes sense to me, but when I do it, it looks rather ugly on the bottom. On one company’s straps that I have their box-x doesn’t appear to do that. So I’m wondering if backstitching in this particular usage isn’t necessary?
« Last Edit: September 04, 2018, 07:35:16 AM by ozzo75 »

BrendaP

Re: Straight line bar tack vs traditional bar tack?
« Reply #9 on: September 04, 2018, 10:47:54 AM »
It is impossible to make a box-x in one pass without doubling up on at least one side of the box - and doubling on top and bottom looks better.  See my scribbled sketch.

If you are making straight stitch bar tacks there is no need to back stitch at the beginning as you will be sewing back over the stitching anyway and at the end just do another couple of stitches going back again if you think necessary, or pull the top thread through to the back and tie them together  [ You are not allowed to view attachments ]  
Brenda.  My machines are: Caroline a Singer 201K-3 born 1940, Thirza a Featherweight 221K born 1949, Azilia a Singer 201K born 1957 and Vera, a Husqvarna 350 SewEasy about 20 years old. Also Bernina 1150 overlocker and Elna 444 Coverstitcher.
http://paternoster.orpheusweb.co.uk/

jesster

Re: Straight line bar tack vs traditional bar tack?
« Reply #10 on: September 04, 2018, 13:50:09 PM »
So, in my last search, I found this way of doing an X box in one pass.  Will be trying it on my next project.   :vintage:

BrendaP

Re: Straight line bar tack vs traditional bar tack?
« Reply #11 on: September 04, 2018, 16:28:12 PM »
That's essentially the same as my second diagram, just a bit neater.

I like that he's using a  :vintage:
Brenda.  My machines are: Caroline a Singer 201K-3 born 1940, Thirza a Featherweight 221K born 1949, Azilia a Singer 201K born 1957 and Vera, a Husqvarna 350 SewEasy about 20 years old. Also Bernina 1150 overlocker and Elna 444 Coverstitcher.
http://paternoster.orpheusweb.co.uk/

jesster

Re: Straight line bar tack vs traditional bar tack?
« Reply #12 on: September 04, 2018, 18:56:19 PM »
It is very similar.  With the added rectangles on each side, you don't have to go over any stitching line twice, which can help with some applications.  Not webbing, but some fabrics can weaken with overlying lines of stitching.  I've always done it your way before, so thought I'd try this.   :)