BIAB bag construction

[SaevaVeritas]

Hey everyone,

I am starting biab and just bought and cut the voile to size. I was under the impression that my wife's sewing machine could do a zig zag pattern (which is necessary for holding the 20-30lbs of grain plus water weight). However the machine only sews in a straight line. Has anyone made one of these and run into this problem? Will a straight seam with a nylon thread be strong enough? Should I hand sew (I'd like to avoid that)? Any recommendations would be very helpful!

Many thanks.

Saeva

 

[wilserbrewer]

IMO a straight seam should hold fine. I would suggest running it through the machine several times. What I like to do is stitch the bag, then turn it inside out and stitch the seam twice. This way you have a more finished seam that is triple stitched. Let the machine do the work and place many fine stitches, this will give you excellent strength. I would not even think of hand stitching if you have a machine.

 

[SaevaVeritas]

Thanks for the quick reply. That sounds like a good idea. Would you use nylon thread? Or can I just use cotton?

 

[dragonbreath11]

I handsewed mine straight and had no problems. I've used the bag with 12lbs of wet grain and it held up fine. Wilsebrewer's method should more than suffice.

 

[wilserbrewer]

Thanks for the quick reply. That sounds like a good idea. Would you use nylon thread? Or can I just use cotton?

I would not use cotton, though i'm sure it would last for a while but may eventually degrade. Either polyester or nylon is fine. I have also found that a fine/regular polyester thread works great. First intuition is that you need heavy/strong upholstory thread, but with such fine material a fine thread w/ many stitches is preferred over using a heavy thread. A fine or standard thread matches the fine weave of the material and works very well. The thread does not need to be "very" strong if the end result is 50 - 60 fine stitches per inch.

 

[z-bob]

[yes I know this is a 5 year old thread]

My wife has a serger somewhere -- I haven't seen it in years -- and I think a sewing machine. I knew how to sew 30 years ago but am *way* out of practice. (damn, I'm getting old) Since voile is a woven fabric, the sewing machine would be better, right?

I really like the idea of turning the bag inside-out and topstitching the seam. Would it be better to use a zigzag stitch for that? Or straight stitch it with a double needle? I don't care what it looks like, but I want it to be strong and have a finished edge.

I also want to sew some loops at the top to hang the bag. Those need to be reinforced, right?