Has anyone tried this seam for tarp?

[Metavo]

I have twoneedle machines in my arsenal.
Has anyone tried "Federal seam"

It's used on military tech parachutes and hot air balloons, sounds as if a good strong stich also. May be sewn with one go, not like french seam.

[Bannerstone]

I'm assuming it would be used for the ridgeline. Would you incorporate a seam tape into the middle?

A doulble sided seam tape might make the assembly easier and achieve the seal at the same time.

http://www.sailrite.com/Seamstick-1-...s#.UtpWQZ4o7IU

David

[Metavo]

That sounds great!
Thanks for the idea.
I'll try seam tape thing as soon as i get my silnylon.

[chickenwing]

I would be careful with the tape. Their site states that the adhesive is very aggressive. I would be concerned about it building up on my needle and gumming up in the lower bobbin. Also I would be really curious how this tape sticks to sil-nylon. About the only thing I've found to stick to sil-nylon is wet silicone and pins.

As always your mileage may vary, so I would love to hear your results if you do decide to go this route.

[nothermark]

The way it is drawn I would wonder about using it. It hides the edges but does not give the added strength of a flat felled seam.

[Mrprez]

I'd pay a quarter to watch anyone try and sew this with silnylon.

[Zilla]

My wife has tried this seam tape and chickenwing is correct, she had a heck of a time with the needle gumming up and in the end it was way more trouble than it was worth

[Redoleary]

There is such a thing as silicone based seam tape that will stick to sil-nylon, but this looks like a lot of extra prep to get it to go thru the machine in one pass. I wonder if they make a folder or some sort of foot that would allow you to do it w/o seam tape?

Just because I'm curious, what do you use your double needle machine for normally?

[Metavo]

It's not mine, but I have access to it.
It belongs to a local company that makes custom fit backpacks.
http://www.matrixpro.eu/

There should be special foot for this, I just haven't found where from to buy this.

[The Old Boot]

One of the great properties of sil fabrics is their ability to resist creasing - that's why we can stuff the gear in our packs and after a few minutes of hanging our tarps look great instead of an ungodly mess.

However, that resistance to creasing also means that one can't press folds into the fabric for sewing.

IMO the time you'd spend trying to prep the seam for 2 needle sewing would exceed the time you'd spend doing a traditional flat felled seam.

I also question using seam tape during sewing. Although the product description says you can sew it (and warns about gumming the needle), I question whether having put holes in it with the needle, you'd end up with a watertight seam. Seems to me that you'd end up with a path for water penetration.

If you do decide to try it, practice on a couple of scraps and then water test before you go ahead and do the tarp.