Seams, Flat-felled vs. DIYGS Hybrid

[Sandman614]

In doing my research to start building my own tarps I have stumbled on diygearsupply.com. Looking through the DIY pages I noted the Flat-felled/French (Hybrid) seam. To me it does not seem that this seam would be ideal, that there would be a slim chance for water to get through. The normal flat-felled seam with it's "clasping hands" design seems like it would reduce the chance of water getting through to zero. I know you all know more than I, please fill me in.

[boulderv7]

In my experience, whatever seam you choose will need to be sealed if it is on the ridge line. That being said, I always do the hybrid seam, because I think it is easier to sew. YMMV.

[gmcttr]

...To me it does not seem that this seam would be ideal, that there would be a slim chance for water to get through. The normal flat-felled seam with it's "clasping hands" design seems like it would reduce the chance of water getting through to zero...

That has been my thinking as well...the flat felled seam has a more tortuous pathway and in my mind should add resistance to wicking. I also don't think it is any easier to construct than a proper flat felled seam.

In reality, with 3 rows of stitching closing the "direct" pathway of the hybrid seam, it probably makes no difference.

And we're back to HYOH.

[The Old Boot]

The water isn't working it's way around the layers of fabric, it's going to come through the stitch holes. No matter what method of sewing the seam, you're going to want to seal the seam.

[cwford]

I don't think it makes much difference. If you pull each of the seams they both have 2 points where the needle holes will elongate and allow water through. They both have to be sealed so I usually go with the easier to sew DIYGS method.


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[Bubba]

I don't know what seam Brandon uses but the Warbonnet Tarp ridgelines are not sealed and don't leak.

[Fronkey]

I have a video coming out in a few hours that shows exactly how to make a tarp that I think will help out with your ridge line question. I'll post a link later today when it's up.

Fronkey

[cwford]

Warbonnet tarps are made like the attached diagram. I believe they aren't as susceptible to leaks because the grosgrain takes the stress not the silnylon.


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[stalker42]

So war bonnet has a vertical ridge when it's pitched?

[turnerminator]

I've seen them leak as much as any of my unsealed tarps.

Is yours an older tarp Bubba? Maybe other factors have affected the water repellency like thread size, needle size and thickness of the sil coating.