DIY Cuben Tarp - minimal sewing, using VHB Tape

[DavyRay]

Great video!

I love VHB tape. I recently started using it in some designs. It is marvelous. I am using the 15 mil VHB to bond polycarbonate sheet to aluminum. The 3M FAE (tech rep) says that this stuff starts to bond correctly after 15psi is applied for one second. Full strength develops in 72 hours.

I wonder if you could use 1/2" tape for the ridge line, and 1/4" wide tape for the hem? This stuff is amazingly strong. I have only experimented with small amounts so far. A long seam does look like a challenge.

Thanks again.

[WV]

When I added cat cuts to my tarp I used 1/4" tape for the folded hem. It's doing fine. I've wondered about using 1/2" for seams, but I still use 1" out of caution. Slitting wider widths to make smaller ones is a sticky business. It's better to buy two different width rolls if you need them.

[gon2srf]

Thanks Sgt. Rock for the great video and valuable link to Zpacks.com. I also wanted to thank the others who contributed additional information to the thread. This is my first post here and although this thread is a bit old now I appreciate the info. Your video also made me smile. Highlights: Cursing when the rollover hem didn't go so well to begin with. You holding the roll of VHB tape in your mouth while pressing down the tape. Dog barking in background, wind blowing your tarp and making you temporarily disappear and finally the rooster. Your low tech/high tech video is what forums are all about and I thoroughly enjoyed it. Looking forward to building my own tarp very soon.

[SGT Rock]

I'm pretty low tech.

[gon2srf]

I'm pretty low tech.

I hope my comment did not come off as insulting? I meant quite the opposite. I'm copying your lemonade cozy idea as well. Very nice, thanks.

[SGT Rock]

No, on the contrary it is what I strive to achieve. Reality.

[gon2srf]

No, on the contrary it is what I strive to achieve. Reality.

Awesome, keep it up.

[JohnSawyer]

Love the tape together tarp. That's a little more logistically challenging, but a lot less work than sewing! I wonder if I could VHB together a Sil tarp... hmmmm...

[WV]

Love the tape together tarp. That's a little more logistically challenging, but a lot less work than sewing! I wonder if I could VHB together a Sil tarp... hmmmm...

Probably not.

[Alligator]

I recently constructed a cuben tarp following the instructions in the video. I opted for a square tarp 10.5'X10.5'. The video and instructions were top notch help in fabrication. I made three minor modifications in the pullouts.

1. I used triangular pullouts 6 inches on the hypotenuse. Four patches can be made from a 6 inch square. Two patches make a pullout. These are effectively the same area as two 3 inch square patches, as the same layering was done on the pullouts as in the video. I do not think there is much difference in effectiveness of a triangle vs. a square.

2. I used the two layer pullouts which creates a pullout with three layers, the two patches and the tarp. I sewed the pullout loops though to one pullout patch, not the tarp. The pullout with the sewn loop was than sandwiched between the tarp and another patch. I put both patches under the tarp. This worked out good because on my first patch the sewing machine feed dogs chewed up the patch and I had to work out a good feed dog height and cut a new patch.

3. Somewhere a poster noted that changing the direction of the bias on the cuben fiber might create a stronger fabric. So I changed the direction of the triangular patches so that one patch was at 0/90 and the other at 45/135 degrees. This could be done with the square patches. However care needs to be taken when assembling as I mixed them up at 2:30 a.m.

I used a 1" foam brush for the primer. This works good for sizing the primer as one inch of primer is needed for all areas. Ridgeline is two pieces of 1/2' tape, the hems are one piece of 1/2' tape and the material is folded over. The foam lays down a good bit of primer though so perhaps a 1" brush would be better.

The tarp was square. This required a second ridgeline. This does not optimally reduce weight. The additional fabric to reach 10.5' is about 22.5" in width. So that additional weight in the ridgeline is being distributed onto a smaller width than a nearly full width piece of fabric.

I used a little silnet that I had to seal the paracord loops. The VHB tape does not appear to bond well with the silnet. I was sloppy in putting it on, so use a brush not a paper towel.

My tarp came out slightly heavier than a SUL tarp might. I know I used a lot of primer with the foam brush plus the extra ridgeline puts the tarp at 8.6 ounces (no stuff sack yet). That's 25% larger area and 33% less weight than may 8x10 silnylon tarp so it works for me.

The 16 pullout patches (which are subsequently doubled up to make 8 pullouts), with paracord loops, I think weighed 0.72 oz total. That includes the tape with the pullouts ready to go on the tarp.

Last tip remember that when joining the ridgeline, for one half, primer for the ridgeline has to go on the opposite side of the fabric as primer for the hems. Rubbing alcohol will take this off if you hastily primer all the way around the second panel. If you have two ridgelines, and don't primer two of the three panels properly, I will repeat that rubbing alcohol will again take the primer off.