Thigh strap installation failures

Hi, after reading all I could on the subject of thigh straps in a packraft and studying Roman’s video carefully I went ahead and ordered Stabond Glue and patches and thigh straps from NRS. BTW shipping of the glue alone cost over 100$.

I followed the instructions closely and both times failed. I let cure 72hours each time (boat inflated). Once the curing period was over, I deflated the boat, rolled it up and off to my watering hole. The first time I was able to peel all 4 patches off using my bare hands. The second time with a little more glue and heat the patches seem to adhere a little better but the forward patch is already peeling on one side. I can’t trust faulty patches like this if I’m going to be upside down in the water.

I’m pretty fed up and am almost ready to sell my raft in favour of a feathercraft that comes thigh strap ready (from what I understand).

Does anybody have any tips and tricks that they used to install patches in a foolproof manner? I have to do it at home, since I live in a fairly rural area…so no luxury of going to an inflatable boat shop nearby for help.

Thanks for your time,
Deeply disappointed.

bummer. i have put thigh straps on five boats now and never had failure…maybe I left something out of the video?

MEK x 3 each side
mix Stabond w/hardener till amber colored
one coat, let dry, second let dry, third coat dry to touch and I just heat up one side with low heat then put together and roll on.

sorry to hear that…did you do it in a warm dry room or outside? If outside maybe humidity causes problem? old alpackas used to have floor separation issues due to bottom glued on at high humidity…

Hi Roman,

Both times this was done indoors with low humidity, although it might have been somewhat cold. The first time I did exactly what you just posted, the second time, I used a bit of sandpaper to rough up the patches and did the exact same thing again, except heating up both patches and boat before pressing and rolling together. The first time, after a 72hr curing period, I rolled up the boat and when I unrolled it the patches were peeling so much that I was able to rip them off by hand. The second admittedly worked better, but the corners of the patches are still trying to lift up…can’t really trust that in an eskimo roll situation.

I’ve been wondering about possible causes for the gluing failures. Did you check the condition of the Stabond and hardener? A bad manufacturing batch or storage conditions or age could be factors. So could be a difference in the materials used in the boat and the patch. NRS sells d-ring patches in urethane, neoprene and PVC; did they ship the right material? Stabond is not listed as suitable for neoprene, and may not hold equally well to PVC and urethane. Did the Stabond remain firmly attached to the patch or the boat, but not the other? What did you have to do, and how hard was it, to remove the Stabond from where it was adhering before the second attempt?

I used a hair dryer to heat my patch up immediately after I glued it on to the boat. Heat it up till is not hot, but very warm to the touch (no bubbling). It will be solid as a rock after that…

I bought the 1" metal d-ring urethane patches and stabond glue from nrs. I’m assuming the patches are the right material and the glue is good, I don’t see why it wouldn’t be unless they were selling me outdated stuff. As for cleaning off the boat and patches, I contacted nrs before doing so and they said that cleaning it of with mek is fine and if some glue were to remain on the boat, that’s ok too. I won’t affect the subsequent gluing. To be fair though, the mek stuff really works well to clean it up, as most of the glue was gone. The straps are pretty solid in there, after rolling and unrolling the raft a couple times, the glue seems to be holding (aside from the first corners that lifted early on).