Wilderness thigh straps and DIY tie downs for packrafting
Gluing stuff on to your Alpacka raft is a useful thing to know how to do well. There are all sorts of things you’ll want to do which the stock tie downs don’t. Two invaluable resources, from which the ideas below were developed, are the Alpacka How to Glue page and Luc Mehl’s pimp my raft tutorial. Read both thoroughly.
Selecting a good glue and using it well is vital. This is not an area to take shortcuts. Aquaseal is not adequate here; it’s designed as a sealant, not a glue, and because it doesn’t completely cure in the absence of air can only be used as a glue when no other options exist (Alpacka discusses this here). I’ve used the ACE hardwear flexible vinyl mender and have not been impressed. It seems weak.
I was able to find a 4 oz jar of the Clifton Urethene adhesive at a local shop. The small size is plenty, and when used correctly this stuff has proven very effective. Conditions are key to a good seal between your boat and patch, you’ll want a warm and well ventilated work space. A sunny day outside is ideal, as the fumes are the worst I’ve ever smelled. A respirator is a good idea. The directions on the jar are easy; mark your patch, clean both surfaces (I used acetone because it was around), let that evaporate, then do a bunch of thin coats of Clifton on both surfaces (about 6) letting each coat mostly dry. Then do a final coat, let it sorta dry, and stick the patch on. Rub vigorously to eliminate wrinkles and air bubbles, and let cure for a few days. For extra security, a thin bead of aquaseal can go around the edges (patch at left, above).
The patch you use will depend on application and budget. The tie downs Alpacka sells seem to fail consistently when used to anchor thigh straps because of the weak stitching. Why they’re not bar tacked I do not know. They also seem expensive for what they are. I had a Seal Line urethene dry bag lying around and used that to make tie downs. The material is a bit heavier than necessary, but works. I imagine Alpacka might sell you some tube fabric scraps which would be adequate.
The tie down above is one of the forward cargo lash points on my Scout. They’re a little over 3 inches in diameter. Each side has two bartacks about 8mm apart. Crucial for these to function easily is a small gap when curved to make it easy to get a strap through. I like these better for exterior use than the loops on the stock tie downs, they’re lower profile and allow for more secure lashing off a single point. I have two towards the back of my Yukon Yak for ski carry, as can be seen here.
Tie downs installed on my Scout, I was going for the least amount which would get the job done. The one of the floor anchors a rolled sleeping mat for a seat, while the forward three are the minimum required to secure a pack. I cut the webbing off the stock inner tie down (on upper red tube), which is presumably designed as a seat tether. If I’d known that came stock I would have asked Alpacka to leave it off. Getting the forward tie down to adhere well over the seam tape required a lot of massaging, but worked.
Aside from ski carry, thigh straps are the most common mod, and one you should consider if you do any whitewater at all. As Luc says in his aforelinkedto article, they make a huge difference. They even keep my legs from falling asleep, which makes them almost worth it all on its own. Use the position guidelines in Luc’s article, and the gluing suggestions above. Do your ski or other tie downs first, as working inside the boat is a bit trickier. Do it with the boat inflated, and remove your spray deck completely.
I have serious claustrophobia, and as I learned in a kayak roll class two decades ago, nothing triggers it like being upside down in water. I’ve never attempted to roll my packraft, and doubt I ever will. Ergo, I wanted to save weight with my thigh straps. I tried 3/4″ and then 1″ nylon flat webbing, which was not satisfactory. Wet nylon stretches, and the thinner varieties never set all that well across my knees and thighs. I finally got some 1.5″ polyester webbing (from DIY Gear Supply), which is the perfect solution. The extra width is just enough, and polys lack of stretch makes a huge difference.
As above, I bar tacked a loop of 1/2″ webbing to the foot end for girth hitching through the bottom tie down. As below, I tied some 3mm cord through the upper tie down, and adjust length via a plastic triglide buckle. Simple, clean, effective.
Wilderness thigh straps like this will add 6-10 oz all in, but like a spray deck once you use it you’ll wonder how you managed without, and by very loath to go back. Try it.