Float bag installation in Kevlar boat

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I’m preparing to drill four 3/16” holes in pairs, 3/4” apart, spaced out very 9 inches down the side of Kevlar wenonah. I’m using paracord for the loops through those holes. I’m using the loops for tie downs for a float bag. I will also have a couple of d-rings in the bottom of the boat as well. Here are some photos of one fellow who outfits his boats exactly like that and claims no problems. Thoughts? A couple of the photos I have toad and measured where to drill.
 

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Two alternatives. One would be to drill into the under side of the hollow gunwales and rivet on some plastic eyelets for tie downs instead. Another thing I've seen, which doesn't require drilling into the hull or gunwales, is to drill out the existing gunwale rivets, one at a time, and forcing the cord loop up around where the rivet would be and re-rivet. From the second photo it looks like the rivets might be spaced well for that but you might have to use smaller diameter cord.

Mark
 
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As Mark mentioned, drilling underneath the gunwales is simple. For gear tie-downs on Wenonahs, I've attached a loop of 1/2" nylon webbing underneath the gunwales with pop rivets with added washers (or use large flange rivets). You can make the loops whatever length you want. The nice thing there is that the force is directed perpendicular to the rivet, as opposed to the outward pull if you just replace the existing gunwale rivets. I've also added eyelets underneath the gunwale as Mark mentioned. Those require two holes, whereas the webbing requires only one. I melt the hole in the webbing with a small soldering iron (a hot nail works too). I've also installed metal d-rings replacing the gunwale rivets, but I have no idea where you can get them now (they were for Kelty frame packs a long time ago)
 
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I’m preparing to drill four 3/16” holes in pairs, 3/4” apart, spaced out very 9 inches down the side of Kevlar wenonah. I’m using paracord for the loops through those holes. I’m using the loops for tie downs for a float bag. I will also have a couple of d-rings in the bottom of the boat as well. Here are some photos of one fellow who outfits his boats exactly like that and claims no problems. Thoughts? A couple of the photos I have toad and measured where to drill.

Your method is fine. I have drilled holes beneath the gunwales to construct an air bag cage in many different canoes, some composite and some Royalex. I usually just lace the cord back and forth across the canoe through the holes with no loops which works fine. However, if you want to remove the lacing with any frequency, routing it through pad eyes or small loops as you propose makes it a bit easier.

If you are really OCD you might become annoyed that with the method you describe if you lace your cordage back and forth transversely the strands will likely not be parallel.

I have found that pad eyes that are attached to the sides of the boat or gunwales in such a way that they project directly in toward the hull interior can become annoying when portaging the canoe, and sometimes when removing packs from the boat. If I use pad eyes I usually fix them to the underside of the gunwales, but that won't work in your case.
 
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If I use pad eyes I usually fix them to the underside of the gunwales, but that won't work in your case.

I've attached pad eyes (the eyelets I've mentioned) underneath the gunwales on an Encounter with no problems. Threading them is not as convenient as the loops I mentioned, but she probably won't be threading them very frequently. And then she could always add a piece of cord to them to facilitate lacing. Lots of options.
 
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I've attached pad eyes (the eyelets I've mentioned) underneath the gunwales on an Encounter with no problems. Threading them is not as convenient as the loops I mentioned, but she probably won't be threading them very frequently. And then she could always add a piece of cord to them to facilitate lacing. Lots of options.

I meant on the undersides of the inwales with the pad eyes projecting directly toward the hull bottom. Are the inwales thick enough for that?
 
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I meant on the undersides of the inwales with the pad eyes projecting directly toward the hull bottom. Are the inwales thick enough for that?

Yes, pointed down. There's not a lot of room, but they work. 5mm cord might be tight, but pcord works.
 
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Yes, pointed down. There's not a lot of room, but they work. 5mm cord might be tight, but pcord works.

Well, that is how I would install pad eyes if I was to use them. But if the clearance between the pad eye and the hull is so small that it becomes difficult to thread the cord through the pad eyes, I would likely just thread the cordage through holes drilled in the hull just below the inwales. That would not be much more difficult than threading it through the pad eyes and it would save weight, time, and expense. If the holes are drilled just a little oversized, it is not that difficult to run the cord through them. That is what I have done with nearly all of my whitewater boats.
 
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In my Wenonah Spirit II with aluminum gunwales, I riveted in aluminum "cable clamps" with a plastic coating, for center paracord tie down points. (Inch worms would work as well, but require twice as many holes, obviously.) I have rarely used them. They seem to work just fine.

photo18747.jpg

I have never liked the idea of drilling through a kevlar hull. I have heard that kevlar can absorb water, and so ideally, one would drill the hole one size larger, fill with epoxy, and then drill the size needed, to seal the hole. I have used this technique in other contexts. I have no idea how much better it might be.

Also, my unproved hunch is that structurally, I would prefer holes in the aluminum gunwale to holes in the hull.

There are many paths to the top of the mountain.
 
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In my Wenonah Spirit II with aluminum gunwales, I riveted in aluminum "cable clamps" with a plastic coating, for center paracord tie down points. (Inch worms would work as well, but require twice as many holes, obviously.) I have rarely used them. They seem to work just fine.



I have never liked the idea of drilling through a kevlar hull. I have heard that kevlar can absorb water, and so ideally, one would drill the hole one size larger, fill with epoxy, and then drill the size needed, to seal the hole. I have used this technique in other contexts. I have no idea how much better it might be.

Also, my unproved hunch is that structurally, I would prefer holes in the aluminum gunwale to holes in the hull.

There are many paths to the top of the mountain.


So, I know next to nothing about any of the hardware that's been mentioned by all of these fine and knowledgable folks, including cable clamps. But, thank you very much Google, I have been searching for images of all of these things. Your photo clearly shows how a cable clamp is attached, under the gunwale. I'm infering that an "inch worm" is a pad eye. I have some support here on the home front for using a drill but I would love a bit more of direction if you can provide that. Would I use a regular drill bit to make the hole for that cable clamp? When you say you "riveted in cable clamps" - I'm not sure what that means. Is riveting basically screwing it in or do I need another "rivet" tool? It's unfortunate that us girls had to take home ec instead of opting for shop!!
 
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The rivets are "pop rivets", which are aluminum (sometimes stainless) rivets which are installed with a specific device (pop rivet tool!). They're cheap, common and easy to use. They allow you to install rivets without access to the other side. The gunwales are installed with pop rivets, so you can see what they are. Tools are about $20-25, and well worth purchasing for general canoe work. The most common size is 3/16", so use a 3/16" drill. For drilling underneath the gunwale, it's easiest if you punch a duvet in the aluminum to keep the drill from wandering. Spring-loaded punches work well.

I took typing (with manual typewriters) instead of shop. With 7 years of college, followed by computers in my profession, it was worth it!
 
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There are a number of ways to skin lacing-attachments for float bags. And/or gear.

If using the paracord loop idea on a kevlar canoe I would spring for quality cordage with an abrasion resistant sheath.

Given my druthers I’d rather drill as few new holes as possible. I figure there are already 70 or so OEM holes along the sheerline for the gunwales. If I use doubled holes for short cord loops, or nylon pad eyes, I’m adding another 70 or so holes for large float bags. 140 holes, plus or minus, is a bit Swiss cheesy for gunwales or sheerline.

Probably not an issue, but in a pin I’d rather not be Swiss Cheesed. And, if you ever had to regunwale the canoe, sheesh, that’s a lotta holes to fill, or try to miss.

I do like nylon pads eyes, enough to order them in quantity. Pad eyes don’t fit on some of our slender aluminum inwales, but on (or under) vinyl inwales they do little structural weakening. Although, if pop riveted underneath an inwale, the pad eye hole isn’t especially convenient to lace through. Stooping over at an awkward angle, trying to lace paracord through a hole I can barely see is not my favorite activity.

If you are planning to lace float bag cord, remove it, and re-lace it with any regularity, bigger holes and easier orientation is a help. If installing/re-installing float bag lacing is enough of a PITA you may say “Eh, just skip it” And may wish you hadn’t. And don’t ask how I know.

Some lacing attachments variations are shown here. Most require a single new hole, or none if you drill out and replace existing gunwale pop rivets.

P4030002 by Mike McCrea, on Flickr

I like the miniature stainless steel D-rings or the larger nylon D-ring with the slender flange (the slender flange slips between the hull and inwale). Either are pop riveted in place, which can be done using new pop rivets between the ones already in the gunwales, or by drilling out the existing pop rivets one at a time; slip the flange in place, drill a hole through the nylon flange part and re-install a pop rivet.

In weight bearing experiments all of those attachments held a significant amount of weight; plenty of weight at least for multi-laced float bags. Some may be insufficient strapped across a 48-pack cooler and 10 lbs of ice ;-)

Weight bearing experiment summary of results here:

https://www.canoetripping.net/forums...909#post107909

(That was the most fun, labor-intensive, week-long and educational shop experiment yet. I had wondered for years what weight different attachment points would hold)

Northwater sells the flanged nylon D that fits between the hull and inwale, shown here bottom right as part of their airbag tie down kit.

https://northwater.com/collections/d...ag-tiedown-kit

If you leave a little flange showing below the inwale it is easy enough to stick a finger under the D and bend it out for lacing the cord.

I’ve put the miniature SS D-rings in a bunch of canoes, often in lieu of backup washers on spray cover stud pop rivets. Miniature pop rivet-able D-rings are available on Amazon. I’ve used both this cheapie version (currently screwed in seaside in Florida, awaiting a corrosion report)

https://www.amazon.com/EXCELFU-Stain...6324109&sr=8-6

And these (I suspect better quality) 316 stainless mini-D’s, which are noticeably sturdier.

https://www.amazon.com/Marine-Boat-S...40041594&psc=1

I should note that the D-rings on both of those are much larger than on the miniscule (1/4” dia) version shown in the weight bearing experiment photo. Both of those from Amazon are ½” minimum, so easier to use with larger diameter cord.

Not sure how well either would fit well on the underside of a slender aluminum inwale.

If you elect to use the P-shaped cable clamps Dave mentioned make sure the hole in the flange will accommodate a 3/16” pop rivet. The (rivet) hole on most of the hardware store electrical variety cable clamps is too small, and if you drill them out to 3/16” you won’t have much flange left.

Cable clamps with canoe outfitting 3/16” dia holes are harder to find; I’ve bought mine from Blue Mountain Outfitters (in the wonderland of wee outfitting parts and pieces in the lazy-Susan bits at the counter)

For any application where I might be using a webbing strap I prefer 1” grommet straps.

https://topkayaker.com/index.php?mai...roducts_id=898

Even with some other lacing attachment method I’d like a couple of those grommet straps for easy webbing use.

I don’t know if you have purchased your vinyl pad D-rings yet, but I’ll put in a word for the functionality of Northwater’s Double D-ring anchors.

With the double D you can weave a naked webbing strap through the two D’s and tighten the webbing, or, if you use ladder locks or side release buckles on the webbing, use one D angled forward (maybe small stem float bag) and one angled backwards (maybe webbing strap over pack or barrel).

https://northwater.com/collections/d...-d-ring-anchor

Outfitting a canoe with well thought out “rigging”, customized for whatever floatation, gear, pack or barrel location, can make lacing in, or loading and unloading much easier.
 

Glenn MacGrady

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I wouldn't drill holes in a composite flat water boat at all. Nor would I likely ever use float bags in flat water.

However, for a big rectangular float bag like the one in the picture, I'd just jam it under the thwart, as it is shown, and then secure each of the four corners with D-ring patches on the hull. In other words, you don't need gunwale cross-strings on top of a float bag to hold it in place unless, perhaps, it is a dedicated whitewater canoe that is likely to repeatedly bash down rocky rapids upside down.

Another reason for my antipathy toward lines strung through holes in a flat water canoe is that the vast majority of time I will not be using the float bags. Then, the lines strung across the gunwales are useless and look ugly; and if I pull the lines out, I have a bunch of holes that are micro-ugly and that attract water into the laminate. To me, gunwale strung lines are a PITA to insert, remove and reinsert.
 
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I wouldn't drill holes in a composite flat water boat at all. Nor would I likely ever use float bags in flat water.

However, for a big rectangular float bag like the one in the picture, I'd just jam it under the thwart, as it is shown, and then secure each of the four corners with D-ring patches on the hull. In other words, you don't need gunwale cross-strings on top of a float bag to hold it in place unless, perhaps, it is a dedicated whitewater canoe that is likely to repeatedly bash down rocky rapids upside down.

Another reason for my antipathy toward lines strung through holes in a flat water canoe is that the vast majority of time I will not be using the float bags. Then, the lines strung across the gunwales are useless and look ugly; and if I pull the lines out, I have a bunch of holes that are micro-ugly and that attract water into the laminate. To me, gunwale strung lines are a PITA to insert, remove and reinsert.

Glenn, this is the Wenonah Prospector 16’. I never plan on doing more than about Class II rapids solo. But, I am doing class II+ tandem in this boat. I think I should have a float bag or two. I like your idea on not even putting in lacing, given that I’m not doing more difficult rapids. My photos that I shared in the original post are from the fellow that is a distributor of Wenonah canoes. He also builds Kevlar canoes and teaches high school students to build them. Given that he is an experienced tripper and that he outfits his boats with holes just below the gunwales, it’s probably ok. But it sure is a leap of faith for me.
 
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Oh my, thank you so much for all the input, links and back and forth discussion. This has been most helpful. I wish I could serve you each a glass of scotch, around a campfire, at the end of a fine day of paddling during sunset. Cheers and thanks much:)
 
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Cathy, running even class II with a float bag I would like to have more of a “cage” than just the corners tied off to a D-ring. I agree with Glenn that cord laced across the sheerline with no bag in place looks ugly, and, sans bag, may actually present more of a hazard in a capsize or on a small stream with brushy overhangs. To that end I try to make re-lacing the cord for when I put in a float bag as easy as possible.

If you are paddling rapids solo you may want to use/add tapered stem bags. Those usually have a tie point at the tip. I just use a D-ring pad centered on the floor to \ / tie down the corners of the wide end, some top cross lacing between the wales, and a length of cord tied to the tip of the bag, usually poked up through the drain hole in the deck plate, run back and tied off to the carry handle. The cord at the end helps keep the bag pulled forward into the stem.

On solo trip campers, if you are not overpacked, you can leave stem floatation in place.

The Canoe Outfitting Weight Bearing Experiment thread (long but photo heavy) shows all of those various tie downs attached to wood, vinyl and aluminum gunwale sections, as well as making DIY webbing loop tie downs.

https://www.canoetripping.net/forums...ing-experiment

Those simple webbing loop ties are especially handy on installed the ends of existing machine screws (carry handles, thwarts, yoke, seat drops). No new holes to drill, just take the nut and washer off, slip the webbing loop over the end of the machine screw and put the washer & nut back on.

P4060002 by Mike McCrea, on Flickr

Mike Yee has a photo gallery of full-on, heavy duty outfitting for serious WW; overkill for your needs, but might give you some ideas:

https://mikeyeeoutfitting.com/outfit...utfitting.html

Let us know what you do, and maybe some outfitting photos.
 

Glenn MacGrady

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Oh, the boat with the bag is not your canoe. Well, different canoeist do lots of different things with bags and everything else, including attachment techniques, of which you've had many good suggestions here.

To me, it would make a difference as to whether I am using 25"-30" end bags in a canoe for both solo and tandem paddling, or one big 36-48" central bag, or both. It would also make a difference as to how frequently I expect to use those bags.

As to a big central bag, you can see from the picture that such a bag usually only reaches gunwale height at its center. Therefore a string cage alone won't hold it in securely and will require a lot of line. It can he held in simply by jamming it under the central thwart of the tandem and tying down each corner to D-ring pads. These D-ring pads can also be used to secure gear when the central bag is not in use.

If you are using short end bags only, then I think a minimal cage is more appropriate because those short bags tend to protrude above the gunwales along their entire length. For short cages only at the ends you will need fewer holes (or other attachment points) and less string. End bags can be left in the canoe more or less permanently for both tandem and solo paddling. My MR Explore tandem has been rigged that way for 40 years. But even end bags can be attached just with one nose attachment and two or three floor attachments with no string going across the gunwales. The strings can run around the top of the bag from the grab handles to the two or three floor D-rings, and are very easy to remove.
 
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The reason that lacing is required is to hold the bags down within the hull. Otherwise any water that enters the boat goes underneath the bags and floats them up above the gunwales. If the bags are secured only at the corners the center of the bag will pooch way up.

I would not trust securing any bags only using grommets on the corners of vinyl bags. I have seen these rip out many, many times. The nylon loops sewn into the corners of nylon bags are somewhat stronger. There is absolutely no risk that holes drilled into composite canoes to secure bag lacing will result in water damaging the laminate. I have done this in multiple such hulls as well as drilled holes in the stems for end grab loops. Many years later there is absolutely no evidence that the laminate has weakened around these holes.

Most composite boats already have many holes drilled in them for screws or rivets to secure the gunwales and many also have holes for end grab loops. These are not in any way sealed by the canoe manufacturers.
 
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