So I don’t really do WW stuff mostly slow rivers and creaks and little to medium lakes. but none the less I was thinking of putting float bags (end bags) in the ends of my Mad River Angler 14 tandom canoe in royalex.
There are two reasons I am considering float bags, partly just anything to make it easier to handle when swamped and shore is a long boat drag away, it is royalex and will just float but not enough to float it properly and bail it out if it is seriously swamped. and partly because I would like to start taking some more aggressive rivers.
So On to the question, almost every how-to, guide, article, that I find that are from the public and not canoe manufactures says to drill through the hull not the gunnels. and almost all canoe manufactures literature (all but one so far, Mohawk canoes says to drill the hull) and kits and yadda yadda yadda says to screw or rivet eyelets into the gunnels! argh!
I have never done either on a canoe before. I am new to modifying canoes so far I have just pushed them around in the water with a piece of wood. If you have modified your canoe and have some comments on what you like or don’t like about the way you did it etc please comment I am stuck on the fence here and don’t know where to go 
thanks in advance.
Easier to Drill the Hull
Drilling the hull is easiest. Beyond that, drilling the hull does virtually nothing to weaken the boat since the adjacent gunwale is what provides the flexural strength. When you drill holes in the gunwales you are weakening (by some amount, not sure how much) the very thing that is most important for hull strength.
Eyelets attached to the gunwales are easier to thread line though, but some people, myself included, keep some sort of permanent line or loops through the holes in the hull, and weave the main lines through those loops that are always there. That makes threading the lines in or out pretty fast and easy.
Here are some shots showing the "usual" method and an alternate, easier-to-lace/unlace method that I now use instead.
http://www.flickr.com/photos/11908573@N00/sets/72157618491549032/detail/
Copy and paste the whole link.
With the newer method, there are no permanent loops that can catch on things. I just pull each side-line tight (and tie the free end to a thwart or the seat drops) and all the loops disappear. I just use a rope for the retaining each bag within the cage instead of a strap of webbing. There's really no advantage to webbing, and if the bag really forces itself against the restraint, webbing is actually much more abrasive than rope when pressed against something as pliant as an air bag, but I just opted for rope to eliminate the need to buy more stuff. By the way, that little bit of white rope visible at each stem anchors one end of the rope that secures each bag within the cage.
agreed
I agree with what Eric has said above. You can buy little nylon "inchworms" that attach to your wood or nylon gunwales with stainless steel sheet metal screws. I doubt they weaken gunwales significantly, but for wood gunwales they might allow an entry point for dampness that could accelerate rot.
I resisted drilling holes through the hull of my boats for some years. Once I did, I couldn't understand why it took me so long. If you anticipate removing the lacing then drill pairs of small holes just below the gunwale line about an inch apart and thread a length of nylon parachute cord through each pair. Make the hole just large enough for the cord and tie the cord in a short loop that will hang inside the hull.
Space these loops anywhere from around 4" to 8" apart and they will function as well or better than the nylon inchworms for threading your bag cage lacing through.
The lacing is required to keep your inflated bags from floating up out of the hull when water gets in your boat. But you must also do something to prevent the bag from floating out of the stem of the canoe towards the center (and it will). The most popular option is to rig a "keeper strap" of 1 inch wide nylon webbing to the stem of the canoe, bring it amidships over the bag, and anchor it to a D-ring attached to the bottom of the hull. D-rings mounted on vinyl patches can be glued into the bottom of your Royalex boat using Vynabond adhesive (and various others).
The sides of the bag may still tend to "pooch back" toward the center of the hull, so some prefer making a somewhat more elaborate and restrictive bag cage using additional hull floor anchors and parachute cord. These links will give you an idea:
http://www.mikeyeeoutfitting.com/o_gallery/pages/Phantom-5.htm
http://www.mikeyeeoutfitting.com/o_gallery/pages/Phantom-6.htm
http://www.mikeyeeoutfitting.com/o_gallery/pages/Rival-4.htm
If your Royalex boat has holes drilled through the hull at the stems through which grab loops or ropes are threaded, you can use a length of parachute cord threaded through the hole on each side of the stem and tied together inside the hull. The parachute cord loop can be used to anchor the other end of your keeper strap. Use 1" wide nylon Fastex "triglides" to secure the straps at each end:
http://www.mec.ca/Main/content_text.jsp?FOLDER%3C%3Efolder_id=2534374302886996
Air bags…
I drilled holes in the hull,below the gunwales to install laces for air bags in 5 different canoes. All of those canoes were used for whitewater. I never had any type of issues, structural, or otherwise with any of them. All my friends I paddled whitewater with installed their air bag lace kits the same way; again, never a problem.
The only problem I see is if/when you decide to sell your canoe. Obviously your canoe is not a whitewater canoe, and a prospective buyer might be concerned about the holes. If you have no plans to ever sell the boat; no problem.
You mentioned Mohawk. I believe they have "how too" illustrations & directions for installing lace kits on their website. You could do a lot worse than following their directions.
So, basically I am in agreement with pblanc, and guideboyguy.
BOB
grab loops
I just started outfitting my canoe and was wondering how far back on the stem you need the holes for grab loops? Is 6 inches enough? I also read about people putting a block of wood on the inside to run the line through…is it necessary?
Thoughts on Grab Loops
Check out the photos I provided a link to in my post above. Holes for the factory-supplied grab loops are near the top of the stem and only a couple inches back. I drilled an additional pair of holes just above each factory-supplied grab loop for anchoring the float bags. The black rope loops are factory supplied, and the little wrapping of white rope at the very top of each stem is a float-bag anchor point. As you can see, I tied the float-bag anchors on the outside just to make it easy.
I think you'd only need a block of wood on the inside if you intended to pull extremely hard on those loops. I've never seen anyone set them up that way. On the other hand, some people put their grab loops very low so they don't tend to flip the boat when lining through rapids, and then people use "Tug-Eyes" or a home-built equivalent system to prevent leakage. When I do whitewater I set my boat up with a quick-install harness at each end that only takes a minute to put in place (a harness is the old-school method that places your lining attachments right on the keel line, so the boat CAN'T flip when the lines hold it sideways to the current) so I'm happy with the grab loops being high on the stems.
6" is a lot
Most factory grab loop holes are around something like 1.5" to 2.5" back from the stem. Just make sure you plan it out and make the rope long enough that you don’t crack your knuckles when picking the boat up by the loops.
I’ve also never seen wood blocks. Just knots.
Drill baby drill!
I too have avoided drilling in the past, just 'cause, I guess. Protestant work ethic? Who knows. From now on, if it's Royalex, I'm drillin'. No good reason not to. Plenty of good reasons to do it (effort, weight, KISS, cost ...). Plus, drilling the hull results in the inflated bags remaining below the gunnels, instead of bulging out like Dolly Parton in a string bikini. Just looks better to me ... talking about boats.
An inch or two is enough
I just looked at 5 boats I have sitting around with grab loops through holes in the stem. The holes have been drilled from 1.25" to 2.5" back from the stem, most about 1.5".
You can use rope for grab loops, but if you are going to carry the boat by the loops, I find 1" wide nylon webbing is considerably easier on the hands. You can knot it off on the interior of the boat as you would rope.
You can certainly drill another set of holes for an anchor for your “keeper strap” if you wish, but it is not necessary to do so. I have never had any difficulty threading a length of 3mm thick parachute cord through the same hole the grab loop goes through right along side the loop. Just reach inside the hull and pull the knot in the grab loop back into the hull a little bit to make space to thread the cord in along side it. Tie the two ends of the parachute cord together inside the hull (I prefer using a sheet bend knot) and the loop will be plenty strong enough to anchor your keeper strap around under the deck plate.
If you want to make the keeper straps easy to remove, you can use 1" wide side release Fastex quick release buckles instead of triglides.
both ways have worked…
Think I agree with the holes-in-the-hull guys, however I’ve pop riveted OC-1 aluminum gunwales along with slightly thicker webbing/rope before and didn’t have any issues…other than covering(padding and/or tape), and shortening…any bolt threads that could’ve rubbed against bag(s)…fwiw.
FWIW I’ve also had good luck with two straps running midship to stem and spread a bit, but may be overkill on most streams. Adding a thwart as close to stem, if not present, has worked well for securing bag(s) and carrying.
$.01
Grab loops
I put wider than my hand sized pieces of flexible plastic tubing on the outside portion of my grab loops. Much easier to carry the boat while holding onto the plastic tubing than rope, and no rope on rope contact with the painters (my painters were attached to the grab loops) when hauling the boat.
Something else I did was drill a hole(slightly larger than para cord) in the stems, about 5 inches down from the decking. I attached a length of para cord to the grommet on the (pointy end)of both air bags. I would thread the para cord through the holes, running to the outside of the canoe. Pulling the para cord through the hole pulled the air bags into place, inside the bow/stern of the canoe. Helped keep the airbags in place whether inflated or deflated. Barrel knot tied in para cord,on outside secured airbag in place. Took only a couple of minutes to put airbags into place or remove them; when air bags were inflated they were already in the correct position. Run center strap over the top of air bags & attach end of strap to fastex buckle mounted in the bilge; good to go.
Airbags less likely to roam about if deflated while traveling; for those who don't remove the airbags when traveling. I always took air bags out of the canoe when traveling; being concerned about abrasion to bags, noise of deflated bags flopping around, and the possibility of bags overinflating from heat.
BOB
thanks for the tips
I didn’t know how easily the rope would tear through the royalex if it was too close to the end. What type/size line do most people use for grab loops?
Buoyancy Blocks for Canoes
Europe has people using foam blocks :
http://www.canoesandkayaks.co.uk/images//bfd-front.jpg
usually 3/8"
Many use 3/8" diameter braided nylon line. Outdoor stores that cater to climbers will often sell short lengths by the foot.
For reasons I mentioned above, I usually prefer 1" wide tubular webbing, however.
wood blocks
I’ve never seen wood blocks backing up grab loops either, though I have seen a couple of grab-loops torn out (by Z-drags and such, not lifting the canoe). Good idea for a boat used in really tough conditions.
A big IF…
IF if comes to having to use a Z drag; problems usually occur when those doing the hauling on the rope substitute brute force for using correct angle of pull.
Pulling at a right angle to the canoe is usually best.
If pulling at a right angle is not possible; try to "guesstimate" what position the boat will be in when it starts to come loose. Ideally, when the boat starts to come loose, the pull will be at/near a 45 degree angle. A suitable anchor point is required, and those ideal anchor points are not always available. The ability to adapt then comes into play;the person/persons rigging the anchor needs to know how to rig redirectional anchor points.
Another useful techniques( which can be used in conjunction with the Z drag) is what is commonly referred to as the Steve Thomas rope trick. Simply put, when a rope(wrapped around the hull multiple times)is pulled; the boat will rotate, and some water weight will be dumped. The rope wraps spreads the friction across the hull, which absorbs most of the pull.
Of course you need gear, and you need people who know how to rig, and use these techniques correctly.
Unfortunately, the number of people who carry the gear, and have the training are few & far between.
Attitude is often, "We don't need no stinkin' training; we don't need no stinkin" gear".
Result: Boats get torn up, or on occasion end up in a worst position than they were in when the recovery started.
In some cases, if the people doing the recovery are knowledgeable; simply manipulating small changes in the boat's position, and using/changing the force of the river can result in success. Something as simple as using people to create an eddy line upstream of the pinned boat will be enough for others to simply lift & roll the pinned boat free. Seen it happen.
It is my opinion that the more complicated the recovery techniques used; the more likely that someone will end up injured during the recovery.
Especially when the people performing the recovery don't "really" have an idea of what they're doing..........but are just making it up as they go along.
BOB