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  1. #1

    Default No Sniffing Allowed

    Or How to stick things to canoes

    Using glue (Adhesive) is probably the most versatile way of attaching things to your canoe hull. It allows you to position things where you want them, even below water line, does not harm the structural integrity of the hull and with care it is usually possible to remove them in the future. When things go wrong it is often because the wrong adhesive was used in the first place. To form an effective bond you need to use one that can overcome the surface tension of the two materials that you are trying to stick together: some materials, notably plastics, have a high surface tension so some care is required in choosing the right one. The other reasons that bonding fails are poor preparation and not following the instructions. It is no good reading them AFTER you have stuck your D-Rings in!

    Non-Structural Bonds

    For canoeists this probably means kneeling pads. Although we don’t want these to fall out they don’t experience an excessive load and mostly the force is sideways, known as a shearing motion which gives the glue the easiest life as the whole of the stuck surface gets a chance to resist the force being applied. From a practical point of view we may also want to replace the pads at some point if they wear out. The best glue to use for this is a contact adhesive, one that bonds as the two pieces are brought together. This removes the need to hold the flat pads on to the curved canoe while the glue sets. Good old Evo-Stik is still probably the best, in the red or green tin, solvent based so you will need to take the little card up to the counter in the store.
    Once you have decided where you want your pads mark round them with a pencil and gently sand inside this line. I generally use wet or dry paper though the new Brillo pad style sheets are good. Next wipe the area with some meths to remove any dirt or grease and allow to evaporate off. Apply the glue thinly to both pad and canoe with a ridged spreader. This will make a pretty pattern and is supposed to help adhesion. Next comes the tricky bit. Wait. Go and have a cup of tea. Check your emails. Talk to your partner. Just wait. You need to let the glue dry and all the nasty solvent escape. If not the bond may not work and the solvent could work its way through into the hull and make it delaminate or go wobbly.
    When the glue is touch dry, probably about 10 minutes, carefully position the pad over the marked area. Then, bend the pad so you can roll it down onto the canoe. Start at one corner, applying pressure as you go. As contact adhesive sets immediately you need to get it right first time but at least with knee pads there is no need to be millimetre perfect.

    Structural Bonds

    Things become much more critical where structural bonds are concerned. If you have a Discovery or one of the other polythene based boats then you will need to take additional measures to ensure that your work doesn’t come adrift.
    Although the canoe dealers tend to sell stuff like Vynabond for sticking in D-Rings by far the best glues are the family of viscous polyurethanes that have come onto the market in the past few years. These also work well for items such as pedestal saddles and can also be used for filling gouges in the hull. Although once the preserve of professional users they are now marketed by Evode for DIY use. I have mostly used Loctite professional range (£8 ish for a cartridge) but I can foresee me switching to the new “Serious Stuff” or “Wet Grab” in the next boat I outfit. At around a £5 for a cartridge this is better value especially when you consider that you only need part of a tube and the rest goes to waste. These adhesives bond well to almost all plastics provided you take time to prepare the surface before sticking things down. Roughen the surface and clean thoroughly with meths or another similar degreaser before applying the glue. Adhesive is only needed for one surface and again should be applied thinly with a corrugated spreader. To improve adhesion Old Town recommend reducing surface tension by flaming the surface of their PE canoes with a blow torch set to yellow flame before applying the adhesive. An alternative to this is a primer such as the ones made for the professional adhesives. These are however pretty nasty so make sure you work in a well ventilated space or better still use a respirator. Polyurethanes do require time to set so should be left overnight before applying any load.
    If you have a composite or wooden canoe then things get so much easier. Adhesives hold much more easily than with other plastics and there is no need to buy expensive D-Rings. A piece of 50mm webbing with a D-ring sewn on and saturated with boat-building epoxy will stick perfectly well to the hull and forms a strong attachment point. Webbing can also be used on Royalex hulls if you saturate the underside with thin polyurethane such as Aquasure or Seamgrip to create a surface for the polyurethane to adhere to. Leave this to cure for a couple of days then stick down as you would a vinyl pad.

    For further information you may want to visit the following links:-

    https://www.mohawkcanoes.com/vynpadinstall.htm
    http://www.myccr.com/SectionGear/GearTips/RoyalexDRings.htm



    Chris
    "All right" said Eeyore "We're going. Only don't blame me"

    www.canoepaddler.me.uk

  2. #2
    monkey_pork's Avatar
    monkey_pork is offline a wind age, a wolf age - before the world goes headlong Super Moderator
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    Without exaggeration, this has been the hardest part of my canoeing experience as far as I'm concerned (so far anyway)

    Be careful with Royalex, being vinyl, one only needs a very thin layer of glue or you'll risk damage to your hull if you soften (or melt) too much material.

    I've historically used the 3M Scotch-Weld™ urethane, which was good to work with, (other than the solvent evaporation ) and held up well enough, but it's alarmingly expensive given it's life.

    I've since moved onto using common or garden Evo-stick and just refixing the pads as and when, or Mondo Bond, (which is a waterproof contact adhesive), and Vyna bond for the Royalex hull.

    I'd agree that having a warm (emphasis on warm) hull definitely helps in getting a good bond, as too does that bit of roughening up first (then cleaning up with isopropanol) to provide some surface key too.

    Not an indoor job this one (unless you like a headache).

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    Good stuff Chris. I am about to get "D" rings and fit then so just in time.

    Can I copy this to the Hints & Tips section of the main site?

  4. #4

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    No problem. before you go out and buy D-Rings you may want to have a go at making some. The vinyl is available as off cuts from a lorry tarpaulin maker. D rings and webbing can be found at many outdoor/ camping stores or I've seen them for sale at B+Q- you don't need steel D-Rings plastic is fine. Either get the tarpaulin maker to sew them on for you or take them to a cobbler. Will cost less than £2 per D-Ring.

    Chris
    "All right" said Eeyore "We're going. Only don't blame me"

    www.canoepaddler.me.uk

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    Good idea Chris, I'll try this.

  6. #6

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    Have seen Evo-Stik fail twice on D-Rings so would definitely not reccomend its use for load bearing situations. It's likely to happen just when you don't want it too! I think it even says on the tin that it's not waterproof?
    "All right" said Eeyore "We're going. Only don't blame me"

    www.canoepaddler.me.uk

  7. #7
    monkey_pork's Avatar
    monkey_pork is offline a wind age, a wolf age - before the world goes headlong Super Moderator
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    Quote Originally Posted by Chris Randall
    Have seen Evo-Stik fail twice on D-Rings so would definitely not reccomend its use for load bearing situations. It's likely to happen just when you don't want it too! I think it even says on the tin that it's not waterproof?
    I usually give mine a tug before I go out to test this, I've had it simply let go too. Hence the move to Mondo Bond for this year. The good thing about Evo-Stick is it's pretty cheap and goes off quickly, so a kinda running repair seems to work out ok. Not ideal of course, as you say, the last thing you need is for it to fail at exactly the wrong time.

    I make sure I have the redundancy by having a good lashing system, and more than on D-ring pad on my airbag cage (everything else is tied to the thwart, or lives loose in the bottom of the boat).

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