Gorilla Tape on hull

Discussion in 'Boat and Accessory Building' started by Tobin, Apr 4, 2018.

  1. Tobin

    Tobin Paddler

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    Used Gorilla tape on a Pinguino 150 build. When I peeled the tape off the deck that has not been glassed yet it was fine, but almost all the pieces left the sticky stuff attached to the hull that has been glassed. Thoughts on the best way to get this off? I was thinking of using white vinegar on a cloth. Thanks for suggestions.
     
  2. Astoriadave

    Astoriadave Paddler

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    White vinegar won't touch it. Acetone, then mineral spirits, aka paint thinner, will take it off. Then wash well with hot soapy water, and rinse with clear tap water. The residual moisture on the glassed/epoxied surfaces will be gone in an hour or so. Wait overnight to attempt gluing or glassing any bare wood that gets wet.

    Fully cured Epoxied surfaces are so resistant to solvents and soapy water that I use the latter as the final prep agent prior to varnishing, etc.
     
  3. Tobin

    Tobin Paddler

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    Thanks Dave. I was wondering if I would need something stronger to get it softened. Just another step in the process.
     
  4. Tobin

    Tobin Paddler

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    Another question Dave. What do you think about using a piece of minicell foam in the bow and stern that would be well epoxied in place, instead of doing a thick bow and stern pour of epoxy? Or is the thick fillet best for structural strength.
     
  5. Astoriadave

    Astoriadave Paddler

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    The latter. Both are strong. Minicell fill will take up some moisture if the plywood is punctured; filled epoxy will not. BTW, use slow resin if a single pour, because the fast stuff will exotherm and overheat, expanding a bit. Filler your choice, with wood flour a tiny bit lighter.

    There must be some tricks on how to do this without dribbling resin mix all over the interior of the hull. I did my end pours after hatch openings were cut to make things manageable. Icky, sticky job, even so.
     
  6. JohnAbercrombie

    JohnAbercrombie Paddler

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    The end pour needs to be only 'just big enough' to bury your U-bolt or allow for drilling a hole in the bow for your end toggle. The ends are the strongest part of the boat anyway.
    On my last few scratch builds, I filled the ends before joining the hull and deck, so just had two flat surfaces to bond together with thickened epoxy.
    When I did end 'pours', I set the boat on end ( a deck or upstairs window to stabilize the top of the boat is handy!).
    I rigged up a little 'bucket' with a Dixie cup which had a (slack) string attached to the bottom with tape. I lowred the bucket right to the end of the boat and then pulled the 'tipping' line. It worked pretty well.

    I agree 100% with the cautions on exothermy...smaller batches work better. Also, don't make the mix too thick. If you want something lightweight (and nicely runny when mixed properly) Microlight filler (WEST) works well. It doesn't have much strength, though.
     
  7. Astoriadave

    Astoriadave Paddler

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    Good advice from John on technique for that end pour. I have also used Microlight filler from WEST Systems for large volume pours. I believe it is akin to the phenolic microballoons System Three used to sell. Neither is affected by water.
     
  8. Roy222

    Roy222 Paddler

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    Tobin,
    You could also glue (epoxy) in a small V shaped wood block in the lower hull where you intend to make a hole for the handle or u bolt. Think of this glued in block as a stem extension.
    There is no real reason to do end pours, as mentioned above, except for sealing the hole for the carry handle/strap. Some strip builders do not use stems in the bow and stern. The real strength comes from the shape of the hull as the curve surfaces come together.
    Some builders simply drill the bow/stern hole. then epoxy in a tube.
    I personally like the belt and suspender approach of using both a glued in block followed by and end pour. Maybe it is the Viking in me. You know, that subconscious desire to ram -- ha ha!
    ( If you are of western european decent there is a high probability you have some Viking in your DNA)
    But before you "pre-pore" the ends make sure the top and bottom hull match for at least 6 to 12 inches from the ends.

    Roy
     
  9. JohnAbercrombie

    JohnAbercrombie Paddler

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    It's not clear to me if Tobin was using the tape to fasten the hull and deck together when he joined them (with glass tape and epoxy) or just to hold the deck panels together when he was assembling the deck.
    If the hull and deck are still separate, one of the techniques to put blocks (or epoxy behind a temporary dam) in the ends could avoid the hassle of an end pour.
     
  10. Tobin

    Tobin Paddler

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    Yep - was just holding the deck together to the glassed hull. Sounds easier to put a wood block in before the hull and deck are joined. Thanks much for all the notes, appreciate the experience!
     
  11. Mac50L

    Mac50L Paddler

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    I've never done an end pour. The bow from bottom planks up (where the sides meet) has a thin bit of tapered wood (wider at the top) to give a slight rounding to the bow rather than sharp point. The stern, because a rudder is always fitted usually has a small transom.

    About 15+ cm aft of the bow a piece of thick wood across the hull that the deck lands on and that a fitting is screwed into. This takes the decklines and lifting handle rope. This is strong enough for more than half the weight of a multiday fully loaded kayak. Half the weight because someone is lifting the other end, either using the aft lifting toggle or lifting by a comfortable hold of the rudder unit.

    You mention a glassed hull? Why? Adds a lot of weight and cost unless epoxy is very cheap for you. I don't know how long an unglassed hull will last as my oldest is only 35 years old though our ply pramm dinghy is over 60 years old.

    So 3 mm ply with a first wetted (test paddle) weight of 13 kg and finished fully fitted out (rudder, lines, hatch covers, etc.) weight of 18 kg, and that could be reduced.

    Strength? If you hit rocks? I always hit rocks, probably every time I go paddling. My partner if landing on a beach will simply power on to it - with an unglassed hull. She does leave grooves in the gravel as the keel has carborundum in the epoxy.

    Finish - paint as UV here kills varnish and is even worse on uncovered / unprotected epoxy.
     
  12. Denis Dwyer

    Denis Dwyer Paddler

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    Goo-Gone removes tape adhesive, tree sap, etc.
     
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  13. JohnAbercrombie

    JohnAbercrombie Paddler

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    Contact cement cleaner is another useful solvent. Stores used to sell two different products - a cleaner and a thinner for contact cement. Lately, it's just the thinner which is labelled as Cleaner/Thinner.
    I don't understand the chemistry involved (Dave could help here) but the contact cement thinner seems to dissolve sealant residues and adhesives even better than acetone, which I usually consider the 'strongest' solvent on the shelf.
     
  14. Astoriadave

    Astoriadave Paddler

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    The industrial grade adhesive removers/cleaners typically have toluene and or xylene in them, also MEK, aka methyl ethyl ketone. These require an organic compound vapor mask to protect you. 3M's windshield adhesive remover is a good choice. At this link you can get good, authoritative advice on how to use it.

    Contact cements typically are polyurethanes, which the 3M cleaner should cut. Lots of other brands out there. Use the ingredients in the 3M product to evaluate effectiveness.
     
  15. Astoriadave

    Astoriadave Paddler

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  16. JohnAbercrombie

    JohnAbercrombie Paddler

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    Thanks, Dave.