Does anyone know how to remove the fiberglass reinforced polypropylene blades from the ovalized aluminum shaft of this paddle? I’d like to shorten it by 20 cm, and trimming back from the middle joint won’t work (see: ovalized).
It is unlikely to be possible to do this without destroying the paddle. You could try heating the shaft to polypropylene melting point, but even if it works you are left with the challenge of re-attaching the blades. Your best option is trying to sell the paddle and buy one of correct length. Second best is looking harder for a way to shorten and splice the shaft away from the blades.
Yes. A bit more work and no weight reduction, but cutting the shank a little inboard of the blade on each side, trim 10cm and epoxy together over a short piece of smaller OD tube would work. Got to mark to keep proper alignment in rotation.
Selling would be less work, but so far no nibbles on Craigslist.
Given that is a $50 paddle, perhaps just buy another of the right size and keep this as a spare. You’d probably be only able to sell it for $20, so why not just keep it.
While buying a new one, you might want t consider going the net quality up - like fiberglass shaft/blade or carbon shaft/FG blade. The lighter weight would make a difference. Looking between $100-300.
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I read somewhere that blades at this price level are attached with what amounts to hot glue. At my altitude, water boils around 200 degrees F. So wondering whether anyone has removed blades by immersing in simmering water.
OK. I finally caught on that blades have stubs that fit into the shadt, not the other way around. Tapping on the shaft, I could tell the blade stub was shorter than the 10cm I wanted off from each half of the paddle. So I cut the shaft inboard of the blade using a hacksaw and miter box. Then I scored through the length of the shaft remaining on the blade stub using a multitool. I softened the glue with a heat gun, although there was so little of it, I hardly needed bother. With a flat screwdriver, I pried open the cut and the blade pulled free easily.
What little glue there was seemed similar to Liquid Nails construction adhesive: kind of rubbery and sticky, not really hot melt glue and definitely not epoxy.
I’m ready to remount the polypropylene blade stubs into the aluminum shaft. I have hot glue, various epoxies (G-Flex, JB Weld, PC-3), and urethane Gorilla Glue on hand. Leaning toward epoxy - I won’t be changing the paddle length again. The stub is ridged and I’ll rough up the shaft inside to key in the adhesive,
Further research about gluing things to polypropylene and polyethylene.
Epoxy, 3M 5200 urethane marine sealant, packaging / carpentry hot glue, silicone sealant, shoe goo, contact cement, butyl rubber, Lexel, construction adhesive - none of these are formulated to adhere to polyolefins such as polypropylene and polyethylene. At best, the adhesive bond is very weak.
However, there are hot melt glues formulated for polyolefins:
3M 3731 high temp and 3764 low temp
Infinity Bond SuperTAC 500 (AE .45" sticks, Q 5/8")
Typically 11 pound minimum order, but some vendors offer one pound for ~$25 (10 - 11 sticks).
And there are 2-part adhesives formulated for polyolefins;
3M Scotch-Weld DP8005 and DP8010
Infinity Bond MMA 500
Prices $55 - $75 for a 45-50 ml double cartridge made to be dispensed in a mixing nozzle gun ($25 & up)
Expensive stuff. Not to be found at your local big box building or hardware store.
It happens that the paddle stubs are hollow with an aluminum reinforcing tube inside, so I could use regular hot glue as gap filler / water seal when fitting the blade stub into the paddle shaft and pop rivets through the end of the shaft into the hollow stub for secure attachment. I have 1-1/2" heat shrink tube (ebay) that I’ve used for paddle grips that would work nicely to cover the joint and rivets.
But I’m getting a pound of SuperTAC 500 sticks. One stick is enough for this project, and I will inevitably have other projects involving low surface energy plastics, including sticking things to polyethylene kayaks. The sticks have an indefinitely long shelf life, unlike the 2-part adhesives, which pretty much need a big enough project to use the whole cartridge in one go.
From the factory, the end of the paddle shaft was dimpled into four small recesses in the base of the blade stub as additional, mechanical attachment. After the hot glue begins to set, I’ll follow up with a hammer and punch over the recesses to see if I can do the same by hand.
Finished.
Scuffed up inside the aluminum shaft with sandpaper, wiped blade stub and shaft with isopropyl.
Warmed up shaft with heat gun. Squoozed SuperTAC 500 hot melt into shaft and onto paddle stub, stuffed together and rotated a bit to spread, wiped off excess at joint.
Removed masking tape, dimpled the shaft into the stub with punch and hammer.
Applied small length of heat-shrink tubing to cover joint.
Looks like new from the factory, but probably stronger and the 230cm length desired.
Ta-Da.
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Thanks for these updates, boatafloat. You do nice work and somebody, someday is going to appreciate the fact that you’ve posted all of this detail.
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I agree with Wolf.
That was an excellent presentation and bit of research, as well as a great tutorial.
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