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Go for a repair
By:Paul G. Jacobson
Date: 11/5/2000, 10:48 pm
In Response To: Cracked Paddle (Mike Hanks)

: . . .I kept trimming it down, thinner and thinner.

Sounds like you have discovered just how far to thin the blades. For the next paddle leave them a tad bit thicker, or glass them.

: . . . I'm thinking of glassing the blades, I would sand them thoroughly and
: clean it with a strong solvent. I used linseed oil, turpentine, and
: kerosene to lightly coat it, but that was some time ago.

Linseed oil is the base for paints, varnishes and other finishes. It slowly dries, combining with oxygen in the air, and polymerizing into a flexible plastic. If I was unsure how old the oli finish was, I'd try to accelerate the process with heat. You'ld want some gentle, adjustable heat source that won't get too hot. A light bar with 3 - 100 watt lightbulbs, each in a porcelain socket should provide some nice radiant heat. Wire the sockets to an extension cord and secure them, about a foot apart, to a 3 foot long 2x4 or 2x6. Hang this over one blade, starting with the ends of the bulbs about 1 foot above the blade. Put a meat thermometer next to the blade turn on the lights. Check the temperature regularly, and raise or lower the light bar so that the temperature stay somewhere over 160 and under 200. Then leave it like that for a day or two. That should be cool enough to avoid damaging the wood, but hot enough to cook out solvents and ensure the linseed oil has polymerized. If you have any scraps that were treated in the same manner, try working with them.

Of course you could always set the thing aside for a few months oryears before trying to fix it, too.

Hopefully the turpentine and kerosene have evaporated by now, and the linseed oil has oxidized. If so, then you'll have a piece of wood with some additonal resins in it, which will hopefully not affect the epoxy. The best you could hope for would be to have the p[addle in a state were the hardened linseed oil reacted about the same as having a bit of dried sap in the wood, but not like oil. Epoxy do-exists with resinous woods, so if that linseed oil is hard enough it should be OK.

: Would I be able to get it cleaned up enough for glassing? Would the glass
: strengthen it enough?

What is your definition of "enough"? 3 layers of 20 ounce cloth on each side would strengthen it enough to use as a lever for lifting baby elephants. Is that 'enough"? :)

Seriously, though. You'll probably want to use some gossamer thin material, say 1 ounce glass or lighter. This will both add strength, and like the glass on a strip-built canoe or kayak, it will act as a surface bond to keep those cracks from spreading. Don't worry about gluing the cracks if you put on glass. there should be enough excess resin soaking into the crask to bond them. Even if the adhesion is not 100 percent, I think that with a good cleaning of the blades, and a light sanding, you should get a significant increase in strength, with an insignificant increase in thickness, stiffness, or weight.

A few other thoughts: A coarse sanding job will improve the chance of adhesion.

You can get a non woven fiberglass mat from Defender (www.defenderus.com) in a weight of about 1 ounce. You would probably use less than 1/2 yard to cover both sides of both blades. With an application of an equal weight of resin you'll add jless than 1 ounce to the paddle weight.

If you can arrange a vacuum bagging setup you might get more resin forced into the wood fibers, and form a better bond. A paddle is a lot easier to vacuum bag than a hull.

You can use that light bar to heat cure the epoxy after it sets up.

hope this helps

In a worst case scenario, you can always sand off a bad epoxy job and hang the paddle on a wall.

PGJ

Messages In This Thread

Cracked Paddle
Mike Hanks -- 11/4/2000, 5:10 pm
Re: Cracked Paddle
peter czerpak -- 11/6/2000, 8:07 am
Go for a repair
Paul G. Jacobson -- 11/5/2000, 10:48 pm
Re: Cracked Paddle
Earl Bailey -- 11/5/2000, 2:03 pm
Retire the Cracked Paddle
Roger Nuffer -- 11/5/2000, 1:56 am
Re: Cracked Paddle, RIP
Lee -- 11/4/2000, 11:37 pm
Re: Cracked Paddle, RIP
Lee -- 11/4/2000, 11:42 pm
Re: Cracked Paddle
Rehd -- 11/4/2000, 10:00 pm
Re: Spare Paddle
Mike Hanks -- 11/5/2000, 1:31 am
Re: Spare Paddle
bob -- 11/5/2000, 8:40 pm
Re: Spare Paddle
Greg Stamer -- 11/5/2000, 6:41 pm
Re: Spare Paddle
Mike Hanks -- 11/5/2000, 8:39 pm
Re: Spare Paddle
Greg Stamer -- 11/6/2000, 11:25 pm
Re: Spare Paddle *Pic*
Kent LeBoutillier -- 11/6/2000, 6:44 am
Re: Bird's mouth Greenland paddle
Shawn Baker -- 11/6/2000, 1:15 pm
Re: Bird's mouth Greenland paddle
Kent LeBoutillier -- 11/6/2000, 1:26 pm
Re: Bird's mouth Greenland paddle
Shawn Baker -- 11/6/2000, 1:35 pm
Re: Spare Paddle
Rehd -- 11/5/2000, 10:39 am
Re: Spare Paddle
peter czerpak -- 11/6/2000, 10:03 am