Gluing Outer stems that are slightly out of shape

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Grumple
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Joined: Thu Jul 03, 2014 7:38 am
Location: Halifax, Nova Scotia

Gluing Outer stems that are slightly out of shape

Post by Grumple »

Hey guys,

So I'm all set to glue my outer stems first thing tomorrow morning. I've studied up on the process, and I've finished prepping the bow and stern of the canoe.

When I did a test fit of my outer stems after initial prep, it looked like I needed to mortise a bit longer groove to get the outer stem to 'push into' the front of the inner stem. I did this and it helped but now I notice that the fit isnt as good along the 'top edge' of the stem.

I think I might have slightly changed the original alignment of inner stem and outter stem when I lengthened my mortise groove. In hindsight, I think they had just changed shape a bit over the months since being made and I misread the problem.

Anyway, I just did another dry fit and they come down nice and snug under ratchet straps, but I did have to apply a fair bit of pressure to bring them down flush where they wanted to float off the inner stem, especially along the tight curve where the front becomes the bottom of the boat.

Is this fairly normal? Should I be concerned about the glue joint being under stress, or will it be fine once the epoxy cures?

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Grumple
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Location: Halifax, Nova Scotia

Re: Gluing Outer stems that are slightly out of shape

Post by Grumple »

Just to update this...I decided not to apply ratchet strap pressure to pull the outer stems all the way down. The gap wasn't too bad, and I figured I could use a medium strength force to handle most of it without having to worry about over-stressing the glue joint.

I ended up use my good 'ol surgical tubing and a generous dose of peanut-butter-epoxy. I won't know fore sure how well it worked til after the glue sets and straps, etc, come off, but so far it seems to have worked well enough!
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Patricks Dad
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Re: Gluing Outer stems that are slightly out of shape

Post by Patricks Dad »

a generous dose of peanut-butter-epoxy.
Did you thoroughly coat the end of the strips (and apply as much as the strips would absorb) and the inside of the outer stem with unthicked (but catalyzed) epoxy first?
Randy Pfeifer
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Grumple
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Location: Halifax, Nova Scotia

Re: Gluing Outer stems that are slightly out of shape

Post by Grumple »

Hi Randy,

Yep, I did soak a bunch of catalyzed, un-thickened epoxy in first. I took the straps off today and got started on shaping. So far so good!

I think next time I might need more wood flour, though. I added enough to make the mixed glue turn cedar color, but now I find the semi-cured glue that I can see in the gap has more of the whiter (filler) color.

Oh, that and I made a bit of a mess of epoxy on the strips near the stem when I glued it up. There was lots of squeeze out around the joint and I did a poor job cleaning it up under all the straps I was using to hold the stem in place. I assume a scraper is what I want to clean some of it off before sanding?
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Jim Dodd
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Re: Gluing Outer stems that are slightly out of shape

Post by Jim Dodd »

Have an idea, that might solve the problem with filled resin wanting to run away from a joint.

Start with some 100% polyester fleece (sweatshirt material), brown in what ever shade you want. Saturate it with mixed resin, and place it between the outer stem and the hull.
This will hold resin in place, and fill slight gaps. It's machineable, and will be easier to clean up. Polyester is compatable with epoxy.
I've been experimenting with this as an alternative to Kevlar felt for skid plates.

I realize it's to late in your situation. But a thought for others, or the next time.

Jim
Keep your paddle wet and your seat dry!
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