I got a “deal” ($175) on an OT Pack. This is what I found under the tape (which was actually waterproof window flashing). I plan to open it up a bit and smooth it out then fill with G-flex, wait a week and put a Dynel and G-flex keel cover on.
I paddled it before and enjoyed the boat so I’m just tacking this up to learning the hobby more. Huge thanks to all those who have come before and posted a huge wealth of repair knowledge on the site.
Looking forward to the “after” photos!
I spent some time heating and scraping the remaining adhesive junk that was left behind and it was a lot! Denatured alcohol didn’t make a dent but WD-40 turned it to liquid and easy to wipe off. I then trimmed up the ragged vinyl/ ABS sandwich with a razor knife and sanded the dirty weathered foam.
Looks good so far. Remove any solid fragments of ABS that overhang the exposed foam core to any extent. I would try to clean out any sanding dust and dirt from the exposed foam core with denatured alcohol which will evaporate. You can use an old scrub brush on the foam core if you need to, but it doesn’t look too dirty. Do not use acetone on the foam core as it will melt it.
Bevel the edges of the solid ABS surrounding the exposed foam core. Then fill in and build back up the area of exposed core using G Flex epoxy moderately thickened with silica powder. This will take multiple applications as you will need to prop up and reposition the canoe to get the epoxy to settle into the core where you want it to go. As the epoxy settles into the interstices of the core you can add more as soon as the prior application has cured “green” sufficiently to keep it from running and sagging.
After filling in the foam core and building that area back up to about flush with the surrounding undamaged hull you can sand the cured epoxy fair to restore the original contour of the hull. Then apply cloth over the area that overlaps onto undamaged hull by 2 inches. As for whether to use Dynel or S fiberglass either will work. I would not use aramid on the exterior as it does not take kindly to abrasion. I think that 6 ounce/square yard S 'glass offers more structural strength then 5 ounce/square yard Dynel, but Dynel has somewhat better abrasion resistance. Ideally, I would cover your area of repair with a layer of 6 ounce S 'glass cut on the bias, then cover and overlap that whole area with an abrasion plate of 5 ounce Dynel. Then paint the whole thing green.
Alternatively you can mix graphite powder into the epoxy used to apply the abrasion plate which will give it a black color that doesn’t look bad, IMO.
So I have made a few steps since my last post. It was washed with soap and water to get rid of the WD-40 oils. After cleaning it up like a wound and taking all the “dead edges” off I put a first layer of G-flex. It was really easy. I put a milk crate under the seat and that brought it close to level to keep the G-flex in place.
I then sanded it rough and layered G-flex soaked Dynel over the area. I picked Dynel 1) before I saw what I had under the tape 2) for the abrasion resistance. I did 1 layer a day, but got antsy and did 2 skinny layers yesterday…apparently multiple layers is okay to do.
I have bought lots of stuff over the years from Cathy and Davy Hearn at Sweet Composites. Agree they are a good source for structural fabrics and lots of other stuff. Dynel and pretty much any other plain weave fabric frays a lot less if you cut the strips on the bias at 45 degrees to the weft and warp of the fabric. The bias cut material will also lay down much more kindly over a curved stem without pleating. And if you arrange to have the fibers crossing a linear crack or repair at 45 degree angles, your repair will be stronger because you will have twice as many fibers crossing the area of weakness.
Dynel fibers tend to be much “thirstier” for resin than fiberglass and also tend to swell up a fair bit as the the fibers take up the resin. You can reduce this tendency somewhat be using mold release fabric (peel ply) over your wetted-out fabric and going over it fairly firmly with a squeege. Allow the epoxy to cure to green before removing the peel ply.
I would also mask out the area of your repair to which you are going to apply epoxy with masking tape. Any frayed fibers crossing over the tape can be cut along the edge of the tape using a sharp blade like that of an X-Acto knife.
