Sorry - fixed it.
Sorry about those links. The one above is fixed and has the whole album.
The Dagger Rival, though short, might
satisfy you. It is fairly round with low wetted area. There are good used Rivals available in Dagger Royalex, or you can get Kaz of Millbrook to make one in S-glass and Kevlar. However, the Millbrook version will need at least occasional repairs, though not as drastic as what you’re facing. I think designer Bob Foote is paddling a Dagger Rival in the “Drill Time” video.
You can watch for a Synergy, though mine is now almost 15 years old and possibly becoming a bit brittle. Still, the Royalex on mine has seemed outstanding.
The new Wenonah ww canoe, a relatively conservative design, might be tolerably fast.
Also, the Mohawk Shaman is from a Harold Deal design which raced in the combined class, where it had to be good at both slalom and whitewater.
wetting out fabrics
I started the cloth patches last night. I did the fiberglass on the outside first, using one layer as recommended above. It went reasonably well but I have a couple of questions:
- The GFlex is pretty viscous and doesn’t wet out the s-glass as easily as I had imagined. Should I warm it up beyond room temperature to get it to flow better?
- I used very sharp sewing scissors for the s-glass and it cut easily but I kept losing fibers from the edges so the net result was that the edges tended to have fibers in one direction. This was made slightly worse each time I scraped the viscous epoxy towards and edge. How do I minimize this?
- I was planning to use the same scissors for the kevlar, which I think is generally a no-no. However, I don’t plan on doing this very often and my wife hasn’t noticed that I took her fancy sewing scissors yet.
- I’m doing this in my unheated shed. I have a closed-system space-heater that I’ve put next to the repair. I’ve hung a thermometer from the rafters and in the general vicinity of the repair it stayed above 60 last night, despite outside temps of 25. It was still a bit tacky this morning so I left the heater on for the day, too. The GFlex says it will still cure down to 40, so I think I’m okay, even though it was tacky today.
- Should I consider putting another layer of just epoxy over the s-glass patch once the first is all dry? This will allow me to feather out the edges a bit better without disrupting the edges of the s-glass itself, I think.
I’m planning to do the kevlar on the inside tonight, so any thoughts on these questions would be helpful!
thanks for the ongoing help, everyone…
some answers
– Last Updated: Nov-06-12 2:09 PM EST –
G Flex is more viscous than other epoxies such as System 3, MAS, or West System 105/205-206. I have found that it wets out 6 oz/yd fiberglass or aramid cloth just fine as long as you are applying only one layer at a time and the working temperature is not too cool. The trick is to be patient and let the cloth take its time taking up the epoxy. Don't be in a rush to force it into the weave. Fortunately, G Flex has a pot life of about 45 minutes at room temperature (longer at cooler temperatures) and an even longer working life so you have time.
Yes, you can warm G Flex and it will reduce the viscosity but it will also reduce the pot life and working life so I would try a couple of other things first. If you have an accessory lamp on a cord put a 100 Watt bulb in it and lay it or hang it under the part of the hull you are working on several hours before you apply your cloth. You might be able to put your space heater underneath the inverted hull if there is a good bit of space between it and the Royalex. Obviously take care to avoid overheating the hull. You can also use a hair drier or heat gun to gently warm the part of the hull you are applying cloth to before you put the cloth on the boat and wet it out.
Fiberglass cuts easily with regular scissors. Aramid does not. I have been successful in cutting aramid cloth with scissors but it does dull the scissors and gives your hand a work out. Some people lay the cloth on a cutting board and use a razor knife to cut it.
All woven cloth will tend to fray as you cut it and wet it out. You will get better at minimizing the fraying as you gain experience. If you are cutting rectangular patches on the warp (along the line of the fibers) be careful to cut exactly along the line of one of the glass fibers to minimize the number of transected fibers that will be susceptible to fraying. Patches cut on the bias actually are less prone to fraying along the edges.
Like a lot of folks, I will cut my patches slightly larger than I want the end result to be and then remove a couple of strands from each side before applying it knowing that they will probably fray anyway. The fibers that are left "sticking out" from the patch are easily sanded off after the epoxy is cured.
As you wet out the cloth start applying your epoxy in the center of the patch and rather slowly progress out to the edges. As you apply epoxy to the cut edge very gently dab it on without dislodging the fibers along the edge and let the fibers take up the epoxy before working that part of the cloth very much. Try not to work the cloth in a direction that separates fibers from the edges of the cloth until the epoxy has become tacky enough to hold the cloth down.
You might find that an inexpensive, disposable, metal handle "acid flux" brush is a good tool for applying the epoxy to the cloth.
It generally takes at least 2, and often 3 applications of epoxy to completely fill the weave of the cloth. With each successive application the cloth will take up progressively less epoxy, however. You might not need to completely fill the weave of the aramid cloth on the inside but you will want to do so on the exterior if you want a smooth surface. At cool temperatures, G Flex may take longer than overnight to cure. If you let the epoxy fully cure before applying another coat then you should either wet sand the cured epoxy or wash and rinse it to remove the amine blush which could interfere with bonding of the fresh epoxy.
I will often feather my patches after the wetting out process before filling the weave of the cloth. As long as the epoxy is cured, or nearly cured, you won't disrupt any fibers in the cloth as long as it was properly wet out. I usually do this by wet sanding with water proof paper using something like 180 or 220 grit. After the cloth weave is completely filled I wet sand again down to maybe 400 grit (or finer).
Fraying glass
I like to stretch a piece of saran wrap over the glass. Then I wet the squeegee and press out the extra epoxy. I tape around the repair first so when the excess is pressed out it stays on the tape. The wrap helps the weave stay in place. I pull off the plastic then the tape while the epoxy is still in its “green” state. (Stiff enough but still tacky). This leaves a nice clean edge on the repair and minimizes drips and sanding. Just my humble opinion as I have only done it twice on royalex 
I would also buy a bit of red dye to add to the epoxy. Nothing you do will match it perfectly as the boat is old and somewhat faded but it will help make the repair less noticeable. The more dye the brighter the red will turn out in my experience. West Marine sells dye in the epoxy aisle.
repaired and paddling strong!
I thought I’d check back in and give an update. Despite some of the generous advice here and elsewhere, I decided to repair the boat. A year and a half later it’s still going strong. I’ve done quite a few Class I-III+ runs in it and have not had any issues yet. I’ve even had a few hard hits in the area with no problems. I ran Seboomook-Roll Dam yesterday at 850 cfs and the boat was solid (although it’s always been a pretty wet boat in the front).
I plan to keep paddling the ME until something worse happens. Thanks again for the input.
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