I am going to reinforce 2 repaired wood canoe paddle shafts with fiberglass cloth or tape and resin(wich I already have). Should I wet the shaft first or after putting the cloth on? Should I wrap the tape spiral or lengthwise? Advise appreciated!
I’d brush on the epoxy first, then lay the dry cloth on. I’d lay it straight and not spiral. I think spiral is just asking for puckers, plus you’d have to overlap.
You can get a fiberglass (or carbon fiber) sleeve that would go over the shaft. The sleeves are woven and expand/constrict to match the diameter of the shaft. They work perfectly and you don’t end up with seams along the length of the shaft. Let me know if you want links to online sources.
Dynel sleeves are often used because
they resist scraping of the shaft, and wear smooth. However, any sleeve material may cause skin irritation when use wears through the resin and into the fibers. I was getting black, cracking skin in my thumb webs and on one little finger, and eventually realized it was caused by Dynel fibers where use had worn through the resin. Varnishing or re-application of resin can help avoid this.
Lay the fiberglass on dry and straight. Use two layers of 6 oz cloth with the top layer a half inch or so longer than the lower layer. If you make the top layer extra long you can tape it in place until the epoxy sets. Dont try to remove the tape until the epoxy sets. You’l’ pull everything apart. The portions of the fiberglass that are covered with tape won’t get epoxied but you can trim and sand them off later.
When you saturate the cloth with epoxy, the epoxy will soak right through to the wood below. You will know that the fiberglass is fuly saturated because it will become nearly transparent. The reason for using 2 layers and making the top layer a bit longer than the lower is so that you feather the edge and don’t have a sharp ridge.
After the 1st coat of epoxy sets add a second and even a third coat, If you sand lightly between coats you’ll get a very smooth surface. Don’t hesitate to heavily sand the feathered edges even if you do sand into the cloth a bit. You want the transitions between the patch and the original shaft to be smooth.
A couple of tips:
- make sure the finished patch is at least an inch longer than the last broken wood fibers at both ends of the break.
- Sand the shaft to bare wood before installing the patch. You want the epoxy to bond with the wood, not to just stick to the old finish.
- You might want to try forcing epoxy into the break and clamping the shaft until it sets before applying the patch.
Dogpaddle Canoe Works
Custom canoe paddles and cedar strip canoes