I made a paddle for whitewater use out of ash, for the shaft, and eastern redcedar for the blade. The redcedar is soft, light, but not the strongest wood so I fibergassed it with auto body fiberglass and polyurethane based resin. I have read about “S glass” and epoxy resin. Should I have used that? Where would one find that stuff in small quantities? Will the stuff I used hold up? The stuff didn’t bond that greatly to the wood but if it gets torn up I’ll pull it off and try something else.
I think you made the right decision to glass the cedar blade of your hand crafted whitewater paddle. But it’s not a good sign if you are saying the glass job you did has not bonded to the wood very well. If water gets in between the glass and the wood there will be trouble. I think you have 2 choices: 1) You can use the paddle as is, but keep a watch out for water between the layers. If this occurs sand off the fiberglass and start over. 2) Just sand it off now and start over. Most marine supply stores should have small amounts of epoxy for sale and probably cloth as light as 4 oz. A commonly stocked brand of epoxy that I’ve had good luck with is West systems. My recommendation on cloth would be 2.5 to 4 oz to keep added weight from becoming excessive, but still providing strength to protect that cedar.
Good idea, but bad execution
Polyester resin (it’s not polyurethane) is a laminating resin, not an adhesive. It’s fine for making layups of layers of fiberglass, Kevlar and such, but it won’t bond well to wood. You’ll need to strip off what you put on and sand back to BARE wood. If you leave the wood sealed, the epoxy that you’ll use to re-glass the paddle will not be able to penetrate and will not adhere as well as it could on bare wood.
Regarding your wood choice, ash is a good shaft material, but I wouldn’t recommend western red cedar (there’s no such thing as “eastern” red cedar) for a whitewater paddle. It’s soft and easily damaged, and not especially strong. I doubt it will hold up to the abuse for long. I use it in sea kayak paddles all the time, but I also reinforce the tips with fiberglass and epoxy. If you reinforce your paddle enough, you may get decent life out of it.
If you don’t have a marine supplier in your area that carries fiberglassing supplies, many Home Depot stores sell Everfix epoxy and fiberglass cloth. It’s probably not the best stuff in the world, but I’ve used it successfully for a lot of repairs and for reinforcing the tips of the paddles I’ve made. A quart kit of epoxy and some glass cloth will run you $25-$30 and you’ll have enough left over to do many more paddles.
Is the common name for Juniperus virginiana. It isn’t a true cedar, but rather a juniper. I think it is a fair bit tougher than western red cedar, but my reference describes the wood as weak an brittle.
expoxy is the way to go for bonding your fiberglass cloth to your wood. Contact system 3 for their sampler at 20 dollars it comes with enough epoxy to fix your paddle and a good little book on how to do it. Polyester resin just is not a good bonding resin for wood and will delaminate.
System III sampler
After reading this thread you’re getting some good advice… you may have messed up a bit with the wrong resin for the glass, but it’s not like it was a full cedar strip canoe either
Epoxy resin is the way to go and either System III or West System makes some great stuff specifically for cedar boats. System Three’s sampler kit is a great way to try it out.
As for the choice of woods… there are lot sof boats built with western red cedar and it’s eastern counterpart. It’s light and clear verticle grain will work well. As for being brittle… you could probably pick things to death if you examined the relative properties of each wood… the bottom line is western red cedar is light weight and when sandwiched between a couple layes of glass with the correct epoxies the “monocoque hull” properties will far surpass any problems with the wood. I’ve built paddles with western red, mahogony, cherry, ash and even birdseye maple. My current WW paddle has a cedar blade and a narrow cedar/ash shaft…it’s also got over 800 river miles on it. The one thing you’ll want to remember is that without any tip protection you WILL damage the tip… but you built it…you can fix it!!! With the epoxy resins you don’t need to worry about sperations and any further damage to the blade…so simply cut off the damaged bottom 1/2 inch… hit it with some fresh resin and keep on paddling!!!
One last comment about epoxy resin… it IS effected by UV light… so after everything sets… give it a couple coats of good marine spar varnish…otherwise the epoxy will turn a milky white.
Hope that helps