I'm building a pair of oars for my new raft. I have some gorgeous, clear, old-growth Doug fir 2x6's ready to be ripped. I was thinking of laminating the shafts, and laminated blades with ash edges.

Do people counterweight wooden oars to help the weight, or is it "good" that they're neutrally buoyant with blades immersed, yet heavy in air?

A good diameter for fir oars for a whitewater raft? 1 5/8"? 1 3/4"? 2"?

Blade size preferences--6" x 36"? 8" x 30? Smaller? Bigger?

Epoxy/glass wraps--tips only or edges + tips?

Shawn

In reply to "Making wooden oars(mbb)", posted by Shawn Baker on June 1, 2004:
>I'm building a pair of oars for my new raft. I have some gorgeous, clear, old-growth Doug fir 2x6's ready to be ripped. I was thinking of laminating the shafts, and laminated blades with ash edges.
>
>Do people counterweight wooden oars to help the weight, or is it "good" that they're neutrally buoyant with blades immersed, yet heavy in air?
>
>A good diameter for fir oars for a whitewater raft? 1 5/8"? 1 3/4"? 2"?
>
>Blade size preferences--6" x 36"? 8" x 30? Smaller? Bigger?
>
>Epoxy/glass wraps--tips only or edges + tips?
>
>Shawn

Hey there Shawn, fancy meeting you here!!

I'm just finishing up building a driftboat for a couple of friends and am about 3/4 way done with the oars.
After extensive research....yeah right...
I decided on doug fir laminations for the shaft with a thin dark cedar stripe in the center, then doug fir, oak, cedar, and ash for the blades.
I went 1-5/8" diameter on the shaft 9' long, and 5-1/2" wide blades x 28" long tapering to a rounded 3/8" at the tip and edges.

I plan to glass the entire blade and then varnish over the whole thing but no counterweight, mainly due to laziness.
It would have been easy to add a chunk of lead or steel in with the shaft layup though. Maybe next time.
Watch the grain orientation on the paddle blades, 2 side by side strips with opposing grain is a bugger....don't ask me how I know.

Ben Staley

In reply to "Making wooden oars(mbb)", posted by Shawn Baker on June 1, 2004:
>I'm building a pair of oars for my new raft. I have some gorgeous, clear, old-growth Doug fir 2x6's ready to be ripped. I was thinking of laminating the shafts, and laminated blades with ash edges.
>
>Do people counterweight wooden oars to help the weight, or is it "good" that they're neutrally buoyant with blades immersed, yet heavy in air?
>
>A good diameter for fir oars for a whitewater raft? 1 5/8"? 1 3/4"? 2"?
>
>Blade size preferences--6" x 36"? 8" x 30? Smaller? Bigger?
>
>Epoxy/glass wraps--tips only or edges + tips?
>
>Shawn

Shawn,
Laminating the shafts will probably be much stronger but you can also make them one piece. 2" diameter is fine. Some commercially available oars have laminated shafts which continue into the blade and then to which other laminations are added for the width. Reinforcement in the way of metal mesh or fiberglass, dynel or kevlar can be added between layers across the width of the blade. I have seen some nice one peice blades with reinforcement added on the surface of the blade for a
asion.
I like a narrower blade for skinny water where a larger one will hit bottom. 6"x30" is fine. Solid wood blades can last a long time if the tips are soaked in oil from time to time.
As for counter balance, I like it. It's very personal from oarsman to oarsman with some traditionalists saying that a light oar makes up for counterbalance. But the simple mechanical advantage a counterbalance gives in easing the weight of the blade is very nice if you are an aggressive rower. For nice light wood oars a two pound weight in the handle should answer nicely rather than the 4 lbs in some composite oars.
I have never made them but have always wanted to try a birdmouth hollow laminated set of oars. They could be very light and strong. There was an article about making hollow birdsmouth spars in WoodenBoat several years ago which you could find if interested. There was a recent article about a simple lathe jig for sanding spars also which could be helpful. Good luck

>Laminating the shafts will probably be much stronger but you can also make them one piece. 2" diameter is fine. Some commercially available oars have laminated shafts which continue into the blade and then to which other laminations are added for the width.

That's the plan.

How thin would you think a DFir blade could get without losing too much strength? I'm at about 3/4" toward the tips right now, and they seem awfully heavy.

>Reinforcement in the way of metal mesh or fiberglass, dynel or kevlar can be added between layers across the width of the blade.

So somewhat of a spline? I've done the same on similarly-shaped Greenland-style kayak paddles. I was checking out the Sawyer oars in your shop one time when Dan gave me a tour once. I think I remembered seeing metal mesh in them.

>I like a narrower blade for skinny water where a larger one will hit bottom. 6"x30" is fine.

Makes a lot of sense, thanks!

>Solid wood blades can last a long time if the tips are soaked in oil from time to time.

Hmm...so an oil finish often instead of an intial epoxy soaking?

>For nice light wood oars a two pound weight in the handle should answer nicely rather than the 4 lbs in some composite oars.

Dang, I already laminated the shafts...I may have to put the big, ugly external Cataract weights on them if I need them.

>I have never made them but have always wanted to try a birdmouth hollow laminated set of oars. They could be very light and strong. There was an article about making hollow birdsmouth spars in WoodenBoat several years ago which you could find if interested. There was a recent article about a simple lathe jig for sanding spars also which could be helpful. Good luck

Yes! I have made several kayak paddles using the birdsmouth technique from that article. I have built in feather between the blades by either twisting the lamination or tapering different staves.

http://www.geocities.com/shawnkayak/paddle/birdshaft.html

Dan made a pretty cool bed headboard and lamp with the birdsmouth technique.

A friend who works for Boeing ran the numbers and told me that one can reduce the wall thickness more than 50% of the radius; you get a 25% weight reduction, and only lose 10% strength, and less than 5% stiffness. I'll try to find his spreadsheet.

I had such beautiful, clear Doug Fir on this go-around that I decided to make them with only one lamination. I may try birdsmouths next time; especially if I have to fight more knots or less straight grain.

Hey, how's your munchkin? Our 2.5 year old is going on 12!

Thanks again,
Shawn

Here's a followup 15 years later...those oars are still going strong after 14 years of whitewater abuse. I bought some Cataract oars a year or so later and sold them because they hurt my shoulders (and I was only 29 at the time)....now I'm going on 44, and still love my wood oars.

I started with 2" stock, and they ended up about 1.75" diameter, 10' overall. Blades are 7" x 30" long.

Built another set at 9.5', seven years later when I bought a 13' raft.

Built yet another set this summer, just because I wanted to, not because I needed to.

Very cool.