Making an oar, longer

[Dokkodo]

I have used this quiet time to do something ive wanted to do for ages, and i have just finished it - a stitch and tape canoe! Maybe ill post on that seperately.

Anyway all thats left to do is make a pair of oars. I have some nice ash boards i milled myself, thing is they are are about a foot too short. Id like to use ash though because itll match the 'thwarts' (seats) in the boat, and i dont really want to buy any more because other than the paint, ive more or less completely made the boat from stock i had already.

So i'm wondering about making each oar too short and then extending it. Only thing is, as oars get quite a lot of lever force through them im not confident either of these will work, but im interested to know what you guys think.

Option A) cutting midway along the shaft and turning an extending piece of a nice contrasting timber to go in the middle. The shaft is supposed to be 28mm diameter so i could make nice long tenons that come out of either end of the extending piece., but thats still not a huge amount of total width to play with. And i just cant visualise if this joint will be strong enough. Part of me feels like good long round tenons in a round shaft, snug and well glued, might as well be one length of wood? Any chairmakers out there with a good instinct for this sort of thing?

Option B) More of a V shaped splice, at the beginning of the paddle. Larger splicing/joint area, could re-inforced more thoroughly, but the paddle gets the most water exposure and bears the brunt of the action

Option C) Like A, but with a length of reinforcing steel bar in the middle as well as tenons. Risks rust, though it will be getting a very thorough sealing...

Do stick your oars in, any thoughts appreciated

 

[AndyT]

No idea if it would work, and I take no responsibility if you get stuck up a creek with no paddle, but I remember a query about long shallow splices in snooker cues. I had been reading an old Woodworker mag which showed a method for cutting the joint which looked like it might work.

Here's the old thread

snooker-cue-splice-help-t67732.html

 

[Phlebas]

Mmm.

I did some rowing at college (where I also inadventently qualified as an engineer). The stresses in an oar under full pressure are pretty hefty. Well, very hefty.

If you just want a paddle, go for it. Anything more full on, I would have my doubts about its longevity.

But what do I know...

 

[profchris]

I have no practical experience in this field, but thinking about the forces on an oar, this is what I'd consider.

I'd laminate the oar along its length from two pieces, each spliced to extend to the full length. I'd glue up the laminate with the splices staggered. Then I'd orientate the shaft with the blade so that the splices were horizontal in use (i.e. the forces are trying to pull the splices apart sideways, rather than levering them open along the splice).

Visually this would be less appealing than other solutions, but intuitively feels strongest. I'm envisaging from what I know, guitar necks with the headstock spliced on. A poor spliced joint could be levered open by pulling the headstock forward, but would probably resist sideways leverage.

But all this is speculation, follow it at your own risk!

 

[Rorschach]

Any extension I would personally do at the handle end since this receives the least water exposure and would be the easiest to repair if needed.

I have seen spliced oars, it's quite common to repair a blade that way it seems but from what I can gather they are generally covered in a layer of fibreglass afterwards.

 

[MikeG.]

.......I did some rowing at college (where I also inadventently qualified as an engineer). The stresses in an oar under full pressure are pretty hefty. Well, very hefty. ...

But this isn't rowing. This is paddling. As it's a canoe, there are no rowlocks. The shaft of the paddle is under very little pressure at all. All the work is done with the lower hand, and there is no pulling against a fulcrum. Therefore I can't really see a bending moment in the top 3/4 of this oar......unless of course this is some strange beast of a craft where it's a canoe shape but rowed by someone facing rearwards, and I've never seen one of those.

 

[Phlebas]

.......I did some rowing at college (where I also inadventently qualified as an engineer). The stresses in an oar under full pressure are pretty hefty. Well, very hefty. ...

But this isn't rowing. This is paddling.

And as I said: "If you just want a paddle, go for it".

 

[Sheffield Tony]

Actually, old rowing blades were made with quite a few bits of wood glued together to make the spoon. The shaft was hollow, made as 2 parts of lighter softwood, often laminated with a thin layer of ash front and back.

I collected some from the F Collar works in Oxford, and got a factory tour in about 1990. The spoons were still hand carved. Now of course they are a fancy composite materials.

I rowed for my college 1st VIII for a little while, so have an (illuminated) example Aylings blade on the living room wall

 

[Dokkodo]

Great stuff, as usual everyone...

Any extension I would personally do at the handle end since this receives the least water exposure and would be the easiest to repair if needed.

I hadn't considered putting the join at the top end, but that does make sense, as its the bottom hand which is close to the spoon that does all the main pulling. Plus then i can still add a nice contrasting bit of wood for show-off points.

It is indeed just for paddling, wont be any racing going on. Though in theory this canoe is seaworthy, the plans came with designs for leeboards and sails, the works. 16' long jobby, you can sleep in it though i made mine in 2 halves so you can bolt/unbolt it together for travel and storage.

I appreciate all the disclaimers everyone! but this is purely a leisure craft, i intend to achieve barely more than a drift down beautiful waterways, taking in the scenery and nature and maybe a gin cocktail. So aside from the gin, there shouldnt be too much risk involved, im a strong swimmer :wink:

Now, ive just got to wait until im allowed out in the thing! Im wondering whether barely paddling and drinking gin cocktails counts as excersize...

 

[Trainee neophyte]

Are you making an oar or a paddle? A canoe ought to have a paddle - with a blade at either end if we are talking kayaking rather than canoeing.

If it's a paddle you are after, then perhaps something like this? http://myoutdoorslife.com/diy/how-to-ma ... addle.html

All the paddles I have investigated have been for a paddle board, so about 2 metres in length. Laminating the shaft and fibreglassing over it seems to be the usual method.

I know nothing about oars and rowboats - it's all rowlocks!

 

[Keith 66]

Scarphing to make it longer is perfectly acceptable, just use a long scarph of 7:1 min preferably longer, when building wooden masts i use 12:1.

 

[Bm101]

If it helps I have a paddle we found in the river my lad wanted to keep it. Ignore the crack that came from a non rowing activity involving a would be burglar. It appeared he was up the creek and I had the paddle. :-"
Anyway the dimensions might be handy and it seems to a well made one. You can clearly see the handle and central part of the blade is one piece with two laminated 'wings'.
Its 105 cm in length. Handle is 8x8cm in its scoop so to speak.
Blade is 15cm at widest and 38ish long depending where you measure to and about 1cm thick. Handle is about 3.5 in both dimensions.

Hope it helps.
Cheers
Chris

 

[Phlebas]

I rowed for my college 1st VIII for a little while, so have an (illuminated) example Aylings blade on the living room wall

Ha ha. Never got near the 1st VIII myself. Rugger and cricket boats only.

I have three problems with rowing:

a) I’m not nearly tall enough.
b) it is pretty mindless.
c) training always seemed to take place early in the morning. Which my, erm, talents would inevitably have meant a sort of Goweresque appearance in a dinner suit.

I do have a couple of blades still, buit I can’t be bother to hang them. They might look a bit oppressive in the small lavvy, along with the 1st XV and 1st XI photos. (It was a very small college).

 

[Trainee neophyte]

If it helps I have a paddle we found in the river my lad wanted to keep it. Ignore the crack that came from a non rowing activity involving a would be burglar. It appeared he was up the creek and I had the paddle. :-"
Anyway the dimensions might be handy and it seems to a well made one. You can clearly see the handle and central part of the blade is one piece with two laminated 'wings'.
Its 105 cm in length. Handle is 8x8cm in its scoop so to speak.
Blade is 15cm at widest and 38ish long depending where you measure to and about 1cm thick. Handle is about 3.5 in both dimensions.

Hope it helps.
Cheers
Chris

As a paddler, that looks like a beast - a fabulous workout, but it may put you off canoeing for ever! I have a selection of low-quality metal paddles, and some carbon fibre jobs. The carbon fibre paddles are about a third of the weight, better made and don't break. I have already broken one of the cheap ones; a loud bang and I went straight over the handlebars. Oh, how they all laughed.

If you are only looking to do quick, gentle trips it won't be a problem, but if you want to do more than an hour at a time, your half-tree is going to be very, very heavy by the end of the day. However, having made the canoe, of course you want to make your own paddle - you can't put a piece of plastic up against such a thing of beauty. My hand-built board was supposed to have been in the water by now, but I haven't even bought the wood yet. I known that when I do get around to it, I will want to make a paddle to compliment it, even if I still use a carbon fibre paddle for actual trips. Just make it as lightweight and strong as you can (laminated, glassed shaft in other words). If it's heavy enough to beat intruders with, it's too heavy.

 

[Dokkodo]

I didnt realise the distinction, but i guess oars sounds grander than paddles in my head! So, I spent part of the day making paddles, or rather trying to direct housemate how to, despite having no idea myself...

I can confirm they did not look like this

because we got both nearly done in a day, and that would take me a week! I turned a couple of simple handle extensions from some cherry, which flare out at the end, with the longest widest tenons i could afford in the material i had, and then i set my housemate/apprentice to the task shaping with spokeshaves, drawknife, rasp and scraper. I also got to use my new Triton mega planer, to taper the flats down to about 6mm thickness, and as this wood is still a bit green they might just dry into a gentle scoop... The stems are a bit thinner than id have liked, but its all the wood i had so im just treating them as an experiment, would be no great hardship to make more, will be better next time round one would hope.

Heres a couple of photos of my pal using a card scraper for the first time to his great satisfaction, for some reason i chopped his head off to preserve his identity.

I think they look quite nice, but a bit skinny. Time will tell if they are too heavy/light/bendy. Im looking forward to seeing it varnished and shiny anyway!

Thanks for the dimensions Chris, interesting to note. I made this one to the drawings supplied (more or less) with the plans for the boat, and its quite different, nearly 5 foot long, the blade is longer relatively, and everything else a bit skinnier, but i guess what you want probably depends what sort of boat your in. The one weve just made is 16 foot long, which it turns out is quite long!

 

[MikeG.]

You're not going to enjoy holding that paddle. One hand goes over the end, which is why they are shaped like in the photo TN posted.

 

[Dokkodo]

Aha, yeah i had noticed they all have flat, flaired tops, including in my drawings. No matter, i have the flair, just need to flatten them.

 

[rafezetter]

I have no practical experience in this field, but thinking about the forces on an oar, this is what I'd consider.

I'd laminate the oar along its length from two pieces, each spliced to extend to the full length. I'd glue up the laminate with the splices staggered. Then I'd orientate the shaft with the blade so that the splices were horizontal in use (i.e. the forces are trying to pull the splices apart sideways, rather than levering them open along the splice).

Visually this would be less appealing than other solutions, but intuitively feels strongest. I'm envisaging from what I know, guitar necks with the headstock spliced on. A poor spliced joint could be levered open by pulling the headstock forward, but would probably resist sideways leverage.

But all this is speculation, follow it at your own risk!

I was thinking similar but the other way - which do people feel would be greater - the glue resistance to shear forces as opposed to opening up by leverage - some angled hardwood dowels near the ends of the splice would also help.

There's also the possibility of binding the spliced joint - either with thin paracord and the like then sealing with something - which would provide grip for wet hands - or if thats visually too bulky a sheet ot two of glass fibre which becomes almost transparent when inpregnated with resin.

I doubt a canoe paddle would have that much force on it tbh - that sort of canoeing isn't known for it's speed if by canoe you actually mean "kayak".

Sounds amazing though - and I totally volunteer to taking it for a test on the river Wye or similar - always wanted to paddle that by canoe (kayak).

 

[AndyT]

The Wye is a great river for canoeing/kayaking. The big meanders mean you can park, launch, enjoy a few hours on the river but only be a few minutes drive back to where you started.

Clean, shallow water with some grade one rapids for beginners.

In normal times of course, not now.

 

[AJB Temple]

Interesting thread. I nearly drowned once in a kayak as I got stuck. Wasn't pleasant and I have given them a miss since then. :mrgreen:

Used to row for college. Even though someone above said it is mindless, there were some bright fellas in the boats. Three of them became doctors. My abiding memory of oars was one of the guys managing to break one during a training session. Instantly unbalanced one side of the boat and we all got very wet shortly afterwards.

Oars were made of laminated and very straight grained wood at that time, and as I think someone else posted, the shaft was hollow. I still row now and again but the oars (boat club) are radically different and made of what appears to be carbon fibre, unless it's wrapped round something else, and the hatchet blades are glass fibre I think.