Introduction: 2x4 Oars
Yes that's right, here's another DIY on how to make boat oars from 2x4s. The difference here is my approach and end result. I'm not knocking any other DIY dude out there but I believe I found a better, cheaper method. The best part about these particular two by four oars is that they were made with prime studs from HD.
Here's a video that says the same stuff.
Step 1: Gather Supplies
Tools
- Draw Knife (By far the most useful tool to shape the handles)
- Spoke shave (optional but also helps)
- Orbital Sander
- Circular Saw
- Tape Measure
- Putty Knife or Razor Blade
- Pencil
- Saw Horse or Workbench
- Clamps (C or Irwin)
- Hand Planer
- Hand Saw
Finish
- Gorilla Polyurethane based glue
- Spar Urethane (has to be UV resistant coating)
- Paint Thinner
- Clean Cloth Rags (I used old white t-shirts cut into strips)
- Good quality brush (Should cost more than 5 bucks
Wood(Depends on length and blades)
- 2-2x4x96in
Step 2: Do Your Research.
There are a million places to go in order to find the best oar type for you. Here are some quick tips.
If oars are...
- Too thick- You'll be exhausted after a short distance but you'll push more water while rowing.
- Too thin- You'll be rowing your heart out but going nowhere.
The Vikings had long thin blades for extended rowing (in order to pillage France) and kayaks have shorter fatter oars for lake touring so you be the judge.
My oars were 8ft long and they were pushing an 80 pound Alumacraft built in the late 80's. The blades were 15x4 inches. A picture above will show exact dimensions.
Note: For oar lock placement, look up the 7-11 rule.
Step 3: Rip the 2x4s.
Rip (cut in half) both 2x4s right down the middle and cut additional pieces. I could go into great detail but the picture says it all.
Step 4: Arrange for Gluing
I'm a novice woodworker at best so I found a way that minimizes the work. The first oar and second oar a little different because I used two different ways to prepare the surfaces to be glued. I will share the efficient way.
Arrange the boards to be glued like the picture above. In later steps there will be a lot of sanding to remove the rough edges so no need to worry about it. This also saves you some time prepping and strengthens the area to be glued since the factor surfaces are already flat.
Step 5: Glue It and Clamp.
Dampen, not soak, the surfaces to be mated. If you are unsure what this means, go to the gorilla glue website and they have a video that explains it. If you screw up this part, the glue will not form a strong bond.
Clamp it and wait overnight. You can wait 2 hours like the instructions say but I recommend waiting overnight because humidity, temperature, and many other factors can play a role. Trust me, overnight is best.
Quick Tip: Precutting the pieces prior to gluing is more efficient. I realized that later.
Step 6: Shape the Blades.
Sand all rough edges until they are decently smooth. Don't worry if they aren't perfect, there will be much sanding in the coming steps.
Using a pencil, draw a centerline on all boards as a reference point. This line will help you keep them balanced as you shave wood away with your hand plane, sander, and draw knife.
Step 7: Shape the Shafts.
So many of you will probably want to round the oar shafts but I think that would be ill advised for two reasons.
For one, squared wood is stronger and less prone to bend than rounded wood. I used studs that costed about 3 bucks apiece so I was worried that they might break.
Secondly, rounding the handles with the tools mentioned was very time consuming and they were only about 6 inches or so.
Step 8: Shape the Handles
Using your pencil draw a guideline and begin to remove with the draw knife. First make an X to find the middle and then draw a circle.
Next, using a saw, make a shallow cut to prevent the draw knife, chisel, or plane from take away from the shaft. I made mine at I went and I cut into the shaft about 6 inches.
Step 9: Sand, Sand, and Then Sand Some More.
This part will take the most time. Using an orbital sander with rough grit, sand all surfaces until they are uniform and then sand them over again with a softer higher grit sandpaper to make them smooth. Using your hands, feel over the wood for rough spots until the whole oar is smooth.
This step determines how easy it is to achieve a glossy finish in the next step.
Tip: A wet rag with a soldering iron can help remove gouges.
Step 10: *(Update)Apply Spar Urethane.
For this step I used Minwax Spar Urethane. I won't say it's the best on the market but I'm happy with the results. Since these will be around the water, they need to be completely sealed in something that is both UV and water resistant.
At around 15 dollars, you can't beat Minwax Spar Urethane. HD sells it.
- Using a dry clean brush apply the SU in clean dust free place. Brush the SU in light even strokes until the oar is covered. Go back over the oar several times and use the brush to clean up any runs, drips, or pools of SU.
- *Use a heat gun to go over the finish. Do not let the great stay in one place. This will eliminate all the bubbles and give you a perfect glass finish every time without sanding in between coats.
- Once completely cured, lightly WETsand all surfaces with high numbered soft-grit sandpaper. Wet sanding is achieved by dipping regular sandpaper in water.
- The surface should look cloudy, not shiny.
- Repeat Steps 1 and 2 until there are 3 coats.
Brush Cleaning Tip: Gather 3 small containers. Fill one with Thinner, another with Soapy water, and the last with regular water. Alternate dipping the brush into the thinner and soapy water. Lastly, dip the brush into the regular water. This will ensure your brush lasts a long time.
Step 11: Final Coat.
After the previous step, I discovered this way to make the final coat perfect. SU tends to form puddles and is very difficult to work with but this step brings it all home.
Mix Spar Urethane and Paint Thinner at a 1:1 ratio or 50% and 50%.
HEAVILY COAT ALL SURFACES once with 50-50 mixture. With a clean dust free rag, wipe off the brush and go back over the entire oar drying the brush with the clean rag in between brush strokes. The goal here is to remove as much excess SU as possible and to smooth out all edges.
Step 12: Throw Them on the Boat.
Not including the time and tools I already had, this project costed me about 20 bucks. I put them on my boat with some oarlocks that I purchased for a homemade boat I'm making. I used PVC, a hose clamp, and poly tubing to protect my oars from abuse since they take the biggest abuse here. I hope you've enjoyed my instructuable.
If you notice I've missed something or have a question comment below and I will add it.
9 Comments
3 months ago on Step 7
Great instructable! I prefer round shafts so I used a spar gauge and planed down to the lines to get to an octagon, then planed again by eye. Electric sander took the remainder down to a pretty decent round profile. I made a 16' timber mast using this method which I might get round to instructiblising (is that a thing?). I also tipped the ends of the blades with epoxy for pushing off.
Mine are 8' but could've gone longer according to the formula. Next time!
+1 for leaving the handles unvarnished...
8 years ago on Introduction
Your blades seem short. My oars for my home built boat (in the same league as the above mentioned alumicraft) have blades that are 24" long. They are 4.5" wide. It moves like a slug under oars (it is a motorboat after all, different hull shape than a proper rowing boat), and I can't imagine trying to do with with blades that are 62.5% of the surface area of my current oars. I would also recommend tapering your blades down to being a 1/4" on edge and 3/4" at the spine of the tips. The only good of having thick tips is that you can use it to fend off bears (or docks) and row away after the encounter. If you plan on using your oars to shove off, you should keep them as stout as you have.
You have a lot of good points that you spell out in here (the 7:11 ratio thing is one thing that most people don't know). Personally, I don't varnish the handles because it gives me blisters. Then again, I work on a keyboard all day and have the soft hands to prove it.
Reply 8 years ago on Introduction
You've touched on some very good points. You obviously know your stuff and everyone here benefits from your experience. Yes, the blades are a tad short and thick. Like you mentioned, thick oars are great for pushing off and that's why I left them thick. The wood I used seems to be a bit weaker than the standard hickory so I wanted to be sure they'd stand up to the abuse I put them through. Had I used a better quality wood (I used home depot premium studs), I would have made them thinner, however, the goal here was cheap and effective. As for the length, these oars where actually made with a homemade 10ft Boothbay Dory in mind. I first created PVC prototypes and tested different lengths for my alumacraft. With the length and surface area, I can get a good rhythm without being exhausted while carrying up to 2 other people with me.
Reply 8 years ago on Introduction
As for the Spar Urethane on the handles, I've yet to experience blisters. I tried wooden handles before without finish and I got some hot spots. The SU allows me to grip the wood better without slipping. Different strokes for different folks. (Pun intended.)
Reply 8 years ago on Introduction
If it is working for you, don't change it. It is easier to leave it unfinished initially, try it out, and finish later if you get blisters.
8 years ago on Introduction
Excellent build! Can you please explain what you meant in step 9 about removing gouges with a soldering iron and wet rag?
Reply 8 years ago on Introduction
Great question!!! Take a wet rag and lay it over a dent or a gouge and placed the hot tip of the soldering iron directly over the dent to give it a nice steam. The steam will cause the wood to expand and rise enough in most cases that the dent will be gone or at least less deep. I'm sure you could do the same with a regular iron but don't let the wife catch you.
8 years ago
You might call them... Two by oars! *ba-dum tsch*
Thanks you, I'll be here all week!
8 years ago
Great job, thanks for sharing.