How to Make a Kayak Drainage Port




Introduction: How to Make a Kayak Drainage Port

I've been Kayaking for several years. As much as I love getting out onto the water I don't look forward to the necessary cleanup. Oh, for the most part it's really straight forward but the way kayaks are designed drives me absolutely bonkers. They mold the kayaks to create a deep cockpit that is absolutely impossible to empty of water. Now don't get me wrong, my kayak doesn't get filled up when I'm paddling about, it gets filled up when I have to hose out the muck and grim that gets inside it from hopping in and out. I usually launch from the water's edge and not a dock so I usually end up with a small amount of mud, sand and such on the inside. The cockpits are lipped on the edge so even flipping it upside down and rolling it back and forth won't get everything out. In I go with my various methods of water drainage - e.g. cups, sponges, towels, etc...

I can't imaging why they couldn't build proper drainage into the production molds but since they didn't I decided to take matters into my own hands. A quick trip to my local depot store for a few odd pieces and I was ready to get started. Never shy to Frankenstein my Kayak to make it more usable, I grabbed my Dremel and swung into work with careless abandon!

[UPDATE] Summer 2022

We've used these modified Kayaks every Spring/Summer/Fall for YEARS and have had ZERO water leakage into the watertight compartment. Nada, zip, zero, zilch. The seal around the drain hose is just as watertight as the seal between the bulkhead and the kayak itself.

If the hole through the bulkhead is smaller than the drain hose, the spongy material does a great job of forming a seal all on its own. Cover all contact surfaces with a liberal bead of GOOP and your worries go from "I hope it doesn't leak" directly to "I hope I never have to remove that".

Step 1: So, Where Do I Put a Hole That Won't Sink This Thing?

I had previously taken a swing at making it easier to empty the water from my cockpit by putting a drainage plug on its side, under the edge lip.  Didn't work very well.  Honestly, it didn't really work at all.  The effort it took to rock the kayak back and forth over this little 1" hole just wasn't worth it and it ended up taking longer than normal methods.

Where to now?  How could I drain the water of the cockpit without sacrificing its water tight integrity?  Front, back, side, top, bottom?  I originally though about putting a plug up towards the bow but the surface curvature was too much and I couldn't figure out how to mount a plug correctly.  Plus, there's a large block of ballast foam stuck way up front and I'd have to dig that out.  Too far up, too narrow and I'm too fat.  Next...

The rear of the kayak was flat(ish) and would make a decent plug mount location but there was the problem of the rear watertight compartment.  I'd have to allow the water through the watertight bulkhead, through the watertight compartment and out the watertight skin.  Three "watertight" items that I've to pass water.  Yeah, perfect, that will do nicely!!

Step 2: Bits and Pieces

I have a good set of tools so I was already set with the things I needed to cut, sand, drill, cut, etc..  Leading the charge of tools I'd use would be my trusty Dremel.  Never dig into plastic without it!

Onto my local "Depot".  There I picked up a few feet of 1" tubing and a tube of Marine GOOP.

The only think I had to order online was a standard plastic drainage plug.  I still had some aluminum pop-rivets from another project so I set two aside for the plug.

Oh, the odds and ends tools included a small butane torch to 'prep" the plastic for gluing, some rubbing alcohol to remove any oils, a marker pen and an electric heat-gun to help bend the plastic tubing.

Step 3: Let's Start by Making This Anything But Watertight

My first step was to mark the bulkhead where the the hose would go through.  I cut a 1" length of hose and used it as a template against the bulkhead.  I marked it with the a permanent marker and when to work with a utility knife.  The foam and glue they used for these bulkheads were stronger and more stubborn than I had thought.  I was eventually able to cut through but my first attempt was less than aesthetically pleasing.  Functional but ugly.

Next step was to feed the tube through the new bulkhead hole from the cockpit side.  I feed the tube all the way through the rear compartment and up the back end until it sat flush to the top.  Mark the length of hose, remove and cut.

I then aligned the plug on the back of the kayak to where I could get it to fit the flattest and then I marked it with a pen.  I used a cordless drill for the rivet holes and my Dremel for the plug hold.

My original idea was to have the tube fit flush to the inside top of the kayak and have the plug walls fit down and inside.  After some dry fitting I found that it was too hard to hold everything together and the space was restricted so I couldn't see well enough to know if the fit was solid enough to prevent any gaps.

New plan.  I widened the hole in the kayak just enough to allow the drain tube to fit perfectly flush with the top of the kayak.  To accomplish this I had to grind down the plastic covering of the rear lift strap bolt (pictured).  With the tube now flush the drainage plug would not sit flush to both the tube and the kayak.  I could not make sure there would be no gaps on final assembly.

Step 4: Bend It Like Beckham

Here's where I had to be a bit creative.  When I originally did the dry fit with the tube I found that it wasn't flexible enough to handle the sharp bend from the bottom of the kayak up towards the top hole.

Easy enough to fix.  I fitted the end with a copper pipe fitting, wound around some wire and then pulled it back against itself.  A few minutes with a heat-gun and the tube became much more understanding.  Once all the tension was released in the bend I put some weight on it to keep it flat and left it to cool.

After a bit I removed the weight and the wire and much to my surprise, it kept its shape!

Step 5: FLAME ON!

I read about this trick a while back.  Not sure where and not exactly sure that it works but every time I've glued something to my kayak I've done this trick and I've yet to have a problem.  So, if it works great and if not, It makes me feel better so again, great!

Anyway, I read somewhere that exposing the plastic that the kayak is made of to a torch removes the oils on the surface of the kayak and allows glue to adhere much stronger.  Again, could just be story but...

I have a small butane pencil torch that I used for all the glue points.  It has a small enough flame that I didn't melt the bulkhead material.  I torched the floor of the kayak in front of, underneath and behind the bulkhead and then torched the plug and rivet hole areas top and bottom. 

It does slightly discolor the plastic which would make me think it's working but not enough to show up on pictures so another check mark in the "I have no idea if this really works" column.

I also swabbed the areas with alcohol right before gluing to make sure that any oils hadn't contaminated the area.


Step 6: Sure You Glued Enough? Glue Some More. and Again. and Perhaps a Bit More...

I now had a tube that sat flush to the floor of the kayak, flush to the bulkhead and flush to the top rear of the kayak.  Now I just needed to keep everything from leaking.

Out comes the GOOP!  Absolutely love this stuff, as long as I use gloves to put it on.  Otherwise I'm cursing it for days. 

The bulkhead is double walled so the first thing I did was put a large amount inside the bulkhead hole, making sure there was enough to work with once I put the tube in.  I also put a good working amount on the outside of the tube that was going through the bulkhead.  I inserted the glued tube end through bulkhead from the dry compartment site, gently rotating it back and forth to make sure that all surfaces had good contact with the glue.  Once through and flush to the other side I then applied more glue to both ends of the bulkhead to make sure any openings where completely sealed.

Next I applied GOOP to the other end of the tube and rear drain hole, same as the bulkhead.  I made sure the tube was flush with the surface of the kayak and I then applied more GOOP to the inside.  Much more.  I wanted to make sure there was no leaking around the edges.  I let that setup for about a day.

Coming back after the glue had a chance to setup the first thing I did was check to make sure that all flush mount surfaces were completely sealed.  I put some extra on where needed.  I also but a thick bead of glue on each side of the tube as it ran down the length of the rear compartment.  Partly to keep it from moving (and pulling out of one of the openings) and partly to keep anything from getting underneath.

The next part was probably the easiest.  Again with the GOOP I put a large dollop onto the rear tube opening, top and bottom of the rivet holes and INSIDE the drain tube as this is where the plug lip would fit.  I also put some on the mounting surface of the plug and dipped both rivets in GOOP.

Holding the drain tube with one hand I gently pushed the drain plug into the rear tube opening  until it was flush with the surface.  I pushed through both rivets and secured the plug with a quick couple of POPS!.  I cleaned the threads of any glue and made sure the outside was tidied up as well.  I then applied another generous helping of GOOP to the inside of the drain plug, hose and rivets. 

Looked like everything was done but the testing!

Step 7: Sink or Swim - or in My Case Paddle.

It was a gorgeous morning and we headed out to some local flat water. As normal, we launched from the water's edge and managed to get a small amount of the local shore inside.

Once home I set the kayak up against a wall and started washing it down. As expected, the cockpit filled up with dirty water. I opened the cover the rear compartment and checked it for leaks. TOTALLY DRY! Buh-yah!

I pulled out the drain plug and WHOOSH! All the water quickly drained and I was able to finish washing out the inside of the cockpit neither fuss nor muss. 

I've done this several times since and I've never had a leak either from the bulkhead side or the plug side. Relatively easy to do and the results were fantastic. I'd really like to see some manufacturers build something like this into their designs. I would imagine it would be easy to build in drainage channels to their mold designs before squeezing the sides together.

Anyway, I would strongly suggest anyone who kayaks doing this modification. Makes cleaning up MUCH easier.

The only thing I still have to do is attach a string to the plug, through the tube to the other end and where I'll attach a stop to prevent it from falling back through. I'd had to loose the screw plug by simply misplacing it. Not that I've ever done something like THAT before.

Happy paddling!

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    6 years ago

    Great way to make drainage in the kayak or canoe. It is very important since when the kayak gets filled with water it becomes very difficult to drain it out.