Thursday, April 24, 2014

Hatches and Secret Passageways

Starting with the stack of hatch opening reinforcements and hatch stiffeners from my last post, I have laminated, cleaned up glue squeeze-out, trimmed, rounded corners and edges, and sanded until I've had about enough of that for a while!  But now they are all ready to go.

Here's a pile of laminated hatch stiffeners on the left and the port seat hatch reinforcement on the right.

Here are the cockpit sole hatch opening reinforcements ready to install.

And here they are clamped up waiting for epoxy to cure.  I made these PVC pipe clamps about 15 years ago when I built my first kayak.  The idea is from Chesapeake Light Craft, and they are made from 4" schedule 40 PVC, cut about 1 1/4" wide, and then cut so they can spread open.  They work well, and are cheap to make.  I find they are best clamping about 1" thickness, they are a bit less effective on this thinner glue-up, so I used a bunch of them.

First coat of sealing epoxy is on those now.  I'll sand the fuzz off and put a couple more coats on before this gets installed.  Same progress with the hatches in both seat tops.

I've also started gluing on the hatch stiffeners to the back side of the hatch lids.  As with the hatches I did for B3, there is some twist in the plywood, so I twist it a bit the other way (see the 4 mm spacer at lower right) and glue it up.  I try to guess right with the spacer so that when unclamped it springs back until it's flat.

As I was doing all this hatch work I was thinking about drainage.  I was thinking that the cracks around the hatches in the cockpit sole are likely to get filled with water in the normal course of events from wet swimsuits climbing in, rain, overflow from filling the ballast tank, etc., and that water would fill the cracks and stay there until it drains into the storage areas if the hatch gets opened.  It seemed to me that could be irritating.

I have seen others rout a channel the full depth of the sole doubler (the top layer) to allow that water to drain away.  But I didn't like the look of that.  After a bit I came up with my idea of "Secret Passageway" drainage!  

I routed a drainage channel on the underside of the sole doubler leading from one corner of the hatch opening to the gutter that runs down to the sump in the rear of the boat.  I cut the channel about half the thickness of the plywood, and angled it back at a 55 degree angle.  The sole has a slight tilt towards the rear so water should drain through here by gravity.

The openings are pretty much invisible, and the cockpit floor is undisturbed.

If these would ever get plugged with gunk it should be pretty easy to poke something through there from the hatch opening side to clean them out.

These channels will be well coated with several coats of epoxy to prevent water from seeping into the plywood, and I'm making a special tool (ok, basically a rounded stick) to run through the channels as I glue the two pieces together, to clean out any thickened epoxy that squeezes into the channel and would block it. 

I think this is going to work nicely.  Any other SCAMP builders that want to borrow the idea please feel free!

July 27, 2014 addendum - I had a question in the comments about the router and templates I'm using for some of the build sequence, so heres' a shot of the Porter-Cable router.  I've had this for probably 20 years - I don't know if they still make this model (#693 with a #6931 plunge base)

Here's a photo of the bottom with a template guide bushing installed, and some of the other spacers that I've used on this project: 

And here's a shot from above showing the knurled ring that fixes the template guide in place.


  1. Dave,
    Wow, very innovative!! I like the idea but am a little scared about routing water between the sole and sole doubler. It will probably work great…just a little nervous for some reason. I love the ingenuity.

    1. Thanks, Brent. I'll be able to get it sealed up nicely, and it's protected from sun, so I'm thinking it won't be any more of a problem than the other places that can get wet. Pretty sure it will be OK. Thanks - Dave

  2. Dave, I'm sure it will work out well for you. I'm so glad you and Craig are ahead of me in this build process. I read both your blogs daily!!! I'm using/stealing/borrowing/absconding with every great idea I find. You guys are doing a phenomenal job…love all the photos too. Brent

  3. How did you get your corners curved so nicely. I've tried using a high end scroll blade on my jigsaw with little luck. Please help because I can't find anything on google on how to successfully make these type of cuts.

    1. Hi, Drew - I used a router to cut out the hatch openings and related pieces. There's an overview of that process in this post:

      I used a 1/8" bit when cutting the hatch opening, so that I could use the cut-out piece as the hatch. This leaves a 1/8" gap around the hatch cover, and that's larger than ideal, but I think it will work out OK, and saves material.

      The keys to this process are to work out your dimensions carefully, considering the bit diameter and the template spacers, and make a nice template with smooth curves to guide the router. I cut my template using a jigsaw, smoothed the curves with a drum sander on the drill press, and smoothed the straight edges primarily with a spokeshave.

      Hope that helps. -- Dave

  4. This is good info. Can you tell me exactly what type of router you use for example top guide, brand, and model?

    1. Hi, Drew - I just updated the post with more information on the particular router I'm using. I haven't bought a router in quite a while so I suggest you look for reviews on various brands as you shop. -- Dave

    2. The router bit I used to cut out the hatch covers was a two-flute, straight 1/8" bit with 1/4" shank that I picked up at Menards. It was a carbide bit (stays sharp longer than high speed steel), but otherwise nothing special about it. For the other cuts on the hatch stiffeners and hatch opening reinforcements I used 1/4" or 1/2" straight bits with the appropriate template guides to get the offset I needed. The bigger bits are more robust and I didn't need to worry so much about breaking them. -- Dave