West Wight Potter Owners Home Port _______________________________________________________________________________________________ |
| Modifications P-15/P-19 Cockpit Floor Grate by David Lee Owner of P-19 Ohana #478 |
In the above photo you can see one of the opening portholes that I installed in Ohana. You can also see
the cockpit grate I made this fall. It came out better than I thought it was going to. A project that
requires a good jig to make the work a lot easier (and even still it was kind of tricky).
For anyone interested in making a cockpit grate, here are some photos of the jig I used for the grate.
This is the top view of the "sled". You can see there is one piece of the board screwed to it as a "stop".
Basically, you have a dado blade in your table saw exactly the width of the width of the strips you want
in your grate.
I think mine are 3/4" as the mahogany I used was 3/4" thickness. You slide the board on to the sled up
to the stop and make a dado cut exactly half the depth of the board. The exact part is the key. Make it
too shallow or too deep and the surface of the strips will be offset. Not a huge deal because you will be
sanding the surfaces anyways but it helps to get it close.
Once the table saw is set up, the rest is easy. You slide the board further onto the sled so the new
groove fits over the stop. You cut another dado and so on until the entire board has cross-cut dadoes
along its entire length. Then you simply rip that board into strips, again making sure the width is
exactly 3/4" (or whatever size you are using). Oh, I also made the cross pieces a little thinner than the
longitudinal ones because I wanted water to drain down the length of it.
It has always bothered me that most grates don't take that into account (well, maybe not "always" )
Here is the underside of the sled. You can see there are two aluminum runners that fit in the grooves in
the table saw table. If you don't have a table saw, this can also be done with a router (maybe even
better). I tried to make runners out of wood but that was a waste of time. I bought these for $20 each at a
woodworking store online. http://www.rockler.com/product.cfm?page=21651&filter=sled Beware –
the Rockler ad pic clearly shows two. You certainly need two to make the jig but they are actually sold
individually.
If you plan to only do this kind of project once, you can no doubt come up with a slick way to make the
jig solely out of wood. I haven’t had much luck making miter bars out of wood. They tend to swell with
humidity and stick in the table saw’s miter tracks. You really need the jig to be very stable to minimize
variation. Even still you will find some pieces fit together very well while others require some coaxing
with a hammer (I broke a few out of frustration – good thing the kids weren’t around!). The goal should
be a snug fit – not so tight that all the glue squirts out and not so loose that it can flex the glued joint too
much. If it is too tight, you might also find that it won’t lay flat when you are done. I also made it a point
to mix strips from different boards as I went along so that any warps in one board (and there is always
some) would help straighten twists in another. I don’t know if that is entirely necessary but I imagined
that it helped.
If you plan everything right and have enough wood the first time around, you only have to set each part
of the system up once. If you are like me, though, you will find as you piece it together that you need
more strips and so you have to go through it all again (although it is easier to set up the second time as
you have pieces to model the width and depth settings).
It takes more wood than you can imagine and generates huge amounts of sawdust! I used mahogany
boards that I purchased at our local Menards (like Home Depot). It's a lot cheaper than teak. For
stain/finish I used Cetol natural teak at $35 for a quart.
http://www.westmarine.com/1/1/31714-cetol-marine-finish-natural-teak-color-quart-from-sikkens.html
You could probably use any old varnish you have kicking around. The color closely matched Ohana’s
natural teak, which made me feel OK about using less expensive mahogany.
A tricky thing about the Potter cockpit, though, it is trapezoidal-shaped (wider fore than aft). So, once I
had a large rectangular grate glued together, I overlaid the trapezoidal pattern and cut the grate to
shape.
Most grates are tongue and groove with the edge pieces. That is easy with a rectangular grate but
really difficult with an odd shape! Believe me, there was a great deal of cussing! In the end I ended up
cutting the grate to exactly the inside dimensions of the frame and countersunk screws through the
frame edges into the ends of the grate strips. I used my drill press and tilted the table to get the right
angle (remember, the side frame pieces are not parallel to the grate strips. I then screwed it all
together.
The last snag was creating the radius on the underside to match the curve where the seats meet the
cockpit sole. I used a router to round it over and then a power sander to fine tune it. That part was a
little frustrating! I sealed/stained it with Cetol, which made it match my teak almost exactly and it isn't
slippery like varnish (although I haven't tried it wet in bare feet).
I think it is pretty strong but originally I had hoped to be able to elevate it to make a sleeping platform
in the cockpit. I'm not sure I have enough confidence to do that and I have too much work in this thing to
risk breaking it. I'm very happy with the look. It will be interesting to see how it weathers. At least now I
have the system down to make another one.
It's a project that rewards patience like few others. If you take your time and create the jig, tune your
table saw, and set it up properly, you could crank 5 of these out in a weekend (or at least create yours!).
Some additional photos and details of the grate:
View of the full grate:
Note that the cockpit is trapezoidal. Normally you would create a dado-type joint around the outside of
the grate to connect the frame but I gave up trying to do that. There are too many little pieces that
chipped out when I tried. Instead, I made the frame first, created a rectangular grate, and then
trimmed the grate to the inside dimensions of the frame. I then used a dowel jig to fasten the grate to
the frame.
Here you can see the ends of the dowels glued in place. These were actually special tapered dowels
that I purchased from Rockler with the special drill bit.
(http://www.rockler.com/product.cfm?page=10483&filter=dowels).
That system was $45 plus I think I bought extra dowels. I drilled the pilot holes using my drill press.
The ones on the side required me to tilt the table so the dowels would go in at the right angle (because
of the trapezoidal shape).
I used a jig on my table saw to create the carefully spaced dadoes so the grate would fit together. I
used mahogany boards, 8" wide by about 60" long and 3/4" thick, that I purchased from the local home
center. Once I had the dadoes cut across the board every ¾” I ripped the boards into strips. A few
boards I planed down a bit before stripping them. These would be the cross pieces because I wanted
water to be able to flow under the grate from fore to the drain, aft (see above). I don’t know if that is
critical. Most grates don’t seem to have that so maybe I worry too much.
There is quite a taper to the cockpit walls where they join the sole. I first tried a router bit but ended up
digging out a hand plane. It was somewhat fussy work but it worked out in the end. I then coated the
grate with several coats of teak-colored Cetol. That stuff is awesome, although I will let you know how it
holds up. If you have some basic power tools and take the time to get things set up, this is not a difficult
project. Total cost, about $85 for the wood, plus cost of the Cetol.
I wished I had kept better accounting records but these projects start more out of curiosity than
anything and just build and build until they are done. Woodworking and working on boats are as much
hobbies of mine as sailing. I have no delusions that adding these things to Ohana will in any way,
shape, or form pay off financially in the end – unless you can put a price tag on that feeling of adoration
you have when you take one last look at your nicely kept Potter as you are walking back to the car at the
end of the day (you guys know what I’m talking about! )
David Lee leex3103@umn.edu
"Ohana" WWP19 #478 Stillwater, MN
