Boatbuilding Blog

September 17, 2014

Minor Hull Patch

Filed under: Building - Painting — tomlarkin @ 1:57 pm

I pulled the Coot out last month to wash the bottom and touch up the bottom paint. Right at the waterline, back about four feet from the bow there was a half-inch divot gouged out, with bare plywood showing, and a crack a few inches long running aft of the hole. It looks like I hit something hard, maybe a bolt head mounted on something heavy. Water oozed out of the crack when I pressed on it.

While the boat was out, I took the dinghy home for sanding and varnishing.

Here’s the damage – hand for scale.

The plywood was very wet. To see the extent of the water intrusion, I figured the plywood would have swelled where it was wet, so I sanded the whole area with a longboard. The sanding took off the bottom paint wherever the wood was swelled. I’m kind of proud of this idea.

So I cut back the glass to the edges of the swelled area and dug down a few plys to see if there was damage below that level. It was damp but undamaged – no cracks or rot.

I sanded the paint off in a larger area, then mounted a heat lamp for a couple days. I kept it pretty hot, during some very hot dry days.
WP_20140826_15_57_53_Pro WP_20140826_16_01_02_Pro

When I decided the wood was dry, I soaked the bare wood with warm neat epoxy until it wouldn’t soak up any more, then laminated small pieces of 6 ounce fiberglass cloth to fill the depressed area flush. When that was firm, I smoothed the area with QuickFair, then sanded that nice and flat.

Finally, I laid a larger layer of glass over the whole area, smoothed with peel-ply to make it smooth and flat.WP_20140828_17_10_43_Pro

A little sanding, more QuickFair, and some bottom paint, and she’s done. Back in the water in time for the Port Townsend boat show.  The boat was out of the water for five days.

My only concern with this fix is that water may have leaked past the area I cleaned and dried, and now it’s locked inside, brewing dry rot. I kind of wished I’d soaked some penetrating epoxy in the area before filling it. I guess I’ll know in a few years if I should have done that. By the way, there’s a watertight compartment behind this area. I would not have sunk even if I’d been holed through.

June 16, 2013

Dueling Tablets

Filed under: Hardware, Longer Trips — tomlarkin @ 1:08 pm

While in Victoria I found a RAM mount, so I screwed it to the dash so I could put both tablets up at once. That’s a Microsoft Surface Pro on the left, running Coastal Explorer, and my iPad on the right running Navionics . Coastal Explorer has a lot more features, but is kind of complex to learn, and the touch-screen interface is poor. Navionics has Active Captain built in, which I like and use a lot. The two systems complement each other, but having too many screens is kind of distracting. The Surface Pro doesn’t have a 12 volt charger, so I needed to run my inverter most of the time, and doesn’t have a built-in GPS, so that’s another wire running on the dash. The iPad looks odd because it’s wrapped in an OtterBox case. I used the iPad for almost all my navigation on this trip, and wrote blog entries and watched movies on the Surface tablet. With a 12 volt charger and a Bluetooth GPS, the Pro would be a good choice for a single computer.


June 3, 2013

AIS WatchMate Anchor Alarm

Filed under: Hardware — tomlarkin @ 11:22 pm

I bought the AIS to let me know what the ships around me were up to, and it works well for that, but on this trip I’ve been anchoring out almost every night and have been using the anchor alarm function. It’s given me real peace of mind each night. For instance, it was very windy last night and this morning, gusting to 30 knots, and hovering around 20 much of the time.  There are boats all around me in the Nanaimo anchorage just south of Newcastle Island, and I wanted to be sure I wouldn’t drag into them.

This picture shows two days of being anchored in the same place. The outer circle shows the range I can swing before the alarm goes off, in this case 150 feet diameter.. The dots are GPS positions of the boat, taken every few minutes. The inner set of dots were after I anchored, when the breeze was mild. I let out about 90 feet of line because the depth was around 25 feet.  Around 2 AM the wind picked up and I increased my scope about 30 feet for better holding – which is the cluster of dots further away from the center of the circle, where the anchor is. If I had dragged about 20 feet, the alarm would have gone off.

You can tell two things from this picture – the wind is from the NNE, and the Coot swings back and forth about 30% in the wind.


May 21, 2013

SPOT Satellite Tracker

Filed under: Hardware — tomlarkin @ 11:32 am

I’ve activated my SPOT tracker. You should be able to see where I’ve been on this page:

It doesn’t work well in IE10 – use Firefox or Chrome. Please comment here or email me if you have problems seeing the page.

Here’s my trip from Blaine to Point Roberts. It uploads a point every 10 minutes.

March 28, 2013

Adding a Dolphin-Whacker

Filed under: Hardware — tomlarkin @ 1:11 pm

As part of getting ready for my Alaska trip I added a heavy bronze flat bar to the stem and first couple of feet of the bow. This is so I can run into logs or debris or even rocks without harming the boat. I bought a chunk of aluminum bronze from Online Metals, 1 1/2 “ x 5/8” x 8 feet long.

(Anyone know what this type of thing is actually called?)

I cut off an 18 inch chunk to practice with. Using the Hossfeld with a 6 foot cheater bar I succeeded in bending the part this much before giving up. It was just too hard. I had to bolt the table down to the floor and run stringers to the wall-mounted work bench because I was dragging the 400 pound steel welding table all over the shop.
Sample Piece

Another view. At this point I mounted a small Mat-Gas torch, pointing at the bend,  and tried again when the bend got hot. The bar just broke at the heated spot. Then I got out the real piece and asked Barry to come over and help. With me leaning on the bender and Barry pulling on the stock, we got it to bend to the correct angle to run under the bow. I had made a plywood template of the bow earlier, and we used that to get the correct angle.

Then I drilled and countersunk mounting holes, sanded off the machining marks, and rounded the top end freehand with a grinder.The lowest mounting hole is about 8 inches above waterline to avoid holes underwater.

I mounted the thing while the boat was out of the water for a tune-up and bottom paint. The mounting holes were injected with neat epoxy to seal them. The little piece of tape is to keep it from running out. I did this a few times until the epoxy stopped being absorbed. I masked the whole area because Sikaflex wants to get everywhere!
Injecting Epoxy

The unit was bedded in black Sikaflex. I used 8 screws,  #14 x 3 1/2” bronze.

Here she is going back in. The bronze should tarnish dark like the rest soon enough. See how the bronze wraps under the bow a couple of feet.

April 17, 2012

Kiwi Grip Non-Skid

Filed under: Hardware — tomlarkin @ 1:49 pm

I finally put down non-skid on the outside decks. I’ve been meaning to do it since I launched, almost two years ago, but every time I had a nice sunny day I went boating instead of tackling this messy, uncomfortable task. It was a dumb thing to postpone so long.

I used Kiwi Grip, which is a thick, water-based paste that you trowel down and roll with a special roller to add the texture. Most of these steps would still apply when using paint with grit mixed in. I like this stuff because the texture is smoother than with grit, so it’s easier on the feet and doesn’t get quite as dirty.  They say not to apply when it’s a very warm day, or in direct sun.  Wash the desks before starting to tape.

Add extra tape on the edges – this stuff is messy and hard to get off if it goes outside the lines. 2012-04-14_13-11-06_224

Make each section a coupIe of square feet so you can do each one in one pass. I moved the cross-pieces around a few times to find a pattern I liked, using natural stopping points and dividing larger areas equally. I stood on the cabin top to make sure everything looked OK. Try to add the tape in short pieces and in reverse order of how you will fill them in, so you can easily remove the tape after each section. Have a plan on where to put the wet, gooey pieces of tape when you pull them up. A helper would have been nice.

I sanded the large areas with 150 grip with the power sander, then used the 150 grit sanding block sponge along the edges of the tape. Get the type of block with very square corners.2012-04-14_15-46-49_557

With the sanding sponge, sand right up to the edge of the tape to get the little area that the tape edge protects from the sander. Try to sight from a low angle to see if any shiny spots remain.  This step is important because the stuff might start peeling up along the edges if it doesn’t bond.  Vacuum and wash with alcohol before starting the Kiwi Grip application.

Application tools. Get the special roller when you buy the non-skid.  I used this small-v trowel this time and was happy with the amount of material it left. Bigger grooves leave too much stuff.  I applied the material right out of the can.

Trowel it on until the grooves are very even and there are no lumps or thin spots. Scoop any remainder back into the can.2012-04-14_16-14-29_22

Roll and roll until the groove pattern is completely gone. Roll slowly or you will splatter. (You will spatter anyway. Carry a damp sponge to clean it up before it hardens.) Remove the tape from each section after rolling, especially if it’s a warm day. Rinse the roller after each couple of sections if it starts to load or the texture pattern will be different.

Looks pretty!


March 26, 2012

Spring Maintenance

Filed under: Maintenance — tomlarkin @ 9:19 pm

Haulout on a perfect early Spring morning:




Bow Repair

– we ran into a dock and a floating log in the past month.

First, I cut out all cracked and splintered fiberglass and wood:

Taped the area and made a little work space:

Sealed the wood with epoxy, then filled the rest with epoxy-based filler:

Took a little break after all that work:

Sanded smooth and washed with solvent:

Painted it black:

Painted the bottom paint:

Changed the lower unit oil:

She’s ready to start the cruising season!

January 14, 2012


Filed under: Hardware — tomlarkin @ 9:12 pm

Carol Anderson made me a beautiful Coot burgee. Here it is with Christmas Lights.


I found this quote from Lindsey Lord, so we decided to make it swallow-tailed instead of pointy:

I sent her this picture. I think she did a great job translating it.


Thanks Carol!

August 17, 2011

Haul Out

Filed under: Building - Painting — tomlarkin @ 11:16 am

Took her out of the water for the first time since we launched. Changed the oil and filter, changed the lower unit oil, scrubbed and repainted the bottom, cut the skegs down and mounted them permanently, and got the boat name painted on. I raised the boot stripe on the stern too, to make her look like she’s floating on her lines instead of being stern-low.

First thing I did was to scrub off all the green scum and repaint the bottom.


Checking out name sizes.

Nancy painted the letters free-hand after outlining with chalk.


Dark gold trim finishes the lettering.

April 25, 2011

Polishing the Dinghy

Filed under: Dinghy — tomlarkin @ 11:49 am

My dinghy was pretty inexpensive, but it was really rough. Thick glass seams on the chines and big blobs of resin were all over the outside. The bright wood finish also clashed with my color scheme. So I spent the past couple of weekends making it (somewhat) beautiful. First I ground down the worst of the high points and then re-sealed the surface with epoxy. Then I troweled on lots of fairing filler, sanded it off, and did it again. One more epoxy seal, then a couple coats of primer, then three coats of the same two-part polyurethane paint I used on the Coot. I added some rub strips on the bottom to protect my new paint and some ‘Gunnel-Guard’ padding all around the gunwales so the dinghy won’t ding up the hull. I hauled it down to the boat today. I think it looks really nice, and they look like they belong together now.

Lots and lots of filler!


Installing the rub strips. The skeg has a stainless steel strip because it gets a lot of wear:

This shows the gunnel-guard installed:

At home on the stern:

I wrote this entry on the iPad using the WordPress app, so the formatting is a little weird. Not as difficult to do as I expected, though.

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