Adding the shear strips

Finally got hull #1 in the shop and all my tools moved around. After many hours in the thinking chair, I have a plan of attack.

  1. Add the shear strips
  2. Fit the bulkheads starting at the bow and moving aft

Ok, so I should have marked the shear line when I still had the boat on the forms. I actually did buy sanded the mark off. So back to placing the forms in the hull and marking the shear line. Once that was done it was quick work to scarf the sheer strip, radius the bottom of it and glue it in place with epoxy. The nice thing about sharing a boat building garage, is now I have access to twice as many clamps!

clamping the shear

This is an excellent time to make sure your sheer flows smoothly and adjusting it before the glue hardens. Notice that I added a radius to the bottom of the strip before glueing.

checking for fairness

Once the epoxy hardened I ran my router with a pattern bit and trimmed the excess hull to the sheer strip.shear after trimming

At this point I am super anxious to see if the hull is still true and square. A simple eyeball test tell me that the front and back of the hull have not torqued. If the are crooked, the front and back levels  will not align.

she is level

There she is! What a beauty! The hull ready for the bulkheads.

ready for bulkheads

Bulkhead #3

Bulkhead #3 is one of the two bulkheads that the cross beam gets connected to, thus deserving special attention. At this point I have dry fitted bulkheads 1, 2 and 3. Before glueing them in place I decide  to add as many of the extra pieces that make the beam box before bonding the bulkhead.

For many of these joints I am bonding with thickened epoxy and silicon bronze screws.

bonding and screwing


Here you can see the 1×2 reinforcements in place and the 12mm doubler that will help in setting the deck


Next you can see 12mm knees that will hold the beam bolts in place

knees knee fitting

bonding every thing together

bh3 doubler bonding bonding the knees


I also added the first brace for the beam box at this time.

Finally after two coats of epoxy to seal everything up the bulkhead is ready to install.

bh3 ready to go bh3 beam sideTo install the bulkhead and keep a good bead of epoxy going, I found it helpful to spread the  sides apart before installing. Unfortunately you can only use this trick moving aft as we go on.

spreading the hull

Clean with water and a scrubbing pad to prep the surfaces one last time, You can tell above how much dust still needed to be removed. Then I clear coated the mating surfaces and added a nice bead of thickened epoxy. Here we don’t care how much oozes out since it will be used to supply the extra epoxy for the fillets. Cargo straps tighten things up.

bh3 bonded in place filet details fillet details 3fillet details 2



Fwd beam box

It looks simple, but it took a good part of a day to measure and cut the pieces that make up the fwd beam box. Luckily I has some help and things kept moving along.

The piecesfwd beam box parts

The glue up. Lots of epoxy oozing out and this baby is going to be solid! We used more screws this time, so less clamps.

fwd beam box glue up

After removing all the clamps and sanding the piece down, time to see how it fits. Perfect!

fwd deck beam shelf detail

fwd deck beam dry fit

fwd deck beam dry fit 2

Now for the two coats of epoxy to seal all the plywood. Notice that I can’t bond this piece to the boat until I drill the holes for mounting the beam bolts. Those are being welded for me and should be done within the week.

fwd deck beam prepping

You might notice that on the picture above you can see frame #1 being glued. A successful day in the shop means one of 3 things happen at the end of the day

  1. I bond a bulkhead or frame
  2. I glue up the additional parts required for a bulkhead or frame
  3. I am pre-fininshing a bulkhead before installation

And right on time for Christmas my beam bolts were fabricated so I was able to drill the holes and bond the beam box to the hull

beam box drilled and laminated

All together we need 16 pieces, and since I had them machine cut, I also made 16 backing plates.

beam bolts

The beam box with the hull cut out and a bracket in placebeam box cut out

More Bulkheads

A busy three weeks adding the remaining of the bulkheads and the transom. She is finally starting to look like a boat.

looking like a boat


A view from the transom looking forwardthrough view


Bulkheads tabbed in

bonding bulkheads

Bulkhead 7 showing the reinforcements for the aft beam box bh7 framed

Bulkheads 4, 5 and 6 ready to be bonded inbulkheads456 framed

And finally the transom

closing the transom



All things before decking…

So before you actually add the deck, you really need and want to take care of some details.

Here is the picture of the hull right before decking

just before decking


I decided that the I was going to add a composting toilet to my port hull. They are taller then a porta potty and basically I decide to sacrifice the aft bunk. Instead I get a nice lazaret.  for stowing lines and bumpers and a nice place for the battery and electrical panel. In this same picture you can see the shelf between frame 2 and bulkhead 6. The shelf is structural and adds a lot of stiffness to  the gunnel at that area

shelves and head placement

The floor and floor supports. The floor is structural in that it adds support for the keel below

floor support floor

The forward bunk and bunk supports

bunk supports bunk boards2

Details on the lazaret framing. note the slope of the frame to allow water do drain. I left the deck edge frame in place to make it easier to lay the deck. it will eventually be cut out and become part of the hatch.


Some more details on the aft section. The rudder post reinforcement and another reinforcement just forward of it were I expect to have a vent. Hidden behind that you can barely see the spinnaker  block pad.

aft detailsThis is also a good time to make sure you have all the bow hardware reinforcement  pads and whatever hardware you have installed before decking the bow.



Decking the hull

So the most import part here is to have all surface as true and smooth as possible. Any thing that doesn’t look good at the point, the plywood won’t fix… Take special care at all edges and the radius of the deck.

I pre fit all of the plywood pieces and trimmed to 1/2 in of the edges. that made it much easier to clamp, align  and screw. A thick bead of epoxy goes on all contact surfaces before final fastening. A helper comes in handy to set the pieces down. The radius on the cabin top was the hardest so I started by screwing the centerline down. Then using a cargo strap to start the bending. Then from the strap outwards adding 2 inch spring clamps, a few on each side the the other side until it was all secure. Now the tricky part to eliminate voids on the radius is to add more screws to the top of the bulkheads. Work from the center down and from the center forward and aft. Without these screws I found that I had areas where the plywood did not touch the bulkheads.

deckingdecking2some details

decking-joint detail decking joint detail 2 decking joint detail 3 beam view cabin flange forward beam box cabin_topand the finished hull.

All decked out and nowhere to go!

all decked out



Glassing the deck

I will add some more pictures here after glassing the second hull. These are the things I learned.

It was impossible to do a large glassing job and keep the glass against the inside radius creating air voids through out the joints. So unlike the picture below where I tried to minimize the pieces of glass to do the job, I am going to try something different for the starboard hull.glassing_measuring_cloth glassing_fwd_deck

  1. Start by fiberglassing the beam boxes first
  2. Then the center deck and up the cabin house
  3. Followed by bow
  4. Then the cabin house top and side
  5. The aft deck and transom

Cutting holes in the boat – Hatches and such

The final product. Port hull leaving the shop showing the cutouts for the hatch, companionway and lazaret.


Here are some additional pictures. I am pressed for time but details will followDSCN2541





DSCN2540 DSCN2545 DSCN2544


This is what happens when you don’t measure properly. the vent what too close to the beam…DSCN2542


Details on the lazaretDSCN2538 DSCN2537 DSCN2555


DSCN2534DSCN2531 DSCN2530 DSCN2535 DSCN2533 DSCN2532 DSCN2550 DSCN2549 DSCN2548

Lewmar hatch installation details

So when you are installing a production hatch, two things are critical.

  1. Making sure you won’t adversely affect the structure of the deck
  2. Making sure the hatch will be placed on a level square surface

These pictures show how I went about installing a Lewmar Size 44 Medium-Profile Deck Hatch on a very curved deck.


Luckily the hatch fits nicely in between two of my frames under the deck, so I did not have to worry too much about adversely impacting the deck structure.

Let us start by drawing a very accurate profile of the hatch opening into a nice 3/4″ plywood pattern. You can do this easily by setting your hatch on top of the plywood and lining it with 1×2″, pushing it against the hatch coaming and using those lines as reference.

DSCN2696My frame is also made of 1×2″ so things line up nicely.

Measure where you are going to set the hatch on the boat. I added two temporary screws to prevent the hatch from sliding and also to help shore thing up.


Now for the first tricky part. Getting the template to lay even on the deck. use some shims and play until you get it where you want. You might notice that I already have two 1×2″ screwed to the template to make it easier to eye the hatch.DSCN2698

Now transfer that angle to the table sawDSCN2699


Trim another 1×2″ to that angle until both sides lay evenlyDSCN2701

DSCN2703Now for the second tricky part. Getting the radius transferred.

Start by placing another 1×2″ on top of the template and find a measuring stick to allow you to transfer the curve


Scribe as many marks as you think you might needDSCN2707

Connect the lines and cut and shave as neededDSCN2710

Glue the pieces to each other, but not the template! It is covered in  clear tape to avoid this costly mistake.DSCN2713

Trim the edges, but save the corner piecesDSCN2716


Carefully trace around the templateDSCN2718

Prepare a nice batch off epoxy goop (6 pumps of west) and apply a nice bead.DSCN2722


With the template protected in tape apply the piece to the deck. Wiggle it some to spread the bead.DSCN2725

Clean and bead as best you can. You will be doing this once more once you remove the template so no need to get it perfect.DSCN2726

A cargo strap came in handy to hold things together.DSCN2731

Once everything dries you can remove the screw holding the template to the frame. DSCN2743Time to cut the deck. If you have the right diameter hole saw this little trick works out great.


Now re-glue the edge pieces, fillet, sand and fair as needed.


Missing from the pictures above is a drill with a drum sander. That makes fitting the radius a simple task.

“Give me a can of filler and lots of sandpaper to make me the carpenter that I ain’t!”






The Rudder

Building is a rudder is time consuming but well within our capabilities. It all starts by cutting the plywood blanks and getting a machine shop to build you the rudder post and tiller assembly. They also took care of making my delrin bearings.



DSCN2808Now we go ahead and piece it together

DSCN2825And shape it to the prescribed foil shape. I used a belt sander to get it to shape


DSCN2828DSCN2826Once you are happy with the shape, time to glass it over. I did the leading edge first. To make sure you can a smooth curve on the bottom cut the glass strips 45 degrees tot he bias

DSCN2830DSCN2831DSCN2832Once you glass the edges. adding glass to the flats is easy. I decided to glass with three 10 oz layers the whole blade



And here is the final product…





Building a Shadow 24ft Woods Catamaran