Bagging the inner, port centerboard case side

Since my vac bag table spent the winter outside in the rain, I had to spend a little extra time preparing it to be used again.

This time, I screwed three full sheets of tongue and groove 3/4 in plywood to a framework of 2x4's and sheathed the whole thing with a 15 X 9 ft. sheet of thick rubber pond liner. My logic here is that I only have to use one sheet of vac bag every time I create a part because I am able to simply seal the top membrane to the lower rubber sheet and use it over and over again. By placing the entire platform up on a few sets of car jack stands, It also provides a nice comfortable , clean work surface.

In this photo, you can see the yellow rubber vac bag tape along the edges of the rectangular vacuum bag area. Also, here are a few more things to notice:

the vacuum manifold can be seen inside the bag on the left. To distribute the vacuum pressure, I use a 1/2 in piece of plastic cpvc pipe with lot's of holes drilled in it. This gets wrapped in breather material and insures that good uniform vacuum pressure is maintained along the entire part.

center board blanks

Time to shape some surf boards..... These things are almost 10 ft long. The upper board blank is still in the bag that I used to vac-bag all the foam pieces into one big board. If you look closely, you will notice cross cuts in the board stringers. These cuts were made to help me gage the thickness when I go to shape them down to size. ( before I bonded all the foam in place, I used a skil-saw set to the precise depth that corresponds to the thickness of the boards called out in the plans.)

laminating the centerboard stringers

Inside of the twin centerboards of this cat will be the most beautiful lightweight straight grain mahogany stringers that the world will never see. Here, I'm using a vacuum pump to help laminate two sets of four 8 inch wide by 78 inch long boards. These boards will then be shaped and then bonded with 45 x 45 x 0 glass and will become stringers that will then be embedded into two separate foam blanks. These stringers will then be shaped and capped with multiple layers of unidirectional glass and the sections that will swing down into the water will be shaped into symmetrical foils.

The next blue sky will find me shaping them with my power planer like two big honkin surfboards.

Varifying the varifications.....

It's always good to have someone check all the layout dimension before taking a power planner after anything. although it's always possible to glue foam back into place if you make a mistake, it can save some time. Here, the inspector is checking the location of the centerboard pivot pin. He has also made various marks on his legs........perhaps to test the functionality of the writing instruments.

the boards

So here's the full size template of the centerboard. The gap in between will actually measure 27 inches and both of the templates are seen here taped onto a 4 x 8 sheet of core cell.

The plan is to slice most of my scraps into uniform widths, laminate them into a 4 sheet thick plug and vac bag the block into one solid blank. Various sections are comprised of high density material ( I'm planning on using straight grain 1/4 sawn Douglas fir for the internal sheer portion of the spar. Since this piece is going to be encapsulated thoroughly and capped with multiple layers of glass and epoxy, I will not feel that bad about using wood as an internal spar.

Next comes the fun part. The plan is to build a 3D Cad file of the boards and have them cut on a CNC router. If it was summer, you can bet I'd have these things on a couple of saw horses in the sunshine and just shape them with a power planner like two long boards .

Soulfull tools

Special thanks to Barney of Hood River, Oregon for passing along his Grandfathers saw. I think most good tools seem to hold the presence of past owners. This is a good because table saws, in particular, have been known to throw things across the shop for reasons unknown to the living. New table saws do not come with the watchful presence of past owners.

It's good to know that Barneys grandfather and I will both be watching out for my fingers.

"Center" board cases

Although it would certainly be easier to fit this ship with dagger boards. I like the idea of making sure that when she runs aground, the boards will simply kick back into the hulls. Here I've lay ed out the board case sides and have pre-cut all of the High density foam inserts that become integral parts of the case sides.

The case sides are comprised of 3/4 in. 5 lb. corecell with various inserst of 12 lb. foam to strengthen high stress points.

Doubling up the sternI uI

 
 This first photo shows the extra pieces that I have cut to add thickness to the hull stern flanges. Notice the slim crescent shaped flange thickener that I have preformed to fit the trailing edge of the stern.  

Here's a shot of all the pieces after they have been bonded in place. I used a v grove flooring adhesive spreader to coat the bonding faces with a generous amount micro thickened epoxy.  

    

in the bag....

After gluing, screwing and clamping all the preformed foam in place, I covered the assembly with a piece of used vac bag sheeting and tucked a little 1500W heater under the cover and called it a good night.......Although the shop temp was around 35F, the aft steps felt like they were in the Bahamas........wishful thinking I guess.

roughing in the aft starboard boarding steps

Although it's darn cold in the shop, I was able to use my easy bake foam toaster ( seen here lower right) to thermoform the end radiuses in the step faces. My technique has been to form and fit most of the pieces and temporarily screw them in place here an there with some sheet rock screws. After everything fits the way I want it to, I come back and mark all the critical join areas with a sharpy ( A ----->A, B------->B, etc ) It also helps to label "up" in case your boat flips over or you fall off a ladder and get disoriented.

Fancy foam fitting feat

Here's a simple technique for fitting a strip of foam to an irregular curve. The foam piece that you see mid photo needs to fit against the lower surfaces so I've temporarily clamped it a full width higher than it will eventually sit. I then took a scrap or stick and used it to scribe the curve by moving the stick up along the curve while making dots with a sharpy. From there, it's a pretty easy exercise in connecting the dots and cutting the excess off. You can spend a lot of time making paper templates and trying to cut things perfect but using little tricks like this can help keep things moving along.

starboard boarding steps

You're looking down at what will eventually become the starboard side stern boarding steps. I've taken a little extra care to sculpt some nice rounded curves to avoid having corners that may some day bruise the hips of careless bikini clad super-models if they try to board the boat in a chop.

more stair work

Here I've added the extra thickness along the edges of the stern. All this foam work will get sanded and shaped smooth. the hull edges will also be gouged out and capped with the usual mix of epoxy, cabosil and microbaloon filler then I'll glass this grand stairway and move along to the starboard hull. When ever I feel like I've made some progress, I look up and realize that there's another hull waiting for me.

port side boarding steps

Here's a little progress made towards building the aft steps. I haven't built the lower step and this will involve boxing in a structure that will house the rudder bearing and it will have the ability to pivot up. I chose to create a slightly rounded cascading detail that eliminates any exposed step corners. Also, the next step is to add another layer of foam along the stern hull edges. The fun part will be going at this thing with a bunch of sanders and shaping tools so that it'll have a nice sculpted form

port side stern steps

Here's a start roughing in the boarding stairs for the port side hull. I chose to go with the boarding platform and radius the stairs to eliminate exposed corners on the steps. I also decided to go with the under slung kick up rudder box so after I build the stairs, I'll go after them with a saws all and create the rudder support portion that will kick up.

unde cover

snug and dry inside the shop......

tucked in for the winter

This is the first posted photograph taken with my new Canon Rebel digital camera. From here on out, hopefully you should see an improvement in the quality of my photographs.

Here's a shot with the morning sun shining through the starboard side hull foam. The make shift scaffolds allow me to risk falling to my "harm" onto the cement floor between the two hulls. Since the cold won't really allow me to lay up the bridge deck floor, I'll most likely build a better temporary walkway between my hulls.

Stern view

Here's a 3/4 stern view. Lot's of work to do but it's nice to see all this expensive foam, glass and epoxy beginning to look like a ship.

Putting the pieces in place

Since the Pacific NW chill is beginning to make her way off the cool Pacific and onto the North west coast, It's time to put the pieces together so that I can set up a protected place to work....mainly "Inside" the boat. I decided to position the hulls as they will eventually go, throw a big 6 MIL plastic cover over the shell and create a snug place to work me through the coming winter months. Of course, the curse to avoid is becoming bogged down in details at a time when large brush strokes are still required.

brother kevlar

My brother flew in from Santa Cruz to help me sheath the port side hull with Kevlar. Unfortunately, "Big Brothers" latest wars have made this stuff fairly expensive. With new leadership, America will most likely be able to reduce the need to turn this stuff into vests. I think it looks better on a boat than a desert tan Hummer.