Be Sides...

Building the Side Panels of the BW

The side panels will be cut from 4-foot x 24-foot 9mm (3/8-inch) meranti.

Panel Selection

Since the BW will be finished bright (natural wood) I spent some time selecting which six 4x8 sheets will be used. I laid all ten sheets out, removed the ugly ones then tried to mate similar grain patterns and colors.

Panel selection

Scarphing and Gluing

Then, as usual, cut the scarphs. Even though the final side panels will be only 32 inches wide, I chose to scarph, glue and 'glass the full 48-inch width since I can use the excess 16 inches x 24 feet boards for other parts such as the side panel backers under the knees.

9mm sheet clamped for scarph cut

After dry fit-up of the joint and clamping the plywood sheets to the work surface so they cannot move, I placed a scrap block under one of the sheets to elevate the joint so I could access both faces of the joint for gluing.

Plywood sheet elevated for access. Pre-wet both faces of the joint
with un-thickened epoxy then apply thickened epoxy.

Then clamp them to squeeze a little thickened epoxy out everywhere to ensure that there are no voids in the joint.

Thickened epoxy oozing out.

After the excess epoxy is done oozing out, which can take
up to 30 minutes, remove the excess before it cures. That is a
lot easier than removing it after it cures.

When gluing the scarph joints, I kept the outside of the side panel up. That way, I could do my best to make the final scarph joint look nice since the finish will be bright. I can't access the other side of the scarph joint and it will probably be an ugly scarph joint. However, the ugly scarph joint will be on the inside of the boat and the inside of the boat will be so busy with knees, fuel tanks, helm, lockers, etc. that the ugly scarph joint will not be noticed.

'Glassing the Side Panels

I chose to glass the side panels now, while they are conveniently laying on my work surface. I 'glassed the full 48-inch width of one side but I 'glassed only 32 inches of the other side so that both sides of the side panels have 'glass set in epoxy. 

The extra 16-inch x 24-foot piece will have 'glass on one side only. The un-glassed side will be laminated so 'glass is not needed on both sides of the 16-inch x 24-foot piece .

Layout of 'glass using dry method. This side gets 'glass on
the full 48-inch width. The other side will get 'glass on only
32 inches of width. I use the full 50-inch width of the 'glass
and will cut the dross off after the epoxy cures. If you try to cut
the 'glass before applying epoxy, you'll get a bunch of annoying
stray 'glass strands in the epoxy.

Saturating the glass with un-thickened epoxy and being
vigilant about squeegeeing the epoxy on thin so the
'glass does not float off of the plywood.

After the epoxy cures I will remove the dross and fill the weave. 

After the epoxy cures, I use a utility knife to cut away the dross. That leaves a really sharp serrated knife edge in the 'glass/epoxy that needs to be sanded to avoid cutting yourself. I learned this the hard way long ago.

Also, do not fill the weave until after the first epoxy layer is cured. If you try to fill the weave before the first epoxy layer is cured, you will float the 'glass off of the plywood leaving ugly waves in the 

finished 'glass.

While using the overhead pulley system to flop the
4-foot by 24-foot panel, I took this photo to demonstrate
the resilience of the meranti and the strength of the scarph.
The entire panel is being held up by a single lift point at the scarph joint.

Filling the Weave

After the epoxy has cured the weave of the fiberglass is still providing relief to the surface. After filling the weave with unthickened epoxy, the weave is invisble and the surface looks like varnished natural wood.

Before filling the weave, I placed boards to mark the 32-inch
portion of the panel that will become the final side panel. There
is no need to fill the weave in the remaining 16 inches that will
end up in an unseen location.

Pour un-thickened epoxy on the surface, roughly spread it with
a squeegee, fine spread it and tip with a foam brush. Use small
batches of epoxy so it does not start to cure before tipping.

Filling the weave on the side that received fiberglass on the
32-inch portion only.

Weave filled

Let the weave-filling epoxy cure then remove the unused
16-inch width of fiberglass.

Flopping Panels

Working alone, I rigged overhead pulleys and ropes to help with lifting. Here is a sequence of photos showing flopping a 4-foot by 24-foot panel.

Cutting the Side Panels

Weave is filled and it is time to cut the side panels to the plan dimensions.

The factory edges of the plywood sheets were not aligned perfectly since I elected to align the sheets as needed for nice looking scarph joints. So I need a straight edge for the baseline.

I struck a chalk line, set a straight edge and cut a baseline.

Measure off of the baseline and cut the side panel to
its final 32-inch width.

Since this boat is a prototype, I need the stations to be permanently
marked in order to record adjustments to the plans, if needed.
So, the stations are permanently marked on the inside of one panel.

Stations and offsets for the BW side panels

Lay out offsets at each station according to the plans and use
a supple batten to draw a fair curve.

Lay the panels together, in mirror image (inside out), and cut the
curve with a jig saw. The curve will be sanded fair later.

Separate the panels and cut a 20° bevel on the bottom
edge of the panel (chine).

While the panels are separate, route a curve on the inside
 edge of the stem. Lay the panels together in their final
configuration, (inside in, pretty side out). Then the stem
is drilled and loosely stitched. The stitches are 16 gauge steel
coated with paste wax so epoxy will not stick to the stitches.

While the side panels are still atop each other,
drill the stitch holes for future stitching
at the chine.

 Store the Side Panels

Bottom and side panels suspended from the ceiling.

Meranti and Moose

My meranti plywood arrived over the weekend. I towed the snowmachine trailer down to Hardware Specialties and loaded up. I towed the trailer home and started unloading.

It will be nice working with BS-1088 again.

All of a sudeen my dog goes ballistic and I look around to find this fella visiting

So I grab the dog and toss him in the garage. Turns out there was a cow moose and two calves. They have been in my yard for three hours now.

I missed the best photo. It was when all three were lying around eating this rhubarb. By the time I got my camera to the window, two of the moose had wandered to elsewhere in the garden.

They're Back

They just won't let me be. I'm trying to cut knees for the BW and...

My dog tried to mix it up with this one.
Lucky for the dog this bull was not interested.

Then the Prince of the Forest showed up

Then a herd formed.

Biggens Outta Littlens

Gotta Think Ahead

I hate that...having to think ahead...I always forget something...but here goes.

Once I stitch the boat panels together, the boat hull will occupy most of my shop space and I will have no room for other work. So, I need to fabricate all of the big items before stitching.

The big items are the long pieces like inwhales, rubrails, sole battens and spray rails.

I found some very nice clear select pine at Lowes. I have used select pine before. Although it is kinda soft, it has a pretty grain and plays nice with epoxy. The 1x10x8-foot pieces were the most economical. I can scarph 8-footers together to make 16 and 24-footers. Well, they will be almost 16 and 24-feet. I will lose 4 inches at each scarph joint. I mean, the boards will lose 4 inches at each scarph joint.

Some of the 1x10s were cupped. This makes scarphing a challenge. So I ripped the cupped 1x10x8s into 1x5x8s. I clamped them down and lined them up for scarphing. Not trusting the factory end, I cross-cut a straight line across all of the boards at once.

To minimize dust in my shop,
I try to do all power cutting and sanding outside.

Then I broke out the Makita power planer with John Henry scarphing jig and cut the scarphs.

John Henry scarph jig cutting 1x5x8s

John Henry scarph jig cutting 1x5x8s

Scarph cuts galore

I struck a chalk line on my work surface and lined up three 1x5x8s for gluing into 1x5x24s.These will be inwhales and rubrails. Once aligned, I clamped and screwed the pieces in place.

1x5x8s secured for scarph joining into 1x5x24s

I removed the clamps and screws from the middle board to reveal the mating surfaces. Then I precoated the mating surfaces with unthickened epoxy. The end grain of the pine sucks up lots of unthickened epoxy so I was very generous with the unthickened epoxy. Then I applied epoxy thickened with silica powder.

I add a dash of wood flour to the thickened epoxy so that the epoxy is (hopefully) about the same color as the epoxy-coated pine. The resulting epoxy is the same color and consistency as peanut butter but does not taste as good as peanut butter. 

Thickened epoxy oozing out of the joint. The tinted epoxy 
makes the scarph joint a bit less obnoxious in the bright finished boat.

Excess epoxy removed before the epoxy cures.

The excess epoxy does not go to waste. I have many joints ready for gluing and the excess epoxy is scraped off and used in the next joint.

The 1x10x8s that were not cupped are scarphed together whole.

1x10 precoated and buttered for joining

Gluing many joints in one session to minimize epoxy waste

After the epoxy cures, the inwhales and rubrails can be taken outside for sanding and routing. It was threatening to rain/snow so I did not take the time to photograph the sanding/routing session. Besides, photos of a sanding and routing session would be way too much excitement for one blog.

Inwhales, rubrails and 1x2x24s for spray rails and sole battens

Laminating 1x2x24s into 2x2x24sfor spray rails and sole battens

Pre-wetting with unthickened epoxy

Buttering with thickened epoxy.
For the spray rails, I only laminated the aft 10 or so feet.
The fore 10 or so feet will be laminated on the boat hull to
accommodate the bending of the hull

Clamped and screwed with excess thickened epoxy oozing out

Excess epoxy removed before curing

When plugging holes, I have tried to level the uncured thickened
epoxy with a putty knife but the plug always ends up
concave, not flush with the surface, dished below the surface.

Now I overfill and and sand the cured epoxy flush.

Ripping the spray rails and sole battens

Spray rails, inwhales, rubrails and sole battens
ready for 'glass

Interesting pattern of the scarphs in the two layers laminated together

Starting to fiberglass

Cutting sections of 10oz. fibergalss

Sole batten is elevated off of work surface so
fiberglass can hang freely.
Notice the polyethylene sheeting on the work surface.

Laying 10oz. 'glass

Sole battens glassed. Will fill the weave tomorrow.

Glassing inwhales and rubrails with 4oz.

Before filling the weave.

Filling the weave

After filling the weave

It is likely that I have forgotten some pieces and will need additional shop space for fabrication after the boat hull is stitched together. I have a two car garage. When I need to use the garage for shop space, should I put my car or my wife's car out in the snow?



Lifting Strakes (12-04-2014)

About two months after fabricating the sole battens, I decided that instead of two sole battens on the bottom, I will install four lifting strakes, two on each side of the bottom. Hopefully I'll find another use for the sole battens.

Half-section of the hull with a pair of
lifting strakes (triangles) on the bottom.

I started by scarph joining four 1x4x8foot select pine boards into two 1x4x16foot boards.

Cutting scarphs

Joining scarphs

Then I laminated the two 1x4x16s together to form a 2x4x16

Laminating

 Then I set the table saw blade at 45° and ripped the lifting strakes out of the 2x4x16s.

After sanding out the saw marks, the corner of the strakes was routed quarter round. Then I coated the two sides that will be exposed. The third side will be laminated to the boat bottom.

In a previous blog, I ranted that pre-coating before applying fiberglass was unnecessary. That was before I worked with 10-ounce fiberglass. I have since learned that 10-ounce fiberglass absorbs so much of the epoxy that the wood does not get enough epoxy. This is known to epoxy-smiths as "starving the lay up". The result is a less-than-optimal bond between the fiberglass and the wood. So now, when working with 10-ounce fiberglass, I pre-coat the wood with unthickened epoxy and let the epoxy cure before applying fiberglass. This allows the wood to soak up as much epoxy as it wants and seals the surface so the wood will not suck epoxy out of the fiberglass.

Pre-coating today is much easier than twenty years ago. Twenty years ago, non-blushing epoxy was not available. Thus, sanding was required between the pre-coat and the fiberglass installation. With non-blushing epoxy, sanding is not necessary.

Pre-coating the lifting strakes

Scarph joints in laminated layers

Applying 10-ounce fiberglass

After the epoxy cured, the weave was filled, excess fiberglass was cut and sanded away and the lifting strakes were stored for installation at a later date.