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.