Sanding and Glassing and Gluing



While pre-glassing the panels before assembly eliminates most of the sanding, there's still a bit left to do. Once everything is taped together, the ridge caused by the selvedge on the tape needs to be sanded smooth. This is done most easily before the bottom is attached.

In the meantime, the bottom can be getting its inner layer of glass. This is the secret to a fast stitch and glue build - overlap the curing of the epoxy with something else. Otherwise, it's just wasted time.



Click on any image below for a larger view


Outside for sanding

External glassing complete, moved outdoors for the sanding to start.

Even scaled down, it's a large boat. The bow is on the left, stern on the right. The puzzle joints show the plywood sheet boundaries, the 3 main bulkheads delineate the hold and cockpit.


View forward

Looking forward from the cockpit over the hold. The natural sunlight highlights the taped seams and sanding dust.


Glassing the bottom

The bottom with its 4-oz layer of glass on what will be the inside. A single 20-foot piece of 50 inch wide glass takes care of protecting the inside bottom from dropped anchors, shoes grinding sand, water, etc. Once the epoxy cures, a razor blade is used to trim the excess glass from the edges of the wood.

The puzzle joints are clearly visible here, though the ones in the foreground will be forever hidden once the deck is installed. The large dot near the center is dust on the camera lens, not a strange glassing artifact.

At this point, the 1/2 inch thick bottom is heavier than the whole rest of the boat combined.


Bottom attached

The bottom has been taped on the inside to the side panels and bulkheads. In case the flood suddenly comes, it's now watertight enough to paddle to higher ground.

Seriously, though, it's starting to seem much more like a real boat. While there's still a bit of flex in it, it's very much stiffer than it was without the bottom.

The entire inside is glassed. The weave will be filled in the cockpit and hold, but nowhere else. It's not needed for strength, so why bother with areas that won't be visible?


Shaping the outside

Now that the bottom is securely attached, it's time to shape the outside. The rough outline needs to be trimmed to an exact match with the hull panels and rounded in preparation for glassing.

This is done with a combination of saws, rasp, belt sander and random orbital sander.

With the weight more than doubled, it's suddenly become a lot more work to handle the boat. It's still (just) possible to carry it, though that involves rolling it over, getting under the hold area, standing up and carrying it on my back like a huge wooden turtle shell. Hitting the right balance point is critical. It's going to be time for mechanical aids, soon.


3D joint

The edge is rounded, almost ready for the application of the exterior tape followed by the bottom glass. The curve of the hull and the curve of the edge intersect with the puzzle joint to give an interlocking structure of odd 3D shapes, like a surreal dovetail joint.

Although the edge is rounded, it still needs a bit more preparation. There are some gaps which need filling with epoxy/woodflour putty before the glass is applied, followed (of course) by the obligatory sanding.

The pencil line is a guide for the overlap of the bottom glass onto the hull. It will also be a guide for masking the bottom paint. It was ruled onto the wood while the panel was flat, before the glass was applied and is now under the exterior glass. This way it will not be accidentally erased during construction. It will eventually be covered by the edge of the bottom paint.

Drawing the line while the panel was flat guarantees an even spacing and was much easier than attempting to apply it after the hull was assembled into a curved shape. There is a similar line at the sheer for applying the rubrails.





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