Finally, it's time to prepare the lower hull and sides before glassing.
The first job while the boat is upside down is to sand the underside of the rub rails.
This was no easy task due to my decision to build the rub rails from six laminated strips consisting of red gum hardwood and hoop pine. (see 10/10/2024 "Rub Rails" post)
Time to raise some saw dust and despite being connected to a vacuum I certainly produced a lot of dust.
After a couple of hours pushing the belt sander and breaking three 80 grit belts I managed to clean up the rub rail undersides.
I then spent the next hour sanding off all the epoxy blobs that flowed through some of the joins like stalactites.
I also needed to smooth the hull bottom to keel section in preparation to allow a smooth fillet.
It's been a while but time to mix up some epoxy filler.
Time to fill all the stitch holes and voids.
I used Q‑Cell which is made from hollow glass or ceramic microspheres. When mixed into resin, it:
Adds bulk without significant added weight.
Improves workability and flow
Provides reasonable compressive strength
And most importanly:
After sanding all the cured stitch holes and voids it was time to lay the large filets joining the keel and lower hull.
As indicated in the construction manual I made a 19mm radius fileting tool.
I started on the starboard side, it was a warm day, so I mixed small amounts and started laying the filets.
Almost half way...
Now the port side.
While waiting for the epoxy filets to cure I made a special sanding tool the same radius as the filets. I used 80 grit sticky back sandpaper over plastic irrigation pipe. should work a treat.
After a lot of elbow grease, I turned this...........
........into this.
For additional strength I decided to tab the keel to hull bottom with 100mm wide fiberglass cloth tape before glassing the hull. This will require a bit more labor feathering in the edges but will result in a stronger finish.
In preparation, I cut all the cloth tape and peel ply and layed plastic for a wetting out area. I also cut a small piece of 50 mm diam poly pipe to wrap the wetted-out tape for easy installation.
Tabing done and peel ply applied.
Starboard peel ply applied.
After removing the peel ply, I spent a couple of hours sanding and feathering the edges of the tape. Then I filled the edges with an epoxy mixed with fairing powder.
I certainly did increase my workload by adding this extra layer of fiberglass tape, but it will increase the strength of the keel to hull.
The remainder of the keel and lower hull was sanded to a smooth finish.
A nice curve sanded on the chines and transom.
The complete area is vacuumed and wiped down with denatured alcohol to remove any dust and contamination.
To prevent resin from running into the centerboard casing I closed the opening with masking tape.
I placed masking tape halfway into the centerboard case and folded it over both sides of the upper opening. Then a strip of masking tape was secured onto the folded sections. This provided a secure area that will allow fiberglass cloth to adhere to the keel edges and allow removal of the opening while preventing resin runs to enter the centerboard case. Well, that's the theory.
The starboard side of the hull is masked up to the provide a 100 mm overlap.
Including the transom.
With everything neatly masked up I laid the cloth over the hull.
With a gloved hand I smoothed it into the contours of the hull and trimmed off any excess cloth.
The cloth was held in place with masking tape tabs.
Preparation time, I poured quantities of resin in cups with marked ratios for hardener.
Stirrers, rollers. squeegee's, gloves and clean up gear all lined up and ready to go.
It took about 1.5 hours to wet out the Starboard lower hull and keel.
After the epoxy tacked off, I trimmed along the masking tape with a Stanley knife and removed the cloth overhang.
And also, along the keel.
Second resin coat rolled on while tacky, giving a good chemical bond.
