Today I put the first section of the 425 gram double bias glass cloth on the exterior of our Didi 40 Cr. It seems a long process to get to this stage from the initial fairing some many weeks ago. All the finishing steps like fitting the stem, adding the 2 mm of glass in the keel floor area under the keel shoe, fitting and shaping the keel shoe, drilling the keel bolt holes, planing the ‘V’ of the bottom and adding back the 9 mm ply layer and then shaping that back to the ‘V’ all takes time. As well I left the glass reinforcement of the exterior side of the butt joins in the plywood to the last so that there would be a good chemical bond as well as physical bond to the overlying glass.
Today’s task was the last layer of glass over the keel shoe, and glassing the last two butt joins. After a break for a late morning coffee it was back to final fairing of the stern section and sanding all the weathered timber from the plywood so that the glass was onto a clean sanded surface.
Next task was to make sure the new ‘V’ on the bottom was exactly on the centre line and straight and that needed some fine adjustment with a sanding board loaded up with some 36 grit abrasive. Some final torture boarding of the radius chine finished me off as far as physical activity for the day was concerned. Finally the time came for the first layer of glass. Then it was mix the epoxy and spread the epoxy then roll it out evenly with a foam roller then roll the glass onto the resin squeezing it flat with a plastic spreader as it was rolled out. This process went surprisingly well as the surface is very flat and the glass rolled onto a cardboard tube was well behaved.
Once the glass was well rolled down with the bubble pricking roller the last of the resin was rolled onto the surface and then spread again with the plastic spreader. With all the bubbles removed the peel ply was rolled out using a second cardboard tube and it went equally well. Using the plastic spreader again all the air bubbles between the peel ply and the glass were spread out an in the process the laminate smoothed out reasonably well.
A butt join grooved ready for the reinforcing glass
A butt join with 1.2 kg of glass per m2 across the join and covered in peel ply
A butt join across the bottom of the hull with continuous glass from radius chine to radius chine