Vaclav's method worked well for me with one self caused problem. When I had the sacrificial gasket placed, and added thickened epoxy to fill the corners I didn't wait long enough to lay the fiberglass. It looked and felt ok but the subsequent layers softened the thickened fillet enough to leave me with air bubbles on the inside edge of the fillet. I later tried to fil the bubbles but it was more trouble than it was worth. I ended up trimming most of the final inside edge off. and it doesn't seem to have caused any real long term problems. The lesson there was to wait longer than you think because the fillet will work best when it's fairly well set before you continue.

The multiple layers went fine but I did one layer at a time, wetting each one out throughly. No bubbles, and a extremely strong lay-up resulted.