Fairing the port and hatch openings

This weekend I put in a few hours fairing and glassing the port openings.  A heat wave has arrived just in time for summer.  Temperatures in the 90s turned the boat house into an oven with indoor temps in the 110s.  Needless to say I was not too keen on working during the midday heat, and the epoxy kicks within 20 minutes.  So I tried to make progress in the morning and evening.  Here is the process I followed for fairing the access port openings.  First I built up a broad fillet with light putty between the edge of the port ring and the tangent of the hull.  I also carved out about 1/8-1/4 inch of foam around the inside edge of the port ring and filled it with putty.  This will make the edge more durable and prevent water from being absorbed into the foam core.  Additional putty was used on the interior seam so the inside glass has a more uniform surface to bond to.

 After the putty cured (a few hours in this heat) I sanded the fillet so it is tangent to the hull.  A small palm sander works well for this type of work.  The handheld belt sander, random orbit sander, and sanding blocks were all used, but the palm sander was the most used.  I also sanded the inside edge of the ring and the interior seam.

 After sanding, the access port ring was nicely blended into the hull.  The broad fillets on the sides don't protrude too much so the overall figure of the hull is still fair.  You might also notice that I softened the edges fore and aft of the opening, which again helps blend the ports into the hull form.  The rotary grinder (aka Dremel) and palm sander made this a quick job.  Of course, care is need to ensure a runaway rotary grinder doesn't wreak havoc on the fair hull.

 Glassing the interior and exterior of the port openings is needed to structurally integrate the port rings with the hull.  I only applied the exterior glass because it was relatively quick and easy, and the heat was making the epoxy kick too quickly.  I slowed it down a little by setting the epoxy pan on an ice pack, which gave me about 40 minutes of working time.  The glass patch is about 3 inches wider than the port ring on all sides.  The ideal time to trim the glass around the opening is after curing for a few hours but before it fully cures.  A sharp blade cuts it clean and quick.

 Here is the opening after trimming.  You can just barely see the outline of the glass patch.  I also used peel-ply to help reducing the final fairing needed.  I will need to do a little sanding to blend the edge of the patch, but it shouldn't be too painful.

Here is the view with the ports temporarily in place.  I followed a similar procedure for the hatch.  The result is a flat surface for the ports and hatch to seal against, while maintaining the sleek lines of the hull.  I still need to glass the inside of the ports, but that should only take a few hours, and hopefully cooler temperatures will help.