Stitch-and-Glue Boat Maintenance

That FIRST scratch.  You have to get that first scratch.  Then it’s just a nice boat and you can get on with enjoying the water.
Kayaks and small boats will accumulate scratches and assorted contusions in the course of a season.  What to do once you’ve gotten the first scratch, or the hundredth scratch?

Short answer:  Not much.
Long answer?  Read on.

Chesapeake Light Craft maintains an in-house fleet of some seventy kayaks, canoes, and small boats.  They are display models, demo models, and prototypes.  And they get used A LOT.  A kayak or rowing boat in our fleet might slide on and off a gravel beach 400 times in one season.   This causes shallow scratches, which we ignore for as long as we can.  Usually two years.
There’s a threshold for what kinds of damage we bring into the shop for repair and what we send on to the next show.  It’s an easy distinction:  did the damage pierce the fiberglass and expose bare wood, or not? 
Refinishing HullHow to deal with shallow scratches


If the scratch or ding doesn’t expose the bare wood, we put off repairs as long as possible.  Since all CLC boats are enclosed in an impermeable layer of epoxy, as long as the wood remains sealed (and the epoxy remains protected from sunlight with varnish), it’s just a matter of looks.  Since we don’t have a lot of extra time, we let our fleet boats get pretty ragged before we bring a boat in for fresh varnish.
The routine for shallow scratches, once the poor boat is looking shabby, is to strip off the hardware, wipe the hull off thoroughly with denatured alcohol, and go at it with 220-grit sandpaper.  If the scratches are really deep, we don’t try to sand all the way to the bottom of the scratch.  We just smooth everything up as much as possible, wipe down again, then brush on a few more coats of varnish.  Even deep scratches disappear visually, though they are still there.  But the boat is shiny again and ready for the big show. 
When you re-attach hardware, don’t forget to put a fresh dab of silicone caulk in the holes.
The important thing to underline is that scratches that don’t pierce the epoxy “envelope” that protects the wood are just unsightly, not harmful to the boat.
How to deal with deep scratches or “divots”


Last week, while photographing the new Mark II Eastport Pram, I managed to sail the beast onto a sharp rock at nearly full speed.  There was an ugly sound and in my wake a streak of the Pram’s white paint now coated the rock.  Back at the shop, I found a nasty bruise on the bottom panel.  The wood was nearly undamaged, but the fiberglass had been cut through, allowing a little water to wet the okoume.
This is bad; water will continue to seep in over time and eventually work its way through the plywood to stain the varnished interior and weaken the whole structure.  This is a fairly typical injury in a stitch-and-glue boat, and it’s worth noting that the damage would have been worse in a solid fiberglass hull.
The first step, of course, is to dry out the damaged area.  I just put the boat in the shop for a week to dry out.  But if you’re in a hurry you can apply heat to dry out the wood, or even dose the damaged area with denatured alcohol.  Alcohol will help evaporate the water out of small cracks.
VarnishingThen off comes the paint and/or varnish around the damaged area.  Use 120-grit on a sander to expose bare fiberglass all around the damaged area.  If the scratch is small enough that only your thumbnail will fit in there, and it’s a lightweight boat, you can just apply unthickened epoxy to fill the crack.  Then sand smooth with 220-grit and repaint or revarnish.  The important thing is to make sure that water can’t get back in.
If you have a gouge, fill the depression with thickened epoxy.  Then epoxy a small patch of fiberglass over the damaged area.  Once it has cured, you can “feather” the rough edges of the fiberglass patch so that the patch is invisible beneath paint or varnish. 

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