Got a few drink-holder-sized holes in your steering console that need patching? Or a spot where an antiquated plotter used to be that needs filling in? To put the finishing touches on the job, you can use any one of several epoxy fillers on the market; most of them work pretty well. You can also mix up your own, of course, using epoxy resin, hardener, and one of any number of high- or low-density materials (microfibers, microballoons, or colloidal silica, for example) that fit the application.
But how do you actually complete the repair? How do you make the filler blend seamlessly with the surfaces around it, so it disappears under the paint or gelcoat you intend to lay down after?
Here’s a trick a boatyard pal told us about recently. It will likely save you a little time and heartache and will produce a great-looking job. Moreover, it requires just about zero effort.
Let’s say you’ve filled in a circular hole that is approximately 3 inches in diameter somewhere in a slab of cored fiberglass aboard your boat. And let’s say you’ve used a plywood disc and some thickened epoxy (or fiberglass fabric and resin) to essentially plug the hole. Now you’re getting ready to carefully smooth and finish the surface of your repair with a relatively thin layer of epoxy filler.
Before you apply the filler using a resin spreader, plastic putty knife, or whatever tool you prefer, form a square or rectangle around the hole with wide swaths of varnishing tape. Make sure the tape is at least 2 or 3 inches from the exterior edges of the hole. If you can’t achieve this, approximate.
The idea here is pretty simple. As you spread the filler within the confines of the tape, you create a layer of filler over the hole and the surrounding area that is equivalent to the thickness of the tape. Once the filler has cured and is ready for sanding (and the tape has been removed), the layer is going to be thin enough so it’s easily removed using a sanding block, but thick enough to allow you to very accurately blend the repair into the surfaces that surround it. This virtually guarantees that you won’t scour out a depression over the hole during the sanding process, a development that will require another time-consuming pass with the filler.
This article originally appeared in the April 2017 issue of Power & Motoryacht magazine.