How To Fix Spider Cracks In Fiberglass Hood

Filling in the Gaps

At that place are many ways to repair cracks in fiberglass—which one's the all-time?

Stress cracks, spider cracks, and hairline cracks in the decks of older boats are, of class, not rare. Sometimes, they're merely cosmetic, meaning they don't penetrate the gelcoat. Sometimes, they get deeper and threaten an underlying laminate, which in many cases is cored. Considering the latter scenario may evolve into a very expensive proposition (replacing coring materials in an existing deck is a messy, pricey task best left to the professionals at your yard), it makes sense to address all suspicious-looking cracks on board your boat equally soon as possible, especially in areas that feel a lilliputian spongy (probably due to coring issues) when stepped on.

Before you brainstorm, notwithstanding, a discussion of warning. There are numerous, cheap products on the market these days that purport to be piece of cake fixes for hairline and other fractures in fiberglass laminates. I've personally tried two of the most popular of the lot—MagicEzy Hairline Fix and Captain Tolley's Creeping Scissure Cure—and, although certainly like shooting fish in a barrel to apply, neither one comes close to being a substitute for doing the job the right fashion, as follows:

Step 1 Figure out what caused the cracks to begin with. Do they emanate from a stanchion base that flexes? Practice they spread out from a radius that vibrates or twists in a seaway? Do they surround an surface area that feels just a little spongy, every bit already noted? Recall about it.

Step 2 Then toughen the laminate that contains the crevice or cracks by solidifying it, either by thickening with more than fiberglass, replacing coring materials, or adding construction. If you don't do this, new cracks will well-nigh probable appear, probably not also long later you've just finished fixing the old ones.

Step 3 Now, one time y'all've removed all hardware, toerails, and other paraphernalia that may ataxia or interfere, break out a Dremel tool with a conical bit. Then follow each separate fissure with the Dremel as if you were wielding a pencil. Utilize the highest speed possible, since low speeds may cause the flake to grab or swerve damagingly from your intended path. And let the Dremel do the piece of work—several shallow passes will produce a cleaner, more accurate task than going for a single, deep, forced march.

Step 4 Equally presently as the crevice has been channeled out, wipe it clean with a solvent like acetone and, using a plastic putty pocketknife, affluent-fill it with gelcoat matched to the color of the surrounding area (if the channel isn't too deep); polyester filler (if the channel is of medium depth); or polyester resin and fiberglass strands (if the channel is very deep and wide). Information technology's a good thought, by the way, to mix up a couple of modest batches of gelcoat to help y'all estimate the color you demand. Also, epoxy can exist used in place of polyester in some situations, although it tends to be much harder than poly and therefore more difficult to sand smooth and stop. And don't forget to temporarily embrace all gelcoat repairs with plastic picture—gelcoat does not cure thoroughly when exposed to air.

Stride 5 Finishing is the last attribute of a proper fix. When dealing with gelcoat, dry out sanding followed by wet sanding, with e'er more than refined, smoother grades of paper (starting with 220-grit and working your way downwards to super-fine 600-grit) is advisable, followed by a skillful wax or polish. When dealing with a polyester or epoxy repair, numerous cracks are usually involved, and you may be looking at a paint job of some kind in the near hereafter.

This article originally appeared in the Dec 2016 outcome of Power & Motoryacht magazine.