Soft Step

Rick Conner of Southport, Florida, asks:"My 1982 sloop has a keel–stepped rig and the balsa-cored deck around the mast partners is saturated with water. Can I drill holes into the deck and replace the core from the top using WEST System epoxy to make the repair? Or should I remove the wet balsa core from around the mast and fill the area with solid fiberglass? What about
Author:
Updated:
Original:

Rick Conner of Southport, Florida, asks:

"My 1982 sloop has a keel–stepped rig and the balsa-cored deck around the mast partners is saturated with water. Can I drill holes into the deck and replace the core from the top using WEST System epoxy to make the repair? Or should I remove the wet balsa core from around the mast and fill the area with solid fiberglass? What about other spots in the deck that have the same problem?"

Don Casey replies:

To plan the best repair you must first understand that the function of a balsa core is to add depth to a structure, much like the central web of an I-beam. The thin skins on either side of the balsa core lack adequate stiffness unless they are attached to either side of the core material. Attached is the operative word here. If the skins are separated from the core, which is what happens when wood core gets wet, the three components of the composite structure will slide across each other when loaded, acting more like a leaf spring than an I-beam.

Instead of a balsa, plywood or foam core, the two skins might be separated by a mostly hollow grid structure or even one that has parallel perpendicular strips firmly attached to both skins. These “cores” are primarily air-filled but they are as rigid as a more solid wood or foam core and are less susceptible to water damage. But because of the fractional amount of contact area, the bond between skin and core will be less robust, which is why most builders prefer solid core materials.

You can create support columns within a damaged core by drilling or sawing holes through both the upper skin and the punky balsa core and filling these with reinforced epoxy resin. For such a repair to be successful, the epoxy columns must be large enough to bond with both the top and bottom skins. They must also be close enough together to adequately support the span between columns.

This method is most appropriate when a relatively small area is involved. To repair a large area you should remove the top skin, replace the damaged core and then relaminate a new skin on top of it. In fact, replacing the core is probably less work and will produce a better result. In my view, any builder who leaves the core material exposed at the mast partners should be ashamed. But now you may be able to use this failing to your advantage.

First dig out the wet core as far back from the partners as is feasible. Vacuum out the debris, then carefully sand the interior surface of both skins with 36-grit sandpaper and wipe away all the sanding dust with acetone. Fill the void with epoxy thickened with colloidal silica. Use either an epoxy syringe and plastic straw or a length of tubing to inject the resin into the back of the void. Inject in small batches and, to avoid overheating as the epoxy sets, let previous injections “kick” before you add more. Make the inside edge flush with the skins around the partners and that should fix the core problem you have around the mast.

As far as other damage is concerned, flexible decks are epidemic in older boats and the efficacy of any repair depends on the value of the boat and the kind of sailing you plan to do. In most cases, however, a well executed do-it-yourself core repair almost always pays for itself in terms of resale value.

Related

BoatTalk-2048

VIDEO: Sailing Not just for Millionaires

Sailing and boating can come with a hefty price tag, but there are plenty of ways to get on the water without breaking the bank. In this episode of Boat Talk, SAIL's managing editor Lydia Mullan and Power & Motor Yacht's executive editor Charlie Levine share tips on getting out ...read more

Cornell-2048x

Elcano Challenge Resurrected

In late 2020, sailing legend Jimmy Cornell set off on his Elcano Challenge, a green-powered circumnavigation aboard the custom Outremer Aventura Zero. Unfortunately, shortly after setting out, the boat encountered major power-generation issues. "I took the decision to turn ...read more

F8V-BOOK-for-SAIL---1

Book Review: The Figure 8 Voyage

“What is the color of the ocean that rolls beneath Pacific trades? How does a wave curl and crash at 47 degrees south? Can an albatross remain awing in the worst of weathers?” Randall Reeves has always found images to be the most compelling part of the stories we tell about the ...read more

AC210117cb_23806

VIDEO: Capsize in the Prada Cup

American Magic's Patriot capsized during day three of the Prada Cup. If you haven't yet watched the catastrophe unfold with your own eyes, check out the above video or any number of others that are circulating on social media. It's truly a tip that has to be seen to be believed. ...read more

210115-AC36

Prada Cup: Brits Take First Two Races

Who saw that coming? After getting skunked in December, INEOS Team UK has swept the first two races in the Prada Cup elimination series of the 36th America’s Cup  Racing took place on racecourse “C,” sheltered between Auckland’s North Head and Bastion Point to take advantage of ...read more

ac-2048x

Hutchinson: 36th America’s Cup will be a Close On

On the eve of the Prada Cup challenger series, the official start of the 36th America’s Cup, New York Yacht Club American Magic skipper Terry Hutchinson says it’s anyone’s game. "As we've seen in the last week, everyone's gotten faster," said Hutchinson said at the event’s ...read more

Episode1_Thumbnail4_00000_00000_00000_00000

Sailing Docuseries Released Online

Endless Media's Reaching Reality is the story of three friends, a 24-foot sailboat and 1,200 miles. With candor and humor, this series proves that you don't need to be an expert or a millionaire to cast off on the journey of a lifetime. Produced by Emmy-award winner Barry ...read more

01-LEAD-nder-sail-3

Prepping for a Transatlantic

Growing up on the coast of northern England, I dreamed about crossing oceans on my own boat. Like most of us, though, education, a family and a career took precedence, and before I knew it, we had mortgages, young children and endless work obligations. We also became landlocked, ...read more