Rot Repair in Fiberglass Boats
Delamination: Decks and Cabins
Delamination Diagram Occasionally decks and cabin sides will delaminate from the core. The core itself is okay, but the glass is popped up on top. You need to drill the perimeter and treat with epoxy. Here is a schematic.

We recommend the use of our Layup & Laminating Resin™ because it is a simple 1:1 mix, very slow setting which allows the epoxy to settle into position and retain a slight flexibility after curing. For filling holes, our Fill-It™ Epoxy Filler goes in neatly on top of the epoxy, smooths cleanly, dries in 24 hours, and can then be easily gel-coated or painted.

If there is wood involved and you suspect deterioration or rot, you can apply CPES™ first to the holes, but this will mean waiting for at least a week for the carrier solvents to evaporate away. Then the Layup & Laminating Resin can be applied.

Rot Repair in Fiberglass Boats
Delamination: Hull Blisters
Blisters on the hull bottom are common on some boats. Water (especially salt water) gets under the gelcoat and into the laminate and bad chemistry results. The laminate is compromised, and unless repaired the blisters will get worse. On the other hand, we've never heard of a fiberglass boat sinking because of delamination blisters. No need to panic, but it does give the mind something to think about.

Vast arrays of blisters is a boatyard job. Few owners will have the time to make the repair themselves. Everything has to be ground down, dried out, and built back up with epoxy. Big job...takes time...costs money.

A few blisters are repairable by the owner, but it will take a little time. Pop them open, clean away the gunk, clean the opening area so it's free and clear, and dry out the laminate. If you've got a long time (say 6 months or more) they will eventually air-dry, or you can vacuum dry them, or you can apply blowing warm air, as from a hair dryer. It will still take time - you gotta be sure things are dry. The ordinary moisture meter won't be much help. There are specialized ones that will work, but they are expensive.

Dry until you are sure it's dry inside. Clean out with our Epoxy Solvent or xylene. Then apply CPES™ to the area, allowing it to wick in as much as it will. Allow 2-3 days to go by, and then apply another coat of CPES™. Allow 2 days to pass. Then another coat of CPES™, one day dry time, and then another CPES™ application. You can do this as long as you want, allowing a day dry time between applications, because what you are doing is building thin layers of epoxy in, on and around the glass matrix. No other epoxy product you can buy will penetrate these very small spaces as well as CPES™. A single 2-pint unit of CPES™ will carry you through a whole bunch of blisters. From this point on you can apply a thick resin coat or go directly to a filler, such as our Fill-It™ Epoxy Filler. Push it in, smooth it off, and paint with an epoxy or polyurethane barrier-coat paint. The repair will be virtually waterproof.

Rot Repair in Fiberglass Boats
Other Problem Areas

Anywhere there's wood on a boat there's a potential for rot or deterioration. We show below hull-to-deck joints, and the various applications of wood. If it looks bad, then clean the surface, remove the fastening, apply CPES™.

Deck/Hull Joints

Mast steps are usually wood based, and they rot or deteriorate. It's often easier to rebuild the existing deteriorated step than it is to pull it and replace. A combination of CPES™ and the L&L Resin™ can result in a strong step that is largely free of existing rot and protected to a substantial degree from future rot.

The wood trim on glass boats is now usually teak, which is good because it won't rot. We should tell you that teak treated first with a coat of CPES™ will hold varnish for a lot longer than teak which is untreated. This particularly true if the varnish is a polyurethane, which seems to stick to CPES™-treated wood particularly well.