Fibreglassed carvel planked boat repair

[rbeck]

Yes...I am one of the unfortunate guys who owns a late 70's wooden boat (yellow pine on white oak) that was fibreglassed over when new.

Situation: below the waterline the planks are very humid and soft (mid to mild rot). The lobster boat is 30' x 10'. Glass work is in very good shape, as are the ribs.

Question: what can I do to save the planks that are on their way to being mulch? Given that I can't pull the planks, is there an approach I can take with this situation. Or do I resolve myself to letting them go.

Cheers.

[Dutch Peter]

rbeck,

I have the same problem with my boat, difference is mine is cold moulded. So I have no ribs, just two stringers and 3 floors for the keel bolts. I scraped out the wood from the inside till I found sound wood again (on some places I hit the glass) and are currently replacing the veneer I removed. The glass on the outside provides a good base for that. I'll post some pics when I come around to it. You could do the same, but for a whole boat it's quit an undertaking!

I wish you luck!

[pungolee]

There are several approaches,all expensive.Dry the boat out in a temporary greenhouse(at least six months depending on geography.Pump much unthickened epoxy resin into all voids with large plastic hypo and carefully drilled holes(we are talking a lot of holes)And a lot of resin.Excavate,vacuum and excavate again rot from timbers,apply three coats unthickened epoxy by brush,when dry,fill with epoxy thickened with cabosil,heavily.You might as well sister those new lower frames(you did cut new timbers?)at this time so the glue will all be cohesive.In a couple of days apply liberal epoxy/cabosil thickened fillets to the whole mess.In other words,if you have enough resin,and paitience,and time and wood,you can have a boat that is good for slow cruising in inland(safe,very safe)waters.

[gonzo]

Gluing epoxy to rot is not a solution. It will not give you a structurally sound hull. The only way to fix rot properly is to remove it and replace it with good wood. Replanking a bottom is not as much labor as trying to patch it little by little.

[PAR]

Sounds like you have a boat in need of some if not all new bottom planks. You could inject 4 or 5 times their replacement weight with resin in a hope that the congealed mess will have enough good, solid structure to hold onto the goo'd in old planking.

Planking is considered "consumable" just like sails or an oil filter, they all need replacement some time, unless kept on a stand in a museum. You could laminate in, an inside out sort of, planking repair, but it be a real mess and difficult. A better idea would be to strip out the interior of the boat (may require bracing) and remove and replace as much of the structure (planking, ribs, stringers, etc.) as you can get at without damaging the GRP skin. In the areas you'll have difficulty getting all of the old structure out, then you can start thinking up inventive methods to pinch some extra life out of old stuff.

In the end, I'll bet you'll find fastener sickness in the ribs where the rotted planking was attached, also other areas that don't reveal themselves without total disassembly. You'll be lucky if the hood ends of the ribs, stringer and framing lands and notches don't have rot in them. I hope you are, as a lot more could be going on then some bad planks.

[Ilan Voyager]

As PAR has pointed it, it's very probable that the hull is very sick. Also, the 20 some years fiberglass is probably as strong and watertight as an old rag.

Consider that it would be surely easier and maybe cheaper to salvage all that is possible to save from the old boat and to build a new hull... and please no fiberglass (and polyester) on the hull's outside. Total epoxy wood, or total "classic" wood, there are no other good alternatives.