FiberGlass Rudder Repair - 18 March 2003

View of the repaired area before painting with InterProtect 2000 Barrier coating.

Close up of the repaired area.

From the center:

  • The gray area is new matt and e-glass laminated vinylester resin (with about a 1" bevelled overlap onto original glass skin, )
  • white ring is original gelcoat and fiberglass,
  • gray ring is the layer of older Interprotect-2000 barrier coating,
  • blue, red and black are bottom paint layers.


I recently did a small repair on Bijou's rudder. It appeared fine when I pulled her out. I "bricked" the bottom and the rudder and the keel. Actually my hubby did most of the grunt work, since I have an injured arm... but I did the final pass over the keel and the rudder myself... gotta keep those foils in the best possible condition, even if my arm doesn't like it.

Then I painted the bottom with black Trinidad SR... and left her in the sun... The next day I noticed a "blister" on the surface of the rudder, about 1.5 inches in diameter, that I know wasn't there the day before. I gently pushed on it and it compressed easily. It didn't have any pinholes or breaches in the fiberglass skin, and nothing squished out. It didn't look like any osmotic blister I'd ever seen, nor did it look anything like any peeling bottom paint I'd ever seen.

I wasn't sure what was going on, so I asked the yard owner to come over and take a look. He asked me for my knife and (without thinking first) I handed it to him. He jabbed it right into the bubble and peeled the skin back, cutting off a big flap of fiberglass skin and exposing perfectly dry (no H2O) matt underneath that was well saturated with resin... then he said, "well, it's not full of acid... it's just a delamination that expanded when the black paint absorbed heat"...

Now, if he'd just put a tiny hole in the bubble and squeezed it to see what, if anything, came out, I could have just injected some epoxy into the delaminated area and been done with it. But since he cut off the skin, that wasn't an option any more... So I ground down the edges,put a laminate of light weight matt and e-glass in using vinylester poly resin, faired it, sealed it with some scrounged InterProtect 2000 and bottom painted it. The whole job took me about 2 hours total, included the time sitting around and waiting for the resin and the InterProtect to induce... not a hard job at all.

The had previously been treated with InterProtect 2000 so the rudder was nice and bone dry. Apparently there were no leaks around the shaft.

Finally, I covered the keel with an old tyvek suit to keep the sun off it for the remainder of the time she was out of the water with the sun beating down on her. I think next time I paint the bottom, it'll be a lighter color.... black looks cool, but has certain disadvantages....

Return to Judy B's Catalina 27 Home Page