Centerboard box

[dave]

Personally, I believe that stuff like this should be built and/or repaired in a way to beef up the area so that it DOESN'T break! Even with "crush box", it's still broken and needing repair even if you are not sinking........................................ or not sinking TOO fast!

Keel trunk areas ARE NOT supposed to break! It matters not whether it's a fixed keel or a daggerboard!!!

[calhoon205]

Jim - I hope all is well with the CB and you're ready for spring! Can you tell me what you learned about the CB box construction? Is is possible to access the bolts that secure the plate for the mast? I'd like to redo the area between the mast step and the CB - where some wires go down into the cabin.
Thanks! Brian

[dave]

I'm not Jim, but sure it's possible, that's how I got the mast step plate off.

[calhoon205]

Hello Dave - how is that you got the plate off? It looks like there's a "shell" that surrounds the actual trunk... Did you have to cut into that to see the nuts for the mast plate or is there access somewhere behind the carpet?
Thanks a lot - Brian

[dave]

It's been so long ago that I removed everything that I don't remember. Do you have the carpet peeled off of the roof yet? Everything should be pretty obvious.

Sorry that I don't remember, but then again, I don't remember it being anything out of the ordinary either. My boat is covered with a black visqueen tent that's taped down or I'd go look. Checked RIGHT NEXT to the edge where the vertical trunk sides meet the cabin top. That's also where the Nylock nuts for the board raising bracket are, but you may not see them, you have to feel for them and then maybe cut some liner away to get to them.

[sj24]

There is a stainless steel plate glassed in underneath the mast step that is drilled and tapped that the mast step bolts thread into. No nuts to fall inside!

Kevin

[dave]

It was a long night last night.............................................. OF COURSE THE BOLTS ARE THREADED INTO THE PLATE, that's what caused the corrosion problems because it's not SS, it aluminum!!!!

Sorry for being so forgetful on something so simple! As I was talking about earlier and have spoken of MANY times in threads on repairing the area, the SS bolts going into the aluminum plate is an accident looking for a place to happen. No resin made sticks well OVER TIME to SS or aluminum. When combined with a compressible core [plywood] under the step, the force of the mast WILL cause that area to start to compress, which breaks the seal of the caulking used on the mast step plate bolts, which results in water seeping down said bolts causing a current to initiate between the dissimilar metals, which causes the aluminum plate to turn into a sacrificial anode and corrode. The oxides that form on the plate cause expansion but it can't go downward because of the CB trunk support, so it pushes back upward and outward. This causes warping under and all around the step area and EVEN MORE seal breaking around the bolts which increases the water intrusion and the whole thing turns into a much bigger and faster rolling snowball as time goes by.

Thanks for reminding me of something that I was subconsciously hoping to forget.......................................

[calhoon205]

Thanks guys - that's some good info! Sounds like it would be a good idea to redo the bolts with some silicone once a year or so.

I would still like to do something about the area between the DB trunk and mast step - mine's a little soft... I'd also like to come up with a better way to pass the wires through the deck. Any ideas??? If I cut a hand hole in the "shell" that surrounds the DB trunk in the cabin would I be able to access that area? Anyone ever go in there???

Thanks again - Brian

[Jim Kloss]

Ambivalence is back afloat. Photo of the repair to the CB trunk is attached. I also upgraded the tackle from 3:1 to 4:1 using two Lewmar high strength face blocks mounted on opposite sides of the tang. The line dead ends to a hole on the side of the crane. Works great.

Jim Kloss
s/v Ambivalence
S2 7.9 #8

trunk.jpg (149.86 KiB) Viewed 8235 times

tackle.jpg (240.94 KiB) Viewed 8235 times

crane.jpg (240.08 KiB) Viewed 8235 times

[dave]

Nice looking glass work there Jim! I hope that ends your problems. The next one may be the skin of your daggerboard peeling away as happened to mine.

Oh well. The board was a warped, crooked POS to begin with so when I rebuilt the whole freeking outside skin I'll redo it the way that it should have been to begin with!

[calhoon205]

Looks good Jim. I had a pro look at mine and didn't find too much damage, but I'm still going to have him take care of it. As I'm sure you know, both sailing sailboats and fixing sailboats are fine hobbies, but sometimes you have to choose just one...
Brian

[dave]

As someone who has been doing the latter for 34 years for pay AND necessary hobby, I assuredly DON'T agree with that sentiment.

To each their own though.

[Jim Kloss]

Well, I'll admit that just lately I've been thinking of changing my favorite hobby from sailing to boat maintenance, but I just got back from a lovely sail to a picnic at Buck Island and the winds were fair enough to use the 155 that hasn't been out of the bag in over a year -- so I guess I'll stick with sailing.

Jim Kloss
s/v Ambivalence
S2 7.9 #8

[dave]

Jim, before you switch occupations you might try doing some rotten core rebuilding.......................... from the inside............................... in the summer. That in itself can be pretty daunting. Now make the area that you are replacing/rebuilding as large as the whole cabin doghouse, or better yet, inside the lazarette! Dude, The CIA could just forgo the "tough" interrogation techniques and instead tell their suspects that it's simple: If they want food and water, get theirs butt's into that lazarette and start grinding and cutting while upside down, in the heat, wearing a respirator, goggles, earplugs, gloves and a Tyvek suit. Oh yeah, then the fun part begins: GLASSING in the same area while wearing most of the same gear!!!!!!!!

They would be BEGGING for the water boarding!!!!!

I've done these two things MANY times and believe me when I tell you that I dread it like having the flu!

[Runaway#23]

Two years ago I decided to replace the mast step on #23. I used a battery powered circular saw and cut the fiberglass deck layers connecting the "dots" of the bolt holes. From there use a chisel to peel the glass back and a dremel or other small cutting wheel to cut the corners square. Below the top layers of glass is the root cause of most problems - wet plywood.

Once exposed, evacuate the visible plywood down to the metal plate. Let the exposed area dry out - a week or two or more is not unreasonable. Using a metal wire brush on a drill, clean up the metal plate.

Rebuilding is a bit tricky, since the depth of the step is thicker forward than aft. I used Coosa bluewater 126 - just cut a chunk of it to fit snugly in place of the plywood and cement in place with thickened west system. Screw the mast step bolts into the metal plate first to keep the metal plate threaded holes from filling with resin. PVA on the bolts helps.

Add successive layers of cloth to build up just below the gel coat layer, then finish off with resin/ gel coat. In order to get a better seal of the new stuff to old, I created a step within the exposed cutout, leaving enough room for a layer or two of cloth on top about 3/8 larger than the filled box down to the plate. As long as the entire repair does not exceed the outer dimensions of the bolt holes, the step plate will hide the entire repair once caulked in place.

Check the step plate before refitting, as it may be bowed on the bottom from mast pressure on the collapsing wood substrate. It can be straightened using a mallet and wood block underneath.

Caulk the outer edges of the plate and around all 4 bolt holes, and then caulk the underside of the bolt heads when replacing as well.

If you have questions on Coosa board, they are in GA and a friendly lot. Check various thicknesses and compression strengths. Their Bluewater 126 was the strongest synthetic plywood replacement product available 2 years ago. Perhaps they have made a better mousetrap since then.

If you don't have these problems yet, GREAT! In the off season, remove the 4 bolts and recaulk. Easier than replacing the guts of the step.