Centerboard repair/patch advice requested

[jdbeckerle]

I have a year 2000 Mod 3 hull id CPSD4890L900.

My centerboard has a ding where it slipped down while trailering, about 1/3 way down along the leading edge. This ding goes through what appears to be a hard thin top layer (say 1/32nd inch), through some softer white filler (say another 1/16th) to a dark brown substrate. I am thinking the dark brown substrate is wood. The exposed wood is about 1 inch square, and the overall damaged area is maybe 3 inches by 2 inches.

The leading corner at the bottom of the centerboard is also worn down to the wood, roughly 6 inches by 3/8 inch. This damage is likely from scraping along the bottom in shallow water or while beaching etc.

I assume that since the core is wood, I need to fix this damage before it spends much time in the water. The boat is stored on the trailer. Please correct me if I am wrong.

What is the actual construction of the board? It appears to me to be more than just gelcoat over wood, simply because it appears to have three layers, i.e. wood, filler, top layer. But I am not an expert by any means, so I might be misinterpreting this.

What is the preferred method of repair? Gelcoat or white marine-tex epoxy putty or ???

Since it is the centerboard I don't really care that the repair be unnoticeable. I just want the centerboard to be protected from further damage.

Thanks in advance!

 

[Allatoona]

Pictures and description of the fix I did on my split centerboard:
http://www.capri14.org/forum/split-centerboard-t2022.html?t=2022

I found the inner material looks like a dense foam core, but also has some metal strips that run the length of the centerboard. The split ran partially along one of these metal strips.

I keep my boat on a trailer, so I was not very concerned about the finish, so I just used some spray paint to seal it up and make it all match.

I have since had a couple of minor chips knocked off the trailing edge of the rudder, I did a more simple version on these repairs.

It has held up very nicely and you cannot tell I have even done a repair.

-Robert
1989 Capri 14.2
1984 Catalina 22

 

[jdbeckerle]

Robert, thanks for the response. I had already seen your earlier thread. My damage is a bit different, and I still wanted a bit more info on the centerboard construction so I would know what I was looking at. Here is a picture of the damaged spot:

View attachment 932

Not knowing any better, I assumed that the dark brown substrate was wood, but that is incorrect (as most here already know). The picture also shows what appears to be a thin outer layer that is peeling away from the white filler layer. I contacted catalina yachts and their support engineer gave me the following description of the centerboard and rudder construction:

"The (centerboard and) rudder molds are two piece molds that were first sprayed with gel coat and then hand laminated with glass. The glass was then trimmed and the two halves were bolted together with glass matt at the parting seam. There is slot at the top of the molds where a two part foam is then poured into the rudder and allowed to cure. The excess foam is then cut away and the seam repaired / faired and gel coated. The darker areas look to be where the gel coat has worn down and exposed the glass, which is close to 1/4 to 3/8 of an inch thick. The lighter material looks to be fairing material used to repair the parting line."​

So the dark brown is the fiberglass substrate, and it looks to be in very good shape. And the thin layer on the outside? According to the catalina that is just a different layer of gel coat that was applied to finish up the seam (fairing as they call it I guess).

Glad to hear that my centerboard had no wood in it because I expect that means it cannot become warped due to moisture. I have had problems with wood centerboards on other boats in the past.

As for the ding repair, I am leaning toward white marine-tex rather than gel coat, because it sounds like marine-tex is easier to handle, and I can buy the quantity I need for less that a can of gel coat. If someone feels strongly that I should use gel coat, please recommend a particular brand and product, as I have read a variety of conflicting opinions about some of the products out there. I will remove any loose material in the ding area, apply the marine-tex, and then sand down until I have a smooth surface and be done with it. If I am missing something here let me know.

Can I also use a very thin layer of marine-tex to repair the worn down gel-coat on the front lower corner of the centerboard, or is this even worth fixing?

I also want to clean up the pivot area of the board, shown below:
View attachment 933
I plan to start with some fine grit wet sanding, but should I follow with a "fiberglass restoring" compound like 3M Marine "One-step" restore and wax, or just wax? Is there a preferred wax or restoring product that everyone uses? I want to be sure the centerboard moves smoothly when I am finished.

Thanks for the help!
John

 

[woodbark]

John, I have a 92 mod 2 and luckily no damage so far thanks to sailing in deep waters. However thanks to forums we are able to learn from the experience of others

Looking at your damage and putting myself in your shoes, I would be inclined to use a thickened Epoxy and since weight is not an issue a cotton or talcum type of thickener would be a lot stronger, epoxy of course for it's superior adhesive qualities.

The thickened epoxy will still have a tendency to sag before it sets so building up in stages would probably be the best way to avoid this, unless it's possible to use tape as a temp mould.
That's my 2cts for what it's worth

 

[jdbeckerle]

Hi George, thanks for your response.

Are you familiar with Marine-Tex?

From what I have read, it is a epoxy-putty, and goes on as a thick paste. It says it can be applied to vertical surfaces, so I guess that it doesn't sag (much).

If you or anyone has experience on whether it would be appropriate for this job please chime in.

John

 

[woodbark]

John, thanks for mentioning this product, I just had a quick look at the Marine Tex web site and I am totally impressed.

It is obviously the epoxy version of polyester body filler but with the superior adhesion and integrity of epoxy. I have no doubts it will do the job splendidly. I plan to pick up a kit first chance I get.