DS1 centerboard drooping

[tc53]

I too am coming late to this thread as I work on my second project (project 1 is refinishing seats, thwarts, and coaming) for this winter: getting my CB to come and stay all the way up. Right now (and since I bought the boat several years ago), in its full "up" position, the board hangs down enough so that about 8" of the aft end (bottom) of the centerboard is completely visible (front and back edges) hanging out of the trunk. This can make it difficult seating the boat properly on the trailer. I know the previous owner dropped the board out to replace the big rubber gasket by the handle shortly before selling me the boat. Is it possible this problem was caused by something not being done correctly in the reassembly?

Greenlake, any photos of the assembly you've been able to recover would be very helpful.

Thanks!

[GreenLake]

I split this off into a new topic.

A "sagging" CB for the DS1 usually means that the square hole into which the handle fits is no longer square. It can be squared again by inserting a shim bent from a suitable metal. Trying to achieve the same effect with fiberglass won't work.

[tc53]

Following up on my last post, I've now begun work on my sagging CB. I took the handle off today and removed the CB. There is quite a bit of fore-aft play in the handle, and after inspecting the handle "axle" and the square hole it appears both have worn to create this play. Greenlake, I want to try your shim suggestion, but I am not sure how to go about this. Do you mean to try inserting a shim with the CB in the trunk or with both handle and board out? In either case, is there some way of attaching such a shim to the inside wall of the hole (or to the handle axle)? It seems I would have to do that in order to make it work. Would a thin stainless strap, bent appropriately, be an appropriate shim material?

I've included several photos of the CB and handle. After taking it out, the orientation of the board struck me as strange. In the first picture, I have positioned the CB on a workbench as it would be in the fully up position in the CB trunk. This position has the angled, straight section (second photo) at the lower, leading edge of the board. Is this correct? I figure it must be because the board was clearly made that way. Assuming this is correct, it seems strange that this angled section would have a flat edge (about 3/8" wide) rather than be fared in some way. Can someone confirm that this is how it should be? Are there class rules about reshaping this section? While I have the board out I will be repairing a few dings anyway.

Finally, while I am working on this I would also like to fix the side-to-side play in the board/trunk once I reinstall. Can someone offer suggestions for this or point in toward another forum string that offers such suggestions?

DS Centerboard.jpg (118.76 KiB) Viewed 11509 times

DS Centerboard 2.jpg (111.73 KiB) Viewed 11509 times

DS CB Handle.jpg (109.56 KiB) Viewed 11509 times

[Alan]

http://www.drmarine.com/proddetail.asp?prod=DS105

Here's the photo of a new DS1 centerboard from the D&R Marine website. The shape is similar to your board's, but the angled section is curved, while yours looks straight.

Is it possible the angled section on your board got its flat edge from scraping on the trailer? That's most likely what happened to the leading edge of the board on my DSII.

[tc53]

Thanks, Alan, for the link to the new CB photo. The flat edge on mine looks like a finished edge, not something that might have been caused by scraping on the trailer. There is still some paint on it. In any case, I will probably reshape it to look more like the new CB.

As for correcting, or "re-squaring" the slot for the lever, all I can think of is shaping an appropriately sized (using the lever arm) square metal insert for the slot (I have some sheet brass that might work for this), then using epoxy to secure it into the slot, filling in between it and the wear and tear "expanded" portions the slot. Does that sound like it could work?

[tc53]

Greenlake, though I now cannot seem to find the post, I think you suggested gluing some sort of thin plastic sheets to the upper potion of the CB (the part that remains in the trunk regardless of board posItion) as a way of fixing the side-to-side play. After removing the CB and measuing carefully, I think I have close to 1/4" of extra space. Do you have any suggestions for finding plastic sheets of approximately 1/8" thickness? Thanks.

[GreenLake]

Angled section: there is no way this is intentional, and if it looks painted,then it's been touched up. The original CB just has gelcoat.

I seem to recall writing a longer post on this subject, but recently have lost a few posts after hitting submit (that may have been one of them).

Anyway, plastic shims to reduce wobble. I usually use the material from plastic cutting boards for this type of application, as it's perfect as far as the type of plastic is concerned.

That would be thicker than what you want, and grinding big flat sections of it to a particular thickness doesn't strike me as a fun activity (Narrow strips should be amenable to filing or sanding with coarse paper though. And all it would take are a few narrow strips)

Not something I tried, but a power planer might work where a sander is likely to produce a mess. A better bet for flat sections might be to look in various stores for items you can repurpose.

Biggest issue would be how you would attach the strips. Glue wouldn't work, that stuff is like wax. If it was a bit thicker, drilling and countersinking for screws might work, as long as they are well below surface. Scooping out a channel from the CB so you can use a bit of 1/4 stock (with 1/8" standing proud) might work.

Just ideas to get you thinking.

[Alan]

You can get plastic sheet of many different kinds,cut to size, here:

http://www.tapplastics.com/

I've bought a fair amount of stuff from them, both online and in their local store.

[GreenLake]

Checking Alan's link: Two 4"x4" "sample" sheets would set you back $4.00, plus shipping. That should be more than you need. Leaves you with finding a way to attach these.

[tc53]

Thanks, Alan and Greenlake, for the advice. The 4" X 4" samples I am finding are 1/4" think polycarbonate. Is that what you were referring to, Greenlake? Is polycarbonate what plastic cutting boards are made of? If I use either, I think I would try to scoop out a groove, perhaps two, on each side of the top of the CB, then attach somehow (countersunk screws, perhaps, though 1/4" does not leave a lot of room for that).

Alternately, I wonder if building up each side of the top of the CB (the section still in the trunk with the board all the way down) with several layers of fiberglass might work?

[GreenLake]

No, HDPE.

Polyethylene is essentially "wax" except with longer-chain molecules, so the melting point is higher, and it's a tad tougher. It does nearly as well in places where you need some "self-lubricating", if sacrificial, pieces.

Polycarbonates are something else altogther. Brittle and transparent. Great for beakers, glasses and windows.

And the samples I saw on the site were 4" x 4" at 1/8"

But, if you are game to create a groove, the just get 1/4" cutting board at your local store. That costs as much, no shipping or waiting, and HDPE is easily cut to size by hacksaw or coping saw, and shaped with a file.

[tc53]

Thanks, Greenlake. I think the cutting board is definitely the way to go if I am willing to create a groove. I have a good router, so I think I could create a groove with a precise depth. As for fastening, I wonder, if I put either side's grooves directly opposite each other, if it might be better to through bolt the HDPE inserts, with relatively small sized bolts countersunk for both head and nut. Might this be stronger than screws? If I go this route, I am thinking of perhaps two, curved (to better work with the raising and lowering motion) inserts per side, of about 8" in length, bolted at the ends and in the middle. One a few inches above the handle/axle slot and another closer to the top of the CB. What do you think?

Any thoughts on the fiberglass build-up path?

Finally, I am still working on a shim method of creating a tighter fit between the CB handle "axle" and the slot in the board. The corners of that slot had expanded outward slightly and rounded, which is creating the slop and consequent sag in the board. I have some sheet brass and aluminum (I think) both about 1/32" (or less) in thickness. I tried cutting a strip of the latter and shaping it into a square using the handle axle as a mold. Then I inserted this into the board slot. This improved things but still left too much play. Am I on the right track, do you think? If I use a longer strip of the metal, I may be able to create an even tighter fit. If so, would it make sense to epoxy that into the slot, trying to "back fill" the sloppy corners. Or perhaps fill the corners first, then file them to 90 degrees once hardened?

Thanks.

[GreenLake]

There were some older threads that included detailed discussion on CB repairs/fixes.

Severely cracked leading edge of centerboard DSII and Winter Repairs, Part 1 come to mind.

I would find some material (even plywood) that's easily shaped and rough shape the missing CB tip. Then glue it to the edge of the cut off. With epoxy, even a blunt glue joint should be fine. Then seal any porous material with epoxy on all sides, and apply a layer of glass fabric (with epoxy). Finally, use an epoxy based fairing compound (like QuickFair) or mix your own and give the whole board a fair shape.

While you are at it, you can slightly improve the shape of your board by making the nose round, moving the thickest section close to 1/3 from the front, and attempt to get as long and straight a tail section as you can manage w/o sanding into the original board.

There's usually a bit of room to make the board a bit wider (just half an inch or so) and still remain class legal (and fit into the trunk). You can use that to get a better trailing edge. My technique for that is described in one of the older threads. All this is fine if you like playing around, but don't expect to get the "best" results.

For those, you'd need to build a board from scratch. You can find instructions for that online, I'm sure. The main difference is that you are creating a new core, which from the start can have a better foil shape. However much work that takes, it is less than the work you spend on fairing, sanding, painting whichever core you end up using. That's why many people would advise you to do the full rebuild -- but I can understand if you feel safer with a repair/modification of what you already have.