Winter Repairs, Part 1

For issues common to different models of DaySailer.
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Re: Winter Repairs, Part 1

Postby GreenLake » Sat Jan 12, 2013 4:03 pm

You can see the squarish patch on my photo as well. Looks original.
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Re: Winter Repairs, Part 1

Postby UCanoe_2 » Sun Jan 13, 2013 10:32 pm

Jay, I really cranked the CB bolts down tight, so no doubt the overtightening problem you described is what happened. New gaskets are on the list to order from D&R.

You have a good idea about putting the boat in the water to check for a leak through the suspected crack. What about instead putting water inside the boat -- not filling the whole boat, but somehow constructing a small dam around the suspect area -- and seeing if any comes out the bottom of the CB trunk? I removed and replaced the thwarts a couple years ago to repair them, but did not sail the boat with thwarts removed.

Green Lake, my gasket is not as bad as yours, but it does show some wear. 1466

Drilling and tapping the end of the CB shaft is no problem, but how do you drill the hole on the port side of the trunk in the right location? Wasn't there a thread about this once upon a time?

The shaft is now removed and the centerboard is supported fore and aft with rachet straps in preparation for dropping it. 1467
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Re: Winter Repairs, Part 1

Postby jdoorly » Mon Jan 14, 2013 1:55 am

Sure UCanoe_2, maybe try plumbers putty, but I'm thinking you should be able to get some fingers in the CB slot, once the boards free, high enough to feel/ see what it's like on the inside.
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Re: Winter Repairs, Part 1

Postby GreenLake » Mon Jan 14, 2013 4:07 am

Canoe, I fixed the image codes for you, so now I can see what you were referring to. First time round you had managed to get them right, but might have forgotten how you did it. Easy enough to do. Just as a reminder, the best way, after you load your images to your gallery is to click on the "Gallery" button right above the editor. That opens a window from which you can directly select your image.
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Re: Winter Repairs, Part 1

Postby GreenLake » Mon Jan 14, 2013 4:28 am

Canoe,

definitely time to replace that gasket. As far as your leak test is concerned, it's of course possible to do it that way - making sure that the total weight of the water is limited. But I would be rather surprised if you were to find any leaks. The CB gasket is tricky. It doesn't leak consistently so you may have checked it and found it dry, but still find water in the boat. So, my money is on that gasket as the most likely source.
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Re: Winter Repairs, Part 1

Postby jdoorly » Tue Jan 15, 2013 1:51 am

I had to re-bed my transom drain to fix a leak there and then fill the bottom gudgeon bolt holes with epoxy and re-drill and re-bed it to fix another leak. Then, of course, there's the ever popular tween the hulls dribble which is the CB uphaul leak (DS2) and the one I should fix this year.
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Re: Winter Repairs, Part 1

Postby jdoorly » Tue Jan 15, 2013 2:01 am

GREENLAKE, In comparing the two photos UCanoe2's CB 'crack' and your CB pivot bolt, and being ignorant of such DS1 things, is the pic of UCanoe2's CB a pic of his pivot except someone has glassed over the hole? How does that pivot work? is there a nut glassed in?
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Re: Winter Repairs, Part 1

Postby GreenLake » Tue Jan 15, 2013 6:40 am

My CB has been modified. The CB bolt has been drilled and tapped from the opposite side, and a corresponding hole drilled into the port side of the CB trunk. There's now a bolt that holds a second gasket and positively fixes the port side of the CB. (I think that modification is an improvement, but it requires some skill and precision). The bolt and washer are also shown in the picture.
1042
As a comment on the sad state of the gasket, there's no different between the original and the additional gasket. But as a picture of the CB trunk, what's shown is the opposite side from the CB handle, and therefore the precise location where Canoe has his "cracK". (I'm using quotes because I'm a bit skeptical whether that's a real crack or just sloppy lamination. On my photo, you can see how that area is reinforced on the CB trunk, which is also the case on his CB, so therefore original. However, it appears that these reinforcements were applied from the cockpit side of the CB trunk. That makes it comparatively likely that the "crack" is just poor lamination of the top layer. (The location is also not one where you would expect a stress crack to form naturally without extending further...but that's my speculation)

The bit of rope is attached to the piece of a bottle I use for small bailing tasks before anybody gets mystified by that. :D
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Re: Winter Repairs, Part 1

Postby jdoorly » Fri Jan 18, 2013 12:12 am

tanx, I have now achieved enlightenment!
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Re: Winter Repairs, Part 1

Postby UCanoe_2 » Thu Jan 31, 2013 10:45 pm

Boat repair time has been in short supply for a couple weeks, but here is the latest on my project.

Lowering trailer tongue with jack to raise stern of boat, and raising tongue to elevate bow.
146914701471

Boat is now supported completely clear of trailer. It is actually quite stable, and not nearly as precarious as it looks! Trailer is rolled forward and centerboard is dropped using rachet straps.
14721473

You guys were right -- there is not a crack in the centerboard trunk. Inspecting the inside from below, it looks to be in pretty good shape.

Here is the centerboard out of the boat. There is a steel rod embedded in the fiberglass which might be rebar.
14741475

The square hole in the CB is worn, allowing it to turn on the square shaft and preventing it from lowering completely. Some posts about CB repairs have mentioned a square bronze bushing in this hole, which my board does not have. It seems like a good thing to have.

Inspection of the transom revealed some rot in a section of wooden core. This will also need to be repaired.
1476
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Re: Winter Repairs, Part 1

Postby jdoorly » Fri Feb 01, 2013 2:43 am

Thanks for the update UCanoe_2, the CB trunk must be a load off your mind.

I'm not very familiar with rebar on DS's but to say I've heard of it's use in various places, but question using a material that rusts. My centerboard was pretty sorry looking when I first pulled it out. It was blunt in the front, flat sided, a short taper to 1/4" aft, the whole bottom third was split, plus, of course, many dings all around, and I wouldn't call it a foil. I fixed it with thickened epoxy but was afraid to try making it a fair foil as I thought it might get stuck in the trunk.

I've drilled holes left right, up down, and center in my DS2's transom and every one had wet plywood. I was apprehensive at first but when I thought about it I decided to leave it unless I decide to do my cockpitectomy project. As I understand it the transom may gain strength from having the stiff wood between the inner and outer fiberglass panels, but that extra strength isn't required for the transoms structural integrity. The fact that the inner and outer panels are of sufficient fiberglass layup and that the two panels are separated by some space (even wet wood) provides adequate strength and safety factor, and also don't forget that there is no backstay load on the DS transom.
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Re: Winter Repairs, Part 1

Postby GreenLake » Fri Feb 01, 2013 4:02 am

Transom - if you are thinking of leaving the transom unimproved, you could do worse than checking out the information on restoring wood on the System Three website.

Center Board - if you have the money, you can spring for a replacement, in which case I'd go for one with the correct profile to increase efficiency. However, if you are cheap, you can restore this relatively painlessly - except for the steel, which needs to be rendered rust free before you can encapsulate it again. For restoring the edges and to provide a slightly better profile, 3M High Strength Marine Filler is your friend. It's relatively quick curing, has some chopped fiberglass incorporated and gets rock hard - unlike regular fillers and fairing compounds you can safely build it up to where it projects say about 1/4" even from an edge. I've used it to fill gouges on my CB, and to provide a round entry and a more shallow V shape exit. That only gets me part way from factory shape to a real foil profile, but the improvement was noticeable nevertheless and I liked cheap.

You could, of course, build your own CB blank from wood and encase that in epoxy and glass (there are different writeups for that, and it sounds like you read many of them). I did this for my rudder, and not for the CB. The reason is that the rudder comes out of the water even when the boat is at a dock or at anchor, and more importantly it gets inspected on each launch. If there's any issue with the encapsulation or damage that might let water into the wood, you'll find that quickly on a rudder - so I opted for keeping the CB the way it was.
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Re: Winter Repairs, Part 1

Postby UCanoe_2 » Fri Feb 01, 2013 7:01 pm

Thanks, guys! After spending more than anticipated on a replacement mast and a bunch of epoxy, a new CB is definitely not in the boat budget, so repair it will be. The rebar actually is in remarkably good shape after nearly 50 years. I was thinking of coating it with one of the rust destroyer products that converts iron oxide into iron phosphate, and then covering with epoxy and glass.

I also thought I would line the square hole with stainless steel shim stock, say .030" to protect the fiberglass from wearing against the CB shaft.

The spot on the transom does not appear to be cored. It is wood with a heavy coat of paint, but without a layer of glass on the inside. I thought I would cut it out with a Dremel and replace it with new wood epoxied in place.
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Re: Winter Repairs, Part 1

Postby GreenLake » Sat Feb 02, 2013 1:59 am

Center Board Repair - in my experience the rust-converter chemicals don't seem to do much beyond a very thin surface layer. That means your success will depend on how well you can sand (first) and wirebrush (second) that rebar. Also, there are two types of the rust converter. One is almost pure acid (diluted to the proper strength) and you can tell it by the fact that it is clear. The other is mixed with some gunk that purports to turn the rust into a primed surface. You can tell it by the fact that it usually is milky.

The former, if you rinse well, will not add any layers to the surface, so with a light wire brushing you should be able to epoxy to something like bare metal. The latter can be insidious in that it can form what looks like a nice "primed" surface, but if you had too much rust in some spots, that surface could sit on the outside of the rust, and there's no way, short of sanding off the "primed" layer to find out what you have.

If you mix your epoxy well and in correct proportions and clean the surface well (soapy water) and sand it, you should be able to still get that high strength filler that I mentioned to bond to it, even though it's polyester based.

Here's an extremely schematic drawing on how you could use filler to improve on the factory foil shape of your CB.

1047

You can make the leading edge very round and try to build up the "ramp" on the leading edge side (top and bottom, not just top as in the drawing). Because I wouldn't suggest sanding into the existing glass cover, it's not possible to make as long a trailing edge as the ideal foil shape would require with this method. However, you can measure your trunk and CB and usually there's room to add .5" to .75" to the trailing edge, allowing you to draw this out to a fine point (and sand off to 1/8" or so). My technique for doing that is to fold a strip of wax paper (or stiff plastic foil) and use that around the filler so you can "massage" it into a rough shape. Once cured, you sand the final shape.

Other people place the CB w/ trailing edge down and laminate some fiberglass cloth on either side that they let hang down. They let the cloth connect at the new location of the trailing edge, which creates a hollow space. They fill that space with thickened epoxy. That technique is fine if you already need to put new glass down (like over a new wood cored CB). If you don't, I like my technique. It gets the job done in a single pass (with some sanding).

Even if you can't get the best theoretical foil shape, getting your CB as smooth / fair as possible and fairly polished will make it behave much better. This almost certainly entails several coats of fairing compound with sanding in between.

Transom - that's good news.
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Re: Winter Repairs, Part 1

Postby GreenLake » Sat Feb 02, 2013 2:02 am

A PS on the CB: if you ever want to race your DS under class rules, make sure your CB doesn't get wider from leading to trailing edge than class rules allow. The factory boards are narrower, in my experience, than required, so you should have some room to build up your trailing edge to make it a bit longer and finer exit.
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