Hull flexing

Topics primarily or specifically about the DS2. Many topics are of general interest, so please use forum sections on Rigging, Sails, etc. where appropriate.

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Hull flexing

Postby nickc » Tue Jan 03, 2023 9:16 pm

How much flex is the hill supposed to have aft of the CB? I am new to the DS, my boat is definitely a project. The hull is warped aft of the CB where it was sitting on the trailer bunks out in the weather. I can’t tell if the hull on my boat is soft and damaged or of this part of the hull normally has some give to it.
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Re: Hull flexing

Postby tomodda » Tue Jan 03, 2023 9:50 pm

It's got some give, especially in a DS1. Put her in the water then see. Or feel, for the DS2 with the false floor. Get in the water and run your hand along the hull. You should be OK. Build longer and wider trailer bunks when you get the chance.
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Re: Hull flexing

Postby GreenLake » Wed Jan 04, 2023 12:18 am

These boats are infinitely repairable, but the DSII cockpit molding may make that trickier than it would be on a DS1.

Get the boat off the trailer and see whether the deformation has become permanent. If that's a yes, you'd need to stiffen that panel from the inside.

With a couple of inspection ports added to the footwell, you may be able to reach the inside of the hull to where you could place a stringer. You may need to use external supports and perhaps screws to pull the hull flat before placing the stringer.

What's feasible would depend on the state you find the laminate in and what the access looks like after you've opened some inspection ports. A stringer can be entirely hollow, the strength comes partially from the glass that's used to laminate it in. An approach where you lay down short hollow sections and then glass over the whole might be as strong as using a foam core. A wood core isn't recommended not only for weight but also because of rot.

If the hull laminate is damaged (soft), you would need to add strength outside and inside. In a panel like that, the strength comes mostly from the skin, and not from the interior of the panel. You may be able to reinforce the inside with a stringer and the tabbing for it would also add to the skin thickness. On the outside, you would want to be flush with the existing hull, which might require grinding a bit of material so you can place some fiberglass, but retaining enough of the hull to act as support.

Without having a look at it, and without knowing how radical you are willing to be in your repair, it's not possible to boil this to a simple recommendation. Hopefully, this gives you some ideas what to look for and we can refine this in further discussions.
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Re: Hull flexing

Postby nickc » Wed Jan 04, 2023 1:23 am

Much appreciated greenlake. The boat is currently upside down inside my moms garage. I am going troy try and make a google photo album to share here. The photos are too large for the forum limit and compressing them makes it hard to tell what is really going on.
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Re: Hull flexing

Postby GreenLake » Wed Jan 04, 2023 4:45 am

The best thing for a collection of large photos is to put them on a picture hosting site that allows direct links and then use the
Code: Select all
 [img][/img]

code to link them into the post if you want to discuss a particular one. If you just link the folder, it may be harder to reference things.

However, I like to note that there's a difference between cropping and compression. You can try to make the image very small in pixel dimension. That will reduce the file size. However, simply selecting a compression to "medium" quality (or 65%) will greatly reduce the file size without making the image smaller. The compression will loose some fidelity but unless you are trying to make a photo book or enlarge the image a lot you would probably not even notice.

That said, cameras have many more pixels than can be displayed on a typical screen. And the forum does not have the ability to scale images on the fly like more modern social media software. I found that scaling or cropping images to where the longest edge is 1200 pixels leave you with something that has a lot of detail, and if compressed to medium quality will have files of a nice size that doesn't chew up our storage limits, but allows others to see enough detail.

I only edit the forum on my desktop (Windows) and there's a nice app "Resize my Photos" that gives me full control. Alternatively, I found that emailing photos from the File Explorer will perform the same reduction. It's an extra step to save the processed files back to a file folder so they can be used as attachments in the forum, but it's a way around when you don't have an app.

Of course, if you have photo editing software, even the (almost free) versions like Affinity Photo have ways to "export" Photos that support setting pixel size and compression ratios. I've used that method for many images I shared here, because it also allows me to crop out unwanted parts of the image in the same process.
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Re: Hull flexing

Postby nickc » Wed Jan 04, 2023 1:48 pm

I put the photos, and videos, into a google folder and I can share the link to the folder here and anyone can view them. Here is the link. https://photos.app.goo.gl/nrBKw3ufNUF679pi6
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Re: Hull flexing

Postby nickc » Wed Jan 04, 2023 1:51 pm

I’m 19 haha so I am doing all of this from my cell phone. When I compress the file size on my iphone it makes the images very grainy because the iphone camera is pretty good. I dabble in photography so I have my phone set to save images at .raw files so the files are huge
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Re: Hull flexing

Postby GreenLake » Thu Jan 05, 2023 4:49 am

About the hull flex.

Watching pictures and videos these things stand out
  1. The trailer bunks are too narrow
  2. There's no support on the center line
  3. The straps may make things worse if too tight
  4. The flex, while not good, does not strike me as extreme
  5. There may be some permanent deformation (hull is slightly hollow, instead of flat)

What we are missing is a picture that shows the hull with a dowel laid across it, so we can judge the degree of permanent deformation. Similar to the picture of the hull from behind on the trailer, but this time without weight and with some straight edge as reference.

The videos make it look like the hull is flexing, but with some spring in it, and not simply soft. That's at least not in the utterly, terribly bad category. Something that would make the boat less competitive in a race, but fine to take out sailing and learning.

Given what you tell us about your age, the guess is that this is your first boat (or first one of that size). I would put my energy into making it sailable so you can take it on the water and see what it's like and how much you like this boat. When sails and rigging are sorted, you can revisit this issue and figure out whether you can work around the access issues caused by the DSII's cockpit molding to add a bit off stiffening to these panels (stringers).

However, I would not put this boat back on that trailer; not without widening the bunks significantly. If there's no centerline support, even 2ft wide bunks aren't too wide. If you can provide support on the centerline, you can dial that in so that it takes over a significant fraction of the weight and you can replace any big loop straps by short straps (one to each side). Shorter straps can ensure your boat doesn't twist on the trailer with much less strap tension than for a loop (which allows the boat more freedom to shift and rotate and which you will therefore be tempted to really crank down on).

Anyway. Back to you.
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Re: Hull flexing

Postby nickc » Thu Jan 05, 2023 8:11 am

I appreciate you assistance greenlake! I will go out and get a picture with a straight edge on it today. You are correct, this is my first sailboat. I took a class on a Sunfish at a boy scout camp up in michigan a few years ago and liked it. This DSII came available from a family friend for 300$ so i kinda impulsively bought it lol. I don’t plan on racing her, I just want to make sure she’s safe and functional for me to enjoy. I’m more interested in leisurely daysailer and maybe some gunkholing/camping with her.

I agree 1000% regarding the trailer and strap set up. I just strapped it like that in order to get her home because that’s all i had in the truck that would work. Now that the boat is off the trailer I am planning on borrowing a sand blaster and blasting the trailer. once it is down to clean metal with the rust knocked off I am going to come up with a way to weld some center support beams on the trailer and mount some keel rollers as well as enlarging the bunks.
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Re: Hull flexing

Postby GreenLake » Thu Jan 05, 2023 3:41 pm

Nick, your planned trailer upgrade sounds good - make sure the bunks extend far enough aft and that your trailer is long enough so that the CG of the boat is forward of the axle for the proper tongue weight. But that may be stuff you already know. Just like the need to repack your bearings and/or fit bearing buddies.

For your stated goals, I would move any hull-related work to the end of the priority list; at some point, you may decide to update the appearance beyond cleaning. But, as before, the best time to do that is after you've sailed the boat and know that you want to keep it.

On a DSII, a common issue of concern is the operation of the centerboard. Lot's of forum bytes have been expended on that, but you should be able to find good discussions of the various issues and proposed fixes. I would definitely encourage you to drop the CB to have a look and also check the status of up and downhaul lines.

Have you had a look at the rigging yet? Or the sails?

If you are relatively new to sailing, you might like to check out the "Basic Concepts and Techniques" thread.
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Re: Hull flexing

Postby nickc » Thu Jan 05, 2023 5:41 pm

Yup, I know a little about trailer stuff. I’ve grown up hauling stuff, i’m just clueless when it comes to sailing and major glass work lol. I don’t plan to do a whole lot of in depth work to the hill before getting her in the water. I’m going to pressure wash it to knock the grime off and repair the bad spots in the gelcoat and call it good for now. I may dig into the repairing the hull deformation next winter if it really bothers me and I will most likely take an orbital sander to the whole boat next winter and paint it with total boat or easypoxy. I appreciate the advice, I’m sure i’ll be asking many more questions here in the coming months!
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Re: Hull flexing

Postby nickc » Thu Jan 05, 2023 5:46 pm

The rigging is a total loss, I knew that when I bought it, but for 300$ with the trailer I thought it was still a good deal. I will be ordering the stays, halyards, and sheets from D&R. I will most likely make my own spreaders, I think I recall seeing the specs in the forum somewhere before, I have a drill press, chop saw, etc so making them should be a big deal. The boat is missing the main sheet block assembly, Rudy has those available online so I will be replacing that as well.

I have the sails but honestly haven’t pulled them out of the bag yet. The lady told me they were good when she put them away and she stored the bag in a cedar chest in her basement so I believe her. I will get them out soon. It’s just been so cold the past week or two I haven’t wanted to mess with laying them out in the yard.
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Re: Hull flexing

Postby GreenLake » Thu Jan 05, 2023 9:37 pm

Sails: they have a limited lifetime compared to the boat, and with our old boats, replacements are more expensive than the boat.

Sails may fail mechanically to the point that seams rip out or there are tears. More commonly, you will find that sails have lost their shape to be viable. Now, that in itself is a sliding scale. Committed racers will frequently buy new sails, as competitiveness is measured in degrees away from perfection.

For casual use, a sail doesn't need to be perfect, but if you can't get it to hold at least a reasonable shape, you might still get the boat to move, but the experience will not be enjoyable (especially not once you learn a bit more about how things are supposed to work).

Unless there's damage, you may well find those sails good enough for at least a test sail; if lucky, they have enough life left in them that you can use and enjoy them while you solve all the other issues.

That said, what went into the bag should be pretty much want comes out of it. Modern Dacron sails don't really deteriorate in storage, but people who put those sails in storage may not have had a good idea of their actual state. So, you might be pleasantly or unpleasantly surprised when you finally try to set them.
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Re: Hull flexing

Postby GreenLake » Thu Jan 05, 2023 9:43 pm

Rigging: if your boat lacks key parts of the running rigging, you should read up on the various ways of rigging a DS. There isn't a one-size fits all and many owners have their preferences. Because you are forced to replace things, the advice of keeping what you have does not apply and whatever you purchase now will effectively make a decision one way or the other.

Sounds like you will need to make a decision whether to go for center-boom sheeting or the kind of traveler system. While you won't have the experience to really know how these relate to your (future) style of sailing, you should probably spend a bit of time reading past posts here to get some ideas.

When it comes to changing hardware that is still in place or adding rigging elements (for example a vang or barber haulers) you can take that slow and not commit until you've had her on the water.
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Re: Hull flexing

Postby nickc » Fri Jan 06, 2023 11:13 am

I know the sails are a roll of the dice. That’s another reason i haven’t mustered up the courage to open the bag yet haha.
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