Need a rudder or plans/dimensions for a Daysailer 3 rudder

Regarding the DS3 only. Note that the DS3 is not a class-legal Day Sailer.

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Re: Need a rudder or plans/dimensions for a Daysailer 3 rudd

Postby Nanga7 » Fri Mar 18, 2016 8:19 am

OK gentlemen
I made the plunge!
I had 2 3/16" aluminum plates made for the rudder head and bought a beautiful piece of Honduran Mahogany. Going to order pintles and other hardware soon. Couple questions: Fiberglass the rudder or just finish it with coating (and what?). What setup do you recommend for the rudder pivot? I have seen 5/8" bolt with nylon or brass bushing. Would you recommend a large washer between the rudder and rudder head or would that decrease surface contact area between the rudder and the rudder head?
Thank you in advance. I am excited to get this thing going and see how she sails!
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Re: Need a rudder or plans/dimensions for a Daysailer 3 rudd

Postby TIM WEBB » Fri Mar 18, 2016 9:59 am

I used 1" diameter nylon washers for the pivot bolt on both sides of the plate on each side. Seems to work just fine.
Tim Webb
1979 DS2 10099 The Red Witch
(I used to be Her "staff", in the way dogs have owners and cats have staff, but alas no longer ... <pout>)
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Re: Need a rudder or plans/dimensions for a Daysailer 3 rudd

Postby GreenLake » Fri Mar 18, 2016 11:39 am

If you use a downhaul, then you are not relying on friction to keep the blade down. The question then becomes whether adding distance in the center (with a washer) will allow play between blade and the plates from the rudder head. Apparently that's a non-issue in practice.

On my DS, I do rely on friction. I learned the hard way that waxing the part of the blade that forms the joint is a no-no. And that the bolt needs to be more than hand-tight. With the setup I have now, boat speeds above 6 knots will start to push the blade out of the vertical. However, conditions for reaching speeds above that, or planing the boat are fairly rare. Because this limits the forces from drag, I can get away with not using a downhaul.

Otherwise, I would have installed one long ago, with one of those v-cleats that auto-release.
~ green ~ lake ~ ~
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Re: Need a rudder or plans/dimensions for a Daysailer 3 rudd

Postby GreenLake » Fri Mar 18, 2016 12:07 pm

Nanga7 wrote:Couple questions: Fiberglass the rudder or just finish it with coating (and what?).


The downside of coating your rudder is that any covering will add thickness which complicates getting a perfect foil shape. I think that downside is somewhat theoretical. The stock rudder is a hydrodynamic disaster, so about anything will be better (and noticeably so).

If you seal the wood, you will need to be sure that you can keep the skin intact, otherwise you'll have a waterlogged board under the covering. One particular trick is to cut off the forward part of the tip, at an angle, and glue it back on with epoxy. That way, if you hit anything with that part of the rudder, and crack the skin, the waterlogged bit will be limited to that forward tip.

A single layer of glass cloth will increase the resistance against abrasions, etc. and reduce the chance that any contact lets water get through to the wood. My take would be that using a glass layer is a logical consequence of sealing the wood with epoxy. If you are thorough in wetting the cloth with resin, the glass layer will be invisible, if not, just add a thin layer of epoxy to fill in any weave.

Epoxy needs to be protected from UV, so it can't be the outermost covering. You need to varnish or pain it.

Varnish will leave the wood visible and pretty (you will not see the glass) but you cannot use anything to fair the foil. Whatever shape you get after applying the glass is it. (Make sure the varnish has good UV inhibition). (I would opt for a polyurethane, those make pretty hard surfaces - if you seal the wood, the varnish does not need to be as elastic, as there will be no expansion due to moisture cycling).

If you use paint, you can add a thin layer of epoxy-based fairing compound (mix your own, or get pre-mixed, like QuickFair). That allows you to correct any defects in the foil shape. Paint is also a good UV cover, and any damage should be noticeable. (I chose paint. I needed to fair my rudder and the wood I used, plywood, wasn't that pretty anyway - finally, I'm happy with having a white rudder on a white hull).

If you elect not to seal the wood, your basic choice is between oiling or using an oil-based stain or a coating (varnish). I've made poor experience with applying PU varnishes on bare wood - the moisture cycling will quickly crack them. I haven't tried oil-based treatments. I don't know how tolerant they are of the (short term) immersion that you would have with a rudder. Their theoretical advantage is that they are easy to re-apply and that by not forming a layer, they are less sensitive to abrasion (e.g. on the edges of coamings etc), and if damaged more easily repaired.
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Re: Need a rudder or plans/dimensions for a Daysailer 3 rudd

Postby TIM WEBB » Fri Mar 18, 2016 10:16 pm

With my "new" rudder head design, the downhaul is necessary in order to keep the blade at the bottom of the pivot bolt slot:

2080

If you look closely at this pic (it's a clicky), there is a bolt just underneath the bottom pintle. There is a small land, or flat area, on the blade forward of the pivot bolt. When the blade is all the way down and forward, with the DH engaged, that land is pulled up against that bolt (actually the spacer on the bolt between the plates), and the blade cannot "hyperextend" forward, rise up in the slot, or pivot backwards.

BTW, the uphaul is not really necessary, because when the blade is rotated up and back, friction holds it there, due to the 3 spacers in the middle of the head being 1/8" shorter than the ones at the bottom. There are a few more pics in my gallery if anyone is interested.
Tim Webb
1979 DS2 10099 The Red Witch
(I used to be Her "staff", in the way dogs have owners and cats have staff, but alas no longer ... <pout>)
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Re: Need a rudder or plans/dimensions for a Daysailer 3 rudd

Postby GreenLake » Fri Mar 18, 2016 11:08 pm

You mean, an uphaul is not necessary to hold the rudder blade up. But I presume you would rather haul it up than have it scrape on the bottom as you beach?

The "flat" landing spot looks like the same as shown in my drawing.

936
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Re: Need a rudder or plans/dimensions for a Daysailer 3 rudd

Postby jeadstx » Sat Mar 19, 2016 3:31 am

I use both uphaul and downhaul lines. As Tim says, the uphaul is not neccesarily needed. The blade will kick up in shallows. For me, I use the uphaul to raise the blade and hold it out of the water, higher than the standard rudder head allows. Some of the shallows that Tim and I beach on in our respective areas need the blade to get out of the water without needing to remove the whole rudder assembly. Both of our rudders use the auto release cleat for the downhaul.

John
1976 Day Sailer II, #8075 - Completed the 2011, 2012, and 2013 Texas 200
1952 Beetle Boat Swan Catboat
Early Rhodes 19
1973 Mariner 2+2, #2607 - Completed 2014, 2015 and 2016 Texas 200
1969 Day Sailer I, #3229
Fleet 135; Canyon Lake, Texas
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Re: Need a rudder or plans/dimensions for a Daysailer 3 rudd

Postby TIM WEBB » Sat Mar 19, 2016 9:07 pm

Yes, what I really mean is that the UH is more of a luxury than a necessity, in that it is useful to get the blade up, but not needed to keep it up. Whether I raise it before beaching has to do with the bottom condition: soft sand, no prob, I'll pop the DH and let it kick itself up, but if it's oyster shells or anything like that, I'll pull it up well before reaching shore. John, you smellin' what I'm steppin' in? <grin>

GL, your drawing clearly shows the land on the blade.

While sailing, I'll do the same with the rudder as I do with the CB: keep both DH and UH tight. Seems to reduce a lot of "noise" from the foils ...
Tim Webb
1979 DS2 10099 The Red Witch
(I used to be Her "staff", in the way dogs have owners and cats have staff, but alas no longer ... <pout>)
TIM WEBB
 
Posts: 1208
Joined: Wed May 18, 2005 10:28 pm
Location: RIVERSIDE, CA

Re: Need a rudder or plans/dimensions for a Daysailer 3 rudd

Postby jeadstx » Sun Mar 20, 2016 2:43 am

Agree with you Tim, soft sand or in my case soft mud aren't really a problem. Oyster reefs or oyster shell beaches can damage a blade however. On the Texas coast we have plenty of skinny water with oyster reefs.

John
1976 Day Sailer II, #8075 - Completed the 2011, 2012, and 2013 Texas 200
1952 Beetle Boat Swan Catboat
Early Rhodes 19
1973 Mariner 2+2, #2607 - Completed 2014, 2015 and 2016 Texas 200
1969 Day Sailer I, #3229
Fleet 135; Canyon Lake, Texas
jeadstx
 
Posts: 1216
Joined: Tue Jul 08, 2008 11:10 am
Location: Dripping Springs, Tx

Re: Need a rudder or plans/dimensions for a Daysailer 3 rudd

Postby Nanga7 » Sun Mar 20, 2016 12:24 pm

So far things are coming along beautifully. The plates are cut out and drilled. The blade is shaped according to my research. The blade is 9 1/4" wide and 35" long past the bottom of the boat. (Does this seem OK?). I still have to shape the foil. I am waiting on the pintles and hardware. I will be putting an uphaul and downhaul line with jam cleats. Tim I was sure to observe the stops that you put in yours to limit down position and up position. Thank you guys for all your valuable advice. It gave me the confidence to undertake this project. I'll post a pic when I finish it...
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