rudder discussions

[ebb]

Andrew,
How 'bout that! Rudder looking good - those open-end wrenches should add a whole lota strength to the layup!


BIG LITTLE WORK.
Dremel has no sawblade arbor cutters except itty bitty teeny weeny ones. For a long time I've used a #542 wheel to cut and work frp. Especially tight curves. But Dremel in their wisdom decided to obsolete them (they were a 1" scalloped metal wheel with carbide grit on both sides - which wore out too quick for me) - now there is #543 which is similar but has the grit only on the bottom of the wheel. Now it can't do any slice cutting. But you can sculpt with the grit on the bottom. $16 an arbored bit.

CUT FRP WITH DREMEL #426!
I was forced to try the 1 1/4" #426 reinforced (carborundum?) cut-off wheels. They come 5 to a pack for around $10, you assemble one onto an arbor and cut fiberglass reinforced plastic to your heart's content. They are thinner than the grit blade, cut deeper, cut quickly, throw little glass dust. Recently had to cut about 20' of 1/8" thick frp. That was cutting down into the surface and following a line. Don't think I changed at all the diameter of the one wheel I used. Very

The only problem was lugging the tool constantly.

[Westgate]

I bought my first dremel tool in 1991 and I still use the same one. Sometimes have to smack it to get it to start (brushes are prob very worn down!). I bought their flex head attachment which makes working in some situations easier. Gotta remember to keep the tool out of the dirt.

It is hard to lay glass in 20 knots of wind hence the place holder wrenches!!

[Westgate]

Well the rudder is finally finished. Four layers FRP all round. I think I used 6 OZ cloth but I don't really know fibreglass?? Came out pretty good. Doesn't look so in these pictures but the surface is like glass. Had some real problems with bubbles forming under the matt in the first few layers. Worked like crazy to get them out but they just kept forming. This wasn't a problem in the last two layers. Funny struggling with this made me completely understand the principle of vaccum bagging even though before I really hadn't a clue what is was all about!! I guess the rudder wasn't fully sealed even though I had covered it with two coats of resin. Just needs some bottom paint and we'll hang her back up. Naturally the yard moved my boat last week so that means I'll have to dig another bloody trench! Maybe I'll take shovel this time!!

Anyway here are a few pics. The close ups show the areas top and bottom that I cut out and filled with thickened prior to glassing. You can also see some of those bubbles. Oh I will also need to cut in the new grudgeon slot.

Andrew

[bill@ariel231]

Andrew.

it looks good, hope to see it installed soon.

[carl291]

On #259 which I recently purchased, the rudder was already removed and laying in the yard. It had been sheathed in fiberglass, it has the 2 piece shaft, the top shaft was hollow thin walled stainless steel, bent and shaped to clear a prop. The bottom shaft was bronze that had 4 ground flat areas with 3/8 stainless wood screws holding the shaft to the rudder. I had second thoughts about even taking it because it appeared to be destined for the trash heap. Today after reading this thread I went out and took a grinder to the fiberglass to see what lay beneath, Well to my surprise there is a new oak rudder attached to that shaft. I ground down one side and found the stainless shaft was held on to the rudder by 2 sheet rock screws, also, it is a 2 plank design and the planks are held together by 2 per side fiberglass 2.5wide x4.5 long x1/4 thick straps which are countersunk and screwed to the rudder. When feathering the edge to remove the coating on the opposite side I found the fiberglass didn't stick to the wood. I was able to slide a gasket scraper under the glass and remove the entire side with no grinding at all. There is also no bevel for the lower shaft, it is cut back flat for the shaft to clear the hull.
My questions are : Should I cut the leading edge back a couple of inches and replace with new wood to allow for a bevel for mounting a new 1 piece shaft? Why didn't the glass stick to the wood? It doesn't appear that this rudder was ever used, which is very very fortunate for the boat owner judging from what I found as a repair. Should this rudder be sheathed in fiberglass when I finish with repairs? Thanks

[ebb]

Hello carl291'
bill231 has to lead you out of this one!

The rudder you describe sounds like a nightmare to me. It sounds like everything wrong that could be wrong was done to it. Really. It even sounds like polyester was used instead of epoxy. The s.s. tube is insane, oak should never be sheathed with glass, and so forth. Perhaps Bill will help you find a way out.
But others on this Board have talked of their experiences, and some have posted pictures.

Photos will help if you can post some. It is hard to 'see' the rudder even as you describe it. It sounds to me like you should build a new rudder. The one you got won't fly!

What is your experience with fiberglass and two part plastic? Many people here have built and/or rebuilt rudders for their Ariels. Pick a style you might like to do and start from there. Do you need a rudder with an aperture? Do you feel OK with a plywood rudder? Do you want an traditional rudder of bronze and mahogany? How about a fiberglass and foam one? etc.etc.

[bill@ariel231]

Carl

I agree with Ebb.. we'll need to pictures for consultation. From the description of the materials it sounds like you will be better off starting with a new rudder built to the drawings in moderator Bill's book. Plank, Plywood or foam could all be built to those dimensions.

good luck
bill@ariel231

[carl291]

Ebb & Bill ,
Thanks for the reply, I tried to load pictures today but I'm on dial up and after an hour of trying gave up.
I think you both confirm my feelings on simply starting over from scratch, which is what I thought when I first viewed the rudder. It's a pity someone worked a nice piece of oak into firewood.
The only work I've done with fiberglass and resin is with race car body parts, mounting and bonding fiberglass body panels to steel frames and such.
The plywood sheathed rudder seems a good alternative, I'll have to revisit that post.
Ironically I also just bought a Pearson Electra that had been in covered storage and not used in 18 years, It came with 3 rudders, the original mahogany, a plywood sheathed and a composet. All of which are good , go figure,

[ebb]

Starting on pg11 of this thread, this method uses plywood to build the rudder.
It would be most useful for a rudder with an aperture, and relatively simple and elegant way for a single piece straight shaft

It uses the same 1" silicon bronze rod for the shaft and smaller available bronze rod drilled through - or tapped into the shaft could be done without welding.`
I believe the plywood could be sheathed or wrapped in glass or just sealed and epoxied if you want the traditional/restored look of plank married to the shaft.
Without thinking twice, I would use Hydrotek meranti plywood from a well established dealer. British Standard: BS 1088. No american plywood merits this high grade. It is perfect plywood if you are following mrgnstrn's method because it is clean, tight, voidless, modestly priced material for woodworking tools It would make a really fine plywood rudder imco.

This rudder when sealed well will probably take extended drying out periods if the boat is pulled for the winter or for traveling.
If put together with good epoxy it would last another 40 years. Damage would be fairly easy to repair - and if it had to be wrapped with fiberglass later to keep it going, that could be accomplished simply. BS-1088 meranti is engineered from red lauan. Imco it will do better than any other plywood underwater BUT edges must be totally sealed.

It will make the tapering and a thin trailing edge that much easier. I have bought meranti dead flat, every sheet of amerkin ply has a built-in curve. Flat material will be so much easier to taper with mrgnstrn's method. Might even factor in a modern foil shape by spreading microlight filler on the flats and shaping with a belt sander - adding a light fabric skin to protect the surface.

[carl291]

ebb,
Where would I get that plywood from, an exotic wood dealer?
I don't want to reinvent the wheel, but I was thinking that a problem with rudders is the loose pins or rods in the rudder. How about if I miiled an 1/8 grove in the rudder shaft about 3/4 " deep and 75 percent of the rudder lenght, slip an 1/8 bronze plate(about 10" wide) in the groove drilled. pinned and peened the shaft and plate. Then "Swiss"cheese drilled the plate to lighten it and to add in gluing the two plywood halves together. Would this make the rudder too heavy? Would this be the framework for a foam and glass rudder? Thanks

[ebb]

carl, There you go! That could work.

Milling that groove could be pricey. You'd have more time at the machineshop for the number of machine screw bolt holes. They would create bumps in the sides of the shaft that turns into the groove in the keel post. Could be done, but a pesky problem.

A shallow groove as an absolute register for the 1/8" plate is a thought - and then have it welded. Everdur 655 welds well. Bronze plate edge welded along the blade length of the shaft would hold forever I think even if you don't groove it to help the welder position it. Remember when you do the machining that the key way for the tiller head relates 100% to whatever you do below in the blade area. And the keyway is another expense along with the inset on the bottom of the shaft for the shoe.

To me welding is cleaner and simpler than a bunch of mechanical fastenings and a deep groove that arguably weakens the shaft. Also the expense of material and labor will knock yer socks off! But the idea of clamping the 10" plate on in your method is a fertile one - not discounting it - just that I think welding is simpler and stronger.


338's (third try at a) rudder is waiting in the shop to complete. I choose to use 2" wide 1/8" strips of bronze welded to the shaft in narrow 'V's. The strips, while vee'd are welded to the back third of the shaft rather then off the sides. This is to minimize the diameter of the rudder turning in the groove in the keel post. I have three of these 'V's - one at the top, one near the bottom, and one in the middle. They stick out 4", 8" and 14". Doesn't sound like much weight added, but much more than the original rod added to the weight of the mahogany plank rudder.

I will be using structural pvc foam for the core and glassing. It will end up weighing a lot more than the original wood rudder, no matter how I try to keep the weight down. Even if I hole saw out holes in the V struts.
There has to be method to the lightening holes too - you don't want to end up with a weak web of metal.

Swiss cheesing your center fin/plate will help a lot. But shaping the plate along its length will cut weight too. If you are making the traditional round shaped rudder you could proportionately mimic the shape on the plate. But how much plate is open to discussion. A single welded on fin or welded on non-continuous weight-saving tabs is a very good idea to build the blade on to.

Center plate a good idea for the plywood rudder. imco. I don't know how much of a fin is needed to anchor the ply to the shaft. I'm always surprised at how skimpy engineers design these sort of things. But it all would be glued together solid with epoxy - probably adding a few layers of glass around the shaft. Done correctly it will be amazingly strong, Could bury mechanical fastenings through the plywood layers and fin for absolute insurance.

I would entertain the idea of swapping out the fancy plywood for divinylcell pvc foam. Use fancy foam instead of plywood. Then decide how much glass fabric you would be comfortable with for the shell. This method while it sounds similar depends on the fiberglass skin for most of its strength.
Glass and epoxy are also weight producers.
A neat trick I saw once is to hole saw openings through the foam (after the foam is fitted, faired. and glued to the shaft and appendages) before glassing. Then glue strips of fiberglass cloth one side to the other through the holes. Then plug the holes with the foam plugs again, fair, and lay on the finish layers of cloth.
How many tie holes for an Ariel rudder? 3 or 4, more maybe? Up to you. But this method is as good as any mechanical fastening could possibly make it imco.
Not only does this provide 'I-beam' structure - it also lessens the chance of the shell layers delaminating off the foam!!! PVC foam and epoxy are friendly, but fabric to fabric insurance is soothing. USE 100% SOLIDS NON-BLUSHING LAMINATING EPOXY. 1 to 1 or 2 to 1.

Why not post pics of your ideas for feedback.

[carl291]

Wow , nearly a year later I have some pictures of the rudder and still no further along on a solution. The question is this rudder worth salvaging? Also is is pic. of the "new" stainless rudder shaft... very sea worthy isn't it??

[JurisG]

Hi All,

I'm the proud new owner of Pearson Ariel Hull#426. I've read quite a bit of this thread, but haven't yet found answers to my specific questions, so I hope someone can help. I'll post pictures of my rudder below - she's looking pretty creaky (I can bend the outer third back and forth like a thin sheet of plastic) and looks fairly well rotted.

Does anyone here have an opinion on whether or not I should attempt a rebuild? Should I just reinforce it with some metal straps (and if so, what metal should the hardware be)? How risky is that as a low budget fix?

I'm tempted to just take it apart using the Ariel Association Manual instructions, draw it in CAD, and just run a new one on my buddy's CNC Shopbot. If I do that, which type of wood should I use? And what should I coat it with?

Sorry for all the questions - I'm sure there will be more to come. Thanks everyone for contributing to such a valuable forum.

Juris Grauds
Hull, Ma

Note: I just realized I posted this to the wrong thread and will re-post in the rudder rebuild thread. Thanks and sorry.

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[bill@ariel231]

At first glance, the rudder looks to be in good shape. recommend sanding off the paint to have a good look. if there is no rot, you may just have to tighten up the thru bolts and repaint with bottom paint.

if you want to fabricate a new one, the original planks were mahogany.

cheers,
bill@ariel231

PS. By the way, you might want to put a Zinc on your prop shaft, the photos imply the last season of use did not have one.

[ebb]

Welcome aboard!
There should be almost enough here from others on a traditional rebuild.
I would take all the paint off the rudder as a first step.
Then you can see exactly what you have..
and decide what you are going to do.

What ever your experience level I think making an original mahogany rudder is your first consideration.
That rudder you have there has survived 45 years and did pretty damn good.
I believe the original Pearson rudder was a beautiful piece of traditional woodwork. It must have been to hold together for more than 4 decades!

Honduras mahogany is still available and is the wood of choice.
Second choice would be old growth teak. Probably unavailable or incredibly expensive. However you don't need too much.


But once you get it stripped you know if you want to save it.
There may be too many issues.
You have to see how the bronze shaft and rods have held up.


If you are going to take the rudder out of the boat, follow the drill.
Remember to undo the rudder strap!
And look for and back out the set-screw(s) on the rudder-head, etc.
Check out the 'tiller head' threads in the Tech section of the Forum if you need to. There may be innovations from former skippers in and around this fitting.