When your rudder breaks off @ 6.8knts

[finding41]

Yes I am making a female mold to cast the male. As for blunt... I tried to get it as close to the original as possible... I haven't had any time to work on it this weekend. It was tough getting over to coat the tiller handle with spar varnish. I did get 4 coats on so far with the new varnish. (I gave up on the old. I think I killed it when I last used it... I mixed a red stain in with it to do my wheelbarrow handles. I made my own 8" longer and easier to lift. They turned out great! But that was a few years ago and judging by the chunks of stuff in the can It may be done.)
I hope to get a few free afternoons this week and get the mold made.
Next time I'm over at the shop I will cut the fiberglass and lay it out so it's ready to go once I get the PVA and gelcoat on.

[Newell]

Great suggestion, but the entire lake, Great Salt Lake, is a shallow sea.

Newell, have you ever sailed in fresh water, and if so, do you find that the boat is less tender in the GSL? It should be, considering the boat's higher buoyancy and the greater weight per gallon of salt water ballast.

Yes, sail several bodies of fresh water and haven't noticed a difference. If the ballast was fresh water and sailing in heavy salt water, perhaps there would be a difference. I know of an accident that happened, because of heavy water, to a cigarette boat motoring and turning at high speed in the North Arm of the Lake. Seems he tripped on his keel and capsized. The captain left his crew of 1 hanging onto the hull, whereupon he swam to shore only to be met by a pack of large and hungry coyotes. The captain walked several miles North, offshore, until he reached the base camp very exhausted. The coyotes kept him company during the trek. Almost a stinkpot justice story.

[finding41]

Well my mold didn't turn out so well. I got a bit carried away when I started adding the fiberglass over the gelcoat. The gelcoat hadn't fully kicked along the 90* edge. (It was thicker there.) So I had a problem of the gelcoat de-laminating from the mold along the edge and some spots on the bumps.
All is not lost. I plan to pore plaster in the mold and reshape the plaster cast I make.
Again pictures are on the other site. link http://forums.macgregor.sailboatowners. ... p?t=152934

[mastreb]

Steve (or anyone else who has broken a rudder)-- Can you confirm the construction of the head of the rudder where the pins go through? Is it a wood block, or what?

[Steve K]

Steve (or anyone else who has broken a rudder)-- Can you confirm the construction of the head of the rudder where the pins go through? Is it a wood block, or what?

mastreb,
Sorry, haven't checked the site in a couple days.

Inside the rudder:
Looks like just wood wrapped fiberglass. I'll take a closer look tomorrow. (set 72 cement blocks today.... just too tired to go out to the shop )

I know for sure there is a wood backbone that goes from top to bottom (it's not quite a 2x3, but thicker than a 1x). The pivot hole is drilled through the center of this wood. It is made of Mahogany, I'm pretty sure (original rudder).

Remember this is the 26D rudder. I imagine the X rudder would be similar in construction.

Anyway, I'll get you the straight detail tomorrow

Best Breezes,
Steve K.

[Steve K]

Well...... had to drag myself out to the shop again anyway. While I was out there I took a good look at the rudder.
I was correct about the rudder post. It is a 1X3 (one inch thick, not 3/4). It runs through the whole rudder. Pivot hole drilled through it.

The top of the rudder is just as hollow as the rest of it (to my surprise). It just has some extra fiberglass around the inside of the rounded edge.

SK

[finding41]

Steve (or anyone) do you have any pictures you can post of the inside of the rudder or even a dagger board?
I would love to see what the inside looks like of both. Also how they put them together.

On my whale fin rudder project: I have coated the inside of the mold I made with Vaseline and put a coat of plaster on the walls. I will put 2 more coats of plaster with burlap until it's full. The burlap will give it strength so I don't bust it in two trying to get it out of the mold. (That's the principal anyway.)
I have a lot on my plate so it may take a bit to get done.

[Steve K]

finding,

I'll snap a couple shots of my broken rudder, as soon as I get a chance. It is very much like the diagram I posted, earlier in this thread, if you melted out the foam. Instead of the carbon fiber tube/post, it has a 1x3, rectangular hardwood core/post.

I happen to know that the dagger board is constructed exactly the same way, as I broke the bottom of it opened on a submerged mountain peak a few years ago. The bottom one foot was opened up like a clam shell and I could see the insides very well

The rudder is a NACA 012 foil and the dagger board is a NACA 009 (roughly). Those were the original specs anyway.

more later......

BB,
SK

[finding41]

Thanks Steve.
i have a new plaster male in progress in the mold I made. (That's about all the mold is good for. Oops.) This next one I will make more streamline on the leading edge. I'll post pictures on the other site when I get some time.

[Steve K]

Well, this time I didn't have time too completely design and build a new rudder. I have, however repaired and re-fared the old one.

Here's what I did:

First, I simply epoxied the rudder post back together at the break. It was easy to fit the splintered post back together and I was able to align the two pieces and tap them together with a rubber mallet until the crack in the skin was only about a 32nd of an inch wide.

After curing overnight, I cut away the skin from the top of the rudder down about eighteen inches and a little wider than the rudder post. Interestingly, the skin is about an eighth inch thick on one side, but is over a half inch thick on the other. I beveled this cut out on both sides and sealed the wood with epoxy and a layer of 3 oz. cloth. (left to cure again)

The next day I sanded everything with 36 grit. I then epoxied in two steel plates (one on each side) and bolted them through the post and together with nine small bolts (#10-24 stainless). All this was done before the epoxy was cured. Oh and the steel plates were ground and acid washed prior to bonding them in. The steel plates now run from just above the pivot hole down about eighteen inches (well above and past the break).

I now had plenty of build up area to fill out to the original surface. I layered combinations of roving, 5oz. cloth and 2.5oz. mat with one layer of long individual fiberglass strands (same length as the steel plates) thrown in there somewhere for good measure. I repaired the lateral crack, left in the skin at the same time.

When this was built out to almost the original surface I let it all cure up to prepare it for faring.

This was all cured up the next day and now the rudder was completely sealed from moisture. I scrubbed off all the amine blush with plenty of water and a 3-M pad and ground everything with 36 grit to prepare it for final faring.

Side note:
It is said polyester can't be used over epoxy. This is true if you don't do the step above

My choice for fairing on structural parts is Bondo Glass. This is polyester auto body filler, but it has chopped fiberglass mixed in that adds strength. It is just a little harder the spread smoothly and sand than regular Bondo. The trick I found for spreading it smoothly is to lay some down on the repair area, cover with waxed paper and then it can be spread very smoothly with a clean squeegee. The smoother the initial application, the less sanding is required later.

Another side note:
We're not talking a thick coating of body filler here either. This is just to get the surface perfect. If you are globbing on Bondo a 1/4 inch thick, you're doing it wrong. The fiberglass work should be fare enough to be able to coat with a 1/8 inch layer of body filler, then block sanding half of it back off.

Anyway, now the whole board is washed down with acetone and blocked with #220. I followed this with a double, wet coat of PCL Poly Primer (polyester, high build primer) and blocked one more time with #220.

The final step is spraying the new layer of gelcoat. I did one coat without wax and let it partially cure and did a second coat with wax, so it would air cure, without having a sticky surface. I then wet sanded with #500, #800, #1000 and finally #1500. Then polished.

Looks better than new and I know the foil shape is better and more accurate than the original ( and better than when I modified the rudder a few years back).

I added about five inches to the bottom of the rudder, around 6 years ago, knowing a high aspect stick is, generally more efficient. However, this can also have an effect on initial heeling. So, I decided to cut about three inches back off, to see if there is a little less initial heel, (and to just get rid of a few strike marks down there). So, we'll see if it makes any difference. The plus is with the added weight of the repair and the couple pounds cut off the bottom, the rudder weighs about the same as it did

In any case, thought I'd share this with you all and I'll try to get some pics up of the finished rudder on my Box account for comparison, in a few days.

I had some gelcoat left over and it was on it's was to going bad. I also had plenty of Bondo glass and other materials left. So while I was at it, I pulled the dagger board to inspect. I had repaired it after a strike a few years ago, but didn't have any finish materials handy at the time. So I decided to re-finish it also (same primer, gelcoat and sanding schedule as the rudder). I still had a little bit of gelcoat left...... and a circular crack all the way around the bottom of my galley sink. This turned out to be the hardest of all these repairs. The sink is so small, everything has to be done by hand (sanding etc.) and not wanting to get overspray all over the inside of the boat, the gelcoat had to be applied by brush (meaning more sanding).
But the Admiral is all jazzed now that the sink looks brand new without the cracks and stains.

Best Breezes,
Steve K.
Mac 26D "Three Sheets"

[Freedom77]

HEY STEVE...Call me or e-mail...Lost your phone #, Sent you a message, don't know if you got it. When are you coming to NV. Better hurry the lake is drying up. WOODY Fair Winds and Full Sails...Old Salt