Rudder Replacement

[Mizerita]

I've read a few of the threads about oversized rudders and looking at having Stuart Propeller build a pair for me. He's asking about current rudder type. I believe mine are the original rudders - hull is 1962. He's asking is it option 1, 2 or 3. I have no clue and guessing I would have to remove propellers. Any thoughts on which ones I have? See hand drawn picture he sent on which options

[Tony Meola]

Unfortunately I am operating from a mobile device and it will not let me post a link. If you go over to bertram31.com the old board should pop up. Find the parts section and open the section on rudder.

It will show you the 3 types of rudders they are talking about. Square stock arm above the rudder shelf. Square stock arm below the rudder shelf and round stock. Also, they used what they called 31 style rudder and then a 28 style and 28 hybrid.

My 31 had the 28 style with the arm below the rudder shelf. I changed it to put the arm above the shelf.

[Mizerita]

Is there a way to know without taking off the rudder? Here is a pic:

[Tony Meola]

Unless I am mistaken that does not look like a stock rudder. Where is the rudder arm above or below the shelf?

Also why not just drop the rudder and take it to the shop and let them figure it out.

[Dug]

Miz,

You cannot tell anything about the shaft configuration from the blade style. Just drop the rudders (both, if you are replacing anyway why does it matter?) and take them in with you as Tony said. Then you can get new bearing while you are at it.

Good luck!

[Mizerita]

Thanks guys. The manufacturer is a 5+ hour drive by car...was going to have Stuart Prop manufacturer the rudders and a yard down here in Key West install them. This is my first inboard boat so I have no clue about rudders. I'll have the yard here pull them and see what we find.

[Dug]

I understand completely about the drive. I also understand the first time inboard world. Anything we can do to help we will for sure! You do need to pull a rudder to see the shaft configuration. Its daunting for sure. I bought rudders from Bobby Soles and they are in FL, I’m in MA, and the boat is in either RI or CT. Its a learning experience. You will be fine!

Dug

[bob lico]

stop-----stop----- stop those are replaced rudders leave them alone go to next project!!!!!!!!!!!!!

[Tony Meola]

Bob, as you said they are not stock, but they look thick. Not one of Capt Pat's.

[bob lico]

replacing them with captain Patrick rudders will do absolutely nothing!!!!!!! they already have the proper surface area, as well as shape just a little thick on trailing edge changing them, will be a meaningless change for a 31 Bertram . spent the money on F/G shaft log with dripless seal.

[Mizerita]

Thanks Bob, they looked small compared to others I've seen, but I'll leave them alone. My only concern was they don't seem to steer well on autopilot. Immediately thought they were stock. Anyone else have these autopilot issues?

[Tony Meola]

Measure the prop to get the surface areas. I posted the size of mine a few months ago. I will see if I can find the post.

[Tony Meola]

http://bertram31.com/newbb/viewtopic.ph ... ze#p123703

Take a look at this link. My rudder dimensions are in the post. See how the rudder area compares to yours.

[Mizerita]

Tony and Bob Lico - I had a chance to measure my rudders and although Bob says "don't change those rudders"...there are a few differences in measurements from what Tony mentioned. The edge of the rudder closest to the prop measures correctly at 15 3/8, but the trailing edge furthest from the prop is only 10.5 inches (not 11 3/4). The bottom of the rudder measures only 7.5 inches (not 8.5). The widest part of the rudder is only 9 inches (not 10).

I haven't operated the boat on 1 engine yet, but should...but I do know my Simrad AP is all over the place. Are these original rudders or just smaller aftermarket?

[Tony Meola]

Those rudders are not factory. They are after market. I have never seen a rudder like that on a 31 before. You need to increase the rudder area. The original rudders where either 104 square inches or 84 square inches. You need to get above 104 square inches.

It does not need a lot more area but if you follow what is in those links you should be good. The ones Capt. Pat used to have made came from Bobby Soles shop down in Florida.

Bobby no longer owns it but I believe the new owners will still make them.

Just to give you reference, my old rudders where the smaller ones at 84 square inches. Running on one engine made the boat go in circles unless you really cranked up the RPM's. An old friend of ours had a 31 when he was alive his had the bigger rudder and he could manage better on one engine but not perfect. But what was funny was at speed I could turn tighter than he could. Go figure. It was probably the shape of the rudder.

The new rudders are a dream.

[Pete Fallon]

Mizerita,
My 1961 express had OEM rudders that were solid bronze with 1" stainless steel shafts with the tiller arms above the rudder shelf bearing. The rudder measurements were 19" from the top of the blade to the aft tip tapper, they were 9" across the top and 7-1/2" at the bottom and the max width was 13-1/2" mid blade . Capt Pat had Bobby Soles make the new style stainless steel rudders after measuring my rudders, they still have the dimensions they were priced at $1,100 back a while ago.
The early 31's had the larger style bronze rudders then they changed them to the 28' Bertram style in the late 60's that were really small and thin bladed. Marlin had Stuart Prop make the rudders for his 31' FBC with 315 Cummins and 1-1/2" shafts.
If you have any wear around the rudder ports on the bottom you can have bushings made out of Delryn material that will take care of the play on the port openings. Good luck.
Pete Fallon

[Carl]

Looks like a stock 1962 bronze rudder to me.
I believe it looks larger cause of the way the picture was taken.
Like when you hold that "almost keeper" fish an arms length in front of you when picture is snapped turns your catch into a trophy fish.


Drop a rudder, find a box or wrap in cardboard then UPS...save yourself 5 hours of driving.
They only need one.
These are not that big or heavy, ground UPS should be quite reasonable.

Or drop, take a picture and send off to guy asking which style...he'll know when he see's picture.
If all seems like a go, then UPS.

If like mine, rudder is Option #4, - Straight 1-1/4" shaft with Keyway on top-

[SteveM]

If the concern is autopilot steering, my guess is you are experiencing poor control at low speeds. Autopilot at slow speed doesn't seem all that locked in IMHO. Slow speed steering feels more in control when you use your throttles manually. You may also want to learn the autopilot system a little better, they each have their own feel.

I could measure my rudders if you'd like so you can compare. I have the large Capt Pat style.

You can look inside the bilge at the rudder box to see what type of connection they have if that's what the prop place is looking for.

But my gut feel is those are already some large rudders you have there. The steering on an inboard boat at slow speed feels very "floaty" compared to an outboard that points the engines in the direction you want to turn. Spend some time practicing with the throttles at low speed it will facilitate a more aggressive turn at low speeds.

PS: I wanna come down and look at that boat of yours.

[Mizerita]

Thanks guys, new rudders is probably on the list.

[Tony Meola]

Carl & Pete

Based on Capt. Pat's drawings of the 3 rudder styles used, the rudder in the picture is not stock.

[Yannis]

They look very similar to some Chris-Craft 315 commander rudders I have seen.
I cant, from where I am, post pics unfortunately.

[Carl]

Carl & Pete

Based on Capt. Pat's drawings of the 3 rudder styles used, the rudder in the picture is not stock.

Here's the best shot I have of my rudders.
Not too great I know, but can see shape and proportions. Anyway, his picture looks to be a dead ringer for mine. IF Not stock, I highly doubt 2 boats happened to grab the exact two non stock rudders. I also know my boat for 36 years between me (24yrs) and the former owner(12yrs). Plus when he bought boat 36 years ago it was all original from original owner...and I do not mean that in a nice way.

[Tony Meola]

Carl

The angle at the top of your rudder from the rudder post to the trailing edge looks different.

[Carl]

Carl

The angle at the top of your rudder from the rudder post to the trailing edge looks different.

The angle of the pictures is different.

[Carl]

Carl

The angle at the top of your rudder from the rudder post to the trailing edge looks different.

The angle of the pictures is different.
What your seeing is the back radius blending into the top surface making it appear longer and steeper.



While I am not a betting man, I would bet on this one. Early Bertram rudder.

[Tony Meola]

That is quite an illusion.

[Carl]

That is quite an illusion.

I'll bet a cold beer or clear on it.

Just have to wait till I haul boat....

[Tony Meola]

Not quesyioni my you just some illusion. Just does not look right.

[Carl]

Not quesyioni my you just some illusion. Just does not look right.

Tony...no worries, I just wanted to get a cold beer.
A bet like that I can't lose. Even if I'm wrong and lost the wager, I get a cold beer as I couldn't let a bud drink alone.

[Tony Meola]

We need a profile pic to really know.

[Carl]

We need a profile pic to really know.

Yup, when I pull boat, I'll take a pic from same angle.

Til then its based on OP's picture, a distant picture of mine and my memory. Suddenly I don't feel as confident...

Nah, I'm still sure, I pulled those things a couple times to fix a rattle along with scraping n cleaning them for years.

[Tony Meola]

Just does not look right from that angle.

[Carl]

Bringing it back to the top so we can take a look and see what the jury decides.