Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 06-11-2013, 19:40   #1
Registered User

Join Date: Feb 2012
Posts: 33
Rudder bushing help

I am in the process of renovating my steering system and am having a hard time determining what rudder bushing if any to use.

The boat is a 1969 rawson 30 that originally had a bronze rudder tube extending from the bottom if the boat up through the cockpit. The stainless steel rudder post is 1.250" in diameter and the ID of the bronze rudder tube is 1.3555", so there is just over 1/10" clearance between the two.

There is a little bit of play in the rudder and I would like to eliminate it if possible.

Option 1: waxing the rudder post then drilling holes in the rudder tube and injecting graphite/epoxy mixture to fill the void and create a custom in place bushing. My doubts with this method are with the epoxy adhering to the inside of the bronze rudder tube. I am also concerned about how thin the epoxy/graphite would be.

Option 2: Having a material such as vesconite machined to fit and press or freeze fitting it into the rudder tube. With this method though I am concerned about the thin wall of the bushing.

Does anyone have any other suggestions or reasons why these options will or won't work?
__________________

__________________
Quixotic is offline   Reply With Quote
Old 06-11-2013, 20:38   #2
Registered User
 
NahanniV's Avatar

Join Date: Mar 2011
Location: On the Boat
Boat: Finnsailer 38
Posts: 1,144
Re: Rudder bushing help

I had a similar situation on my boat.

In my case the bronze rudder tube had a 10mm wall thickness; Thick enough that some could be removed without making it too weak. So, I removed the tube and had it machined so that I could fit a bushing with a larger wall thickness.

I had the bushing machined from Acetal (got a replacement made at the same time.

Have one season on it now, and no problems.

Cheers,
JM.
Attached Thumbnails
Click image for larger version

Name:	P1008753.jpg
Views:	149
Size:	462.3 KB
ID:	69996  
__________________

__________________
NahanniV is offline   Reply With Quote
Old 06-11-2013, 21:07   #3
Registered User

Join Date: Feb 2012
Posts: 33
Re: Rudder bushing help

Good idea! I haven't checked the wall thickness of the tube yet but I will. A section of my rudder tube was cut out to access the rudder stock and install a quadrant for wheel steering. That being said, the rudder tube is in two pieces and the top piece is currently removed for cockpit sole repairs. I would be able to take it to be machined, however the lower tube is heavily glassed into the bottom of the boat and I really don't want to remove it.
__________________
Quixotic is offline   Reply With Quote
Old 07-11-2013, 04:02   #4
Registered User

Join Date: Mar 2012
Location: Aus
Boat: Owner Builder
Posts: 115
Smile Re: Rudder bushing help

I use bushes for my rudders
They have a flange so can not slip up
or down shaft tube.
Have used delrin as the material
They have lasted 10yrs.
No UV so no problems
Suspect this was not the best choice of
Material

Cutlass bearings are about 1/4 or 6mm
For a 1" shaft
My rudder bushes are about 8mm wall.

I intend to replace them with vesconite or
vesconite hilube.
Same for my cutlass bearings, as vesconite
Is more suited for this use (bushes both wet & dry)

Vernier your measurement & have them made.
Talk to a plastics engineering firm for advice on minimum
Wall thickness.
I personally would not go less than 4mm
If using plastics.
I am not an engineer so seek advice.
Consider having them made about .1mm
On the large side if you can not fit them
By freezing then take to them with 180-240 grit
Sand paper & keep checking the fit.
They are no good if loose fit.
__________________
BriaF is offline   Reply With Quote
Old 07-11-2013, 04:09   #5
Mooderator
 
capngeo's Avatar

Cruisers Forum Supporter

Join Date: Jul 2010
Location: Key West & Sarasota
Boat: Cal 28 "Happy Days"
Posts: 4,211
Images: 12
Send a message via Yahoo to capngeo Send a message via Skype™ to capngeo
Re: Rudder bushing help

+1 on plastics… I have made several rudder shaft bushings out of Noryl
__________________
Any fool with a big enough checkbook can BUY a boat; it takes a SPECIAL type of fool to build his own! -Capngeo
capngeo is offline   Reply With Quote
Old 07-11-2013, 04:24   #6
Registered User
 
Dave852's Avatar

Join Date: Mar 2007
Location: Tavernier, Fl
Boat: Outremer 50
Posts: 658
Send a message via Skype™ to Dave852
vesconite is the gold standard but your application would be way to thin.
Dave852 is offline   Reply With Quote
Old 07-11-2013, 05:51   #7
Registered User
 
capt-couillon's Avatar

Join Date: Mar 2013
Location: Onboard (Boot Key Harbor)
Boat: Cornado 25
Posts: 494
Re: Rudder bushing help

Used your epoxy/graphite system on my old Coronado 45 and it worked great. Dropped the shaft far enough to get a good heavy coat of Johnson paste wax 6" above the bottom of the tube, then raised her back into position and sealed the shaft to the hull with masking tape. Drilled 4 1/2" holes around the rudder tube 4 inches above the hull and used a fat drilled out syringe to push the graphite filled epoxy through the holes. Epoxy was filled to a little thinner than "mayo" consistency to flow down the tube. Added epoxy till it it runs out the holes. I poured 4 times, 2 hours apart to avoid exotherm problems with a deep pour. Use slow hardener on a cool day. Used the last of the left over epoxy and some glass tape to seal the holes in the tube. Bob's your uncle... A little twist of the rudder by hand to break the release wax loose, and she was still tight when I sold the Escape 10 years later.
__________________
"It seemed like a good idea at the time"
capt-couillon is offline   Reply With Quote
Old 07-11-2013, 05:58   #8
Registered User

Join Date: Mar 2012
Location: Aus
Boat: Owner Builder
Posts: 115
Smile Re: Rudder bushing help

Just occurred to me

Have a look into bearing or shaft sleeves ?
These are used to slip over shafts when
A seal has worn a groove in the shaft
Should be available at bearing or auto parts
suppliers.
I think they are available in stainless ?
Wall thickness ? (thin)
It might just do the trick
__________________
BriaF is offline   Reply With Quote
Old 07-11-2013, 06:23   #9
Registered User

Join Date: Feb 2012
Posts: 33
Re: Rudder bushing help

Thank you BriaF the sleeves sound like they could work I will look into that.

Capt Couillon, sounds like your rudder tube is made of fiberglass correct? This method sounds ideal however since my rudder tube is bronze I am worried about the epoxy not adhering to it very well.
__________________
Quixotic is offline   Reply With Quote
Old 07-11-2013, 07:40   #10
Registered User
 
capt-couillon's Avatar

Join Date: Mar 2013
Location: Onboard (Boot Key Harbor)
Boat: Cornado 25
Posts: 494
Re: Rudder bushing help

@quixotic

Yeah, my tube was glass, but believe me, the epoxy will stick to the bronze... Make sure you get a good coat of wax on the rudder shaft, or you will give a new meaning to sailing a ruhmb line.

I once used West epoxy filled with colloidal silica to patch the cast iron crankcase web on my 4.107 after the unscheduled departure of a rod end from the crank poked a 1"x2" hole in it. That's another story, but the patch never moved in a high heat/high vibration environment. Crude but effective and lasted till I could afford to replace the block.
__________________
"It seemed like a good idea at the time"
capt-couillon is offline   Reply With Quote
Old 07-11-2013, 08:18   #11
Senior Cruiser
 
colemj's Avatar

Cruisers Forum Supporter

Join Date: Oct 2005
Location: Presently on US East Coast
Boat: Manta 40 "Reach"
Posts: 10,049
Images: 12
Re: Rudder bushing help

Is the play on the top of the shaft or in the rudder shoe on the keel? I had a boat where the loose rudder shaft was due to the hole in the rudder shoe getting worn. I bushed the shoe and all was well again.

Mark
__________________
www.svreach.com

You do not need a parachute to skydive. You only need a parachute to skydive twice.
colemj is offline   Reply With Quote
Old 07-11-2013, 08:31   #12
Registered User

Join Date: Feb 2012
Posts: 33
Re: Rudder bushing help

Good deal thank you captain! I also spoke with West System tech support and they said the epoxy would adhere sufficiently to the bronze especially if it is abraded. They also said the small clearance between shaft and tube shouldn't cause any problems. Their other suggestion with the procedure is to only inject the epoxy at 3 points around the tube. The points should be spaced 120 degrees apart. This is the option I am leaning toward now as it seems to be easy and cost effective.
__________________
Quixotic is offline   Reply With Quote
Old 07-11-2013, 09:17   #13
Registered User

Join Date: Feb 2012
Posts: 33
Re: Rudder bushing help

Colemj, there is very very little play if any coming from the rudder shoe. I made sure to check there first before pulling the rudder from the boat. There was no type of bushing between the rudder stock and the rudder tube and I believe most of the play was coming because of the loose fit between the two. The upper section of the rudder tube was also poorly supported because a leak between the cockpit sole and the tube allowed water to penetrate the plywood stringer below the sole which provided support for the upper tube. I was able to wiggle the tube a bit by hand which probably means that a bit of the play was coming from here as well. I have removed the rotted wood and am in the process of tabbing in a new piece that is thoroughly coated in epoxy.
__________________

__________________
Quixotic is offline   Reply With Quote
Reply

Tags
rudder

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 04:30.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.