Rudder stock bushes?

[Clyde_Wanderer]

I would be interested in hearing what type of bearing/bushing system is on your boats where rudder stock passes through the hull.
Not interested in modern boats, ie Bavs etc, (No offence intended) more interested in boats of the 80s with skeg or part skeg.
I experience problems every season with my steering (tiller stg) getting very tight to turn, she doesent have any lubricating system on the stock, just a s/s shaft passing through a matching aperture on the lower end of a 2" dia s/s tube which is glassed into the hull and a hanger on the lower end of skeg.
Similar I would imagine to the Elizabethan 30.
C_W

 

[Billjratt]

Sounds like someone has fitted a nylon bush to the bottom (probably) of the tube.
Nylon swells in water, it should be delrin or something like that - we had a westerly with exactly the same prob in TCC last year.
Mine's the right age but has a sterngland type fitting at the top and a lump of bronze way down at the bottom, so no help I'm aftraid.

 

[Clyde_Wanderer]

Sounds like someone has fitted a nylon bush to the bottom (probably) of the tube.
Nylon swells in water, it should be delrin or something like that - we had a westerly with exactly the same prob in TCC last year.
Mine's the right age but has a sterngland type fitting at the top and a lump of bronze way down at the bottom, so no help I'm aftraid.

Bill, there is no bush of any kind where the stock passes through the hull, just s/s to s/s.
The two half brackets on the bottom of the skeg clutch two half tubular bushes of some type material but I think the problem is where the shaft passes through the hull.

Hows the grp repair comming on?

Thanks, Eamonn.

 

[theforeman]

sounds like the answer might be to tap a stern greaser tube into the 2" s s tube and give it a couple of turns now and again and see how that goes.

 

[Seajet]

Still sounds like swolen nylon, in this case at the bottom of the skeg; the stuff is notorious for exactly these symptoms.

 

[Halo]

Rudder Bushings

I replaced the bushings on my old Westerly. These had worked well from 1966 until 2007 but the play finally got too much. I removed the rudder during crane out and removed the old bushes by cutting two slots vertically in them with a hack saw blade (bit of tape to make a handle). I then measured the stock and aperture with a vernier caliper and had new bushings turned. The material I used was medical acetal which is very durable and stable. I will have a look for the drawing I made of the bushes and post it if you are interested. Basically the bottom bush is an inverted mushroom shape with a big through hole and the top bush is a simple collar
I expect these were pretty similar on a range of boats in the 60s and 70s
Martin

 

[neil_s]

My Seal 28 (1977) has a 1inch stainless steel rudder shaft passing through a GRP tube glassed into the hull and the deck. There is a half -skeg with a s/s on s/s bearing. I also have problems keeping the rudder moving freely. I feed WD40 in at the top of the rudder shaft and hope that it migrates down the tube. The fit is so tight that I can only get drops to go in at the top and I have never seen any come out at the bottom. That said, the technique does appear to work - over the course of several years treatment the tight steering has gradually eased.

I paniced myself last year thinking that it was corrosion of the rudder shaft inside the tube - where it couldn't be seen. I had visions of the rudder shaft breaking - and indeed, that failure was reported as happening to another Seal 28 in the owners journal. I didn't have the facility to lift the boat to extract the rudder, so I devised a test of the whole rudder assembly instead. I bolted a couple of lengths of 2 x 4 from the keel to the rudder to lock it amidships and then put a load on the tiller to see if anything would break. It didn't and I felt a lot happier!

Neil

 

[doug748]

The Contessa 32 uses a pressed in bearing at top and bottom. These were originally Tufnol but are now generally replaced by a bronze item available from the manufacturer.

 

[Neil_Y]

Fisrtly what sort of clearance does the system have? if it's stainless to stainless there is probably a bit of play. If stainless is in an area of static salt water you can get corossion as there is the possibility of reduction in dissolved oxygen locally (oxygen is reuqired to replenish the passivation layer which protects 316 from corrosion so you need water flow or movement). So check for signs of corrosion.

There are newer materials now that are very effective where a thin sleeve may be used, the new materials have far lower thermal expansion rates as well as lower moisture absorption rates. Often seizing is more temperature related than moisture or corrosion. You work the rudder hard and as the bearing warms it swells and gets tighter if it is constrained by a metal tube which remains cooled by seawater.

If you have drawings/photos of the set up I'm happy to give advice from a bearing perspective.

 

[Billjratt]

Sorry Eamonn, I didn't take in the facts from your original post!
Are you saying it frees up unaided when out over winter, or is there some process you do to get it loose for the start of the season?
Could something in the skeg area be at fault, causing misalignment up the tube? ( I saw the lower fitting on an Elizabethen needing work over the winter too)
Any sound accompanying the stiffness (binding in the tube?)
Have you dropped the rudder to see if there is evidence of a high point between the stock and tube?
Sounds like something is changing shape as the boat either gets wet or takes a pounding.
Has a guy called Andrew from TCC contacted you re the forehatch? - if so, you could discuss the lower rudder fitting with him as well.
Sahona is now watertight again, but engineless, and being rewired. Some time to go before the big splash methinks.
CU, Bill.

 

[Spyro]

If it gets gradually worse after relaunch I'd tend to agree with Bill. More likely to be the lower half bushes swelling.
I fitted a new set of half bushes on my semi skeg hung rudder 2 years ago. The new set I got made up in delrin at QD plastics in Dumbarton. They were slightly tight when I fitted them so turned them down a bit with a flap wheel fitted to a drill.

 

[Spyro]

Sahona is now watertight again, but engineless, and being rewired. Some time to go before the big splash methinks.
CU, Bill.

Are you getting a new engine or is the old one going back in. Sorry about hijacking your thread Eamonn

 

[Billjratt]

Hi Ian - sorry Eamonn!

Didn't want a new engine, as the 4108 goes very well underwater, and they'd no doubt offer a yanmar or something equally spares-expensive.
Starter and alternator off for refurb - interestingly, the former probably survived - and was able to do multiple starts while submerged- due to the fact that the main oilseal had been leaking and the bellhousing and starter were full of oily sludge -great protection!
It's the gearbox that died - or at least requires stripping and de-gunging as it has a dipstick and breather that allowed it to imbibe the oggin. Yellow emulsion started to come out of the top, and as it doesn't have a drain, I had to remove the filter and fire it out of there by turning it over - messy job!
Still couldn't flush it thoroughly, so a bit dubious really. It's back home in TMP for R&R.
Meanwhile, Eamonns boat is still going round in circles, sorry sir. Carry on.

 

[Clyde_Wanderer]

Didn't want a new engine, as the 4108 goes very well underwater, and they'd no doubt offer a yanmar or something equally spares-expensive.
Starter and alternator off for refurb - interestingly, the former probably survived - and was able to do multiple starts while submerged- due to the fact that the main oilseal had been leaking and the bellhousing and starter were full of oily sludge -great protection!
It's the gearbox that died - or at least requires stripping and de-gunging as it has a dipstick and breather that allowed it to imbibe the oggin. Yellow emulsion started to come out of the top, and as it doesn't have a drain, I had to remove the filter and fire it out of there by turning it over - messy job!
Still couldn't flush it thoroughly, so a bit dubious really. It's back home in TMP for R&R.
Meanwhile, Eamonns boat is still going round in circles, sorry sir. Carry on.

No Bill, its my arms that are getting longer

 

[Clyde_Wanderer]

3 winters ago I fitted a new 25mm dia stock to the rudder, a big job!
The old stock was 1" which is a little bigger than 25mm and did result in very slight radial play between the stock and s/s tube.
While doing this job I had a new top bush housing made and a 275mm long Delryn top bush made, so I know that the top end is fine.
The two half bushes at the skeg are original and possibly made of a Nylon of sorts.
And yes the steering tightens up as the season progresses and loosens when boat out of water for winter.
I will be dropping the rudder and inspecting for gauling between the stock and s/s through hull tube as this is something that has been worrying me for a while, (not knowing)
Unless it would be possible to bore out the s/s tube aperture I cant see any way of fitting a bush here as the clearence is only 1-2mm which should be enough to let a flow of water past the stock and up the tube although it would be fairly static inside the tube once the level reached outside level.
Any way to bore/ream this out in situ?
Bill not had any contact from anyone at TCC reg hatch.
Thanks everyone for your replies.
C_W

 

[Deleted member 36384]

http://www.westsystem.com/ss/assets/HowTo-Publications/Fiberglass-Boat-Repair-and-Maintenance.pdf

See section 8.4 of the West Manual for a possible solution. I know you state its stainless on stainless but the Graphite / Epoxy mix might be an option.

On my own boat I have a bushing with packing, don't know what type, with a greaser. The rudder sits in a skeg shoe with another bushing but plain type, sea water lubricated.

 

[Clyde_Wanderer]

Thanks BOB, but I doubt if this system would work on the inside of the s/s tube especially since the clearence is only a couple of mm max.
I think the only cure would be to drill out the aperture that the stock passes through and have a delryn bush made.
As I say drilling/reaming out the aperture in situ is the stumbling block in this case.
Thanks, C_W

 

[Billjratt]

The odd thing is, there was less clearance on the old shaft than on the new one, or is that why the replacement was done? Was the original binding as well?

 

[Neil_Y]

Thanks BOB, but I doubt if this system would work on the inside of the s/s tube especially since the clearence is only a couple of mm max.
I think the only cure would be to drill out the aperture that the stock passes through and have a delryn bush made.
As I say drilling/reaming out the aperture in situ is the stumbling block in this case.
Thanks, C_W

Maritex can be made up as a bearing sleeve on a 50.00mm shaft at 54.00mm (0.08-0.18 clearance on shaft and 0.2-0.3 clearance on carrier tube for epoxy bedding) This clearance allows for thermal and moisture swell. If you use Delrin make sure you allow for thermal expansion as well as moisture expansion, as rudders work it's easy for the bearing to warm up and expand. You can use this calculator to see clearances on a composite bearing, clearances for Delrin will be different. Enter shaft OD and carrier ID, clearance breakdown is under chart.
http://www.h4marine.com/Downloads/Maritex AQUARIUS General Calculator REV 20100519.xls[url]