Help with refitting my propellor shaft

[Byron Douglas]

Hi All,
I have been restoring my 21ft couta boat for the last 10 years and are getting close to finishing the project. I need to reinsert the propellor shaft through the stuffing box. It has an external bearing and a grease nipple on the internal stuffing box where there is a bearing nut? (see attached photos - one shows the stern bearing prior to bolting into place and the other being the internal side of the stuffing box). I have two questions. The first is, do I wrap the silicon packing material on both the external and internal sides of the stuffing box and then grease the stuffing box through the grease nipple?? I am assuming that I create rings between the stern bearing and the stuffing box and the same on the inside.
My other question is about electrolysis - original the stern bearing bolts had stainless wire around them runinng to an anode - one had a hole drilled through the head that the wire ran through. In this instance what's best? Is another option to put an annode on the prop shaft - can this be placed inside the boat or does it have to be external to the hull. Any help would be great.
Cheers
Byron

[Hwyl]

I,m having a hard time understanding yout\r post. I thought I'd put the pictures up any way.

Is another option to put an annode on the prop shaft - can this be placed inside the boat or does it have to be external to the hull.

It has to be in the water.

http://www.woodenboat.com/forum/attachment.php?attachmentid=523&d=1243764700

http://www.woodenboat.com/forum/attachment.php?attachmentid=518&d=1243764277

[The Bigfella]

I had responded to this but the forum editor has chosen to remove three days of my replies.

[peter radclyffe]

I,m having a hard time understanding yout\r post. I thought I'd put the pictures up any way.



It has to be in the water.

http://www.woodenboat.com/forum/attachment.php?attachmentid=523&d=1243764700

http://www.woodenboat.com/forum/attachment.php?attachmentid=518&d=1243764277
your system is different to that which im used to, so i am loathe to advise you without a diagram, is this standard sterngear on a couta boat, you could ask richard blake at, boats by blake, melbourne, a good boatbuilder

[paladin]

and I betcha that "stainless safety wire" was not stainless unless placed there in error....it should have been Monel wire.....

[seo]

It's not unusual for older boats to use an external stuffing box as a stern bearing. Particularly when there's no liner in the shaft log, because it limits leaking through any checks in the stern timbers, while a cutless bearing is a full flow arrangement. My guess is that the stuffing box with the grease fitting was meant to be used outboard.
You can't use both an external stuffing box and an exernal cutless bearing, unless the cutless bearing is in a strut. That would be unusual.
Anode has to be immersed in the electrolyte, which is the water, in this case.
What the heck is a Couta Boat?

[peter radclyffe]

It's not unusual for older boats to use an external stuffing box as a stern bearing. Particularly when there's no liner in the shaft log, because it limits leaking through any checks in the stern timbers, while a cutless bearing is a full flow arrangement. My guess is that the stuffing box with the grease fitting was meant to be used outboard.
You can't use both an external stuffing box and an exernal cutless bearing, unless the cutless bearing is in a strut. That would be unusual.
Anode has to be immersed in the electrolyte, which is the water, in this case.
What the heck is a Couta Boat?
thank you Seo, its still not clear to me tho, and the engineering principles here dont seem to stop the outer stuff box sleeve trying to turn against the bolts, e.g if it was caught on , or snagged a line, there seems to be no solid register to stop it turning, just 2 bolts

[seo]

There should be a jam nut on both the stuffing boxes that are used to lock the packing gland nut in place.

[The Bigfella]

We need a better second photo. It looks to me like there is a pair of standard stern bearings in the photo - an old one and a new one (looks like a Briggs casting to me)

http://www.briggsmarine.com.au/images/products/Stern-Bearing.gif

If it is... there should only be a few rings - probably 3 in the stuffing box. Cut the stuffing material square (it looks like beige waxed square cotton material - whatever you do, don't use graphite stuffing material) - and stagger the cut joints as you would piston rings in an engine - 120 degrees apart. Don't over-tighten, as it will cause too much friction (stuffing box shouldn't run hot) and a drip or two a minute won't hurt - the water lubricates the shaft.

http://www.briggsmarine.com.au/images/products/Stuffing-Box.gif

No - you don't need to fill the gap between the stern bearing and the stuffing box with rings of material. The shaft hole will likely have been sealed with tallow to prevent water problems. Modern constructions might glue a liner in instead of that. Pretty hard to glue to something that has been tallowed though.

Can you put up a higher resolution photo. Something around 100kb on say photobucket.com - then link the photo to this site?

[Byron Douglas]

Hi All, Sorry about the confusion - I could't work out how to get a good photo up on the site without exceeding the download limit. I will try and link them to this site tonight with a couple of photos of the boat. The "bigfella's" photos are pretty much correct except that the stern bearing has no thread on it.

What I have is your classic stuffing box (i think) except where the shaft exits the boat where there is an external bearing. The stuffing box has a bronze pipe joining the internal fittings to the one on the outside (sorry don't know their name). On the outside is the stern bearing that bolts on to female fitting on the boat. Its here that I'm not sure what to do about packing etc. My illegable photo shows the bearing not yet pushed into its housing. It doesn't have any tallow in it? I think better photos will help explain my situation but the "bigfella" is pretty much on the money.

[Byron Douglas]

Hi all, I am newish to this forum so thanks for your patience. I have added some photos to photo bucket - http://photobucket.com/coutaboat Hopefully they will tell a better story than I can tell. Basically I need to know what I pack the stern bearing with. I assume that I use packing on the inside, grease through the grease nipple into the tube .... and something externally.

A couta boat is a type of fishing boat that was used from the turn of last century to fish for baracouta (a type of fish) in Bass Straight off the coast of Victoria here in Australia. They generally range from 21ft to 30ft. Fortunately about 30 years ago people started restoring them and they have become very popular. They are a gaff rigged boat with a steel centreboard.
Cheers
Byron

[The Bigfella]

Here's some of the photos. I don't think you should have that new stern bearing. What you need (I think) is a cutlass bearing in the existing one. Its an insert... but the whole insert would normally be bolted to the keel.... where yours is cut out



http://i674.photobucket.com/albums/vv109/bdouglas_photos/IMG_8334.jpg

I just run the cursor over the image in photobucket, which brings up the tags underneath. Left click on the box where it says IMG Code, then right click and click copy, then past it straight into the quick reply box on the WBF

http://i674.photobucket.com/albums/vv109/bdouglas_photos/IMG_8329.jpg


http://i674.photobucket.com/albums/vv109/bdouglas_photos/IMG_8331.jpg
http://i674.photobucket.com/albums/vv109/bdouglas_photos/IMG_6122.jpg

Nice boat. What engine?

[The Bigfella]

Here's another thread with quite a discussion on the issue. I'm sure if you do some searches on here you will find more.

http://www.woodenboat.com/forum/showthread.php?t=94290&highlight=bearing

[The Bigfella]

You've done a fair bit of work I see

http://i674.photobucket.com/albums/vv109/bdouglas_photos/CoutaBoatbow.jpg

http://i674.photobucket.com/albums/vv109/bdouglas_photos/CoutaBoat.jpg
http://i674.photobucket.com/albums/vv109/bdouglas_photos/IMG_6120_1.jpg

[Byron Douglas]

Hi all, special thanks to the Bigfella for helping get the photos up - really helpful.

I would be interested to know what you mean by a cutlass bearing? I have looked around other boats but have not seen such a set up as mine but it is what the boat had when I bought it. Do you think it would work with packing on each side of the stuffing box (between the stern bearing and stuffing box and on the inside at the stuffing box) with grease in the stuffing box tube? I'll certainly look for the packing material you suggest and not use the silicon stuff.

For those interested we have installed a Simplex 8-10hp petrol engine. Would have liked a compact diesel engine but we are on a budget (if that's ever possible with a boat) ahahaha
Cheers
Byron

[The Bigfella]

When I bought my stern bearing ( a Briggs casting via Mike at Wooden Boat Fittings) - there was a choice of two types - with or without a cutlass bearing insert. I've got the one without - which is like the new one just in front of your prop. The old fitting just in front of it would appear to be the style that takes a cutlass bearing.

The cutlass bearing allows water in to lubricate the shaft as it turns.

Here's a shot of a cutlass bearing that has just been installed in a strut.

http://www.pbase.com/mainecruising/image/111689384.jpg

That photo comes from another forum and its a good post by the guy who replaced the bearings on his yacht. I just found it when I googled up cutlass bearings - obviously a bit different, given its on a strut.

http://forums.sbo.sailboatowners.com/showthread.php?t=107374

I don't know who the local prop people are, but if I had your setup, I reckon it would be worth taking it to them (I know Porters in Sydney)

Have you had that old stern bearing out? It looks to me like a modification after a problem in that area. Shouldn't be a worry if it is solid and aligned.... but as I say, I think you just need a cutlass bearing insert in the old fitting.

[hansp77]

Nothing add to your queries, just saying a quick Hi and Welcome.
Nice work on your Couta.
Where are you going to moor it? There are a few nice Couta's around my swing mooring in St Kilda.
Hans.

[peter radclyffe]

When I bought my stern bearing ( a Briggs casting via Mike at Wooden Boat Fittings) - there was a choice of two types - with or without a cutlass bearing insert. I've got the one without - which is like the new one just in front of your prop. The old fitting just in front of it would appear to be the style that takes a cutlass bearing.

The cutlass bearing allows water in to lubricate the shaft as it turns.

Here's a shot of a cutlass bearing that has just been installed in a strut.

http://www.pbase.com/mainecruising/image/111689384.jpg

That photo comes from another forum and its a good post by the guy who replaced the bearings on his yacht. I just found it when I googled up cutlass bearings - obviously a bit different, given its on a strut.

http://forums.sbo.sailboatowners.com/showthread.php?t=107374

I don't know who the local prop people are, but if I had your setup, I reckon it would be worth taking it to them (I know Porters in Sydney)

Have you had that old stern bearing out? It looks to me like a modification after a problem in that area. Shouldn't be a worry if it is solid and aligned.... but as I say, I think you just need a cutlass bearing insert in the old fitting.
i agree, is the old bearing white metal, how do you grease it thru 2 sleeves, is the old shaft badly worn at this point

[Byron Douglas]

thanks so much for your help - sounds like it would be worthwhile for me to go in search of a cutless bearing. I'll try and search out a propellor etc expert in Melbourne. I have shortened the propellor shaft because I have mounted the engine aft. When we got the boat the centreboard case had been plugged up and it had a motor mounted in the centre. The original shaft had some bad scoring in it so when I had it shortened I cut that section off. I have also had to have a new tube for the stuffing box made up some time ago which we refitted as the old one had worn away. I suspect that the old engine that had been in the boat (a lister I think) was not properly aligned.

I hope to have the boat in the water for this summer - a ten year restoration is long enough!!!! (we did put it in moth balls for a few years while we built an extension to our house). The last two major projects before getting it caulked is to make a new petrol tank and have a 1/2" steel centre board made for it. Then its connect the engine, electrical wiring and .......Bob's your Uncle its in the water....welll isn't it? We plan to moor the boat in Mordialloc Creek down here on Port Phillip Bay and hope to hook up with other Couta boats.

The help on the forum is very much appreciated!

[The Bigfella]

Byron, I've got a couple of photos here of various bits and pieces.

First up, this was a setup I bought via ebay... the prop separately, but here is how it was on someone's boat. They have used a stuffing box externally as a stern bearing.... as has someone else in the third photo. Back to this one... this is the external setup

http://i240.photobucket.com/albums/ff112/igatenby/iansecond/p1.jpg

and the internal part, which uses a bit of rubber hose to allow the stuffing box to self-align.

http://i240.photobucket.com/albums/ff112/igatenby/iansecond/p2.jpg

This setup came with another engine I bought.. a self-contained setup. Sorry about the picture quality

http://i240.photobucket.com/albums/ff112/igatenby/iansecond/p3.jpg

The two pieces here are new Briggs fittings, via Mike at woodenboatfittings.com.au - the stern bearing on the left, the stuffing box on the right

http://i240.photobucket.com/albums/ff112/igatenby/iansecond/p4.jpg

I'm using an epoxied-in PVC conduit between the two. That way, the water can be inside the tube and not affect the timber in the keel. The old way was for the hole through the keel to be tallowed... a pot of hot tallow would be poured through the hole to seal the timber before inserting the shaft, bearing and stuffing box.

Finally, a shot of the nut off the new stuffing box. It has two rings of waxed flax in it. I think I mentioned two or three earlier, but it is definitely two.

http://i240.photobucket.com/albums/ff112/igatenby/iansecond/p5.jpg

The flax isn't recognisable in the other stuffing boxes I have unless you pick at it with something sharp, because it packs down and gets dirty looking - nothing wrong with that as long as it seals OK. As I said earlier, the idea is to have a drip or two coming in anyhow, otherwise the nut is probably too tight.

Cheers
Ian

[Byron Douglas]

Hi Ian,
Really appreciate the pictures!!! Its amazing how helpful they are. My set up is similar in that I have a bronze tube that threads on to both ends of the stuffing box but that my external fitting is weird when compared to others. It almost appears that the stern bearing is a bit surplus if the fitting that is screwed to the boat had a cutlass bearing. Given that this was how the boat was set up and it has a bronze tube connecting both fittings would it work as is if I put grease in the tube and the packing material at both ends and bolt the external fittings together???
Cheers
Byron

[The Bigfella]

The inside bit of your boat is what I would consider usual - just a normal stuffing box. It is the stern bearing that has me a bit flummoxed. As I mentioned earlier, it seems to be a repair that has been made over the years after something has happened to the keel.

What does the shaft bear on in that old fitting? Why is there a gap around the shaft at the rear? Was there a white metal bearing or cutlass bearing that is now gone? Or, something that screwed in there?

Sorry... more questions than answers. Any old couta boaters around where you are who could take a look?

[peter radclyffe]

The inside bit of your boat is what I would consider usual - just a normal stuffing box. It is the stern bearing that has me a bit flummoxed. As I mentioned earlier, it seems to be a repair that has been made over the years after something has happened to the keel.

What does the shaft bear on in that old fitting? Why is there a gap around the shaft at the rear? Was there a white metal bearing or cutlass bearing that is now gone? Or, something that screwed in there?

Sorry... more questions than answers. Any old couta boaters around where you are who could take a look?

me too, ive never seen 2 stuff boxs on a shaft, which is what it appears

[Byron Douglas]

Hi There,
I agree with you guys that it is an unsual set up (nothing is ever straight forward). Yes I agree that inside is normal but the outside is not. Thanks I think I have got the photo thing happening now!
http://i674.photobucket.com/albums/vv109/bdouglas_photos/IMG_4236.jpg

http://i674.photobucket.com/albums/vv109/bdouglas_photos/IMG_4237.jpg

The second photos shows how it is threaded on the the tube that connects to the internal stuffing box. The other fitting just bolts on to it - the shaft is a snug fit. I haven't seen this on any other boats. You could be right that it is some sort of repair - I'll check the fitting tonight but I'm pretty sure there are no signs of bearings, bolts etc.
Cheers
Byron

[Gary E]

Since what you have here is a small boat, and usually driven by sail, and only sometimes driven by a very low powered motor that the drive was designed for very intermitent use, in other words, 10 mins to get the sails up, and 2 hrs later another 10 mins to get them down and the boat tied up.

Now, assuming that, I see a grease fitting on the inside and a close fit bore to the shaft on the outside just ahead of the prop. Is it possible that the intent here is to fill the space around the shaft with grease and what drifts out the stern bearing is replaced by a couple a shots from a grease gun every once in a while? I think this is what I would do with THIS BOAT... remember, it's not a high torque high speed shaft running at high RPM and it's not turning for a very long time. Its only a toyboat, used once in awhile.

In case the rear fit is not "close" and I mean in machinist speak, a "good fit".. I'd install either a short cutlass brg or a proper fit bronze bushing to prevent any side to side or up and down shaft movement.

[peter radclyffe]

Since what you have here is a small boat, and usually driven by sail, and only sometimes driven by a very low powered motor that the drive was designed for very intermitent use, in other words, 10 mins to get the sails up, and 2 hrs later another 10 mins to get them down and the boat tied up.

Now, assuming that, I see a grease fitting on the inside and a close fit bore to the shaft on the outside just ahead of the prop. Is it possible that the intent here is to fill the space around the shaft with grease and what drifts out the stern bearing is replaced by a couple a shots from a grease gun every once in a while? I think this is what I would do with THIS BOAT... remember, it's not a high torque high speed shaft running at high RPM and it's not turning for a very long time. Its only a toyboat, used once in awhile.
for peace of mind i would fit a cutlass

[The Bigfella]

Yep, that new stern bearing shot does it for me. You should be able to order up a cutlass bearing easily enough from a prop supplier. Three dimensions needed - shaft diameter, outer diameter of bearing (ie the diameter of the hole) and the length.

When I did Grantala, we had to turn down the bearings to fit inside the struts, but you might be lucky and get an off the shelf size. The same supplier should be able to sell you some stuffing box material - you will only need a foot or so max. Don't go overboard loading the tube up with grease. The idea is to be able to spin the prop fairly easily. Check that it does with the clutch engaged too (take the plugs out of the engine). You should have the flanges lined up with a max runout of 1 thou per incb of flange diameter to ensure good running. Check it again in the water.

[Byron Douglas]

so are you sugesting that the cutlas bearing goes into the stern bearing or the external fitting on the boat? If I'm assuming correctly that it is the later (the external fitting on the boat) then do I do away with the stern bearing altogether?
Cheers
Byron

[The Bigfella]

Yep. You should only have a total of two fittings - the stuffing box (inside) and a single fitting on the keel - a stern bearing, which in your case will have a cutlass bearing in it. The shinier stern bearing can go into your spares box then.

[jackster]

I think I disagree, (yet another interloper).
In the second picture on post #24, it shows the lip to compress the packing, which is compressed by what you are calling, I believe, the stern bearing by tightening the nuts.
I think (I could be very wrong, though) the reason for two stuffing boxes was to keep the water out of the shaft alley, as has been mentioned.
With a cutless installed with no seal, water would be allowed where it hasn't been before.
At least that is my take on things. What do you all think?
There is a " Tournament Series" Buck Algonquin stern bearing in the Hamilton Marine catalog that seems identical in concept. www.hamiltonmarine.com search 'stern bearing'
And the grease fitting inside kept the alley full of... well grease.

[boattruck]

Bryon, You have what the old timers called a 'packed' or 'built up' bearing, it used many strands of flax packing, they were used by boats that worked in close to the beach to reduce sand damage to the shaft. I have one on my boat and have used it hard for 15 years, add a strand or two every haulout... You are going to need to cut off the long bronze boss off the newish aft most fitting, turn it around so it snugs up against the packing strands, it is important that the bronze clamping bolts have some sort of wire keepers, as there is vibration potential here, the other more modern option is to fit a rubber cutlass bearing (the housing may need to go to the machine shop to be bored to receive the bearing) hope this is some help, Cheers.

[The Bigfella]

Well done Boattruck (and welcome)

[peter radclyffe]

Bryon, You have what the old timers called a 'packed' or 'built up' bearing, it used many strands of flax packing, they were used by boats that worked in close to the beach to reduce sand damage to the shaft. I have one on my boat and have used it hard for 15 years, add a strand or two every haulout... You are going to need to cut off the long bronze boss off the newish aft most fitting, turn it around so it snugs up against the packing strands, it is important that the bronze clamping bolts have some sort of wire keepers, as there is vibration potential here, the other more modern option is to fit a rubber cutlass bearing (the housing may need to go to the machine shop to be bored to receive the bearing) hope this is some help, Cheers.
thank you for explaining this bearing system

[Byron Douglas]

Many thanks with the assistance - I have learnt heaps from all your shared knowledge. I now have more of an idea what this part of the boat does now. I feel a lot more at home with the woodwork stuff on the boat but a bit 'out to sea' with this engine type stuff but i am slowly learning. Thanks again!

[Byron Douglas]

hi all,
Just to let you know that I took the plunge and refitted the propellor shaft after being out of the boat for the last 10 years during the rebuild. I found the packing that the Bigfella recommended and fitted to both sides of the stuffing box which went in really well. I took Boattruck's advice and cut down the stern bearing by about an inch and rebolted. The prop now turns really well - no slop in the shaft. I guess the real test will be when I get the boat finally back in the water at the end of the year and tighten up the stuffing box nut. Anyway - thanks again to all the gang for the help!!!!!
Cheers
Byron

[Gary E]

Yep. You should only have a total of two fittings - the stuffing box (inside) and a single fitting on the keel - a stern bearing, which in your case will have a cutlass bearing in it. The shinier stern bearing can go into your spares box then.

The original setup has a GREASE FITTING...
What's it for?

[Byron Douglas]

I assume the grease point is to provide grease to the bronze shaft log and the propeller shaft - I have pumped some grease in there - will be interesting to see how it all works - its from the original fitting so I can only assume that this is what it was for.