Cutlass Bearing Housing from Epoxy ?

[Reefmagnet]

Hi Guys,

Just about to start installation of a Beta Marine 14 into my Albin Vega. Because the original bearing housing has been sawn off flush where it exited the boat, I need to reconstruct a new bearing carrier. Having put some thought into this and not really finding anything available to replicate the original setup, I'm leaning towards building a bearing housing out of epoxy / cloth in situ to take a standard 1" x 1 1/4" x 4" non-metallic Johnson Duramax bearing (I'm using imperial drive shaft components). I'm intending to coat the bearing in release wax before bedding into the carrier with epoxy in order to make future replacement easier, as I have read that this is an acceptable method.

Here's a picture of my boat:


On the Vega, the prop shaft is about 4 feet long, poking out about another 8 inches from this carrier holding the only bearing. The outside diameter of the bronze tube (the remains of the old carrier) is about 1 3/8". It goes back into the shaft log about 2". The shaft log itself has an ID of about 1 1/18".

Now, before I commit, does anyone see any reason why this would not work with the Vega, particularly in regards to overall strength and water flow into the shaft log to keep the bearing lubricated?

[psneeld]

Holding the bearing is not really a problem...to a point...our fleet of Shamrocks (power boats) originally came with culass bearings in a fiberglass strut to keel setup.

After years of heavy work, often in heavy sand/silt environments (talking over 25 years)...the bearing hole did enlarge and it was difficult to keep the cutlass bearings in place till we retrofitted with a stainless strut/keel setup.

Also...not sure how you are going to add this set up to your existing keel so I can't comment on planned strength of your idea.

Did the last setup have a water tube line going into the stuffing box?

[Reefmagnet]

Hey thanks for the reply. Doubt I'll still have the boat in 25 years so any long term wear can be someone else's problem LOL. The original setup has long gone and I have never seen the original stuffing boxes though the trend is to use a Volvo or PSS stern gland. I'm going with the Volvo on this job. I do know the original bearings were a solid type made from something like vesconite, but I have no idea how long they were originally.

[SabreKai]

I'd suggest trying to remove that 2" section of bronze tube and see if you can put in a new piece the same length as the original. Then build up the missing glass section with cloth, roving and epoxy.

Getting the tube out will be a trail but I think it can be done by using a hacksaw blade or long bladed sawzall to cut slices down the length of the bronze tube, then chisel or beat out the bits with a drift and hammer. Once out, set the new one in place with epoxy, then start the build up.

Option two would be to put a snug tube into the original bronze tube, then add a new section over the insert. Then build up the fiberglass around the new piece.

[Boracay]

Why not have a "tube" machined up to fit into the existing tube, with the centre machined to fit the cutless bearing. You may need to drill a hole for a set "screw" to stop it turning.

It could be done in epoxy/fibreglass but I'd always worry about getting an accurate fit and wear and tear.

I would not be surprised to find that cutless bearings take a little bit of misalignment but they'd need to be solidly and securely supported.

[Sonrisa]

We went though something similar when installing a beta 28 into our boat a couple of years ago. We ended up purchasing a bronze shaft log from a company called Buck Algonquin.

This is the one that we installed:

Buck Algonquin...Quality Marine Hardware Since 1955

But I just noticed they have another line of products called "Albin Bearing Housings", which state they were originally manufactured for Ablin Manufacturing... maybe one of those would fit...

Buck Algonquin...Quality Marine Hardware Since 1955

Good luck!

[osirissail]

Rather than do all that work why not bolt on a "stern bearing" which is a bronze fitting that bolts to the outside of the hull and accepts a cutlass bearing. The base flange comes without holes so you can drill them where you need depending upon the boat's hull configuration. Here is an example and source: STERN BEARING HOUS 1" 3.25" X 5" OVAL BASE 103579

[psneeld]

Originally Posted by osirissail

Rather than do all that work why not bolt on a "stern bearing" which is a bronze fitting that bolts to the outside of the hull and accepts a cutlass bearing. The base flange comes without holes so you can drill them where you need depending upon the boat's hull configuration. Here is an example and source: STERN BEARING HOUS 1" 3.25" X 5" OVAL BASE 103579

Good point... that's what's on my Albin 40..

[Reefmagnet]

Originally Posted by osirissail

Rather than do all that work why not bolt on a "stern bearing" which is a bronze fitting that bolts to the outside of the hull and accepts a cutlass bearing. The base flange comes without holes so you can drill them where you need depending upon the boat's hull configuration. Here is an example and source: STERN BEARING HOUS 1" 3.25" X 5" OVAL BASE 103579

Thanks again guys.

That was the original plan A but I don't think there is enough "meat" around the existing hole to screw the flange to so I would need to build it up and the other thing is those things are darn'd expensive compared to the epoxy route if I don't allow for my labour, which I don't. Now that I've been sitting on this for a couple of days, I'm thinking I'll use a piece of 32mm pvc electric conduit as a former and wrap 4 or 6 inch tabbing cloth around it til the OD builds to the 1.5" I have available. I'll then wrap 2" tabbing cloth around one end to build up to 1.75 inches. The 1.5" end will be trimmed to a 2" depth and inserted into hole where the old carrier was (after extracting the stub of brass tube). This will leave 2" in and 2" out for the bearing. Since the engine itself has a plastic / rubber anti-vibration coupling that I guess will shear in the event of something serious grabbing the prop while it is spinning, I think that this arrangement would be strong enough.

Ideally I would like to get hold of a piece of 1.25" x 1.5" naval brass or 316 stainless tube, but around here it's nigh on impossible to buy in a 4 inch length!

[Don1500]

Originally Posted by Reefmagnet

Thanks again guys.

That was the original plan A but I don't think there is enough "meat" around the existing hole to screw the flange to so I would need to build it up and the other thing is those things are darn'd expensive compared to the epoxy route if I don't allow for my labour, which I don't.

I'd be a little cautious about that. At $129 I don't think it's too expensive. If only for the peace of mind. Building up the mounting area is easier and more secure than attempting to do something you haven't done or had anyway to test. I would not want the bearing to fall out or the epoxy casing to fail 50 miles off shore.

[Reefmagnet]

Originally Posted by Don1500

I'd be a little cautious about that. At $129 I don't think it's too expensive. If only for the peace of mind. Building up the mounting area is easier and more secure than attempting to do something you haven't done or had anyway to test. I would not want the bearing to fall out or the epoxy casing to fail 50 miles off shore.

Hey Don, at that price I would get 2 as I was quoted $380 from a mob in Sydney! Still, because of the weird offset shaft log of the Vega, there would still be a degree of work required anyhow to get it to bolt up.

[Don1500]

Sorry, Didn't notice the Qld.

The piece shown in the link is $129, add shipping to that, if it's the right size.

STERN BEARING HOUS 1" 3.25" X 5" OVAL BASE 103579
ENGINE / DRIVE ACCESSORIES



Item #: BKA-STBO100

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List Price: $163.31 / EACHYour Price: $129.99 / EACH * Item on order. Will ship when available



Oval Base Shaft: 1", Casting Bore: 1-5/8", Pilot Dia: 2-1/8", Pilot: 1/2", Flange: 3-1/4"x5", Length: 5-3/8"

Still think this is the way to go.

[4HMainer]

An easier solution is get a composite bearing made to suit the existing tube, and bed on epoxy as you planned.

Have a dry run with the shaft chocked and you'll see if it is all aligned then coat in epoxy and insert bearing.

These guys work with composite bearings that can be finished to any OD and perform very well when compared to other materials such as rubber.
info@stellamarine.com.au seeing as you seem to be in OZ?

[sdowney717]

An easier solution is get a composite bearing made to suit the existing tube, and bed on epoxy as you planned.

Vesconite comes to mind. They can machine cut any size you wish and the material is used for prop shafts.

I replaced two rubber lined bronze bushings for very little money including the air delivery shipping. The price difference was extreme and the vesconite product was just fine. I saved at least 150 dollars
These bushings self lubricate and last a long time.

Vesconite Manufacturer Home Page: Low maintenance bushes and bearings

there are two version of vesconite, vesconite and vesconite high lube.