New cutless fitment issue?

[Saltyhog]

I'm replacing the cutless bearing on a Bayfield 32. It's a full keeled boat and the cutless bearing is in the tail-piece on the trailing edge of the keel. Prop is in an aperture. The cutless bearing is only about 2" long (I had to cut a new bearing in half) and fits into the tail-piece. There is a shoulder in the tail-piece that determines the cutless bearing length. Bearing is for a 1" shaft and is 1.5" OD. I removed the old cutless bearing and the new bearing is not what I would call an interference fit. It readily slides into position. It's not sloopy loose, but it's not really tight either. There is a set screw to hold it in place in the tail_piece, but I would think the bearing should need to be pressed into place. I was thinking of wrapping the new bearing in some copper foil before installing just to tighten things up. Or am I over thinking this and should I just install it?
-Tom

[rtbates]

Don't use copper, dissimilar metals equal electrolysis

I've heard of folks using epoxy..

[Saltyhog]

Originally Posted by rtbates

Don't use copper, dissimilar metals equal electrolysis

I've heard of folks using epoxy..

Hmmm... The tail-piece is bronze (mostly copper) and the cutless bearing is navel brass (also mostly copper), so I'm not sure that electrolysis would be much of a problem (Although I admit I don't remember much from my chemistry classes). I do like the epoxy idea though. Would be easy. I wonder if thickened or unthickened would be best. There is not much room for it, so I'm thinking maybe very slightly thickened would be best.

[sdowney717]

I used a plastic bearing. Much much cheaper. Like $100 cheaper at least.
It is called Vesconite. I got it by airmail from South African company.
Nice guys and even called them up to talk.
They got two types of vesconite for shafts.
I think one is better if always in the muddy water.
http://www.vesconite.com/

[barnakiel]

Same inner dia can come with different outer dia. You sure using the proper size?

b.

[bobconnie]

Gee any machine shop even a school shop could make a bearing to fit as you want it to for probly the same or close to the same price, and you can get it to even fit !!! I know Im being nasty but thats what machine shops are for LOL is to get things to fit without epoxy which will make for a all new problem when ya change it next time !! Believe me Ive been there done that trying to get things from Marine stores to fit the way they should!! it's easy to take a few mesurements and get one made just to fit your needs !! Just a thought

[Cheechako]

a cutlass bearing only 2" long? wierd.... Is it posible some other brands are larger on the OD? I'd rather see it machined to just lightly force in than too loose.
Hey Bob, how is the machine shop going to make the rubber insert?

[bobconnie]

Same way they always have !! With machines !!LOL who do you think make these for the Marine stores to sell, a machine shop somewhere even if its in China, it's still a machine shop !! again just my 2 cents

[gunkylump]

Originally Posted by Saltyhog

I'm replacing the cutless bearing on a Bayfield 32. It's a full keeled boat and the cutless bearing is in the tail-piece on the trailing edge of the keel. Prop is in an aperture. The cutless bearing is only about 2" long (I had to cut a new bearing in half) and fits into the tail-piece. There is a shoulder in the tail-piece that determines the cutless bearing length. Bearing is for a 1" shaft and is 1.5" OD. I removed the old cutless bearing and the new bearing is not what I would call an interference fit. It readily slides into position. It's not sloopy loose, but it's not really tight either. There is a set screw to hold it in place in the tail_piece, but I would think the bearing should need to be pressed into place. I was thinking of wrapping the new bearing in some copper foil before installing just to tighten things up. Or am I over thinking this and should I just install it?
-Tom

For what it's worth, in my opinion, I would first make sure that you have the proper replacement, you really shouldn't have that much play, you should have to press it into place. I would think that if you use epoxy or the like, that if you ever have to replace the bearing down the road, you will be in for some additional complications removing the old bearing. Did you have to press the old one out? Most applications call for pressing the old one out, perhaps the wrong bearing was already there?

Check out the specs for a new bearing from the manufacturer perhaps, and if that option is not available, take some measurements and get a proper fitting bearing. Might take you longer, but down the road, you'll appreciate having done so.

Just my 2 cents....

gunk

[Cheechako]

Originally Posted by bobconnie

Same way they always have !! With machines !!LOL who do you think make these for the Marine stores to sell, a machine shop somewhere even if its in China, it's still a machine shop !! again just my 2 cents

I guess I had assumed the rubber insert with the grooves was molded in the brass tube.
For the OP, I suppose it would work out to use brass shim stock as your bearing is only a couple of inches long. But there are differences in bearing OD's sometimes.

[cal40john]

My friend's Cal 34 has a loose fit. He used brass shim stock to make a slightly tight fit. Put some flats in the cutless bearing where the set screws seat. I think the bearing was always loose as the previous owner had a bearing removal tool that was just a springy rod bent in a U with outward turning tips. You flex the sides to get the top of the U in. When it gets past the bearing the outward bent tips pop out. You grab the bottom of the U and pull.

I discovered my Cal 40 has a loose fit when the cutless swam up the stern tube. Can see the spiral scratch marks of the set screws as it spun up the stern tube Installed the bearing the same way as above. Previous owner had put in a new G-10 stern tube just a few years before, so it wasn't wear.

Both the Cal 34 and 40 have the prop shaft coming out of the back of the keel.

John

[Cheechako]

Good Point: be sure to make a divit with a drill point where your set screw hits the cutlass bearing!

[Blue Stocking]

Isn't the Bayfield a Canadian built boat. If so, like my earlier C&C Redwing, you may be mixing metric sterntube with Imperial bearings.

[Saltyhog]

Originally Posted by Blue Stocking

Isn't the Bayfield a Canadian built boat. If so, like my earlier C&C Redwing, you may be mixing metric sterntube with Imperial bearings.

Yep, Canadian boat. The shaft is 1" (25.4 mm). Definitely not 25 mm. The only close fit metric bearing is for a 25 mm shaft and 40mm OD. 40 mm = 1.575 in. There is no way there is an .075 slop there. I think more like .002 - .004. It slides in, but there is little or no slop at all. I know it's been replaced in the past based on the cuts visible on the inner surface of the tail piece. I'm guessing someone emery papered the inner surface to "help" the new bearing in, and they over did it a bit. Already dimpled the new cutless bearing for the set screw.

[4HMainer]

Just to add a bearing supplier perspective to the discussion and clear up some worries.

Maritex bearings are always fitted as a clearance fit in the carrier unless the customers insists on an interference fit.

The recommended fit process is to have them a close clearance fit and then bedded on a thin film of epoxy. As someone mentioned removal being an issue, as long as you use the recomended epoxy (low temperature) a little heat softens the epoxy and wllows the bearing to be slid out. There are never any corrossion issue which is a particular benefit on Al struts/tubes. We even use an epoxy bedding in GRP tubes and the epoxy splits and seperates easily (epoxy less than 1.00mm thick in thin film doesn't strictly bond)

This method is approved by Lloyds for class vessels and is used on hundreds of leisure/commercial vessels with shafts from 1" to over 20"

Maritex bearings are finished to whatever size carrier and shaft is there, so sizes metric or imperial are not an issue, you just order based on shaft OD and carrier ID. Or you can finish the OD locally using our calculator.
http://www.h4marine.com/Downloads/Ma...2020100519.xls