Evan,
Welding a stern tube in place will almost always cause cupping and
distortion because of diagonal nature and the length of the weld. When I did
mine, I used a much larger tube for welding, Then suspended a straight tube
within the welded tube and filled the space between the two with casting
plastic, which is used to make engine mounts on large ships. The inner shaft
tube is supported inside the hull by a thrust bearing assembly and outside
by an integral P bracket. In my case, I used a oil pressure fed bronze
bearing & lantern ring assembly followed immediately by a packing gland with
a compression ring. These are positioned directly under the P bracket at the
rear end of the tube.
Steve

"Evan Gatehouse" wrote in message
...
Paul Baker wrote:
Hello all.
I have a 34' aluminum sailboat hull that was built some time in the
late 1970's but never finished until now. The stern tube is sch.80
aluminum pipe and was welded by the builder, my question is two fold,
first does any one know of a cutlass bearing to fit pipe approx 1.9".
And second the stern tube seems too be a bit oval, maybe (3/64"-1/32")
probably from welding. Any suggestions?
Thanks Paul

What is your shaft size? - if ~1" then you could fit a cutless bearing
with a 1-3/4" OD. Pack the ovalized gaps between with epoxy thickened
with microfibers. Coat the cutless bearing with a few layers of mylar
packing tape else you will never get it out!

Otherwise, remove the distorted one and re-weld in a round one.

As others have pointed out you should use a bearing with a fiberglass
shell, not bronze. Not as common but they do exist.

Evan Gatehouse