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momo034 · 30-01-2022, 07:26

So I suffered a bent prop shaft from snagging a line that fell in the water (yea I know). When removing the old prop shaft the chunk of the stern tube about 4 inches (10cm) that extended out from the stern of the boat (and that held the cutlass bearing) broke off. I cant just slide the cutlass*bearing into whats left of the interior fixed stern tub because then the prop shaft would stick out way too far without any support and would get a bunch of wobble. Can't make a shorter shaft otherwise the prop would be hitting the hull.*

The boat is kindof an old junker and I plan to sell it soon so dont need the most perfect fix, but also want it to be safe and functional.*

The ideas I have so far is to have a 4cm in diameter solid bronze tube machined to specs that would slide into the existing inner stern tube with set pins and extend out with the correct specs to hold the cutlass*bearing and*then do some fiberglass work around it on the outside. But this will cost a lot of money (machine guy estimates 800 dollars). Attached some schematics to show how that would look.

I could also try and bore out 15cm or so of the existing stern tube and then find some stainless tube with a thin wall thickness and step down my cutlass bearing to one with a thinner OD and then slide the stainless in, secure it with set pins and (resin? Epoxy?) then slide in the cutlass bearing and then do some fiberglass work around it on the outside.*

I am pretty new to boating so not sure which of these ways would be the best considering cost, effectiveness, ease of implementation, etc.?* Or*perhaps another way entirely? One question: If I go with the idea of boring out some of the existing inner fiberglass stern tube, is there a trick to doing that? How far would I need to go to ensure stability and alignment*when I insert the new tube?

pcmm · 30-01-2022, 07:39

The best fix for the stern tube is to bore out the remnants (assuming it is fiberglass like other Out Islands) and glass in a new tube. Its not as hard as it sounds (I've done it) you just need 2 hole cutting saws. One the same as the ID of the stern tube and another the same as the OD of the stern tube. Assemble them on a mandrel and the smaller saw will act as a guide to help you bore out the tube and the tube only. then you can epoxy and glass in a new tube. Its about a weekends worth of work..

BTW. there is no such thing as a Morgan Out Island 8.5. Morgan didn't use metric in the model numbers of the Out Island. Its more likely that you have a Morgan Out Island 28.

momo034 · 30-01-2022, 09:29

Thanks, yea I am thinking that might be the simpler solution. I didnt realize they make hole enlarger bits: https://bit.ly/3HdDEob Would make the job pretty simple. Would just need a mandrel extension. One question....Im in a big rush to do this so would like to use whatever material I can find near where I live to avaoid having to wait for shipping. Is there any reason I couldnt replace the bored out fiberglass stern tube with one that is aluminum or stainless if I can find that easier? And just put some set pins in to hold it in place along with a bunch of epoxy?

Cheechako · 30-01-2022, 09:42

Quote:

Originally Posted by momo034

Thanks, yea I am thinking that might be the simpler solution. I didnt realize they make hole enlarger bits: https://bit.ly/3HdDEob Would make the job pretty simple. Would just need a mandrel extension. One question....Im in a big rush to do this so would like to use whatever material I can find near where I live to avaoid having to wait for shipping. Is there any reason I couldnt replace the bored out fiberglass stern tube with one that is aluminum or stainless if I can find that easier? And just put some set pins in to hold it in place along with a bunch of epoxy?

Not a good place for aluminum or SS. Just get a stern tube.
A fiberglass tube isn't too hard to make, but far easier to buy one. By the time you get materials and make one a bought one could be there.

foufou · 30-01-2022, 13:47

I replaced a stern tube (stainless steel) with a G-10 epoxy one from Mc Master Carr. it cost a bit over $100. I don't know if they ship to your location but I imagine someone does. And it is likely you have a tube that is not metric so a US source might be the best bet. I lined it up to the coupling to ensure alignment. I glued it in with 5200 and it has been fine for five years. An easy chore. Good luck

momo034 · 30-01-2022, 14:13

Quote:

Originally Posted by Cheechako

Not a good place for aluminum or SS. Just get a stern tube.
A fiberglass tube isn't too hard to make, but far easier to buy one. By the time you get materials and make one a bought one could be there.

Yes I found one with the right OD and ID that could work, super cheap even if I consider the overnight shipping. This guy: https://mgs4u.com/product/1-12-od-round-tube/

But does it have to be "marine grade"? I dont think this is made specifically for marine use, not sure it matters....

Martkimwat · 30-01-2022, 14:29

Heres a place in UK that does them and I'm sure they ship to Spain,

https://www.abcstore.co.uk/--LE--/Ve...7-187-725.aspx

or

https://www.abcstore.co.uk/--LE--/Ve...7-187-725.aspx

This second supplier I think has outlets in Europe (Nautic Expo)

With boats it's important to do the job properly or don't do it at all...

momo034 · 30-01-2022, 14:48

Thanks but I am all the way in Florida at the moment!

Martkimwat · 30-01-2022, 14:52

Quote:

Originally Posted by momo034

Yes I found one with the right OD and ID that could work, super cheap even if I consider the overnight shipping. This guy: https://mgs4u.com/product/1-12-od-round-tube/

But does it have to be "marine grade"? I dont think this is made specifically for marine use, not sure it matters....

It needs to be spiral wrapped tubing, not pultruded which is not anywhere near as strong despite what they advertise. The strands are unidirectional (one direction which is parallel to the length of the tube.) it will likely split as soon as your prop hits something and could then sink your boat if the split migrates up inside the boat..

momo034 · 30-01-2022, 15:27

Hmmm, well, glad I asked and thanks for the answer. That's unfortunate. I havent been able to find anyone in the US that has the proper stern tube and that cna overnight mail it to me (Im in a huge rush).

scherzoja · 30-01-2022, 15:31

Quote:

Originally Posted by momo034

Yes I found one with the right OD and ID that could work, super cheap even if I consider the overnight shipping. This guy: https://mgs4u.com/product/1-12-od-round-tube/

But does it have to be "marine grade"? I dont think this is made specifically for marine use, not sure it matters....

I bought tubes from mgs4u and they were suited my non-structural needs, but those tubes are very low quality, full of air pockets. I wouldn't use those for a stern tube. Even had un-wetted mat. They have a dye, so you won't be able to tell how well wetted-out or how much glass/resin.