Severe aluminum shaft log corrosion/deterioration

Unfortunately you are looking at a fairly extensive and expensive repair. Bronze cutlass bearings are a no-no in aluminum shaft tubes, even when potted in with Chock-fast there is usually an electrical connection to some degree that will swiftly eat the adjacent aluminum. Composite bearings and seals are essential to long life in those tubes.

We just went through a shaft tube replacement on an older aluminum hull that a P.O had replaced the bearings with bronze and they were also corroded to the point of failure, most severe pitting was at the inside end of the bearings. Those tubes also pass through the main fuel tank (what kind of designer came up with that brilliant idea?). Tanks had to be drained cleaned and certified safe for hot work by a marine chemist. Here's a couple pics of the damage.

Because it was outside our area of expertise, Ocean Alloys/Seaworthy Services in Palm Beach Gardens was contracted to make the repairs and I can wholeheartedly recommend them. They specialize in aluminum hulls and repairs and do this everyday. Before installation make sure you have them barrier coat the insides of the tubes which will greatly increase their life span, most OEM's suprisingly do not do this.

I've utilized Ocean Alloys/SS several times and they have also earned my recommendation. Talk with Randy.




Moderator please remove if not allowed; thanks.

Just went through this on an 1988 Broward, looked the same on the outside. On the inside the log had corroded so badly that it broke the fiberglass cutlass bearing and squeezed it into a heart shape! We ended up cutting 6' of the logs on the end. Nobody involved could believe the shafts even turned! Boat jumps like a sportfish now when you drop it in gear and fuel burn was cut buy 40%!

Several of the Browards I ran over the years had a good amount of pitting from where the stuffing box dripped. Most of them were changed to dripless stuffing boxes to aleviate that.

You're being very generous. I'm sorry but, those welds look awful.

I agree.

Those logs look like they were welded without first having the oxidation cleaned/removed............. And yes those are awfull looking welds, too cold ,no penatration. They should be ground out and redone. The blackness around the welds to me suggest maybe a mig with flux core wire might have been used ????? Thats far ,far away from a quality weld job.You can't magnaflux aluminium but you can dye test and check for cracks/voids under UV light.

Either a mig with 100% argon shielding gas or a tig welder should should have been used.

I have to agree, those welds are atrocious and need to be ground out and completely redone. This is what the ones looked like on that Burger project I referred to, not shaft tubes but this is what they should look like..