Restoring outboard skeg

[fizzy]

My outboard skeg - aluminium - is quite heavily pitted through electrolytic corrosion. Leg left down in the water too long when I was too ill to attend the boat.
Anyway I was thinking of sanding it or wire brushing to remove loose deposits. Then filling it with epoxy mixed with aluminium powder as a filler.
The aluminium is pretty powdery - do I need to etch it first? An epoxy supplier told me to apply the epoxy and rough it up with a wire brush through the liquid epoxy.
Or is there a better way?

 

[the snooper]

I would find a method of removing the corrosion especially if it has been in salt water as the salt expands I had 2 bolt on covers on my engine block and unknown to me salt was expanding behind them and eventually pushed holes through the covers

 

[brightspark]

sandblast it back to good metal 1st then fill it

 

[fizzy]

Only blasted steel before - is normal grit too harsh for aluminium? I have some crushed glass maybe softer?

 

[brightspark]

Only blasted steel before - is normal grit too harsh for aluminium? I have some crushed glass maybe softer?

use the kiln dried sand that your not supposed to for health reasons .; its great on ally a verry fine finish no damage

 

[fizzy]

Well I use a British Army Avon S10 gas mask - should cope lol.

 

[rtbcomp]

Don't use new glass grit on ally, it will embed. I use very worn down glass grit OK, but you need to use it on steel first.

 

[Fazerruss]

use the kiln dried sand that your not supposed to for health reasons .; its great on ally a verry fine finish no damage

I have used sand also with excellent results. My dad used it for 20 years blasting alternator brackets with no health issues.

 

[fizzy]

Obviously the health and safety brigade have never been caught up in a sandstorm. I lived in desert regions as a kid and they were a regular occurrence. You would need to put a blanket over your windscreen to stop it getting blasted. Wearing shorts it would sting rather a lot.
Obviously breathing large amounts of ANY dust is bad for you - whether it be sand, sawdust or similar.

 

[awemawson]

It's the silicosis in your lungs that's the issue, and it shows sometimes quite a long time afterwards - can be decades

 

[phill d]

why not just use bicarbonate of soda / baking powder / it wont hurt the ali and can be rinsed after wards with water.


Now being its a skeg on the bottom of your outboard, you probably need a new tab anode on the leg to stop it happening again.
when you put a new anode on make sure the area its going to is not painted, you need it to be on bare metal so it can do its job.

once you have cleaned it up and i mean real , just use chemical metal then when dry sand it back nice and smooth.
coat it with zinc outboard primer then put on the top coats etc.
while at it give the complete gearbox a fresh coat of paint to help keep it all looking nice.

is this by any chance a suzki ? suzi's were known as disprins down the coats due to almost dissolving in salt water.
Mainly because anodes put on top of thick painted surfaces, and the wire from the bracket to leg is not fitted to Suzuki outboards.



phill