Motor Boat Forum

by **MartynG** » 10 Apr 2016, 19:50

When the boat was lifted the legs were a rather dark colour. Seems like limescale and responds to limescale remover.
Cleaning off the coating has taken quite a bit of work .

.

by **Ianfs** » 11 Apr 2016, 20:32

Good job bringing the legs back to life, they look like new.

Do you think that the props have been sacrificed, i.e. they're aluminium and the weakest part which has had paint taken off and therefore become exposed? Concluding that the Magnesium or Aluminium anodes, not sure which one's you may have for the waters you boat, might be more resistant i.e. may not be as sacrificial?

by **MartynG** » 11 Apr 2016, 21:24

Ianfs wrote:Good job bringing the legs back to life, they look like new.

Do you think that the props have been sacrificed, i.e. they're aluminium and the weakest part which has had paint taken off and therefore become exposed? Concluding that the Magnesium or Aluminium anodes, not sure which one's you may have for the waters you boat, might be more resistant i.e. may not be as sacrificial?

Aluminium anodes are fitted .
The anodes have corroded somewhat, which is of course what they are supposed to do , but the anodes live to fight another year.
The paint has flaked off the props. It doesn't seem to me unusual to lose the paint off duoprops . I take your point about the props have possibly acted as anodes a little .
We are on fresh water with occasional salty trips so aluminium anodes make sense . Magnesium risks fizzing away to nothing in sea water .

by **Ianfs** » 11 Apr 2016, 22:23

I read somewhere that an investigation and survey which tested outdrive parts and propellers, depending upon where the boat is moored, that is, in brackish, fresh or sea water, that if you have more sacrificial material than is necessary, it may be possible for your items which should be protected to become the sacrifice.

I've not experienced this yet but, I can see the potential. It is actually quite scary, however I would rather have my props worn away and spend a few bob having them refirbed than having an outdrive replaced.!

by **ColinR** » 12 Apr 2016, 11:35

All cleaned up, nearly there

: Monterey.jpg (73.04 KiB) Viewed 12556 times

by **Ianfs** » 12 Apr 2016, 11:56

Blimey Colin, you had better not put that boat on the water if the sun is shining, the reflection will be so bright if people are not wearing sunglasses they'll be blinded! :mrgreen: