Propellors Ally or Stainless Steel???

[timbad]

I have a Princess year 2000 V42 with Kadd 44s with 290 duo prop legs, she will come out around June time for anti foul etc... She needs new props as original aluminum B4’s have pin holes, corroded and generally very tired. (Will send them away for rebuild & keep for spares)

Can’t decide if I should replace with Ally, relatively inexpensive for a boat that is!
Cost is approx £800 both legs and I am lead to believe they are not too bad for galvanic corrosion.

Or should I replace with Stainless steel (approx £2000 both legs) to give me better grip in the water, slightly better performance / fuel consumption
Against cost, double the price and will have to double & add anodes
Does anybody have any experience or advice they can pass on as I don’t want to get it wrong.

 

[capnjack]

Tim,
Ask yourself, will you keep the boat for a further 5 years? If not then why waste the difference in performance for the larger cost?

If it were a powerboat or a sportsboat looking for performance I would always recommend stainless over ali as aluminium will flex under power to a greater extent than stainless steel.

You have already answered the question to a degree, by asking about the fuel economy and by quoting the difference in cost. It's the old rule, if you have to ask, it ain't worth it.

As far as corrosion is concerned, yes aluminium will be less corrosive than stainless. The aluminium in the legs with stainless props will be more vulnerable, but this is not a major issue and a few more zincs will help.

The main consideration has to be performance against cost and to be fair, £1600 is not a massive difference. However, you can still get cavitation with stainless props and when this happens, they can wear every bit as much as aluminium.

I think, if this was me and I had just bought her and she required new props, I would buy stainless, but as it is now why worry?

 

[duncan]

I would echo all that and add the following

1. trade the old props in against the new stainless ones or pm depsol for a quote for new props (which may be better than the price you have already). Unless you are Col you shouldn't need spares with stainless.
2. where you boat also has a bearing - shallow (mud, shingle, sand) like Poole Harbour or the East Coast will finish alloy props pretty quick (just look round the racking boats in Poole harbour!!!) but simply clean stainless ones!

I did 2 alloy props in 3 months cruising the Medway with my first boat and have had stainless on all 3 boats since without more than a tiny nick in the leading edge of one blade.

Have a good season whatever.

 

[Col]

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[oldgit]

In the for sale section are a couple of dirt cheap stainless 290 props,rears only but it would only leave the fronts to purchase.