Piranha anodes ?

syvictoria

Well-known member
Joined
12 Oct 2009
Messages
1,848
Location
Europe
Visit site
Hi. Does anyone have any opinion on Piranha (hull) anodes? They are much cheaper than MG Duff!

Also, thinking about going aluminium, rather than zinc, this time... We'll be heading for the French canals before long and plan to (perhaps!) use a hanging magnesium anode whilst moored. Do we need to worry about the heat exchanger anode (Beta, zinc)? It's expected to be a sloowwww trip (with a likely overwinter).

TIA!
 

vyv_cox

Well-known member
Joined
16 May 2001
Messages
25,979
Location
France, sailing Aegean Sea.
coxeng.co.uk
I don't know Piranha. Do they give compositions or specifications for their products? In the past the forum has seen some bad corrosion as a result of using unknown anodes.

If you go aluminium you will not need magnesium. It is not normally good practice to mix zinc and aluminium but as the engine is pretty much isolated it will probably do no harm.
 

syvictoria

Well-known member
Joined
12 Oct 2009
Messages
1,848
Location
Europe
Visit site
I don't know Piranha. Do they give compositions or specifications for their products? In the past the forum has seen some bad corrosion as a result of using unknown anodes.

If you go aluminium you will not need magnesium. It is not normally good practice to mix zinc and aluminium but as the engine is pretty much isolated it will probably do no harm.

Thanks.

I haven't found any specs for Piranha anodes so far, but I will perhaps email them to enquire! They're based in Cornwall and distributed by Aquafax.

It's a shaft drive with continuity maintained through the R&D coupling via a silver strip. There are no other anodes (just the h/ex pencil and a hull one). Skin fittings are all plastic. Does that still concur with 'probably' okay or would you err on the side of caution and stick with zinc?
 

Tranona

Well-known member
Joined
10 Nov 2007
Messages
42,771
Visit site
Perhaps worth checking with Beta as many of their engines operate in freshwater and they may do a zinc anode. Agree, so problem with using aluminium for the hull anode and zinc in the HE as they are in different water.
 

Tradewinds

Well-known member
Joined
12 Jan 2003
Messages
4,104
Location
Suffolk
www.laurelberrystudio.com
Hi. Does anyone have any opinion on Piranha (hull) anodes? They are much cheaper than MG Duff!

Also, thinking about going aluminium, rather than zinc, this time... We'll be heading for the French canals before long and plan to (perhaps!) use a hanging magnesium anode whilst moored. Do we need to worry about the heat exchanger anode (Beta, zinc)? It's expected to be a sloowwww trip (with a likely overwinter).

TIA!
I have an unused hanging MG Duff magnesium anode - price will be heavily discounted. PM me if interested.
MG Duff MD57LKIT Hanging Magnesium Hull / Mooring Anode Kit (0.8kg)
 
Last edited:

syvictoria

Well-known member
Joined
12 Oct 2009
Messages
1,848
Location
Europe
Visit site
No reply from Piranha, sadly...

@Tradewinds Sorry, manic week! Thanks for the offer. I'm potentially interested, although it will very well just sit gathering dust in a locker!
 

syvictoria

Well-known member
Joined
12 Oct 2009
Messages
1,848
Location
Europe
Visit site
@vyv_cox
Is the desired spec for aluminium anodes US Mil Spec 24779B? I can see a US spec mentioned in the MGDuff catalogue for zinc, but they appear to omit this information for aluminium anodes. Invicta/UK Anodes Ltd state that their anodes meet both of the US specs. Many thanks!
 

vyv_cox

Well-known member
Joined
16 May 2001
Messages
25,979
Location
France, sailing Aegean Sea.
coxeng.co.uk
It seems many suppliers of aluminium anodes give compositions but not any specifications they may meet. The composition quoted in my article is from MME. The US MIL spec 24779B is tighter than this and 24779C is even more restrictive.
 
Top