cleaning sacrificial anodes

[Dignity]

Have a 150hp merc, 1991 vintage and notice that the large anode under the bracket is very encrusted. Should anodes be cleaned regularily, do they work better cleaned or should I leave well enough alone.

sam

[tigermullet]

I don't know but do clean mine regularly with stainless steel wool. Sometimes I remove the anode and give it a soak (not for long) in cleaning vinegar as well and then make sure that the holding bolts are well greased. There is a danger that the bolts will break off if the anode has not been removed since new - manufacturers seem to enjoy putting everything together with dry bolts. The first job for me on acquiring a new motor is to undo as many bolts as possible, particularly on the leg and coating them with lanolin grease.

On the bigger boat which has many anodes, cleaning is a regular chore. If not cleaned regularly they become encrusted with barnacles weed etc., and, I suspect, lose their effectiveness. Anyway, the method seems to work as there is no sign of corrosion on any part of the hulls after nine years of being in the water permanently.

The small dinghy motor lost its anode some time ago and, on the advice of an outboard mechanic, I haven't bothered to replace it. The motor only runs for about 40 minutes per trip and is always lifted out of the water when at rest.

[andrew&lucy]

should be cleaned @100hr service or once a year and don't forget the anodes in the water jackets that can be removed to be clean as well.

[Dignity]

tigermullet, thanks for the tip, fortunately my motor the bolts all undo relatively easily. Will clean the anode but was just wondering whether there was a significant effect in the performance when encrusted. My motor does not have any corrosion except at the yoke and though this might have been caused by the anode not working to full capacity.


should be cleaned @100hr service or once a year and don't forget the anodes in the water jackets that can be removed to be clean as well.

How does one access the ones in the water jackets??

[finga]

Never use a wire wheel to clean them.
I bead blast mine so there is no chance contamination.
I also use a conducting gel where they contact the outboard as well just so there's no possibility of a high resistance joint.

I can't believe a mechanic said not to worry about them Tigermullet. They're a very important protection device whether the outboard is in the water or not.
Maybe the mechanic was just too lazy to find one for you for the amount of money he was going to get from selling you one.

Methods of getting to the wtaer jacket ones vary from maker and model so some more info would be required.

[tigermullet]

I can't believe a mechanic said not to worry about them Tigermullet. They're a very important protection device whether the outboard is in the water or not.
Maybe the mechanic was just too lazy to find one for you for the amount of money he was going to get from selling you one.

I was a bit puzzled too but went along with the idea even though I am fanatical about anodes on the big boat. I will get one and put it on.

I would also like to know how to get at the internal anodes given that my policy in regard to servicing by a mechanic is a bit slack. Apart from renewing water pump impellers, checking plugs and greasing my motors are rarely serviced. The old 30 hp Mariner was the best - one service in 17 years and it never missed a beat.

Anodes must not be as effective when encrusted with anything - painting is definite no no so I suppose any substance that degrades contact with the water would also be detrimental.

[Dignity]

[quote=finga;595888]Never use a wire wheel to clean them.
I bead blast mine so there is no chance contamination.
I also use a conducting gel where they contact the outboard as well just so there's no possibility of a high resistance joint.

quote]

finga - why not use a wire wheel and what is "bead blasting"

[FNQCairns]

I use a stainless wire wheel on the grinder, I am pretty ignorant of electrical theory can wire cars, boats and stuff but any deaper than that and I am lost.
Would like to know also if I am creating a problem.

cheers fnq

[Spaniard_King]

A wire wheel will impregnate the zinc anode with Iron particles actually causing them to appear rusty and will increase the rate at which they will errode. Best thing is a mild pool acide solution dropping them in for a few seconds at a time and washing them off in fresh water untill all the white powdery look is gone

Garry

[finga]

Good on ya Gary :)
Good simple explanation on why not to use a wire brush.
Bead blasting is like sand blasting but use glass beads instead so there's no contamination possible.
It does a really good job on alloy too :)
Using a stainless wire wheel would depend on the grade of stainless.
Gary's pool acid trick is a really good method as long as they're washed really well with claen water afterwards.
Don't leave them in the acid too long though as a hard black crust can build on them. Just lots of short spurts.

[FNQCairns]

Cheers for the info, pool acid is hydrocloric acid I think, a 100 uses! have got another to do, will get some and see how it goes.

cheers fnq

[Dignity]

And it seemed such a simple question - not having a pool dont have any pool acid - not willing to use hydrochloric as I ca well remember from old building days it was how we made the flux for soldering - take some zinc (off cuts of roofing etc was ok) stich it in some hydrochloric. Would be nice to own a bead blaster so might end up using the old faithful blunt chisel to scrape it off.

sam

[finga]

Where abouts are you Sam??
If your near the M1 as it goes over the Logan then your more then welcome to use my beadblaster. I have a portable one as well if you have a compressor.
Cheers Scott :)

[Dignity]

Scott, thanks for the offer - have pulledthe big one off and given it a good scrapping with an old chisel I had. It looks plenty clean now but next time will drop in and see you.

sam

[Roughasguts]

And it seemed such a simple question - not having a pool dont have any pool acid - not willing to use hydrochloric as I ca well remember from old building days it was how we made the flux for soldering - take some zinc (off cuts of roofing etc was ok) stich it in some hydrochloric. Would be nice to own a bead blaster so might end up using the old faithful blunt chisel to scrape it off.

sam

Mate Super cheap have a hand held sand blasting gun, it uses a few differant shape rubber nozzles that when held against your work, will rip the sh!t out of anything, and not get too messy with dust every where.
You just fill a small sock with dry sifted sand and away you go.
(still need an air supply though)

I have also put an extention hose on mine and stuck the end in a bucket of sand still works well.

Just make sure you wear a face mask, sand equales silicoses, pretty much akin to asbestos contamination, not good.

There around 50-60 bucks from memory, worth having for the odd job.

[Dignity]

Thanks for the info RAGS. Have a compressor and have thought of getting a sand blaster but didn't know of anyone who had one, will have to get one now just to try it. finga, can I use beads on the one RAGS mentioned or is that another kettle of fish.

sam

[Roughasguts]

Hi Dignity never thought of using beads, where would you get beads from?? this gun of mine will blast a fan of 30mm wide.

I just use sand, it use to do a bloody good job of cleaning the paint of me skeg, so! sold on the idea I bought a purpose built one.

[Roughasguts]

Actually I'll pull a zinc anode off tomorrow and give it a go, let you know what happens. If it goes sour don't matter I have spares.

[Mr__Bean]

Just keep in mind guys that the most important thing with an anode is the electrical connection to the engine.

Do not paint the connecting face on the engine and be wary of what you use as a thread protector.

The anode will not protect what it isn't electically connected to.

- Darren

[Roughasguts]

Hi Bean, I have noticed for some time since flushing my motor in a flush tank 5 years, that the fin anode under the cav plate has gone a blue colour, and is not furry as the other ones.

Wondering if the anode obsorbs the 2 stroke oil, and becomes useless, seems to still be slowly eating away but only on the inside surface, the outside no holes in it. Is that cause of the airation on the lift side of the anode causing it to pit ??

[Dignity]

[quote=Roughasguts;599010]Hi Dignity never thought of using beads, where would you get beads from?? this gun of mine will blast a fan of 30mm wide.

quote]

rags, it was finga who suggested beads, as I haven't used a sand blaster yet I have no idea

sam

[Roughasguts]

Well the sand blasting cleans the crud off, doesn't wear the anode out any more than it was. But kinda, expected it to go all nice and shiney, Nup same blue colour.

Got some digi pics, if anyone can give me there email address and host the piccys.
Buggered if I can do that post a picture stuff.

Got a comparison brand new, alongside old, and the sand blast result alongside each other if anyone is interested.

[dogsbody]

pm sent rag

Dave.

[Roughasguts]

Thank's Dave sent. Should of sent them at work Yaaaaaawn, think there a bit big.

[dogsbody]

Ok Rag got it sorted sorry it took so long one of em didn't want to play fair.

Dave

[Roughasguts]

Ok Rag got it sorted sorry it took so long one of em didn't want to play fair.

Dave

Thank's Dave it's easy to post pics, when you do it for me.

The first piccy is of them all blasted off, plus one dirty one for comparison.
The second piccy of new anodes, and anodes that have been on for 12 years.

Was it worth the effort not really, tried spraying one of them with Carby clean and had the same result, as sand blasting them.

[Dignity]

rags, will trade you a couple of old ones for the new ones;)

sam

[finga]

Beads will work with the same blaster and will work faster then sand.
They come in different grades and are a lot cleaner to work with then garnate or sand.
The beads are cheap as chips if you know where to get them.
I wish I could remember the name of the place but it's an engine reconditioner at the top end of Moss St. opposite Devil radiators I think it is.
If you want to try some glass beads Dignity let me know and I'll donate some.
PS sorry about delay in giving info. Been away.

[Dignity]

Beads will work with the same blaster and will work faster then sand.
They come in different grades and are a lot cleaner to work with then garnate or sand.
The beads are cheap as chips if you know where to get them.
I wish I could remember the name of the place but it's an engine reconditioner at the top end of Moss St. opposite Devil radiators I think it is.
If you want to try some glass beads Dignity let me know and I'll donate some.
PS sorry about delay in giving info. Been away.

thanks finga - have to nuy some equipment first - usually try and get the missus to but it for me but if she doesn't get the hint will have to do it myself

[RobGoesFish]

They're a very important protection device whether the outboard is in the water or not.



HI Guys,

Just wanted to point out that a sacraficial anode is actually useless when out of the water. They only work when they can set up a galvanic cell which basically means that a current has to be able to run through the outboard and the anode. Out of water this is not possible. So if your car dealer every tells you to put sacraficial anodes on your car tell him you'll be ok.

Cheers,

Rob

(nothing personal finga, I just found this very interesting when I learnt it)