Jump to content

How many anodes?


MHS

Featured Posts

We recently had our well used, 4 year old 57’ comastic painted Mike Christian boat out of the water for blacking. 

 

The boatyard described the condition of the hull as immaculate. No rust, with just a few gouges on the flanks from scraping underwater obstructions. Shame comastic has recently banned under EU law as it’s obviously good! We have used SML Ballastic, so time will tell. 

 

The yard suggested protecting the hull further, by investing in fitting an extra 2 slim anodes per side. (to add to the typical 2 bow, 2 stern arrangement) I declined as I reckon we would probably knock them off while cruising. 

 

My question is, if these extra anodes are such a good idea, why do most boat builders not fit them from new?

 

Link to comment
Share on other sites

3 minutes ago, MHS said:

I declined as I reckon we would probably knock them off while cruising. 

If you already have 'gouges on the flanks' then I'd agree that fitting additional ones could be a short-lived thing.

 

You would expect any business to try to up-sell wouldn't you ?

Link to comment
Share on other sites

25 minutes ago, Alan de Enfield said:

If you already have 'gouges on the flanks' then I'd agree that fitting additional ones could be a short-lived thing.

 

You would expect any business to try to up-sell wouldn't you ?

Just a couple of scrapes. A bit like Shirley Valentine’s stretch marks they are signs of living!!

 

Yes, I wasn’t surprised by them trying to upsell, it’s how businesses make their profit. 

 

If the extra anodes would help why do builders not make shells with the extra anodes recessed?

Edited by MHS
Link to comment
Share on other sites

3 minutes ago, MHS said:

Just a couple of scrapes. A bit like Shirley Valentine’s stretch marks they are signs of living!!

 

Yes, I wasn’t surprised by them trying to upsell, it’s how businesses make their profit. 

 

If the extra anodes would help why do builders not make shells with the extra anodes recessed?

'Cos it would cost a lot more and make disconuities in the hull -vey fiddly to do. I wonder how many boats have their anodes ripped off, and whether that was due to being put in the wrong place to begin with? 

Link to comment
Share on other sites

6 minutes ago, MHS said:

If the extra anodes would help why do builders not make shells with the extra anodes recessed?

For the same reason most boats aren't fully 2 packed from new I suppose - cost.

Link to comment
Share on other sites

How many locks will you get stuck in? Johnys shells are made with good quality steel from the uk/sweden/germany which is why they generally are in good condition [I am blacking mine now its 10 years old and is very good] he used spencer coatings cormastic and does the bottom plate as well [I have seen the boats lifted to do this] I dont know what he uses now but it may be Joton as he was chatting to Shane at Castleford boatyard about it.

Link to comment
Share on other sites

1 hour ago, MHS said:

Shame comastic has recently banned under EU law as it’s obviously good!

It's not so good for wildlife, the environment, or humans exposed to it. Nasty European Commission legislating to protect our safety and health, and that of the natural world. Why can't we be left to poison all and sundry at will?

 

Perhaps a little more thought about priorities is called for? This is the sort of casual anti-EU remark that has contributed to the fiasco we currently find ourselves in.

  • Greenie 2
Link to comment
Share on other sites

1 hour ago, MHS said:

We recently had our well used, 4 year old 57’ comastic painted Mike Christian boat out of the water for blacking. 

 

The boatyard described the condition of the hull as immaculate. No rust, with just a few gouges on the flanks from scraping underwater obstructions. Shame comastic has recently banned under EU law as it’s obviously good! We have used SML Ballastic, so time will tell. 

 

The yard suggested protecting the hull further, by investing in fitting an extra 2 slim anodes per side. (to add to the typical 2 bow, 2 stern arrangement) I declined as I reckon we would probably knock them off while cruising. 

 

My question is, if these extra anodes are such a good idea, why do most boat builders not fit them from new?

 

As anodes only have an effective protective radius of about 2 meters you would need  a lot more than an extra 2 anodes to protect all the hull. The ones at the back should help brass propellers being eaten away or the copper in propellers eating the hull, the ones at the front I am not so sure about. By and large just four anodes seem to protect most boats well enough.

  • Greenie 1
Link to comment
Share on other sites

Its the 'corners' that get the most damage and hence loose the coatings first and then corrode first.

Hull centers only get waterline pitting, if neglected. The exceptions are probably 70' boats where a recessed center anode may be advantageous.

  • Greenie 1
Link to comment
Share on other sites

1 hour ago, Tony Brooks said:

As anodes only have an effective protective radius of about 2 meters you would need  a lot more than an extra 2 anodes to protect all the hull. The ones at the back should help brass propellers being eaten away or the copper in propellers eating the hull, the ones at the front I am not so sure about. By and large just four anodes seem to protect most boats well enough.

 

3 minutes ago, Boater Sam said:

Its the 'corners' that get the most damage and hence loose the coatings first and then corrode first.

Hull centers only get waterline pitting, if neglected. The exceptions are probably 70' boats where a recessed center anode may be advantageous.

I think these responses summarise the real issues with anodes. As Tony says they aren't a solution for general protection because they only have local influence. Both posts give good reason why they logically may be advantageous at the fore and aft.

 

To add to that I suspect the level of protection offered by any blacking product owes more to the quality of preparation of the hull prior to application than it does to the product itself. Anything that forms an impermeable barrier between the water and the metal will work.

 

JP

 

 

Link to comment
Share on other sites

2 hours ago, Machpoint005 said:

It's not so good for wildlife, the environment, or humans exposed to it. Nasty European Commission legislating to protect our safety and health, and that of the natural world. Why can't we be left to poison all and sundry at will?

 

Perhaps a little more thought about priorities is called for? This is the sort of casual anti-EU remark that has contributed to the fiasco we currently find ourselves in.

It wasn’t anti-EU, just a little sarcasm, hence the exclamation mark.  

 

As comastic can last 6 years, is it really 3 times worse than bitumen that is repainted every 2?

Edited by MHS
Link to comment
Share on other sites

1 hour ago, MHS said:

It wasn’t anti-EU, just a little sarcasm, hence the exclamation mark.  

 

As comastic can last 6 years, is it really 3 times worse than bitumen that is repainted every 2?

It’s the nasty Xylene that’s the problem, isn’t it?

Link to comment
Share on other sites

30 minutes ago, Machpoint005 said:

If the xylene comes from coal tar, yes it is.

Dr Bob will be along in a bit to keep us right, but a quick google says it’s a petroleum distillate of well known toxicity:

 

Quote
  • Xylene is irritating to the skin, eyes, and respiratory tract. It can cause systemic toxicity by ingestion or inhalation. The most common route of exposure is via inhalation.
  • Symptoms of xylene poisoning include CNS effects (headache, dizziness, ataxia, drowsiness, excitement, tremor, and coma), ventricular arrythmias, acute pulmonary edema, respiratory depression, nausea, vomiting, and reversible hepatic impairment.

Anyone who’s been near Comastic being applied will know how disgusting it smells.

Link to comment
Share on other sites

8 hours ago, MHS said:

The boatyard described the condition of the hull as immaculate.

Did they say why they thought an immaculate hull after 4 years was evidence of extra anodes being required?  

 

 

  • Greenie 2
  • Haha 1
Link to comment
Share on other sites

23 minutes ago, Sea Dog said:

Did they say why they thought an immaculate hull after 4 years was evidence of extra anodes being required?  

 

 

Precisely my thoughts at the time. 

“To help protect its immaculate condition in the future”

Yes, but the blacking managed it for the last 4 years. 

Link to comment
Share on other sites

1 minute ago, blackrose said:

I've got 6 on each side of my 57ft widebeam. 2 x fore, 2 x aft and 2 thin ones down the middle. 

 

They're protected by the baseplate overhang and seem to be doing the job.

 

 

 

 

044.jpg

Glad they are working well for you. The baseplate can’t fully protect them from say a protruding bolt. 

Link to comment
Share on other sites

6 minutes ago, MHS said:

Glad they are working well for you. The baseplate can’t fully protect them from say a protruding bolt. 

True, but then your blacking and your hull wouldn't be protected from a protruding bolt either. 

 

Unfortunately there are some things we can't do much about.

 

I went through a bridgehole in Watford about 10 years ago and was scraped all the way down the cabin side by a length of steel reinforcing bar for concrete that someone had left protruding out by a couple of feet. I was just lucky it didn't take my windows out.

 

Edited by blackrose
Link to comment
Share on other sites

1 hour ago, blackrose said:

I've got 6 on each side of my 57ft widebeam. 2 x fore, 2 x aft and 2 thin ones down the middle. 

 

They're protected by the baseplate overhang and seem to be doing the job.

 

 

 

 

044.jpg

043.jpg

Well they're being eaten away nicely, but I can't see what they're protecting as the sides are insulated by blacking and there doesn't seem to be any bare metal in the vicinity.  

Link to comment
Share on other sites

Just now, Sea Dog said:

Well they're being eaten away nicely, but I can't see what they're protecting as the sides are insulated by blacking and there doesn't seem to be any bare metal in the vicinity.  

Yup, that confused me too. 

Link to comment
Share on other sites

9 minutes ago, Sea Dog said:

Well they're being eaten away nicely, but I can't see what they're protecting as the sides are insulated by blacking and there doesn't seem to be any bare metal in the vicinity.  

They could just be reacting with stuff in the water. Or maybe they have been working to protect the hull and the boat has just been blacked. It's still only a local effect though. You would need lots of them all over the hull to give full protection.

 

JP

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.