Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 22-01-2019, 21:49   #1
Registered User

Join Date: Feb 2017
Location: Sydney
Posts: 18
Lost zinc inside engine

I went to change the zincs on the engine that came with my boat (Yanmar 3GM30) and they had corroded so badly that the studs came out but a big hunk of zinc was left behind in the engine. I can't get it out. Will it be a problem to leave that hunk of zinc inside the cooling water channels?
__________________

wesley is offline   Reply With Quote
Old 22-01-2019, 23:04   #2
Registered User

Join Date: Apr 2007
Location: Australia
Boat: Island Packet 40
Posts: 2,186
Images: 7
Re: Lost zinc inside engine

Probably not. The biggest risk is that it may find it's way into the coolant path and block a discharge but, from my recollection both the entry and exit points for the cooling water are in the head or high up on thew front of the block and all the anode installations are in the block so it will probably drop into the bottom of the block and stay there until it corrodes away. Since there are multiple paths from the block into the head and from memory they are all relatively small holes or slots I cannot perceive of it finding it's way out of the block until it corrodes down to a fairly small size.
__________________

RaymondR is offline   Reply With Quote
Old 22-01-2019, 23:38   #3
Moderator
 
Jim Cate's Avatar

Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 13,895
Re: Lost zinc inside engine

I used to have a raw water cooled engine, and used HCl to dissolve the salt buildup in the cooling passages now and then. One time I forgot to remove the anodes from the engine and within a short time the HCl had eaten them up. Aggravating, destroyed the zinc and pretty well neutralized that batch of acid!

This suggests that if you want to be rid of the lump, filling the cooling chamber with some HCl will remove it pretty smartly! I'm not familiar with that engine so don't know how awkward it would be to accomplish.


Jim
__________________
Jim and Ann s/v Insatiable II lying Sandy Bay, Hobart,
Jim Cate is online now   Reply With Quote
Old 23-01-2019, 04:55   #4
Senior Cruiser
 
delmarrey's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Philippines until May
Boat: Boatless Now
Posts: 10,886
Images: 122
Re: Lost zinc inside engine

I'd go with RaymondR on this one. Zincs are heavy and will sink down into a bottom void and corrode away, just without the plug. Just add a new zinc plug and be on your way. It never happened.
__________________
Faithful are the Wounds of a Friend, but the Kisses of the Enemy are Deceitful! ........
The measure of a man is how he navigates to a proper shore in the mist of a storm!
delmarrey is offline   Reply With Quote
Old 23-01-2019, 06:16   #5
Registered User
 
Olddan1943's Avatar

Join Date: Aug 2017
Location: Aventura, FL
Boat: 2008 American Tug 34 #116
Posts: 644
Re: Lost zinc inside engine

Quote:
Originally Posted by delmarrey View Post
I'd go with RaymondR on this one. Zincs are heavy and will sink down into a bottom void and corrode away, just without the plug. Just add a new zinc plug and be on your way. It never happened.

Just watch the temp. If necessary, pull the end bell off the cooler and get the piece.
Personally, I wait and see.
__________________
And you folks thought I knew what I was talking about.
I do believe my intuitive gene has died.
Olddan1943 is offline   Reply With Quote
Old 23-01-2019, 10:51   #6
Registered User
 
mvmojo's Avatar

Join Date: Mar 2018
Boat: Robert Beebe Passagemaker 49-10 in steel
Posts: 158
Re: Lost zinc inside engine

Flush your engine with Barnacle Buster and let it sit in the engine for a day. It will dissolve any zincs in there. When I remove zincs that have a piece left in the nut, I drop the nut in a cup of Barnacle Buster. A day or so later, the little piece of zinc is gone and I can "reload" the nut with a new anode. Much cheaper than buying a complete zinc & nut!
mvmojo is offline   Reply With Quote
Old 23-01-2019, 13:17   #7
Registered User

Join Date: Apr 2007
Location: Australia
Boat: Island Packet 40
Posts: 2,186
Images: 7
Re: Lost zinc inside engine

Even though raw water cooled 3GM30 Yanmars have no alloys components in the cooling water circuit I'd be careful not to introduce full strength acid into them, there is copper in the head gasket and the thermostat.

I used to flush mine with vinegar, which is mildly acidic. Zinc is so reactive that a mild acid would probably dissolve it over a few hours.

To do a vinegar flush I would remove the hose from the water pump and substitute a small 12 V submersible and remove the hose which goes between the outlet on the block and the exhaust manifold and use a plastic hose on the block end as return line to a bucket.
RaymondR is offline   Reply With Quote
Old 23-01-2019, 14:52   #8
Registered User

Join Date: May 2012
Location: Tweed Heads,N.S.W. Australia
Boat: Dinghies to Admirals Cup contender,the lot.
Posts: 79
Re: Lost zinc inside engine

been there ..done that ..twice..... same engine....nothing happened.....then I realised the zinc was almost a friction fit into the block......and the zinc was releasing from the nut......so I ground the sides down before replacing......and stepped up the frequency of checking......to monthly..........and recording the dimunition in size.....zincs are so easy to check that is was no hardship......
grahamb is offline   Reply With Quote
Old 23-01-2019, 18:09   #9
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 22,905
Lost zinc inside engine

That is the trick determine waste rate, then you know in advance when to change.
I pull mine on my generator every oil change as I believe wastage is based on operating hours and not calendar time.
a64pilot is offline   Reply With Quote
Old 23-01-2019, 18:19   #10
Registered User
 
mvmojo's Avatar

Join Date: Mar 2018
Boat: Robert Beebe Passagemaker 49-10 in steel
Posts: 158
Re: Lost zinc inside engine

Quote:
Originally Posted by a64pilot View Post
That is the trick determine waste rate, then you know in advance when to change.
I pull mine on my generator every oil change as I believe wastage is based on operating hours and not calendar time.
Wastage is a function of both calendar time and operating time. The zinc will waste away even if the engine isn't run at all due to galvanic corrosion between less noble and more noble metals. But, it will was away faster in the presence of moving water. Good idea to check at every oil change as long as your usage is fairly consistent. But, you also have to check based on the calendar. If you let the boat sit for 6 months or a year (example only), the zinc will still be wasting away and protecting your engine from galvanic corrosion even if you're not using the engine. You have dissimilar metals in an electrolyte (salt water) meaning something's got to give, whether the water is moving or not. Better it be the zinc than a part of the engine!
mvmojo is offline   Reply With Quote
Old 23-01-2019, 18:20   #11
Senior Cruiser
 
delmarrey's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Philippines until May
Boat: Boatless Now
Posts: 10,886
Images: 122
Re: Lost zinc inside engine

Quote:
Originally Posted by a64pilot View Post
That is the trick determine waste rate, then you know in advance when to change.
I pull mine on my generator every oil change as I believe wastage is based on operating hours and not calendar time.
I would imagine this is true. Salt water is an electrolyte for electrolysis. Once the salt and oxygen has disapated into the system the corrosion would slow to a minimum. Like a bottle of wine being sealed. Providing the system is sealed.
__________________
Faithful are the Wounds of a Friend, but the Kisses of the Enemy are Deceitful! ........
The measure of a man is how he navigates to a proper shore in the mist of a storm!
delmarrey is offline   Reply With Quote
Old 23-01-2019, 18:48   #12
Registered User

Join Date: Sep 2007
Location: Queensland, Australia
Boat: None at present--between vessels. Ex Piver Loadstar 12.5 metres
Posts: 804
Re: Lost zinc inside engine

Car radiator cleaner will also dissolve zinc--it contains caustic alkali--and in doing so will release hydrogen. but it will also attack ANY alloy parts in your engine and will not be good for rubber hoses either..

Short of removing the cylinder head or a frost plug and going fishing with a flexible clutch-claw, mine has a small lamp on it so I can see what is in front of it, I think it is going to be there obstructing the water passage for some time before natural erosion removes it.

I think you should get it out. First you have to locate it, and an endoscope would be useful in so doing.
.
Mike Banks is offline   Reply With Quote
Old 23-01-2019, 18:56   #13
Registered User

Join Date: Nov 2005
Location: 5 Mile River
Boat: Bristol 41.1 Keep on Dancin'
Posts: 642
Re: Lost zinc inside engine

Last year I serviced my heat exchanger, after 18 years, took off the end caps to replace the gaskets, and had planned on the radiator shop routine, etc. The passage says were clean of deposits, but I was amazed at how much debris was in there from broken down zincs. It wasn't salt or mineral deposits, it was the stuff from all the zinc I had used over the years. I would just watch operating temps, and go from there. I don't believe they totally go away, at least from my experience.
keepondancin is offline   Reply With Quote
Old 23-01-2019, 19:09   #14
Registered User
 
Olddan1943's Avatar

Join Date: Aug 2017
Location: Aventura, FL
Boat: 2008 American Tug 34 #116
Posts: 644
Re: Lost zinc inside engine

Quote:
Originally Posted by keepondancin View Post
Last year I serviced my heat exchanger, after 18 years, took off the end caps to replace the gaskets, and had planned on the radiator shop routine, etc. The passage says were clean of deposits, but I was amazed at how much debris was in there from broken down zincs. It wasn't salt or mineral deposits, it was the stuff from all the zinc I had used over the years. I would just watch operating temps, and go from there. I don't believe they totally go away, at least from my experience.
It cannot hurt to clean the heat exchanger. There may be a lot of old zinc sludge in there but, IF you watch the temps, you will have more observed evidence to make that decision.
__________________
And you folks thought I knew what I was talking about.
I do believe my intuitive gene has died.
Olddan1943 is offline   Reply With Quote
Old 23-01-2019, 19:18   #15
Registered User

Join Date: Sep 2018
Posts: 16
Re: Lost zinc inside engine

Zinc should corrode evenly, ie it won't turn into chunks, so I wouldn't worry about blockage. It's a bit of a pain to open up the intake end of the heat exc so as others suggested I would simply monitor temp.
__________________

timeout2 is offline   Reply With Quote
Reply

Tags
engine, lost

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Can I Zinc INSIDE the hull? MarkJ Plumbing Systems and Fixtures 55 08-05-2017 14:27
Convert HEX pencil zinc to regular bonding/zinc system zboss Engines and Propulsion Systems 6 14-04-2016 19:02
Zinc anode quality and positioning inside bilge phipseml Construction, Maintenance & Refit 10 28-10-2014 03:45
Lost Radar Cable Inside Mast Dockhead Construction, Maintenance & Refit 24 04-02-2013 17:03
Lost Thrust! Lost Prop? OffSeason Monohull Sailboats 20 07-06-2009 00:57



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 19:58.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.