Members Login
Username 
 
Password 
    Remember Me  
Beta Marine Repower Solutions -> Beta Marine Engines -> Heat Exchanger zinc replacement
Post Info TOPIC: Heat Exchanger zinc replacement
w32pamela


Newbie

Status: Offline
Posts: 1
Date:
Heat Exchanger zinc replacement
Permalink  

I would like to reuse the brass plug that holds the heat exchanger zinc but have been unable to remove the old zinc.  See attachment.

Is there a trick to this such as using anti-seize or something like silicone grease on the zinc threads.  I under stand that there must electrical conductivity between the zinc and engine block.

Any tips would be appreciated.

Bob

 

 



Attachments
__________________
Stanley


Guru

Status: Offline
Posts: 958
Date:
Permalink  

That zinc anode is gone. The only way that you will remove it from the brass plug is to use a pick and break it out bit by bit. You may be lucky and the thread will not have dissolved and it may eventually turn out saving you some time.

__________________
Rowboatload


Member

Status: Offline
Posts: 9
Date:
Permalink  

Cut the zinc off flat. Drill in the center for a "screw extractor".

www.amazon.com/Irwin-Industrial-Tools-53535-Extractor/dp/B00004YOBF/ref=psdc_2225074011_t2_B07GZ17QD9

That did not work for me, so I drilled the hole in the zinc as large as I could without getting into the Bronze threads of the nut and like Stanley says break it out big by bit.

__________________
Blue Moon


Veteran Member

Status: Offline
Posts: 66
Date:
Permalink  

My HE zinc wears WAY too quickly and I guess it is undersized and potentially poorly located on the otherwise-excellent engine. I have tried every means of removing worn zincs from the brass cap in order to reuse the cap, without success. The only approach that even partially worked was to use soapbox or similar acid to dissolve the remaining zinc from the cap by submerging it for some while. But the result was clearly also de-zincifying the brass cap, which gradually turns pinkish in the acid.

My HE zinc lasts barely a month and that is NOT in a marina and without any other indication of unusual electrolysis, so I have started buying new cap w/ zinc parts in quantity.



__________________
NeilMcCubbin


Veteran Member

Status: Offline
Posts: 52
Date:
Permalink  

When we cant unscrew the zinc we leave it in a small cup of Ospho  overnight  (rust remover consisting of phosphoric acid and some corrosion inhibitors)

This dissolves the zinc debris with no apparat damage to the brass

Zincs last us about 3 months.

When changing, we just close the inlet sea**** and operate the footpump in the galley that pulls seawater  When we take the sink oiut, it sucks air with no leaks 



__________________
Blue Moon


Veteran Member

Status: Offline
Posts: 66
Date:
Permalink  

Thanks for the suggestion, Neil. I used Ospho on a couple of caps with residual zinc stuck in them and it did in fact dissolve the zinc. But the brass caps themselves turned a bit pink, most likely indicating that some zinc in the brass alloy also dissolved. I guess these part are not working under high pressure and so I'm confident that the Ospho'd pieces are fine for another round of use, but not sure I would be equally comfortable using them after two or more Ospho cycles.



__________________
NeilMcCubbin


Veteran Member

Status: Offline
Posts: 52
Date:
Permalink  

We have reused often, with no ill effects

We have never seen the classic de-zincification pink

Normally leave in Ospho about 12 hours, sometimes shake it a couple of times.  Never tried longer



__________________
Page 1 of 1  sorted by
 
Quick Reply

Please log in to post quick replies.
Beta Marine Repower Solutions -> Beta Marine Engines -> Heat Exchanger zinc replacement
Tweet this page Post to Digg Post to Del.icio.us


Create your own FREE Forum
Report Abuse 		Powered by ActiveBoard