Re: Forward head black water tank copper fitting replacement

Andrew & Kate Lamb

We have replaced both lower holding tank outlets and replaced with PVC tubes – both were straight copper tubes with very little inside the tanks – both very corroded and starting to leak. I drilled a hole through the visible part and twisted to remove, with some work with long-nose pliers afterwards, but this was relatively easy to do.

We have replaced one of the inlet copper pipes – it was less corroded than the outlet pipes and was much harder to replace because there was much more copper pipe inside the holding tank and on the end inside the tank was attached a piece of 38mm hose that formed a loop into the tank. We had to remove the lower part of the copper tube first and then had to pass a grinding tool inside the pipe to cut the upper portion of pipe inside the holding tank.  Once this was done we were able to retrieve the inner copper pipe piece and attached hose. This was replaced by a long straight piece of 40mm diameter PVC tubing it was not possible to add hosing on the inside again but I was able to pass the PVC tube close to the top of the inside of the holding tank.




Ronpische SM472



From: <> On Behalf Of Alan "Woody" Wood via
Sent: 29 November 2021 12:56
Subject: Re: [AmelYachtOwners] Forward head black water tank copper fitting replacement


Nice job Kevin.

I’m thinking of replacing mine soon, not because of corrosion but there seems to be a blockage in it. I presumed it was calcium and tried acid but to no avail. Next step would be to drill into it but would the original fitting have had an inverse U-bend inside the tank to prevent back pressure on the feed pipe when the tank is full?

I’m not sure if I read that somewhere or just made it up in my head but it would make sense and I wouldn’t want to destroy it with the drill if there is. 

Anyone know anything about this?

- Woody

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