Toilet pipes crud build up

[BlueChip]

I used to work on acid etch machines for the printed circuit industry, they were all plastic. I think Polypropylene but I'm not sure. They had various seals and plastic pumps which worked for years. Anything metal would disappear in a very short time. I can't remember what acid was used but I would be wary about leaving it in a seacock as it would remove copper in minutes in our machines.
Allan

That would be Nitric Acid for etching copper

 

[BlueChip]

For taming the toilet smell I've got one of these in the inlet line of each of our heads
https://www.leesan.com/shop/flush-w.../leesan-adjustable-head-treatment-system.aspx
I get a chlorine block used for a swimming pool or jacuzzi, break it up into small pieces and add a small pea size piece of the block into each reservoir.
The flush water passes across a sinter disk at the end of this reservoir which doses the flush water with a shot of mild chlorine solution and sterilises the water killing the bugs.
I bought two of those devices second hand at Beaulieu boat jumble about 20 years ago and they've been doing their effectively job ever since.

 

[vyv_cox]

That would be Nitric Acid for etching copper

Yes, nitric is a different matter altogether. As I posted earlier, I have tested dilute hydrochloric on brass and bronze and found no reaction. Many of us have been using it in a wide variety of toilets for many years, never had a problem.

 

[rogerthebodger]

That would be Nitric Acid for etching copper

When I used to make prototype PCBs I used Ferric chloride to etch the copper from the board.

Just be careful when using Hydrochloric acid as if you use too much and it caused the crud to block the outlet seacock it can damage the pump.

The henderson pump on my lavac exploded and ended up in two pieces.

 

[VicS]

That would be Nitric Acid for etching copper

Concentrated nitric acid will react with copper , dissolving it to form copper (II) nitrate. and producing red-brown fumes of nitrogen dioxide
50% nitric acid will react with copper to produce copper nitrate and (colourless) nitric oxide, but this reacts with oxygen in the air to form nitrogen dioxide.

I believe ferric chloride solution is used as an etchant for printed circuit boards.

 

[RichardS]

Concentrated nitric acid will react with copper , dissolving it to form copper (II) nitrate. and producing red-brown fumes of nitrogen dioxide
50% nitric acid will react with copper to produce copper nitrate and (colourless) nitric oxide, but this reacts with oxygen in the air to form nitrogen dioxide.

I believe ferric chloride solution is used as an etchant for printed circuit boards.

One of my party pieces at home in the 60's was to put an old penny/halfpenny into nitric acid and impress friends with the brown fumes which snaked along the table and fell to the ground. I think that I was probably breaking the law in destroying The Queen's Currency but that was probably the least of my infringements. :ambivalence:

Richard

 

[SiteSurfer]

Can’t offer advice on the crud, but for the pipe I’ve just switched from the cheaper inflexible hose to the butyl lined version which is more expensive and I am delighted with the ease of fitting,
.
I popped the end in a cup of hot water and it slid over the new sea cocks first time, the hose was super flexible and caused few sweaty moments compared to the same task last year on my old boat with the more rigid stuff.

 

[geem]

I find that Hydrocholoric Acid in the form of Brick Cleaner once per year works fine. I make sure I do this at sea and put it through about one loo half full every five minutes to give it time to fizz and remove the build up. I respectfully suggest once a fortnight is excessive in terms of pollution and cost

Hydrochloric acid is a cheap as chips in the Caribbean. We use a small amount regularly to keep the loo clean

 

[oldgit]

Removed 3 metres pipe and used rubber hammer to break up crud.
Flushed out vast quantity of crusty chunks using mains pressure from hose pipe.
My 75mm" id pipe had been be reduced to something like 10mm before it finally refused to pass anything at all.
Cleaned pipe simply because the price of correct recommended poo hose was pretty impressive.
Been working OK for last 18 months or so.

 

[Birdseye]

Well you live and learn !
I would point out that the HCL emerging from my gut isnt enough to clear the build up of pee derived crud in the system !

I assume you are referring to your prostate - whats clogging that isnt carbonates.

 

[Birdseye]

That's not correct I'm afraid. Phosphoric acid is a weak acid and the amount in coke is extremely small. Vinegar is much more acidic.

Richard

Not sure you are right. When it came to de-staining the toilet in the M-I-L's sheltered flat, phosphoric acid was the only thing that worked. I tried brick acid and vinegar with no result.

 

[vyv_cox]

Not sure you are right. When it came to de-staining the toilet in the M-I-L's sheltered flat, phosphoric acid was the only thing that worked. I tried brick acid and vinegar with no result.

Over the years several posters have descaled engines successfully using phosphoric acid. I think VicS has pointed out a few times that some brick cleaners are phosphoric, not hydrochloric, acid. I doubt very much that Coca Cola would have had any noticeable effect.

 

[VicS]

Around here there's a product called CLR, which has lactic acid as the main ingredient IIRC. Also coke is good - phosphoric acid being particularly strong.

That's not correct I'm afraid. Phosphoric acid is a weak acid and the amount in coke is extremely small. Vinegar is much more acidic.

Richard

Not sure you are right. When it came to de-staining the toilet in the M-I-L's sheltered flat, phosphoric acid was the only thing that worked. I tried brick acid and vinegar with no result.

I am quite sure Richard is correct. Strong acids are those which are to all intents and purposes completely ionised in dilute aqueous solutions .

Weak acids are those which are only partially ionised

Phosphoric acid has a pK_a of 2.15, which makes it a weaker acid than oxalic acid, pK_a 1.27
Lactic acid, which has been mentioned, is weaker with a pK_a of 3.86 and acetic acid even weaker with a pK_a of 4.76.

Hyrdochloric acid has an estimated pK_a of -9.3 while sulfamic, commonly used as a descaler, has a pK_a of 0.99 making it somewhat stronger than the common weak acids but no whre near as strong as the common strong acids.

 

[RichardS]

Not sure you are right. When it came to de-staining the toilet in the M-I-L's sheltered flat, phosphoric acid was the only thing that worked. I tried brick acid and vinegar with no result.

There are several different issues at play which complicate matters.

Acetic acid and phosphoric acid are both weak acids, similar to oxalic acid which is also prevalent on boats.

However, in general and definitely with weak acids, the higher the concentration of the acid in water, the more effective the acid is. The concentration of acetic acid in vinegar is much higher than the concentration of phosphoric acid in coke so, in most applications, vinegar is more effective than coke.

The third factor is that some acids are more corrosive towards certain substances than other acids, such that there are circumstances where a weak acid will dissolve/attack/convert a particular substance more effectively than a stronger acid, even where the weaker acid has the same, or even a lower, concentration.

Richard

(Sorry - was typing this and repeated some of Vic's contribution)

 

[fisherman]

53 posts in, I'm beginning to think bucket and chuck it isn't so bad after all. There must be a better way than dismantling and beating a pipe full of tough squit against the pontoon. I presume all of this is basically because the bog has to be below the W/L, with a swan neck on the outlet? Would semtex help?

 

[geem]

53 posts in, I'm beginning to think bucket and chuck it isn't so bad after all. There must be a better way than dismantling and beating a pipe full of tough squit against the pontoon. I presume all of this is basically because the bog has to be below the W/L, with a swan neck on the outlet? Would semtex help?

Haha, hence our treatment with a little hydrochloric acid every couple of weeks. Crud free bogsrus......