Flushing D6 with Rydlyme

[Andy Bav]

Thought I’d have a crack at some preventative maintenance this year, and flushing the raw water circuit with Rydlyme seems to be a covered quite extensively on the forum.

Question is, how many litres would I need for a pair of D6s. A friendly SCM forumite has offered transport for me, but I don’t want to burden him, weigh him down too much !

Any experiences from someone who has done this whilst in the water (we are on legs) would be appreciated.

 

[BruceK]

Not sure about your D6 but my KADs managed on 10l per engine diluted 50:50 . (i.e. on 10l bottle was sufficient) Ran it for 4 hours and the Rydlyme was still active enough to dissolve some test barnacle shells so I believe the 10l could have gone a lot further.

Though to be honest I think it managed to clean out everything a lot sooner as the initial foaming of the return was vigorous, but only lasted 20 minutes or so.

 

[jimmy_the_builder]

Thought I’d have a crack at some preventative maintenance this year, and flushing the raw water circuit with Rydlyme seems to be a covered quite extensively on the forum.

Question is, how many litres would I need for a pair of D6s. A friendly SCM forumite has offered transport for me, but I don’t want to burden him, weigh him down too much !

Any experiences from someone who has done this whilst in the water (we are on legs) would be appreciated.

I want to have a go at this as well; does anyone other than Seamark Nunn sell it?

 

[Andy Bav]

I want to have a go at this as well; does anyone other than Seamark Nunn sell it?

I have seen a product called Cementone brick and patio cleaner from Toolstation. Comes in a 5l container cheaper than 1 l of Rydlyme itself, but not sure it’s as “potent” .... tried to call them but phone lines are closed due to inclement weather...

 

[BruceK]

Any experiences from someone who has done this whilst in the water (we are on legs) would be appreciated.

It would not make any difference whether you do this in the water or not as you need to circulate. The presumption here is you have an exhaust elbow too*. The pipe that feeds the elbow being the last stop becomes your entry point and the pipe that exits the raw water strainer the exit in a reverse flush.

edit: * and it's above the waterline

 

[jimmy_the_builder]

I have seen a product called Cementone brick and patio cleaner from Toolstation. Comes in a 5l container cheaper than 1 l of Rydlyme itself, but not sure it’s as “potent” .... tried to call them but phone lines are closed due to inclement weather...

Brick cleaner is usually just dilute hydrochloric acid; that feels a bit aggressive to be running through the (very expensive) coolers...

 

[BruceK]

I want to have a go at this as well; does anyone other than Seamark Nunn sell it?

I bought it from them and it was a prompt delivery.

 

[[165042]]

I bought mine from Rico:

http://www.ricoservices.co.uk/products/?by=cat&id=17&reset=1

 

[jimmy_the_builder]

I bought mine from Rico:

http://www.ricoservices.co.uk/products/?by=cat&id=17&reset=1

Thanks. I can't actually see prices or even how to add a product to the cart on their website though, how did you do it?

 

[Portofino]

My only reservation with any flushing regime is —-
I believe Man wants the HE cleaned every couple of years so the o rings don't get over compressed and saltwater start seeping around the o rings causing corrosion. Its then an expensive repair or replacement. Mine were opened up last year ,but everything was fine -had new O rings fitted - no symptoms beforehand .

I would have thought hardening O rings effects all - inc VP ?

I would ( if you are not doing it allready ) instigate a closed cooling fluid change as well .
You are only flushing solutions only get to the seawater side .A film can build up on the closed side - re- flushing this may help too .

I can fully appreciate trying to extend for a couple of years or so ( if the flush works ) a potentially expensive strip down .

Agree with Jimmy s thoughts on strong HCL - I suspect as well as dissolving the calcium deposits/ scale etc. If left too long microscopically it may etch the metal surface .
Making it more likely to scale up next time round .
Rydlime - allegedly has some neutralise agent to prevent this after it’s removed the scale .So does not roughen up the tubes .
Having said that —- unless you soak them ( after strip down ) yourself overnight in VP or MAN or what ever proprietary HE cleaner —- your “ white van man “ may have dunked en in B+Q brick cleaner @ £1 / L as well .

Getting an approved agent to do the work -strip / soak / reassemble—— obviously costs more I would think .

I,am I over worryingly about acid etching the internal surface of the pipes - useing brick cleaner ?

But I think I am right to raise the O ring issue .

 

[BruceK]

@portofino

After using Rydlyme I flushed the raw water system with fresh water, non circulatory, for 10 minutes and then filled the raw water system with a 50:50 mix antifreeze while on the hard.

 

[Portofino]

@portofino

After using Rydlyme I flushed the raw water system with fresh water, non circulatory, for 10 minutes and then filled the raw water system with a 50:50 mix antifreeze while on the hard.

That’s winterisation.-
What I mean is the closed —- otherside of the HE
How do manage that side ? —— if at all ?

 

[BruceK]

That’s winterisation.-
What I mean is the closed —- otherside of the HE
How do manage that side ? —— if at all ?

I believe that can benefit from Rydlyme too from other posters here. I change my coolant every year and one of the things I look for is brown rust bath rings in the expansion box after draining and similar to the pipe fittings. So far I have none. I am therefore confident that the prescribed coolant is doing it's job which has anti-corrosive and anti -limescale etc properties.

Edit: Yes winterization too, but not only. The antifreeze also inhibits any corrosion etc while the system is not in use and further dilutes / neutralises whatever remains of the Rydlyme of flushing

 

[volvopaul]

Andy don’t use brick acid the D4/6 coolers do t like it s it can attack the solder on the tube stack .

 

[jamie langstone]

I want to have a go at this as well; does anyone other than Seamark Nunn sell it?

Golden arrow marine sell it .
5 litres for around £50

 

[Bandit]

Dont use brick cleaner its much too aggressive about 15% hcl (iirc).

If you dismantle the cooler you can soak the cooler stack in Rydlyme in a windowsill plant pot those long rectangular ones (use a new one or take the plants and soil out first).

Rydlyme leaves the cooler looking the same colour as a new one not pink as it does when you use brick cleaner.

We tend to flush through with two lots, make sure your container for pumping out of and returning to is well oversized as it froths like hell to start with.

 

[jimmy_the_builder]

Golden arrow marine sell it .
5 litres for around £50

Thanks - very helpful.

 

[[165042]]

Thanks. I can't actually see prices or even how to add a product to the cart on their website though, how did you do it?

An old-fashioned invention - the telephone!

 

[[165042]]

Golden arrow marine sell it .
5 litres for around £50

£35 delivered from Rico

 

[Hurricane]

Brick cleaner is usually just dilute hydrochloric acid; that feels a bit aggressive to be running through the (very expensive) coolers...

Andy posted a similar thread on our marina forum.
I commented that a friend with a sailing cat used the local Agua Fuerte acid (similar to Brick Cleaner that we buy in the local supermarkets) to unblock his heat exchangers.
Much smaller heat exchangers of course and he dismantled them completely but the Agua Fuerte did the job very nicely.
I saw the end result before the heat exchangers were reassembled.
With those small engines, it was possible to keep the Agua Fuerte away by only using it in removed components and thoroughly rinsing afterwards.
On the forum, I didn't suggest that Andy should do the same.
I said that in his case, it would be safer to stick to Rydlyme.

That said, I've done tests and the Agua Fuerte that we use a lot in Spain doesn't seem to damage components.
I have left various rubbers submerged in neat Agua Fuerte for several months and it doesn't seem to damage rubber.
It only seems to react with calcium based materials.
The first time I bought the stuff was in our local Fisherman's Coop - I accidentally dropped a bottle of Agua Fuerte on the floor - the bottle split and the floor started melting!!
So, it really reacts with concrete.
The big thing though, is that Agua Fuerte reacts with barnacles so it is a really useful tool for cleaning marine growth (particularly on the props and other underwater metalwork).