cleaning raw water cooled system

[oGaryo]

Hi, having taken the head off a raw water cooled 3.0l Mercuiser today it's notable that there's alot of sediment build up in the system.. is this a fact of life for a raw water cooled system or is there something that can be done about it like adding radweld flush additive to a barrell of water and running the engine from it for a while?... the sediment looks pretty hard (rust coloured) so I'm guessing it'd need something very potent to disolve the build up. I'll take some photo's tomorrow of the inside of the thermostat intake pipe which gives a good indication of the condition of the waterways.

my only worry is that I've used the likes of radweld in the past on cars and done a great job of knackering the system due to all the crud that detaches itself from the walls and finds its way in to the radiator, water pump etc causing a blockage

cheers Gary

 

[hlb]

Brick acid seems to be the thing, never tried it.

 

[Firefly625]

Gary

IMHO not sure if radweld is the stuff to use on this occasion, I would get some Wynn's Professional Formula Cooling System Flush...... this is what the can states;

Powerful acid free radiator cleaner, dual action. 1. Removes scale, 2. Eliminates Rust, deposits and oily residue. Safe for all metals and hoses and cooling systems. Directions, shake can add to cooling system via expansion tank if part of the circuit or radiator....etc.... warm up engine; run for 10 minutes, stop engine, drain system; while still open flush with water until runs clear, then close & refill with coolant..... obviously car instructions.. but in your case use the same as you had planned to do with radweld..i.e. add it to a bucket and go from there, Cost of a 325ml tin around £12

.

 

[splosh]

There's some stuff called "Rydlyme" that I saw a chap using on an intercooler.
Worked well in cleaning the scale off.
Here's their address.
http://rydlymemarine.co.uk/

 

[stefan_r]

another vote for rydlyme

 

[oGaryo]

thanks... that'll be the next job once I've remembered why I bought the boat in the first place... wasn't to spend every weekend under the hood ;-) it's not overheating so I guess it can wait a few weeks

 

[AndieMac]

Gary


Hate to say this mate... but I think you are a closet tinkerer! (smiley icon)


While you have the rocker (tappet) cover, thermostat, manifold etc.. off, clean them up, sand off and repaint. Do it all with one can, and will look a treat.

Good luck