On draining down the S-type in my boat to protect against the recent cold snap I decided to remove some of the inspection plates to check all the water was gone. On doing so I found that the jacket appeared to be quite scaled up. I put this down to a lifetime of having canal water pumped through it. Even though I don't believe it to be a problem at the moment as water still gets through and the engine is never too hot. I feel that I should take the opportunity to try and rectify the problem as part of my winter maintanance. Can anybody suggest a cure? In one of my old S-type handbooks it suggests a substance is added to the water to de-scale the engine but as I don't operate tank or closed circuit cooling I will have to seal the engine for this job.
I used kettle de-scaler (ISTR formic acid) on my Petter M. It was stripped to bare castings at the time so I treated the head and block separately. Took a few goes but eventually the lime was soft and crumbly enough for most of it to be prodded and poked out with a selection of proddy pokey things.
I was involved with restoring a Rolls-Royce 20/25 some years ago and - having spent it's life in the Cotswolds - was pretty thoroughly scaled up. Poking out the lime scale was all very well, but it wasn't possible to get in the nooks and crannies. A professional restorer recommended a couple of gallons of cheap supermarket vinegar with just enough water added to make it go round, repeat as necessary. We were dubious, but having tried on his aged electric kettle, decided that it was worth a try, being both cheap and easy!
We ran the engine (and drove the car!) for some days, changing the coolant every time it began to look milky . We got through a lot of vinegar, but eventually the engine stopped overheating the honeycomb radiator had no cold spots and we'd saved the owner a fortune.
His only complaint was that on hot summer days there was a faint odour of chip shop .....................
Perhaps this cautionary tale from a friend of mine in Bath bears repeating...........
Here, the ground gets into the pipes something rotten. It was none too good when we moved in, but the hot taps were finally down to a very small trickle, and a bath involved an hour and twenty minutes. The senior management wasn't too happy about this. So it was down to a not very local shed on a bypass for £20 worth of something that turned out to be 4 kilogrammes of sulphamic acid (and I should know what that is ...)
Mix it up in a bucket it said, and chuck it in - oh and an instruction leaflet about water systems, which the shed didn't have.
Hot tank + header in small airing cupboard. Whoopee.
In it went with a large dose of crossed fingers, hoses and the site of a drain c*ck located.
It didn't go 1,2,3 fizz. It sort of went FIZZZZZZZZZZZZZZZZZZZZZZ!!!!!!!!
They'd warned about the possibility of foaming, but then got the chemistry right so it didn't. They said the fumes were non toxic, and they weren't - still, interesting sensations when you have your head in the airing cupboard observing none the less. Thanks chaps!
An hour later and it had cleaned the header tank back to the metal and was starting on that ... I ran the hot taps downstairs to drop it into the main tank and it got very enthusiastic about what it found there. Quite vocal too. Being fairly sealed apart from the vents, there was the sound of something having a fight in the bottom of the tank coupled with a copious farting noise from whatever orifices it could find.
Ominously the hot tap then ceased to flow completely.
Even more ominously, it then started again, but rather fast. I shut it off to trap the mixture in the pipe. Redoubled farting noises like a very busy dachshund.
The stuff is self indicating, two hours and it seemed not to be able to find anything carbonatey to dissolve so I thought I'd let the stuff out, with pauses to encourage it to find things in pipes. All taps, pipes are now running freely and turn and, miracle, shut off easily. By some other miracle, the exercise hasn't released a flood of corrosive liquid through the place like some scene from Alien ... don't know how often I dare to repeat *that* exercise though ...
Might be just the stuff for that tight lock on the Huddersfield Narrow Canal though. It turns out that I dropped a small amount on the back steps which are Bath stone. The results are pretty dramatic and would give bank robbers a whole new way of getting into banks round here ...
I think there are 2 challenges here - one to descale the waterjacket of existing muck and two to try to prevent too much being laid down in the future.
For descaling any commercial descaler or weak acid (citric, acetic (vinegar), formic (but beware it's dangerous in its pure form)) will eventually clear the chalky deposits without damaging the metal - weak acids work best when hot, so not a bad idea to run the engine to warm it up, but stop the circulation and dilution with fresh water. Strong acids such as hydrochloric, sulphuric, nitric will clear the chalk but also take metal with them, so avoid all but brief contact.
Once clear how do you stop reformation?? This could be a problem if you are constantly circulating river/canal water through the jacket - each fresh volume of water will deposit its load of chalk when heated, then pass on "cleaned" so to speak. In a closed circuit, the water is only carrying so much chalk, and once deposited it's done until you add more hard water. I suppose a heat exchanger (eg radiator) would be out of the question? A rad would also stop the freezing problem as you could add antifreeze to the cooling water - not practicable if circulating river water.
I will try out one of the commercially available products on the jacket of the exhaust box at the weekend as a test. I will let you know how I get on. Many thanks to those who posted.
Incidentally I met a chap the other day who used to work on the canals in the late 50's towards the end of commercial carrying. He instantly recognised the engine, which is unusual as most people confuse it with the more common and well known Bolinder. He told me that his brother lost two fingers starting an S like mine because he didn't take up the floor pannel when starting so his fingers got torn of between the floor and flywheel pin. I have to admit to a torn pair of overalls myself once by getting too close so now I never have on lose clothing or allow any impediment near me whilst starting. Treat them with respect.
I have here a propellor which was thought to have come from an 'S' type, from the former hotel boat (and former horse boat and Oxford canal 'number one') 'Mabel'. Whether it really did, I've no idea, but it was far too small for the Armstrong which replaced the Petter - though it did get her & her butty around the canal system for many years. There used to be an identical propellor stored in the bilges. It is bronze, Bolinders & some other engines of the period were usually fitted with cast steel props.
I also have some fluid which was sold for descaling steam cleaner coils, it appears to be (not very) dilute Hydrochloric acid. I've also seen hydrochloric recommended, in a Rustons manual AFAIR, as an aid for loosening scale prior to pulling out stubborn wet liners.
A dark art prop sizing. I have sent you an email off group Tim.
I will hav to look up the name of the product mentioned in the Petter literature. Perhaps it may still be available. I imagine that I should be most worried about the cylinder head surrounding the combustion chamber. Am I correct in understanding that higher temperatures encourage more scaling? Thus a viscious circle as less cooling is available where it is most needed.
After descaling, we ran a dilute solution of Jenolite through the 20/25's system, reasoning that it would perhaps kill future rusting, we being concerned that we had exposed bare iron for the first time in many years.
- and at risk of having me wrist slapped ;o)) Jenolite removes every bit of scale and unpleasantness from toilet pans you would consider only fit for the tip!
I have never managed to take a particularly decent photo of the engine. The instalation doesn't lend itself to photography. I have a picture somewhere that I will try and dig out that looks sort of ok. As to where to post it I have never set up a webshots page or posted to alt.binaries. I had thought of sending one to Paul Evans to put on the Internal Fire site if I could ever get a decent shot. I'll see what I can do. I have got some rather nice video footage in mpeg format on a cd. The problem there is that the clip is part of a video of a boat trip. I need to see if I could get it cut with my dads video editing stuff. Then I could again see if Paul Evans would like it for the IF site.
There is available a descaler which is inhibited Hydrochloric. We used it to descale brewery pipes. I'm not sure where to get it these days though. You could ask a small brewery, especially one in a hard water area. The product worked very well indeed but don't use it in a confined space.
Was this known as "killed spirit of salts"? It always seemed to function much as ordinary dilute HCL to me. A quick search reveals the descaler is inhibited with an amine which prevents the acid reacting with ferrous metal.
We knew it as Inhibited Hydrochloric Acid. The exact chemistry was left to our suppliers. I do remember that it worked extremely well, especially on stainless steel brewery pipe.
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