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| Scale - color, and how to eliminate |
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Message |
    
Brent
Visitor
| | Posted on Thursday, May 18, 2006 - 02:12 pm: | 
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Got a new (used) catboat that came with a Palmer P-60. I pulled off the water inlet flange on the block so I could replace the cooling line from the water pump and discovered scale in the flange and block openings.
Given the engine's age, that's no surprise.
But the scale is black. Having never owned an inboard before, I'm a bit of a novice at this; I expected something more rust colored. Which leads me to my questions:
1) Is this color "normal"? Perhaps due to the raw water? Or the wintertime anti-freeze? Maybe the previous owner managed to suck up some sludge off the bottom?
2) How would I go about getting rid of this? Is there a "Draino" for raw water cooled engines? It's obviously constricting the passage and I'm concerned about pieces breaking off and clogging things up.
Thanks in advance! |
Eddie Ross
Senior Member
Username: eddie
Post Number: 130
Registered: 04-2003
| | Posted on Thursday, May 18, 2006 - 06:20 pm: |
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It's corrosion and maybe some residue. Best to replace the fitting or at least scrape the loose scale off. Don't use Draino. Not even in a sink but definetly not around or in the engine. Now maybe you can understand flushing with fresh water after each run. |
Brent
Visitor
| | Posted on Thursday, May 18, 2006 - 07:33 pm: |
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No, I wasn't thinking about using Draino; just wondering if there was anything that might help remove this stuff.
Would regular fresh water flushing help?
What about some sort of mild acidic solution? Perhaps a vinegar/water mix?
Any suggestions would be appreciated. |
Ben Sidaway
Member
Username: ben
Post Number: 18
Registered: 05-2005
| | Posted on Thursday, May 25, 2006 - 10:41 pm: |
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Brent,
I had the same trouble. I would recommend taking the head off and flushing the whole block out. Check out the discussions at
http://www.oldmarineengine.com/discus/messages/3430/6234.html
and
http://www.oldmarineengine.com/discus/messages/3430/6937.html |
Brent
Visitor
| | Posted on Monday, May 29, 2006 - 08:24 am: |
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Ben,
Being new to the engine, I'm a bit paranoid, but not enough to want to go through the trouble of rebuilding the engine just yet, or even to simply remove the head; I'm just replacing what I can so I can be more confident of the engine (hoses, impeller pump, raw water strainer, fuel filter, fuel pump, coil, cap, etc...) for the season.
However, I was curious about the other options mentioned in the threads...
1) A primer product for disolving rust (Osso?).
2) An old frayed speed or tach wire cable attached to a drill which flails around inside the block.
3) Flushing with radiator flush.
4) And where does one get muriatic acid and how do you use it? I'm assuming that it can only be used if the head is removed (i.e., not flushed through the entire cooling system, hoses and all).
Thanks, Brent |
Ben Sidaway
Member
Username: ben
Post Number: 20
Registered: 05-2005
| | Posted on Monday, May 29, 2006 - 10:02 am: |
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Brent,
I did exactly as you are doing when I first got the engine, just replaced the easy things. After a year or two the engine started to overheat. It gradually got worse and worse. One winter I ran dilute muriatic acid through the whole system with the engine running. It seemed to help for a while. You can get the stuff at a hardware store, it’s used in swimming pools and pickling metal. Some would not recommend using this acid as it might eat away at thin areas. After a while, water stopped running through the engine completely. I found and removed globs of silicon that somehow found themselves into the hose from the pump to the block….but that didn’t solve the problem. I took off the water inlet flange as you did and found a wall of scale on the block. Removed that with a screwdriver, but water still wouldn’t run through. A friend who worked on big engines recommended the frayed tach wire technique but after seeing what I saw when I took the head off, that technique wouldn’t have worked. So I decided to take the engine out and replace with a diesel. After winching the engine out, I decided to have a go at rebuilding it. That wouldn’t have been possible for a novice like me without the help of Dick and other folks on this website. Anyway, getting off the head proved very difficult because many head bolts broke off either at the head or in the block. Two bolts had to be drilled out of the block and helicoils put in. If you take the head off, you will have to get a custom copper head gasket made if you intend to use the engine in saltwater. It was quite shocking to see the amount of scale in the water channels in the block when I took off the head. It was obvious that not flushing technique would have worked on that amount of scale. I had to poke out every channel mechanically and then I blasted a hosepipe down each channel. Handfuls of scale washed out the inlet. So in conclusion, muriatic acid and radiator flush would work for minor scale but if you have chunks of it like I had, mechanically removing it might be the only solution.
Good luck,
Ben. |
Brent
Visitor
| | Posted on Monday, May 29, 2006 - 10:13 pm: |
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Ben,
Your comments raise some questions; if you don't mind...
1) The dilute muriatic acid - what constitutes 'dilute'? Is that the strength it comes in, or is it like the concentrated Round Up where I need to add X parts of water to X parts of the acid? Is there a particular percentage?
2) You say that you ran it though the engine when it was running. Is the typical cooling hose OK, or do I need something special? Mine is a Goodyear brand that I purchased from West Marine.
3) Where would I start feeding the acid; directly at the water pump?
4) Where should I be collecting the acid? When it exits the manifold? Should I let it go though the exhaust as well?
5) Then what do I do with it? I suspect that if it is sold in any hardware store, it must not require any special disposal. That said; even oil is sold in hardware stores, and it requires careful disposal.
6) Is one pass enough?
7) How much do I need?
Forgive my ignorance; although I'm relatively comfortable with a gasoline engine, I know nothing about raw water cooling. Your insight is much appreciated.
Brent |
Ben Sidaway
Member
Username: ben
Post Number: 21
Registered: 05-2005
| | Posted on Thursday, June 15, 2006 - 07:06 pm: |
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Brent,
I'm afraid all my answers are just guesses, I had no guidance on what to do, but it seemed to work ok for me. 1. I used about 25% acid/75% water. 2. I just fed the mixture through the whole system, including the exhaust by putting the intake hose off the through hull into a bucket. I collected the acid as it came out of the exhaust. I probably ran 5 gallons through, let it sit for five minutes and then flushed it out with fresh water sucked out of the bucket. This technique did not get rid of the chunks of scale, only mechanical removal worked to unblock the water chanels after I took off the head. Before trying this I would test a bit of your dilution on samples of your pipes, engine block etc. Again I'm not sure I'd recommend this technique, if the acid is too strong it might eat though any thin areas. |
Brent
Visitor
| | Posted on Friday, June 16, 2006 - 09:19 am: |
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Ben,
Thanks. For the moment, I'm going to pass on this.
In the end, the only heavy scale I found was at the inlet and outlet flanges on the block & head. The block and head themselves didn't seem too bad; there was obvious rust inside, but nothing like the black scale I encountered on the flanges. I can only assume that the excess found there was perhaps due to the mating of the surfaces.
I cleaned the flanges, and after getting the engine started I had a nice healthy flow of water out the exhaust. I'm cautiously optimistic for now.
We'll see what the season brings.
Brent |
Ben Sidaway
Member
Username: ben
Post Number: 24
Registered: 05-2005
| | Posted on Friday, June 16, 2006 - 09:44 am: |
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Brent,
I think scale tends to accumulate at the lowest level in the block, i.e., at the water inlet fitting so once or twice a season you could take off the flange and see if any scale has settled there. That would be a good indication of what's going on in the block. Good luck, just keep an eye on the exhaust water and the temp gauge. |
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