Rust scale in exhaust manifolds
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=23930
Printed Date: November-18-2024 at 3:34pm
Topic: Rust scale in exhaust manifolds
Posted By: MI-nick
Subject: Rust scale in exhaust manifolds
Date Posted: October-24-2011 at 10:22am
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every time i drain the manifolds i get about 1 or 2 bottle caps worth of rust scale...is this normal...should I be concerned about this??
------------- As far as I can tell, I'm not quite sure... |
Replies:
Posted By: 8122pbrainard
Date Posted: October-24-2011 at 10:25am
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It's normal and you don't need to worry about it. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: MI-nick
Date Posted: October-24-2011 at 3:00pm
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thanks pete, that makes me feel better. ------------- As far as I can tell, I'm not quite sure... |
Posted By: karthur
Date Posted: October-26-2011 at 12:15pm
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I noticed that too when I drained mine. I could put my small finger up inside there and feel a bunch of rust flakes. I tried to drag out as many as I could. Thought about taking the water jacket off and cleaning it all out, but didnt have time.
Maybe I will use a magnet and pull out what I can before spring. |
Posted By: SNobsessed
Date Posted: October-27-2011 at 12:43am
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Kirk - Careful poking your finger into the manifold. I did this & got a bad cut - the threads were really sharp n the back side.
I could be wrong but don't think iron oxide (rust) is magnetic. Maybe you could use a garden hose & back flush them somehow. I used some 'The Works' cleaner in mine when I had them off, that clenaed out all kinds of nasty stuff. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: east tx skier
Date Posted: October-29-2011 at 5:45pm
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Not sure if CC ever had petcocks on their block drains, but one problem with rust in the engine is clogging up the petcocks. On any boat we have owned with petcocks, they were quickly replaced with NPT brass plugs (1/4" for the block). You can use a coathanger wire to poke around in the hole to be sure any chunks get pushed out with the draining water. ------------- http://correctcraftfan.com/diaries/details.asp?ID=2383&sort=&pagenum=7&yrstart=1996&yrend=2000 - 1998 Ski Nautique (Red & Silver Cloud); GT-40; Perfect Pass Stargazer; Acme 422. |
Posted By: poovs
Date Posted: October-29-2012 at 2:10am
So, drained my engine block and exhaust manifolds for the first time winterizing this year (boat now in CO versus TX for its entire life). Didn't see any "rust" scaling, but found major "other" deposits.    Bought this 1998 Air Tique in 2003 knowing next to nothing about engines or powerboats for that matter. Never had to drain the engine as we pretty much used the boat year-round. Now I'm worried. My question is... are these manifolds pretty much toast? Worth trying to flush/salvage? Or should I just invest in new? Thanks |
Posted By: 8122pbrainard
Date Posted: October-29-2012 at 7:12am
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Justin, Your manifolds are fine. What you are seeing with the flakes is from not draining and running the boat in hard water. It's called "plating" which is when mineral deposits form on a hot surface. It's very common in boilers and tube and shell heat exchangers if the water is not treated (softened). Drain and probe the holes on a regular basis. I suggest installing removable stem petcocks. I have them on all my boats. They are nice since the whole stem comes off so you can still probe the drain hole and they do not clog like the cheap radiator petcocks. McMaster has them up to 3/8" NPT so you will need to bush the exhaust manifolds. I suggest a 45 degree street el in the manifold, the bush and then the petcock. The large elbow will still give you plenty of room for probing.  Welcome to CCfan. How about some pictures and a diary entry? ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: poovs
Date Posted: October-29-2012 at 11:26pm
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Thanks for the feedback. With the amount of plating... I'm thinking of pulling the manifolds for the winter and finding a shop locally that can blast/treat 'em. I can't imagine that the manifold is very efficient as-is. I'll think on the diary entry; not too proud of my Tique at the moment :( |
Posted By: Gary S
Date Posted: October-29-2012 at 11:41pm
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Don't think I'd bother,they woun't be able to do much to the inside water jackets anyway. You could just pull them if you want and soak them in some muratic acid and give them a paint job. They are as efficient as you need. Save your money for some new ones in the future ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: poovs
Date Posted: October-29-2012 at 11:49pm
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Sounds good then... that's exactly what I'll do, soak & poke 'em, + I like the drain petcocks idea. Friggin limestone lake in Texas did it, no doubt. Diggin the feedback; great group! Thanks again. |
Posted By: Gary S
Date Posted: October-30-2012 at 12:25am
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Not only that but it may have been a long time since the plugs had been removed. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: Jllogan
Date Posted: October-30-2012 at 12:21pm
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if you are using muriatic acid, follow the safety instructions, gloves, mask and eye protection. It can be nasty stuff and can burn your lungs without you realizing. Just a friendly tip from the ccfan safety patrol! Dont forget a towel. ------------- http://correctcraftfan.com/diaries/details.asp?ID=5792&sort=&pagenum=1" rel="nofollow - 1986 Ski Nautique 2001 |
Posted By: SNobsessed
Date Posted: October-30-2012 at 8:21pm
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Having a garden hose handy is a good idea too (to quickly rinse off any spatter that gets on you). I try to stand upwind - you can see fumes when the bottle is opened! ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: poovs
Date Posted: October-30-2012 at 11:27pm
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I'm familiar with muriatic acid. My old man used it years ago to clean the bottom of his 32' sailboat while it was dry-docked. He had on gloves, but he was working overhead and the acid worked its way down his arm into his armpits... Burny Hotty! |
Posted By: 62 wood
Date Posted: October-31-2012 at 12:24am
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I have a muriatic acid tank (55 gallon plastic barrell with a gal of acid in about 40 gal of water). I use it for steel, but dont like it for cast iron. I have only tried it a couple times with CI, but find it hard to get all the acid out of the metal's pores. I hear it can be neutralized with baking soda, but must be done multiple times? Also seams to rust very easily making painting it hard.. You guys have any tips I missed on it? A friend suggested http://www.evaporust.com/index.html" rel="nofollow - Evapo-rust . He swears by it. I am going to try it on a set of manifolds for my 73 this winter. Has anyone ever tried http://www.spaco.org/Blacksmithing/Rust/ElectrolyticDerusting.htm" rel="nofollow - electrolysis ? ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1117&sort=&pagenum=6" rel="nofollow - 64 American Skier 62 Classic.. 73 Ski Nautique |
Posted By: Gary S
Date Posted: October-31-2012 at 2:05am
I have Steve,it makes your legs feel silky smooth  I also tried it to remove rust! The pic below is my trailer axle bubbling away.I made a tank out of a 55 gallon plastic barrel for tractor parts,but this being an odd shape you can see I used 2x4s and plastic. Rebar makes a good anode. I also used Savogran TSP. When your done a quick once over with your bead blaster and your good to go. Some parts I have done could be done in the cabinet but the heaver the rust the longer it takes as you know.So I'd throw it in the tank overnight instead, you can get alot done while your passed out.It will remove paint too. PS just realized there is a trailer fender in that picture in the blue bucket getting the same treatment.If you use TSP the phosphate in it stops flash rust too.  ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
62 wood wrote:Posted By: 8122pbrainard
Date Posted: October-31-2012 at 8:44am
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Before you go with the muriatic route, you may want to go with something safer. Lime-Away or there are products available from HVAC supplies. I have used them on tube and shell heat exchangers and they work great. The nice thing about them is they contain a corrosion inhibitor so when the solution gets to the metal, it doesn't start eating it up. Electrolysis won't work on inside surfaces unless you can somehow get the get the anode inside the manifold and keep it from touching the metal manifold. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |