Rust problem

May 5, 2017
30
Catalina C36 mkII PA
Hello members, I have quite extensive problem with rust showing and discolouring everything around. It's and older (1986) Cat30. After cleaning rusty spots just after 1-2 days at sea they come back and make everything look ugly. Any ideas what is causing this and is there anything I can do to stop this? Thank you for any pointers and advice.
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Oct 9, 2008
1,739
Bristol 29.9 Dana Point
Replace the screws. Use marine stainless. They're probably through-bolted so you'll have to find the underside in the cabin or locker.
Also rebed the bases of the stanchions. Use "Bed-it" tape - you can slide it under there without removing the whole pulpit rail. Maybe. Or you may just want to rebed everything anyway.
You may have to polish the undersides of the stanchions if they are rusting too.
 
Feb 14, 2014
7,400
Hunter 430 Waveland, MS
It looks like water that gets INSIDE the stainless tubes, even Stainless needs Oxygen to be "clean"

Classic corrosion problem is from the unseen Inside of pipes.
Jim...

PS: just guessing from the circular type stain pattern from around the tubes.
 
Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
That is a lot of rust.
Is this all pipe?
Do you have coated wire lifelines attached to the pipes?
The rust appears to be in more than one place, what links those places together?
As suggested, examine the stanchions for evidence of rusting inside. Stainless steel is "Stain-Less" not stain free. If it is the stanchions, they may have been a lower grade of stainless when manufactured. Water is intruding. Sitting inside the pipes and rusting them from the inside. You can test the pipes by tapping and squeezing them on the middle to lower third of the pipe. If you squeeze and they collapse you have identified a problem.
More investigation is needed to identify your issue and develop suggestions for resolution.
 
Sep 8, 2014
2,551
Catalina 22 Swing Keel San Diego
ALL older Catalinas were manufactured with 304 SS tube to make the Rails and Stanchion tubes. 304 is stronger than 316L but less corrosion resistant. Somewhere you might have a non stainless bolt or screw causing that mess, but also like others have mentioned the tubes can actually rust on the inside.
I wouldn't be surprised if you dismount all that stuff and broken off screw or bolt comes tumbling out the tube, all rusty. You are in Canada, so this looks like a good winter project for the cold months. You'll want to take everything off (its a royal pain that takes two people). Like Skipper said, replace all the screws. Order from a reputable hardware place online so the you know you are getting 316L alloy machine screws & nuts.
There are various chemical cleaners that deal with rust. CLR is one, but not very strong (it used to be stronger). If you know a welder or you live near a welding supply shop try to find a metal cleaner/descaler/degreaser that contains phosphoric acid as the primary ingredient. Don't worry, its just a spray cleaner and won't burn you, just don't get in your eyes or nuthin (same safety precautions as many household cleaners). The stanchions can be soaked in a bucket (you can cut the cleaner with 2/3 hot water). This will clean out all the rust from the inside of the tubes. For the bow rail, you'll have to just spray the inside of the tubes. It would hard to have a vessel deep enough to submerge the whole thing into a solution.
When all that stuff is off your boat it would be a great time to epoxy 'pot' all the mounting holes. This is also a great way to leave them sealed up for the winter while you work on the other stuff. Over-drill all the holes to 5/16", tape them off below and fill the holes with epoxy. Leave them sealed up for the winter, in the spring drill them to 1/4", that leaves you a nice seal of epoxy around the bolts so if water ever gets in it won't harm the wood core.
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
I tend to agree that it's salt water inside the tubes that's doing it. Of you ever take this apart, it would be prudent to passivate the stainless inside the tubes. This is done with an acidic preparation, usually phosphoric acid. The product I use with great success is Wichinox, but it's kinda expensive.
 
Sep 8, 2014
2,551
Catalina 22 Swing Keel San Diego
Do a little research on DIY electro polishing. This is a process that must be done on Stainless welds so they don't rust when chromium is burned up in the welding process. The phosphoric acid cleaner I mentioned above is the same 'fluid' that is used in this process. Some people apply just a few amps with a car battery charger... sounds crazy but if you see how its done in an industrial setting you'd understand the concept. I did a similar process, not electropolishing but rather cleaning by elctrolosis on a V-8 engine block, lowered into a 55 gal drum of water with washing-soda (not baking soda, 2 diff things), using a battery charger to supply a few amps at 12V. the rust literally jumps off the metal and goes to the sacrificial anode.
 
Sep 8, 2014
2,551
Catalina 22 Swing Keel San Diego
I tend to agree that it's salt water inside the tubes that's doing it. Of you ever take this apart, it would be prudent to passivate the stainless inside the tubes. This is done with an acidic preparation, usually phosphoric acid. The product I use with great success is Wichinox, but it's kinda expensive.
Where do you get that stuff at? The product I use is $12 a gallon but its only available as a store brand at a place Called Industrial Metal Supply here on the west coast.
Its kind of a generic metal cleaner, I'm pretty sure any welding supply place has it you just have to ensure Phos Acid is the main ingredient.
 

jviss

.
Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
Where do you get that stuff at? The product I use is $12 a gallon but its only available as a store brand at a place Called Industrial Metal Supply here on the west coast.
Its kind of a generic metal cleaner, I'm pretty sure any welding supply place has it you just have to ensure Phos Acid is the main ingredient.
I got a jar of it at West Marine years ago. I just looked at WM and Amazon and it appears it's no longer available, and they have this replacement called Wichard Greenox Stainless Steel Cleaner. Ugh!
 
Sep 8, 2014
2,551
Catalina 22 Swing Keel San Diego
I got a jar of it at West Marine years ago. I just looked at WM and Amazon and it appears it's no longer available, and they have this replacement called Wichard Greenox Stainless Steel Cleaner. Ugh!
Yeah, anything from WM or Winchard (French stuff, but high quality) will be way over priced. Find a welding supply store such as Praxair or AirGas. Tell them what you are looking for and they should have it for much cheaper.
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
he product I use is $12 a gallon but its only available as a store brand at a place Called Industrial Metal Supply here on the west coast.
What is the product called? Is it a paste?
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
Ah, yes, I have that and use it; but it's not the same as Wichinox. I have gotten superb results with Wichinox on stainless on the boat; it's easy to handle (a paste), can be applied with an old toothbrush, rinses easily with cool, fresh water, and passivates the stainless as well as polishing it up, so that it goes a long time before needing cleaning again. I have tried Naval Jelly to much less satisfying an effect.
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
Check Maine Sail's thread about using Spotless Stainless, good stuff.
Thank you, I have. I think Wichinox solves some of the problems and shortcomings of Spotless Stainless. As MaineSail says, SS needs to be kept wet (without diluting with water), and takes time - as in, hours. Wichinox is a paste, it keeps itself "wet," and works in just 20 minutes. So, you can around the deck, applying it to lifelines, stanchions, rigging turnbuckles and fittings, the wheel, etc., and come around in 20 minutes with the hose to rinse it off, and done!
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
By the way, there are lots of products out there for this application. I just ordered a 22 oz. spray bottle of Citrisurf 2310 gel. I like what I read about application, time, temp., etc., so I'll give it a try. I found a supplier who still has some Wichinox, but it so wicked expensive: $24 for a 5 oz. tube, where the 22 oz. spray gel of 2310 can be had for the same price. I will report back on results!
 
Apr 5, 2009
2,774
Catalina '88 C30 tr/bs Oak Harbor, WA
I have tried a lot of different stainless cleaners but Wichinox is the only one I have been happy with. Here are some before and after photos of my dodger bases. I wiped it on with a scrap of terry cloth, waited 20 minutes and hosed it off. It was done in spring and still looks great.
20170629_193357_resized.jpg after.jpg
 
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jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
Nice, Hayden! Yea, I love the stuff, and I only have a smidgen left in my original, little, plastic tub, but i'm trying the Citrisurf 2310, as I mentioned. I will report back.
 
Nov 6, 2006
9,885
Hunter 34 Mandeville Louisiana
I've seen stains like that when the bedding is leaking and the through bolts are doing the crevice corrosion thing.. When you remove the bolts and find them significantly reduced in diameter, you'll be happy ya changed them and rebedded the whole she-bang..