Rust on new chain plates

[Cheechako]

Originally Posted by Island Time O25

What would be the total cost of getting this ss plate and cutting/drilling/passivating, etc? I recall in a brand specific forum a few years back (3-4 yrs may be) one owner posted that he scored a good deal on a titanium sheet for a few hundred $$ and had that cut and drilled into chain plates for an older 36 footer. I vaguely remember that his total outlay was around $400. I forget the size of his initial sheet but he had leftover piece that he sold cheaply to another forum member. Considering titanium's properties I gladly would pay 50% to double of the ss prices.

I'm not sure, but getting the right place to do the job reasonable is never easy unless you are lucky for sure. Ti or Bronze eliminates the need to find polishing, passivating etc..... so good point. Ti can be a bit ugly if you want things shiny. Bronze bar may be a bit expensive intitial cost, but easier to "get 'er done" maybe.

[CSY Man]

I took my 316 SS chain plates to a chrome shop and had them electro polished.
Still look like brand new 14 years later.

[aquarian]

We had plates made by a very good metal shop - great people with the best of intentions. We needed 316 stainless. We got unpolished 308 food grade stainless. They were trying to save us money and didn't understand the importance of the difference. We ended up selling those plates (almost 100 pounds of metal) for about $10 because the carbon content was so high a magnet would stick to it. It is definitely worth investigating. It is also very true that tooling materials will leave rust able metal fragments behind.


Love the citric acid soak suggestion - I have polished my butt off in the past trying to get rid of left behind's rust.

[aquarian]

Originally Posted by CSY Man

I took my 316 SS chain plates to a chrome shop and had them electro polished.
Still look like brand new 14 years later.

Great idea! Thanks

[PC45]

Sorry, I have no answer yet, but I have sent a question to a friend of mine and hope he will have a better knowledge of the cost of that special steel. When I have an answer I will come back.
Pelle

[Cheechako]

Originally Posted by aquarian

We had plates made by a very good metal shop - great people with the best of intentions. We needed 316 stainless. We got unpolished 308 food grade stainless. They were trying to save us money and didn't understand the importance of the difference. We ended up selling those plates (almost 100 pounds of metal) for about $10 because the carbon content was so high a magnet would stick to it. It is definitely worth investigating. It is also very true that tooling materials will leave rust able metal fragments behind.


Love the citric acid soak suggestion - I have polished my butt off in the past trying to get rid of left behind's rust.

BTW, 308 and 316 are both specified at .08% Carbon max. 316L is lower though. Your plates may have been work hardened from just some cold rolling/working making them magnetic.

[PC45]

Re: Rust on new chain plates
You have to use a stainless steel like Sandvik SMO 254 or Avesta Sheffield SMO 254 if you want real stainless
Crevice corrosion test: When stainless 316L corroded >3 mm (3 of 3 test panels) after 18 month submerged in the sea, watertemp. 5 - 30ºC, SMO 254 corroded 0,09 mm (only 2 of 12 test panels) in the same test.
-----------------
What would be the total cost of getting this ss plate and cutting/drilling/passivating, etc? I recall in a brand specific forum a few years back (3-4 yrs may be) one owner posted that he scored a good deal on a titanium sheet for a few hundred $$ and had that cut and drilled into chain plates for an older 36 footer. I vaguely remember that his total outlay was around $400. I forget the size of his initial sheet but he had leftover piece that he sold cheaply to another forum member. Considering titanium's properties I gladly would pay 50% to double of the ss prices.
----------------------
I think the material SMO 254 will be about 4 - 5 times more expensive compared with 316L.
Other names of SMO 254: SS2378 (Swedish Standard) or EN 1.4547
If you can understand Swedish you can look at the attachments.steel.pdf Views: 41 Size: 189.6 KB ">Different-IRJDSUNE9932123321222xxeww-sorts-IRJDSUNE9932123321222xxeww-of-IRJDSUNE9932123321222xxeww-steel.pdf
Prislista rostfri plåt, stång, rör 2010-05-03.pdf

[buzzstar]

Originally Posted by PC45

[edited] In a brand specific forum a few years back (3-4 yrs may be) one owner posted that he scored a good deal on a titanium sheet for a few hundred $$ and had that cut and drilled into chain plates for an older 36 footer. I vaguely remember that his total outlay was around $400. I forget the size of his initial sheet but he had leftover piece that he sold cheaply to another forum member. Considering titanium's properties I gladly would pay 50% to double of the ss prices.]I think the material SMO 254 will be about 4 - 5 times more expensive compared with 316L.

I have been interested in titanium for boats for a number of years, primarily because of it corrosion resistance and strength, but also because of its increased availability, lowering cost, the increased number of sources, and places with the capabilities of properly working with it. Although I do not know if they are still around -you would have to look for yourself- there was an outfit that had a fairly extensive line of titanium marine hardware, including chain plates, probably using measurements from previous orders. If I recall correctly, the company was called Allied Titanium (although I am only sure it had "Allied in the name). I also remember that with some shopping I was able to find the raw material and at least one shop that would produce them for quite a bit less. Unfortunately, I do not recall any additional specifics. The chain plates would have been intended for a Dreadnought 32. Sadly, the deal for the boat itself fell through, and I have never had reason to go further into the subject since.