Need new chainplates - Where to buy the stainless? 316 vs 2205?

[neoxaero]

I recently bought a 72 Santana 21..

I'm in the process of making all new standing rigging for it (Using nicopress fittings)

Now that I'm done with that I decided to pull the chain plates before I step the mast. Its a VERY good thing that I did.. Both of them broke when I was trying to get them out. They were completely rusted through where they pass through the deck.

So where could I possibly find the stainless locally? If I have to I'll order it from McMaster-Carr but I was planning on getting the mast up and seeing what other goodies I'm going to need before I get this thing out on the water.

Also should I buy 316 or 2205? Its my understanding that 2205 has higher crevice corrosion resistance as well as being stronger...

With either one of these should I go with 1/8th plate that is there right now or upgrade to 5/16th plate?

[mitiempo]

5/16" is probably overkill as it is 2 1/2 times as thick as what was there. I would use the same thickness that was there originally. It did last 38 years! Type 316 is the best choice - 2205 is best used for its design purpose, pipes and tubes. And you want bar stock, not plate cut to size.

The key to their longevity is keeping them dry where oxygen is not present. Your deck must be cored and it is no doubt wet or there would have been little or no corrosion. I'd look at the core as well.

As well, you are probably compromising the rigging strength by using nicropress over a good machine swage I think.

I don't know where you could find any locally because I do not know where you are.

[davidpm]

Originally Posted by mitiempo

And you want bar stock, not plate cut to size.

What do you mean by this statement?
Why does it make a difference?

[Stillraining]

Here is some good reading about Nicopress usage.

nicopress standing rigging? [Archive] - SparTalk

[mitiempo]

David
If cut from plate the heat of cutting can change its characteristics of the alloy depending how it is done. Also the edges may not be perfect and have machine marks which can lead to localized stresses. Bar stock, which is available in many sizes, comes from the foundry that way and requires no machining, only cutting to length.

[neoxaero]

I didn't realize that i hadn't filled out the location and stuff in the user cp..

I'm from Austin, Tx

I'm not to terribly worried about the Nicopress fittings failing.
The boat sits on a trailer with the mast down most of the time and I wont be taking it out in crap weather.

[RXBOT]

There is no heat if a shear is used to cut ss plate which is the common practice. A normal cutting torch cannot cut stainless but a plasma arc can. There would be no harm in upgrading to 3/16 plate. Any metal fab shop should have some scrap pieces around big enough to suit your needs.

[mitiempo]

neoxaero
RXBOT is correct - if done properly the new chainplates can be cut from plate material. The edges have to be finished smooth for longevity though, and ideally electropolished.

Did you go to the link posted by Stillraining? Brion Toss is one of the best riggers in the country and his opinion is worth something. He recommends against nicropress except for halyards of 7 x 19 construction, wire not suited for standing rigging. They do not work well on 1 x 19 stainless rigging wire.

[CapTim]

Macgregor has been using the nicopress for a while... he sells a few boats every year. I'm not suggesting nicopress for every application, but it has it's place. Which isn't to say that Brian Toss isn't the rigging god. His book is well worn and still sits with easy reach.

Neoxaero.. were you able to retrieve an entire chainplate, even if it's in two pieces? Most shops will prefer to work from a part, rather than knock something out with just measurements. Of course, either way, you shouldn't have much trouble.. it's a pretty straightforward piece.

Gratz on doing so much work yourself!

[DelmarRey]

Originally Posted by RXBOT

There is no heat if a shear is used to cut ss plate which is the common practice. A normal cutting torch cannot cut stainless but a plasma arc can. There would be no harm in upgrading to 3/16 plate. Any metal fab shop should have some scrap pieces around big enough to suit your needs.

There is water jet cutting which is what is recommended for SS especial. Laser cuts great too but does create heat. West Coast Waterjet - Precision Water Jet Cutting Metal, Steel, Stone, Glass, Wood - Greater Seattle, WA


YouTube - ‪WATER CUTS STAINLESS STEEL‬‎

BTW-2205 is commonly known as Aqualoy used for prop shafts.