Replacing Chain Plates

[cheoah]

Originally Posted by sabray

As posted prior drilling holes in SS you don't need to go small or buy real expensive bits. Water lots of it and Sharp proper sized bits. Learn how to sharpen the bits on a wheel. It's not hard. Belt sand and increase then belt sand with scotch belts then polish or send it out for electro polishing. Most of the work is in polishing. If I do this again it will be titanium.
I don't understand titanium grades. It's also not so easy to find common size bar stock. Thinking about doing my drogue bridle plates in titanium but I have some homework to do. Reason is they will be very exposed have huge loads and I would rather do this and be done.

Are there drawbacks to titanium besides cost? And apparently some a availability issues?

I would be inclined to use it over stainless if its not too ridiculous.

[sabray]

Cost for raw stock seems 4x the price of 316L. I haven't looked very hard though. Otherwise it seems superior. Not sure how titanium bolts do with sheer strength but expect that is equivalent.
One piece that is missed is the optimum torque on the bolts.
When I did mine some of the bolts were horrific with corrosion. The knees had gotten wet and I saved one. See picture.

[sabray]

better picture of bolt

[Noreastern]

Wow, that bolt is scary! Not sure what a "knee" is but bolts in our boat looked near perfect after 49 years. One thing I liked about this older Pearson design is that the sleeve that the chain plates where in was completely open on the bottom. Ruined the interior teak if not properly caulked every couple of years but water was never allowed to accumulate in the sleeve.

[Mycroft]

I just bought a 1984 Slocum 43 and the survey said that the chainplates had corrosion Because of the way the boat was built, in order to inspect the chainplates properly, it required that the cabinets and teak paneling be cut out, so nobody had done it in 30 years. The previous owner thought the surveyor was full of it because he'd sailed in some serious winds around San Fran without a problem. But, the problem is that the chainplates hold until one of them doesn't.

I made a Flickr set of my standing rigging replacement. One of the plates was so bad, it looked like the only thing holding it together was rust. It fell apart in the rigger's hand when he took it out.

[RainDog]

This is an interesting, and kind of scary, read on old chainplates:

chainplate followup - SailNet Community

"Last spring I replaced the chainplates on our 1982 Crealock 37.Upon removal we thoroughly inspected the old plates including a dye test.The old plates looked and tested fine,no cracks and no corrosion." Yet it seems maybe they were not so fine.

Pictures are in post #12.

[Stumble]

Originally Posted by cheoah

Are there drawbacks to titanium besides cost? And apparently some a availability issues?

I would be inclined to use it over stainless if its not too ridiculous.

I used to sell them, but returned to practicing law (mostly) about a year ago. Frankly I think going with anything but titanium is a little silly. Titanium is more expensive, but typically not much more 20-30% assuming the stainless is electropolished not just polished on a wheel.

Beyond that they are immune to corrosion in the marine environment, and can be made roughly 5 times stronger for the same size (316 vs. G5).

The major problem I saw was in convincing owners that they really could go with plates as small as the NA recommended.

[ravinracin]

Something I don't understand. I use todays steel and it is like worthless. I am talking about things I work with, bolts, nuts, screws, light metals. the steel made today is much weaker than say before the US stopped making it. My boat is 44 years old, the chain plates look like they were just installed, bolts, nuts also. I don't think they have ever seen water except the eye above deck. Do I want to replace them with todays steel and if I did, should I double or triple the size because of the inferior product made today?

[Lojanica]

Originally Posted by sabray

As posted prior drilling holes in SS you don't need to go small or buy real expensive bits. Water lots of it and Sharp proper sized bits. Learn how to sharpen the bits on a wheel. It's not hard. Belt sand and increase then belt sand with scotch belts then polish or send it out for electro polishing. Most of the work is in polishing. If I do this again it will be titanium.
I don't understand titanium grades. It's also not so easy to find common size bar stock. Thinking about doing my drogue bridle plates in titanium but I have some homework to do. Reason is they will be very exposed have huge loads and I would rather do this and be done.

Made my own titanium chain plates. Bought military surplus titanium plate. Paid to have it water jetted. Finished of by grinding and filing and sanding and reaming. Pretty cost effective. $500 for the titanium (10 plates) @ 1/2" x 2" x 14". Bending them was the hard part. Oh yeah titanium eats tools for lunch.

[zboss]

Originally Posted by ravinracin

Something I don't understand. I use todays steel and it is like worthless. I am talking about things I work with, bolts, nuts, screws, light metals. the steel made today is much weaker than say before the US stopped making it.

I agree with that, I have had trouble sourcing a good vendor for real quality 316 stainless nuts, bolts, washers, and screws. The ones from any old hardware store rust after 3 months.

[HappyMdRSailor]

Originally Posted by Lojanica

Made my own titanium chain plates. Bought military surplus titanium plate. Paid to have it water jetted. Finished of by grinding and filing and sanding and reaming. Pretty cost effective. $500 for the titanium (10 plates) @ 1/2" x 2" x 14". Bending them was the hard part. Oh yeah titanium eats tools for lunch.

And breakfast... Brunch... Dinner... midnight snacks...

Originally Posted by zboss

I agree with that, I have had trouble sourcing a good vendor for real quality 316 stainless nuts, bolts, washers, and screws. The ones from any old hardware store rust after 3 months.

Gotta go with the big industry sources.... McMaster Carr can't be beat... Fastenall, many others... An Ace/Depot/Lowes SS fastener is worthless...