Bronze or Stainless

[RichH]

Robert .....

The problem here is perhaps a characteristic of being ANAL. "Admiralty" defines for most people in the metals/marine/chem. process business an alloy thats at least 70% copper and if admiralty bronze, not much zinc/iron. It is (was) one of the commonest marine/process chemical/power industry/ marine engine / bearing grades of bronze there is --- worldwide (but apparently unknown on the Hudson Valley). Yes indeed you can get silicon and managnese bronzes (at higher expense) .... but lets simply return to the simplicity of the original question: whats better?: The answer is BRONZE. If true bronze and the various formulations of bronzes disturbs you Im sorry, the answer is still BRONZE .... and the BEST bronze for saltwater applications is still NickelAluminumBronze. Parse that ......

 

[Robert Gainer]

You have presented a good argument it is the best

RichH,I have no problem with Admiralty Bronze and don’t dispute its composition or existence. I only maintain that in the marine industry in this country it’s a definition that has been replace by something else and if you walk into a chandler and ask for it they won’t know what you are talking about. Sorry about that but that’s the way it is and I can’t do anything about it. You say it’s still used as a definition in some other industry but what do you want me to do about that. Use the word if you like it and it doesn’t bother me at all and after all why should it. My catalogs just don’t have it anymore and it’s been a long time since I had a catalog that included it and even then it was imported items from England where the word is still used but even there it’s falling out of favor.You said,“Yes indeed you can get silicon and managnese bronzes (at higher expense) .... but lets simply return to the simplicity of the original question: whats better?: The answer is BRONZE”Are you saying that silicon and manganese bronze are not bronze? What did you just say in this statement?You also said,“and the BEST bronze for saltwater applications is still NickelAluminumBronze”OK, you have presented a very good argument and it is the best bronze ever made and I should use it. But I can only find the inferior but more popular Manganese Bronze because it’s the only metal used in the catalog of marine fittings I have. They just don’t seem to make the stuff in another metal. Sorry, and maybe we should complain to the manufacturer. Or, better yet, you must know of someone that makes hardware in NickelAluminumBronze. Who makes underwater gear such as struts, stuffing boxes and thru-hulls in NickelAluminumBronze instead of Manganese Bronze? I would like to price it in NickelAluminumBronze, who has it?If you can suggest a source of NickelAluminumBronze hardware please let me know otherwise you have your way and I have mine and we should leave it at that.All the best,Robert Gainer

 

[Ross]

This thread has lost irs way. NY Sail wanted to

know Bronze or stainless? If I ask red wine or white. Those are the choices I haven't been offered Chateau La Fete` Burgundy or bordeaux. I haven't been offered Chardonnay or chablis Only red or white. ONLY bronze or stainless. How can that be so hard?.

 

[Fred]

Robert, actually, he said both

what metal is best, and I can get the part in bronze or stainless, which should I use?I'm agreeing with you. Use what the supplier can supply, use bronze where you can, and stainless where you have to. Best case is to have nice straight runs with no chafe. On my Catalina 22 the pipe for the cable was rubber exhaust hose.Chafe the cable or chafe the pipe? The board isn't a hazard if it's down on a broken cable. You can stop a leaky pipe. Take your pick, Captain. Boating is always a compromise, and there can be more than one right answer.

 

[Robert Gainer]

Long rambling post on headstays and other stuff

Fred said,“Chafe the cable or chafe the pipe? The board isn't a hazard if it's down on a broken cable. You can stop a leaky pipe. Take your pick, Captain”You are correct Fred and it’s a toss up depending on where you are and what your sailing at the time. But without hijacking the thread let me give you an insight into how I think about things like this and why I chose my answer.I started working part-time in a large rigging shop in 1967 in a gofer and file this or sand that type of job. The shop had both bronze and stainless clevis pins at the rigging bench. I had the job because I was friendly with the owner and this meant I had the opportunity to discuss how it all worked and why he designed things the way he did and I learned a tremendous amount. He explained in great detail that things should be designed to fail gracefully and should also be designed so that you could fix it in the future. In some rigs he used bronze clevis pins so that the pin would wear instead of the chainplate, tang or turnbuckle. It was easer and less expensive to replace a clevis pin on a regular basis then it was to replace a chainplate etc. I still think in terms of what’s the way to build something so that it’s both easy to maintain and so that if it does fail it fails gracefully instead of dangerously.Losing a rig is always a disaster but losing it because the headstay went is an even greater disaster because it will fall back into the cockpit possibly hurting someone. There was a very early English roller furling system that replaced the headstay and when the bearing failed the whole system would let go and the rig would drop into the cockpit. Specifying that gear on a job is an example of designing something that doesn’t fail gracefully. A roller furling system that is built around a headstay is a better system because you retain the integrity of the headstay. The system may fail but the rig will stay. I think that’s an example of something designed to fail gracefully.Now why did I prefer to have a small leak instead of a broken centerboard pennant? If you sail in the Chesapeake having a centerboard stuck down is very awkward but so what its not life threatening. And if you sail in Long Island Sound it’s not a problem because you just motor over to a yard and get hauled, then fix it. But I naturally think in terms of how I sail. I enjoy offshore sailing and as a rule I think it’s a combination of simple failures that sink the ship. In this case if my centerboard fails (Tartan 34C) and I am in bad weather the combination is more dangerous then being in bad weather and having just an annoying but manageable leak instead of having a stuck centerboard and not being able to heave-to because of it. Just my opinion and it may not or almost certainly will not apply to others. Fred also said,“Boating is always a compromise, and there can be more than one right answer”I think I would enjoy sailing on your boat. It sounds like a friendly and democratic process takes place. But on my boat there is only one way and that’s my way. That may be the biggest reason that I always seem to sail solo. With only a few exceptions all my trans-Atlantic trips have been solo. Sorry to take up so much bandwidth but it is a discussing board so maybe it’s not too inappropriate.All the best,Robert Gainer

 

[Larry]

Centerboard Shackle Corrosion

I bought a new Centerboard rope/pennent from D & R and it has a stainless shackle and clevis pin. Much to my surprise the clevis pin was rusted and worn thru almost 40% after only one season (6 months). CB shackle is under water I guess.Is this a case of poor stainless and/or how can I determine the quality of the new pin that I need to purchase?Thanks All

 

[Robert Gainer]

Larry, it doesn't take an expert

Larry,It sure doesn’t take an expert to see that you have a problem. With so much cheap imported stainless around I would guess you have a greater chance of getting something bad instead of good just by the odds. But knowing that doesn’t help you does it.I don’t know of a way to just look at stainless and be able to tell how good it is. Even the magnet test isn’t fool proof. I think the best thing you can do is buy from a “trusted source” so that you get quality stainless. A sailmaker for instance will know more about the hardware he buys then the people at West or other discount houses and he has a reason to have small high quality shackles in stock. Also buying a “name” like Schaefer Marine will increase the odds of getting quality.Do you have other options instead of a shackle? For instance some boats use link plates and bolts with nylock nuts instead of shackles. Or maybe you can nicopress the wire (with a thimble) directly to the centerboard and bypass the shackle altogether. If that’s possible that’s the way I would go but I have a nocopress tool which you may not have handy.Good luck and all the best,Robert Gainer

 

[Fred]

Robert, I think you would

enjoy sailing on my boat. It is a place where we discuss this sort of issue at great length.However, it is MY BOAT, and like you, I decide what is right on my boat. I have been involved in democratic voyages. The problem with democracy is that it's slow, and when thing get nasty, there is no time. Also democracy assumes everyone knows what they're doing, which, in my experience on boats is not the case.Democracy on the thread and in the coffee shop. Absolute dictatorship on my boat!It works.

 

[Ross]

I enjoy democracy on my boat but reserve

the right of absolute veto power.

 

[RichH]

Larry .....

With regards your shackle..... the 'pin' of a shackle should be 'just slightly smaller diameter' that the clevis you are trying to attach to. If the pin is much smaller that the clevice hole diameter; then, you will get 'point to point' contact instead of surface to surface contact .... pt. to pt. contact will wear (deform actually) rapidly under load as you 'may' be exceeding the ultimate tensile (compressive) strength of the materials - called 'fretting' which is a characteristic that yields excessive wear (when under load) --- this is how a 'ball-peen' hammer works when used to shape metal. To make this simple: a 'pin' should be just very slightly smaller than the clevis, eye, etc. it fits into. In your case, to test the chemical stability of such a shackel in seawater, simply put into a pot of hot seawater or plain salt water on the stove and let it 'simmer' for a few hours. If its inferior stainless then you will soon notice the degradation from halide/chloride attack. (Then let the pot soak in hot vinegar, etc. to remove the formed carbonates on the pot sides to keep your wife/SO happy)....... betcha the 'pin' of the shackle is too small or the 'hole' or the pendant is too big.

 

[RichH]

Geeze mom, look at all the Little Napoleons on

this bulletin board. On 'MY' boats anyone who has the confidence and knowledge is free to do **absolutely anything** that is prudent or worthwhile, including 'experimental' ... and you dont even have to ask! The ONLY rare limit is in obviously dangerous situations I reserve the right to over-rule ... but there may be a very brief discussion of 'why' and then I may 'turn it back to you' so you can complete it. Its called 'team building'. I dont sail/work/relax with 'little Napoleons' and usually dont permit 'Little Napoleons' on my boat, etc. as life is too short to be an anal control-freak. Besides I want everyone on my vessel to be "as good as I am" .... so I can relax and enjoy especially when someone is learning, etc. because if we're all at least in 90% agreement ... . I'll keep my mouth shut for the other 10% of the time, because it 'usually doesnt matter'. I can just imagine throwing one of you Napoleons a life ring .... and and then expect you to probably refuse it (and then drown) because its not in total conformance to the latest USCG regulations, wrong color, straps are twisted ... or something analy non-essential, etc., etc., etc., etc., etc., etc., etc. Been on too many race boats/work places/,etc. skippered by 'martinettes' ... and they usually dont finish well because primarily because of the needless 'authoritarianism'. I never seem to lack for enthusiastic crew or 'company' ..... and my boats usually end up 'in the money'. .... end of rant.

 

[Robert Gainer]

fretting?

RichH,Neat word and I had to look that up.The ASM Handbook on Fatigue and Fracture defines fretting as: "A special wear process that occurs at the contact area between two materials under load and subject to minute relative motion by vibration or some other force."And to quote from another source,“When two pieces of material, pressed together by an external static load, (for example, bolted flanges, riveted lap-joints, press-fits such as a gear or bearing on a shaft) are subjected to a transverse cyclic loading, so that one contacting face is relatively displaced cyclically parallel to the other face, in the presence of high contact stress, wear on the mating surfaces occurs. If the magnitude of the displacement is less than about 0.003 inches, the wear is termed "fretting".Fretting occurs by contacting asperities on the mating surfaces continually welding together then breaking. That leads to surface pitting and the transfer of metal particles from one surface to another. In addition, the small fragments of metal which are broken off oxidize, forming oxide particles which, for most engineering metals, are harder than the mated parts. These particles become trapped between the mating surfaces and cause abrasive damage and scoring.Briefly, the characteristics of fretting are:(1) It is most serious when oxygen is present, although it can also occur in an inert gas;(2) It is worst under perfectly dry conditions;(3) It increases with contact load, slip amplitude, and number of oscillations;(4) Soft materials generally exhibit more susceptibility to fretting than do hard materials of a similar type;(5) Lubricants, particularly when used with surface treatments such as phosphating, reduce fretting damage”I am not the expert that you are Rich but this problem doesn’t sound like the description above. The most interesting things are that fretting requires small movements measured in the thousandths of an inch and a shackle shaking in a hole doesn’t sound like movement in the thousands of an inch. It also sounds like the shackle is under water and fretting doesn’t happen when the parts are lubricated with water and of course the pin and centerboard would not be considered “soft.” Also it doesn’t have anything to do with a materials “ultimate tensile (compressive) strength” as you say. And by the way tensile and compressive strength are two different things.Your boiling experiment sounds like fun. What will he use for a benchmark? All stainless will suffer from halide/chloride attack and it’s just a question of degree. As fun as this sounds it might not be a practical way to buy hardware. But I will try it and see if it’s worthwhile as an experiment for one of our presentations in boatbuilding.Did you get a chance yet to find a source for underwater fittings made from the better bronze? I was in the office today and didn’t find anything yet in any of our catalogs.All the best,Robert Gainer

 

[Robert Gainer]

Napoleons?

Tell a captain in the navy about this. He will get a kick out of it.All the best,Robert Gainer

 

[Ross]

I don't know from "little napoleons" . Is that

a pastry? How about a large group of "peter the greats". As concerns the pending distruction of all moving parts that are made from sub optimal materials I can not understand how we kept our machinery on the farm together while we spread chemical fertilizers, hauled fermenting organic livestock fodder and parked the equipment out in the weather for years. Good engineering calls for a matching of material suitable for the job within the service life of the machine and not to exceed the cost figures in our budget. I am quite sure that stainless steel cable running on bronze guides will last longer than stainless steel running against stainless steel. That is why they use babbit bearings for support of steel shafts. steel bearings supporting steel shafts "pick-up and gall". I am not refering to ball or roller bearings. Rich, you may have great knowledge of the composition of materials but you haven't demonstrated a very broad knowledge of good and acceptable engineering practice.

 

[grigs]

WOW

AM I THE ONLY PERSON WHOS COMPLETELY LOST OUT HERE ??? NY SAIL HAS LEFT THE BUILDING. GRIGS

 

[NYSail]

Still here

I love how a basically simple question in my mind can lead to so much knowledge and discussion about the subject of metals and their respective properties.Man once again I will say it, you guys are real smart and I am glad to have you as a resourse!!Carry on!ThanksGreg65 days and counting!

 

[Robert Gainer]

Greg, may I ask?

Greg,May I ask about “65 days and counting”?All the best,Robert Gainer

 

[NYSail]

uhhhhhhh

Just another great day!

 

[Terry Cox]

12-pounder Napoleon...

The Napoleon was the most popular smoothbore cannon used during the civil war. It was named after Napoleon III of France and was widely admired because of its safety, reliability, and killing power, especially at close range. It was the last cast bronze gun used by an American army. The Federal version of the Napoleon can be recognized by the flared front end of the barrel, called the muzzle-swell, whereas Confederate-manufactured Napoleons had straight barrels.

 

[RichH]

Sorry Robert a naval Captain will agree with me ..

Sets the goals, sees that they are accomplished, inspires others to rise above their present 'limitations'.... the job of anal stuff is for **PETTY** OFFICERS as they're the ones who are commissioned to deal in PETTY stuff, hence the name. If a captain quoted chapter and verse from every reference book in his limited library to his crew, etc., he'd be soon demoted to a PETTY officer ... or have a mutiny on his hands.