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How do you tell s/s or monel by look I and helping a mate on his boat and noticed a keel bolt washer loose and going to twitch it up in a day or two How can you tell in looks monel or stainless ,or is there a different

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Yes they have some slight green on the nuts All polished highly as they are seen I tried to spanned one that had the loose washer and I could see the bolt twist a tad , so will soak with crc the day before to help tighten it when ready

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are these large bolts? Over 1 inch dia? If so, a simple test. Put the biggest socket and bar on them you can fit. Out your back against a bulkhead, and your feet on the bar. Torque is over 250 ft pounds (for 1 inch stainless), so on a 2 ft bar that's 56 KG....

If you can break them with manual force, they are knackered...

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thanks IT i think they quiet long i see the bog spots on the lead about half way down so they could be a foot or two long or more so it looks like they were fitted after the lead pour baby and they are about 3/4 in good nick it has a keelson and a sister keelson above about 10 inches wide and solid to the main keelson so is very strong ship  

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There's another answer to identification right there. Lead will "meld" (solder) to some Monel, but not SST.

I answered the the question of can you identify by looking at the two and that is very hard to do. But there are other tests to identify accurately and even identify what species of Monel or SST.
The simplest is the scratch test. Monel is soft and easy to file or nick with a hacksaw blade. SST is not. But that will not tell you the type. To do that requires the use of Nitric and Phosphoric Acids and I figured that a bit beyond the realm of the original question. A drop of Nitric does nothing to SST. It instantly reacts on Monel. A drop of 45% Phosphoric Acid will slowly bubble on SST. Then it gets a little more complex for identifying the types and probably not needed here.

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may need a retighten once in the water,at the moment(if out of the water) the hull is resting on the keel,once in the water keel will be hanging with no weight so may need a retighten.

 

The person who brought my wreck has removed the keel and replaced bolts 1  4 5 6 7 8

2 and 3 is a s/s u bolt fitted at pouring and this is the bolt that broke a nut off,did suggest drilling a new bolt alongside but seems happy to refit with by cutting thread off and welding new one on. 

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Chris Robertson 10 mtr I think from the Anwers we’re having some green on them they could be monel I thought monel was hard substance ,

 

Mine are monel MJ, wasn't built by the yard so not sure if that affects any relevance to any of his other boats though.

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I thought monel was hard substance ,

No, it is just really good at being corrosion resistant. But it is bad in a galvanic corrosion situation.

Monel is an Alloy. There are 6 types. The alloy is of mainly Nickle at 63%, copper at around 30% and then small amounts of Iron and Manganese and then the 6 different monels have trace amounts of differing metals to make each unique in their roles.

Monel was the fore runner of SST and was invented by Robert Crooks Stanley in the beginning of the 1900's and the name Monel was the name of the Director of the Company, The International Nickle Company.

One of the most famous stories involving Monel, was in 1915, when an entire 215ft Yacht Hull was built from the metal. Now bare in mind that Monel is incredibly expensive. I don't know who the owner or Builder was, but it must have cost a fortune. I believe the Boat was built in New York, which had a number of Ship building yards back then. I believe the internal frame work was steel and it badly reacted with the Monel. The entire boat was damaged so badly in just 6 weeks, that they had to scrap her.

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No, it is just really good at being corrosion resistant. But it is bad in a galvanic corrosion situation.

 

And so is SS: which is also bad in a low oxygen situation. So monel should be better if protected properly?

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But then I have seen some 316, thirty years old that was perfect. (visually) 

As a SS fabricator I wouldn't be trusting any ss 30yrs old unless it has been fully exposed to the atmosphere it entire life: Period.

And my own boat at 45+ yrs has plenty onboard which still looks fine: what I can see of it :)

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The building s/s is crap , 304 or less. Even the building inspectors Say it’s shinny looks like s/s tick the box . I add onto a deck I built a couple of years ago I had to take one bolt out of the bearer to connect another bearer and there was rust and dulling . The dulling was weird , no shine ..

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