Is a stainless steel boat possible?

nickel

http://www.nickelinstitute.org/index.cfm/ci_id/13943/la_id/1.htm

applied a stainless steel boat

oktay çemberci

 

Tesekküler Oktay,

but we can hardly call Cupronickel a "stainless steel" there is no FE in it!
And it is known for long that it could make a good boatbuilding material (like Monel or Titanium too) but being ten times the price of mild steel (all of them), is a shocking start for most clients.

btw: you like to meet for a cay?

Regards
Richard

 

How About a Titanium Foil ?

First off I was considering a Dutch Built 316 SS Hulled Pilot House Ketch that had been available in the San Fransico Bay Area. What was odd in it's construction was that after going to the expense of using all Stainless Plates, stringers, keel, etc. they used mild steel for the deck house and deck. Seemed like they should have finished the way they started. I believe it was a poor decision (in hind sight admittedly) because the hull showed to be in superb condition but the deck and house had serious corrosion problems.

The work hardening issue brought up previously would be a serious concern. Although this boat was over thirty years old and the hull looked fantastic.

On a slightly different thread what about a Titanium Foil lamination on a Glass or Composite (Kevlar, Carbon Graphite) hull. Maybe the foil could be laid in a female mold and allowed to setup during lay-up. Or maybe an epoxy or super adhesive could be sprayed on a finished hull and the foil applied in that manner to just above the water line. Providing a foul free bottom (granting you don't damage it) !

Anyone heard of or seen something like this ?

Sincerely,
Eric

ps: Please excuse my dreaming aloud !

 

The reason for the steel superstructure was probably pure economics. SS has historically cost around 4-5 times the price of mild steel. Constructing the hull and wetted areas from a Stainless alloy would be an expensive and technically complicated affair (as this forum has shown). The topsides generally needed no more routine maintenence than the average commercial fishing boat. If it was in a poor state, it was probably neglected. Of course, the electrolytic action between the noble SS and the Mild steel at any weld interfaces would be another complication and could have been significant at the joints. This is generally manageable as most outboards get away with a mix of these and many more metals without too much problem. I believe the work hardening issue to be another design consideration. Any metal will eventually fracture at a repetetive stress point weld or not, and some quicker than others. A good designer would ensure welds were sited with appropriate stiffening and carried out to ensure no strength degradation in the joint. Regarding an earlier post re. the comparible service life of 3 series SS and 2205. The quoted 120 year service life of 2205 is hypothetical as the alloy has only been used commercially over the last 30 years. It is widely used on undersea pipelines with a 25 year minimum design life. It would probably be ideal for a SS boat project. The downside is the controlled welding conditions it requires. ie. it would need to be fabricated by professionals.

 

It would be an interesting experiment to fit an alloy outboard engine to a stainless hull. You can probably see the outboard dissolving once it touches the water.

There is an interesting book, Rise and fall of a dream maker, about John Z. DeLorean who built stainless steel cars or at least tried to.

 

More robust anodes would be required. I suspect the tiny standard ones would diappear like Alka Selzer. Connecting the engine electrically to the hull's anodes should do the trick. I have also seen boats at rest with a large anode dangling in the water connected to the outboard by a length of copper wire. I presume it helped. Ps. Delorean's problem would have been similar to the boatbuilders, outside shell of SS and loads of other metals inside to worry about.

 

Stainless steel
may be the grace jones of marine metals, a shiny, expensive, brutal, sexy, diva, unforgiving, cold , brittle & inflexible, it thrives on constant attention, oxygen & exposure, but if you cover it up or ignore it , it may snap on you when you least expect it, & may break your arm or leg , it lacks the strength of grain found in copper , steel & iron, such volatile behaviour is at odds with most of the reliable, comforting , dependable materials on most wooden boats

 

Well, it´s just a dumb idea to make a SS boat.

If one is willing to spend several times the money he would need for mild steel or Al, he can go as well for Titanium, that is sure the right choice!

Regards
Richard

 

I don't think SS can handle the same amount of flex as mild steel. I can see a large boat not lasting very well.

If SS was up to it then you would get SS ie trailers. SS is not suitable for flexing apps.

I'm not aware of any electrolytic action between the SS and mild steel. SS and other materials yes, but steel and SS ?

 

I see loads of SS road tankers every week. Can't say I've spotted one thats fallen apart at the seams. Unfortunately naval architects are generally ignorant about the strengths and engineering characteristics of SS. Annealled SS mill plates are seriously strong. (think mild steel plus at least 50% weight for weight). The metal has been widely used in offshore marine environments for may decades. Apart from the more obvious Oil and Gas production facilities, it is now being specified for some critical ship building applications. It has been used in modern double hulled tankers where it is used to create the lighter inner hulls and LPG cargo tanks. Stainless Steel, like most metals has shortcomings but no more than Steel. (remind yourselves of the Titanic) Each potential problem is now well documented and can be designed out of a hull fabrication. Welded Joints may become susceptible to stress fractures... so we must ensure seams are located at or near scantlings. SS may well become susceptible to pitting and crevice corrosion in welded oxygen depleted areas..... so design crevices and standing seawater out of the equation. The theorists might suggeat that inside of wet sterntubes would be a classic location for this but SS propshafts have survived in there for decades, has ayone ever heard of one corroding through... As for the actual sterntubes, excellent Super Duplex alloys are now available which are designed for these localised highly corrosive areas, and, they are compatible electrolytically with normal SS.

Regarding Peter's well described Grace Jones analogy, might I suggest Serena Williams might be a better comparison.
Wood?... might I suggest (tongue in cheek)..... Twiggy.

Len.

 

I'm rebuilding a stainless boat. It appears to be the same model as Biothree's. The decal on the back is RMC of America? Does this ring a bell to anyone?

 

stainless 14ft boat

This boat is registered as a 1955 regal. I think it is unlikely since Regal is celebrating their 40 anniversary. Anyway, this is a stainless boat less the wood trim and seating (much of it structural) It gleams! there is some dripped varnish/ wood preservative but that will soon be stripped away. It was made from two sheets and spot welded together.
I'll be happy to send close ups of details.

 

I don't want to enter the wider debate, but whilst I've never seen one corrode right through, I've seen plenty that have suffered corrosion as a result of oxygen depletion to the extent that they had to be replaced

 

There was a 50 foot IOR race boat built for a Japanese owner that was entirely Titanium. This guy, and pretty much the rest of the IOR 50 fleet, was "fabulously well to do." He wanted a Grand Prix race in Japan, so he paid to have the fleet -- about 20 boats -- shipped by air from Florida and Europe to Japan. During the racing, his Titanium yacht was involved in a collision (possibly with a mark during a rounding), and it SANK in deep water. The boat was raised within a few days.

 

I have ha experience in making a product for use in sea water that was submerging all the time. We made it from "Super Duplex" and it worked fine. This has better corrosion resistance than 316L.

I think the ideas of using stainless from containers is false economy. Scrap prices are very good for stainless. Buy the blanks in virgin laser cut shapes. There the material will be nested efficiently from sheet in clean material ready to weld.

Has any one tried "Super Duplex" stainless for boats and/or laser cutting?