What ever happened to Monel?

Discussion in 'Materials' started by FAST FRED, Apr 12, 2016.

  1. FAST FRED
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    FAST FRED Senior Member

    Back in the day fuel tanks and many boating items were made from Monel.

    Most still exist today.

    Today we hear about Titanium, but not everything needs high strength.

    There are many sources for Monel (on Google) just almost no use.

    Any idea why!
     
  2. Mr Efficiency
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    Mr Efficiency Senior Member

    Did I read somehere about a ship built of it ? There was some kind of problem with using it though.
    A big problem ! from wiki.....
    "However, because of the problem of electrolytic action in salt water (also known as Galvanic corrosion), in shipbuilding Monel must be carefully insulated from other metals such as steel. The New York Times of August 12, 1915 published an article about a 215-foot yacht, "the first ship that has ever been built with an entirely Monel hull," that "went to pieces" in just six weeks and had to be scrapped, "on account of the disintegration of her bottom by electrical action." The yacht's steel skeleton deteriorated due to electrolytic interaction with the Monel.[8]"
     
  3. sdowney717
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    sdowney717 Senior Member

    Monel manufacturers priced themselves out of the fuel tank market.
    I have monel fuel tanks, twin saddle tanks in the 1970 Egg Harbor 37 boat of 145 gallon each, made by SeaFare.

    Tanks seem ok. The fuel pickup though has completely rotted, seems to be made of brass.
    So will repair with copper.

    Was having serious odd issues, kept thinking fuel pumps and fuel lines not my monel tanks!
    This is about 6 inches too short.
    [​IMG]
     
  4. PAR
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    PAR Yacht Designer/Builder

    There's nothing wrong with monel and it's one of the best materials to use, given it's weight and cost. Boneheads have used this metal inappropriately and had disastrous results, but many commercial vessels also have with few difficulties.

    Monel is heavy and costly which is why you don't see it much. Scrap monel prices are ten times more than scrap lead and still twice that of titanium. Monel is also heavy 556 pounds a cu. ft., whereas titanium is 283 pounds. New processing are bringing titanium costs down too.
     
  5. Jamie Kennedy
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    Jamie Kennedy Senior Member

    I used to use monel for pop-rivets into aluminum, used to be available in the UK.
     
  6. gonzo
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    gonzo Senior Member

    183.538 Metallic fuel line material
    It allows nickel/copper (monel) and copper as the only metals for fuel lines.
     
  7. sdowney717
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    sdowney717 Senior Member

    I cleaned off the corrosion, and it looks just like brass to me, of course from 1970 the rules are always changing.
    I drilled out the brass tubing and soldered on a pure copper 3/8 pipe, the bendable stuff, people use it for hooking up their dishwashers, and I have some already.

    The tank pickup tube sits inside a bigger tube and that tube seems to go all the way to the tank bottom. So a tube in a tube arrangement. I setup the new pickup tube end to sit about 1/2 inch from the bottom of the outer tube which is likely close to bottom of tank.
    Why would the tank maker do this tube in a tube? I know it is a tubular structure since the rod I put in the hole is restricted as if in a tube, you can tell as you push it down all the way to bottom.
    Someone at marina suggested to protect the pickup tube, although wonder what could damage that seeing it is inside the tank.

    My though just now is it protects the tank itself from a person tightening the pickup tube in the tank. The monel sheets are thin and torquing this big fitting maybe could damage the tank.
    And also if a striking force was applied the the pickup fitting, the outer tube as a structure joined to tank bottom prevents tank damage as in bending the monel sheet and maybe cracking it open.
    Another idea is long term vibration damage, the connected line working the fitting around might fatigue the monel sheet cracking it.

    And why would brass decay to this extent inside a gasoline tank over 45 years?
    Is there that much salty moisture-humidity inside?
    Is brass anodic to monel?
     
  8. SukiSolo
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    SukiSolo Senior Member

    Still is available. I tend to use it where heavy duty loads on masts and booms need it, in preference to the aluminium (proper high grade) rivets. However it is best to be selective.

    Monel (in drawn form) has also been used for high strength fishing line, useful for heavy bottom feeding fish like Halibut.
     
  9. Mr Efficiency
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    Mr Efficiency Senior Member

    Pretty sure I have some monel pop rivets on chromed brass fittings on a glass boat for many years that have stood up well.
     
  10. Landlubber
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    Landlubber Senior Member

    WE still use and can purchase monel, one of the best fasteners available here.
     
  11. PAR
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    PAR Yacht Designer/Builder

    I use monel staples on stuff I don't want any issues with. Way better than stainless, strong durable and corrosion free.
     
  12. FAST FRED
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    FAST FRED Senior Member

    This is about 6 inches too short.

    A short fuel pick up is a cheap way to allow contaminates to stay out of the engine.

    Far Far better is a sump that can be drained as required , but they are more co$tly to build , install, than a simple short fuel pickup.

    As sump will save the owners huge bucks over the decades , no fuel "polishing" , or casses of filters needed.

    For the long distance fold it is the ONLY way to solve a big bad watered fuel problem.

    Time and gravity solves the problem 100% .
     
  13. sdowney717
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    sdowney717 Senior Member

    I pulled the other tank pickup tube and measured out at 21 inches, which is right where I cut the one I made.
    It was also brass, and partially corroded, but intact.
    I cut it off, drilled and soldered in a new copper pipe to get a full 21 inches from end to end, the entire thing.

    6 inches too short is way to short for my tanks, I would be leaving a lot of fuel in the tank. Fuel you can never get out if you run low.
    OEM looks like the pickup tube is an inch above tank bottom. Tanks sit at an angle.
    With a dry tank, if I add 5 gallons, that gives me a couple inches on the measuring stick. Every additional 5 gallons into the tank raises about one more inch.
    So maybe I can not get the last 2.5 gallons from my tanks.
     
  14. FAST FRED
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    FAST FRED Senior Member

    With the stuff collected in the tank bottom over the years it might be wise to use a full sized tube once a year and pump out the water and diesel debris from the tank.
     

  15. sdowney717
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    sdowney717 Senior Member

    Yes, that is good idea. I did it last year and today going out to purge the tank using a copper tube down the fuel fill hole connected to an electric pump.

    I plan to pump old fuel into 5 gallon gas cans and burn it at up to 50-50 in my old Saturn fuel injected car.
     
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