Rust - a question and a suggestion

Discussion in 'eXmark' started by BigDave, Apr 10, 2003.

  1. BigDave

    BigDave LawnSite Member
    Posts: 148

    When my new Lazer HP 23 hp Kaw was delivered a month or so ago, somewhere along the line, I was delivered a left-over 2002 unit (without the cannister filter, etc.)

    The startling thing was, the hydro motors were completely covered with rust, and so were all unpainted parts of the engine. When you looked at the top of the engine down into the air intake, all the metal that the fan sits on top of was rusted.

    Well, my dealer blamed his distributor for the mistake, apologized for the left-over, picked up it up, and delivered a 2003 unit that I asked him to personally inspect.

    The new unit looks *much* better, with much less rust. However, it has the same rust situation visible when you look down into the engine's intake. So, I am wondering, should this be of any concern to me?

    Lastly, I'd like to suggest that Exmark paint their hydro motors so they are less prone to the rust I saw in first unit I got. I plan to paint mine myself. I notice that Scag paints theirs.

    Thanks for your help, and for listening.
    Dave
     
  2. eXmark

    eXmark Manufacturer / Sponsor
    Posts: 4,258

    Dave,

    Great question and I'm glad to here your dealer was able to fix you up on the mower.

    As far as the engine goes I assume you are talking about the cooling air intake. I wouldn't worry about that either. The engine manufacturers don't paint them for several reasons.

    One of them is environmental because you would probably need to use a liquid paint. Most of the paint used in industrial applications today is a powder base and all Exmark paint is powder. Powder coat paint is great for the environment compared to liquid paint but it is difficult to use on something like a flywheel. Due to the varying thickness of the flywheel casting it's difficult to get consistent heat through it to cure the paint properly. If the paint isn't cured right it simply flakes off. If you use liquid paint it's probably not going to be as durable and can cause the potential environmental issues.

    As far as the hydro motors go it kinda falls in line with the same reason the engine manufacturers don't paint the flywheels. In addition the seals in the wheel motor won't tolerate the heat required for powder coat and you have not choice but to use liquid paint. Besides with all the heating and cooling the liquid paint in many cases doesn't last very long on a wheel motor and it only takes about one hydro leak to get rid of all the paint.

    The flywheel also has a pickup that tells the coils to fire giving the engine spark. If the paint flakes off it could in theory interfere with the pickup and cause a misfire. At least in theory.

    Last but not least because the flywheel is a big fan that feeds the cooling fins with air it also pulls in dirt, dust, sand, debris etc. All of these would quickly abrade away the paint as well. Generally the flywheel is considered "out of sight" for the most part and doesn't get a great deal of attention in terms of cosmetics. More than likely the initial stages of rust probably begin before it's ever installed on the engine then moisture in the air continues the process.

    Please let me know if I've not answered your question.

    Thanks

    Terry
     
  3. BigDave

    BigDave LawnSite Member
    Posts: 148

    Terry, thanks VERY much for your informative reply. It made a lot of sense. (Also, I trust you got my email a few weeks ago thanking you for your reply on my pull-behind aerator question).

    A couple of follow-up questions, and then I'm done. :) I bought an enamel paint good to 500 degrees F. that I was planning to spray on the hydro motors. Do you see any reason not to do this?

    You said that if a hydro motor leaks, any paint is done for. Is this (leakage) something that happens from time to time? I would think you'd have to replace the motor if this happens?

    Thanks again.
    Dave
     
  4. eXmark

    eXmark Manufacturer / Sponsor
    Posts: 4,258

    Dave.

    The high heat enamel would be a good place to start. The wheel motors will never reach that kind of temperature.

    My point regarding the paint is that most liquid paint, especially spray paint unless it's designed to be fuel proof or resist solvents doesnÂ’t fair to well when it is exposed to petroleum base products. To be honest I'm not sure how it will hold up against the Mobil 1 synthetic fluid.

    Leaks aren't common but they are always a possibility. Usually if there is a compromised fitting (too loose or too tight) or a bad seal it will show up very early after use, say around 20-50 hours. I'm not aware of any reason why you couldn't paint the wheel motors.

    Thanks

    Terry
     

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