yamaha NS-200Ma

Discussion in 'Speakers' started by memustbefree, Oct 19, 2013.

  1. memustbefree

    memustbefree New Member

    Found this Yamis in an old warehouse we cleaned out at work today, everything was going to the dump but not this ones they got a ride home with me. And now iam really glad i saved them!
    They sound GOOD but one cabinet are badly water damaged, anyone have fixed a cabinet this damage?
    what would be the best way to clean up the aluminium around the woofer?

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    Last edited: Oct 19, 2013
  2. memustbefree

    memustbefree New Member

    I toke out the drivers and clean them up but its just mold every were in the cabinet so i think i will build new ones.
    but my Q are should i just copy the original or go with something different?
    I have Australian ash to build a par of the originals, hard wood vs particle board vs MDF?
  3. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

    As far as cleaning the alu frames, iirc from my etching days tap water and rainwater is usually slightly acidic, say ph 5.5 to 6 or so. We used to clean up aluminum with a slightly caustic solution, say ph 8 or so. ph 7 is neutral.

    So you could try putting a small amount of baking soda in some water, and use moist scotch-brite to polish them. Dip your scotch brite and wring out the water till it's just moist. You can get scotch-brite in various grits and can polish alu quite fine with it. Take your time and wipe clean with a cloth from time to time to check how it looks.

    Depending on how deep the corrosion went they will probably still be pitted but you can at least remove the scale that way. Dry them completely and if you want to protect them from further damage carefully brush them with clear lacquer. Make sure they are 100% dry first.

    The area where those steel mounting screws are/were will probably be the worst because of dissimilar metal corrosion. The screws themselves rusting accelerates things. SS screws would be a better choice.

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