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Thread: oxide layer on aluminum or brass and meat transfer

  1. #11
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    Nov 2008
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    Cleveland Ohio
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    I'm going to make this up but it should work. Get a bag and put the piece in inside along with the sandpaper pad and the glue. Blow some nitrogen in the bag, sand it, glue it, remove it to the place you want to stick it. Frankly I can't see why cleaning the surface real well in the air and then immediately adding the glue will not make a good enough bond for anything we might do in a laser projector.
    I think the lapping of the surface to make it even and smooth is more important by a lot thermally than the oxide layer. I also use a special thermal epoxy rather than grease. With the new scanenrs it almost doesn't seem to matter anymore. The drivers are a different issue of course and thermal grease works great.

  2. #12
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    Feb 2011
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    New Hampshire
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    The oxidation occurs in milliseconds. So, you will never be fast enough. The sanding under the glue works and is easier than a glove box. You are correct about the value of lapping and about the negligible thermal effect of the oxide layer. The only reason for removing the oxide layer is to improve bond strength and here it is very significant. Bond strength is rarely an important consideration for optics, but makes a lot of difference when using epoxy to attach highly loaded structural components.

  3. #13
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    Nov 2008
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    Cleveland Ohio
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    Wonder if there is a flux action glue! A little base or acid the cleans the surface in the glue and then gets neutralized as the glue cures.

  4. #14
    Join Date
    Nov 2014
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    mid michigan
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    in some cases like I think with aluminum the oxide layer is fairly good at transferring heat, sanding the areas so it's still a little rough will give a better area for the glue to stick to and makes the thermal surface larger, I guess just a light sanding then cleaning that off leave the oxide layer and just glue and go, I use thermally conductive epoxy from the same makers that make the good goo, like artic silver and the epoxy I think uses the oxide from aluminum as the heat carrying part of the epoxy. on some cheaper lasers that I have repaired where only epoxy from the start , I clean the old off, leave very slight scratches so the new epoxy has something to hold on to better
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