Blast cabinet media

Discussion in 'Maintenance Bay' started by Jdm, Dec 16, 2020.

  1. Jdm

    Jdm Pre-takeoff checklist

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    After all the years of freeloading I’m finally getting around to setting up a small blast cabinet in the hanger. Back when I worked in a shop environment we kept one stocked with glass beads. I can’t seem to remember the grit we used. I noticed that Granger has a wide range of bead grits to choose from.
    So, to those you who regularly use a blast cabinet I’d like to know what’s the best general purpose glass bead grit for aircraft use. I know there’s a ton of other media options but I’m only familiar with the glass bead type. Appreciate suggestions!
     
  2. Kenny Phillips

    Kenny Phillips En-Route

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    I've given up on glass beads and gone to crushed walnut shells. Not a fan of silica dust! But when I did use glass beads, I recycled them a bunch, so I started with pretty coarse stuff, and it eventually became pretty fine.
    Back in the day, everyone cleaned cylinder heads by glass beading; we stopped it after some errand beads got into the oil system.
     
  3. Dan Thomas

    Dan Thomas Final Approach

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  4. Rob58

    Rob58 Pre-takeoff checklist

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    Media blasting has many variables. Selecting the best media is one, pressure is another, and even the style of the blast nozzle is relevant. However most of us cannot afford the time or cost of becoming a blasting scientist so we need to come up with pretty much a single media solution. I think it is safe to say most people do use glass beads, but walnut shells, and other softer media types are popular too. I use an 80 grit glass bead and adjust the pressure and distance between the nozzle and the workpiece to achieve different results. One important note that you are probably already aware of: the process of blasting with glass beads can hide cracks in your workpiece, especially with welds, by rolling the metal to hide these defects. So the trick is to really turn down the pressure in these areas. Also, change your media often so that you are not blasting with microscopic rust particles as part of your media.
     
  5. Jdm

    Jdm Pre-takeoff checklist

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    Great information
     
  6. Tom-D

    Tom-D Taxi to Parking

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    I generally use Rose Garnett at 180 grit. then turn up/down the pressure to meet the needs
    I have used 1100 grit glass beads but they are pretty spendy for every day usage.
     
  7. Dan Thomas

    Dan Thomas Final Approach

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    The advantage with glass beads, especially on aircraft parts, is they they're spherical to start with and once broken they round off quickly, avoiding creating small stress risers. Alox or crushed copper slag is really harsh. Sand shatters into dust instantly.
    Disadvantages to glass are cost and the ease with which it hides inside stuff.