Converting a Small Blast Cabinet to Soda

  1. melle Member

    Messages:
    322
    Location:
    Bath UK/ Dublin IRL
    Mine's one size up, but yours should definitely work for carbs I'd think.
     
  2. Wallace

    Wallace Member

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    6,492
    Location:
    Staines, Middlesex, England.
    Throw the filter away, use that hole for a vacuum cleaner and cut another hole in the opposite corner with a filter externally so you get a flow of air across the cabinet. Does it have mesh in the bottom?
     
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  3. brightspark

    brightspark Member

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    26,996
    Location:
    yarm
    without a mesh those cabinets are a bit small and it will pull all the media out :laughing: I put a 4inch hole in mine and ran a flexible duct over the unit and put a cheapo 4inch fan on the end outside . it works real well takes the dust out but not the beads or media
     
  4. Yes it has a mesh in the bottom.

    Any pics to see what you mean?
     
  5. Wallace

    Wallace Member

    Messages:
    6,492
    Location:
    Staines, Middlesex, England.
    I left the workpiece mesh out as parts kept falling through. I leave an old pair of pliers in the cabinet to hold small parts and save blasting the gloves.
     
  6. brightspark

    brightspark Member

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    26,996
    Location:
    yarm
    il take some and post shortly. heres small cabinet with 4inch duct with a fine mesh filter across the outlet and heres my larger one with filter this has a 4inch woodchip extracta on the end and can pull at least 40 cfm of air and dust out
     
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  7. melle Member

    Messages:
    322
    Location:
    Bath UK/ Dublin IRL
    I also use a 4" fan, works a treat. @brightspark's mesh is a good idea, but it may get clogged up. I added some T-pieces to salvage any media that gets sucked out, because on my cabinets the mesh would be a bit difficult to monitor/ reach.

    @JonnyAlpha, you said in your cabinet the light is missing; fit the best light you can find/ afford and make sure it's a dust proof one.

    The blue cabinet is my non-ferrous glass beading one, I use the red one for blasting steel with aluminium oxide.

    [​IMG]
     
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  8. optima21 Forum Supporter

    Messages:
    2,635
    Location:
    halifax, England
    you can use glass grit on delicate surfaces, just turn the pressure down. I was blasting my matchbox lorry chassis down tonight using old glass grit, but at 25psi and it came out like this

    DSC02290.JPG

    DSC02292.JPG

    maybe not the peened surface that you get with glass beads, but still a pretty smooth finish, wouldnt take much to polish it.

    and this is my small cabinet like yours

    https://www.mig-welding.co.uk/forum...ting-cabinet-modifications.71897/#post-977493
     
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  9. So after watching the Remembrance Parade and doing some gardening, I managed to fire up the cabinet and have a first attempt.
    First piece I did really quick but the next piece was a struggle, came out ok but the media just wasn't flowing.

    I need to mod my Compressor first as the Air Flow is being restricted by the stock regulator and although the water trap is catching lots of water I either need a better one or a second one nearer the cabinet.

    I used the Aluminium Oxide that came with the cabinet, what I found was that the end of the suction tube kept getting exposed and I had to keep tilting the cabinet to get it covered. In the end I just took of the mesh and kept moving the media with my hand.
    Where does the media go as it certainly went down?

    The cabinet is leaking dust in a few places, there is no light yet or extractor so I need to sort all that out too.

    They are small and whilst OK for small parts I am going to struggle with the Clutch Bell Housing and Flywheel cover that I planned to do from my A Series Metro Engine that I am re-building.

    I also now have no room in my garage to carry out the front end upgrade on my Mini :-)

    [​IMG]

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    Last edited: Nov 10, 2019
  10. Wallace

    Wallace Member

    Messages:
    6,492
    Location:
    Staines, Middlesex, England.
    Is the steel tube clipped to the cabinet base? Try with just the tube open end buried in the media as the tube draws air in where the hose connects and doesn’t work so well completely buried.

    The leaks will be due to the lack of vacuum in the cabinet as you are positive pressurising when you pull the trigger and you need enough extraction vacuum to keep on the negative side of atmospheric pressure. When it’s right you cannot open the lid and the locks are redundant, I haven’t used them in 20 years!

    You are now on the slippery slope of fighting for space to work in. As Captain James T. Kirk said, “Space, the final frontier.” :laughing:
     
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  11. Ok so Soda turned up yesterday and I spent today setting up the cabinet, long story short first attempt = BIG TIME FAIL!!

    I disconnected the media collection tube from the gun and connected a new hose that I then ran through the bottom the cabinet into a 5 litre container with Armtex soda in it.

    At first I tried 50 PSI, then about 75 PSi and then 100 PSI all no joy, it was pulling up media but in fits and spurts. At first I tried just a hose in the media and then I tried a metal tube on the end of it - same problem.

    The smallest Nozzle I could find was a 5mm, which I think is too big.

    I had a vacuum setup attached to the existing filter. I had two LED torches inside the cabinet, too much dust and no visibility!!

    Tomorrow I am going to try the blast pot into a tumble dryer carcass just to try and catch some of the media.

    Any tips to get the small cabinet working?

    Pick up tube straight in media:

    [​IMG]

    Pick up tube held in place using a converted bottle top:

    https://i.imgur.com/pBDT2z4.jpg[​IMG]

    [​IMG]

    Exhaust tube and Air Line in:

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    Pick up tube back in cabinet:

    [​IMG]

    Didn't clean the Ali up at all :-(

    [​IMG]
     
  12. optima21 Forum Supporter

    Messages:
    2,635
    Location:
    halifax, England
    the tube directly into the soda could be one of the issues, you need to allow air in just above the pickup so that the power becomes more "fluid" and flows like a liquid rather than a solid. you can see the valve to bleed the air in on my small cabinet

    [​IMG]

    when I used small suction gun from a bucket this is the setup I used, with a metal tube going into the bucket with a valve just above it

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    if you're using the same nozzles as me like the machine mart ones below

    [​IMG]

    Im using the 4mm nozzle, although I think 5mm will work although Im guessing that the velocity will be less of the soda. Im also thing that as the soda will be dust it doesnt have much energy when it his the parts so does less abrasive cleaning on then. Ive never used soda, so Im just guessing at this part.

    the suction systems are very slow to work anyway compared to pressurised systems.
     
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  13. brightspark

    brightspark Member

    Messages:
    26,996
    Location:
    yarm
    put some kiln dried sand in its more abrasive but still wont have much power even on ally being a suction gun run it through a pressure pot at 90 psi and it will skin you alive a steel car wheel can be done in no time
     
  14. I have a 32L Blast Pot with a Soda conversion kit. What I don’t get though is the conversion kit adds a suction pipe to draw up the media as opposed to putting the Soda in the pot, won’t this suffer from the same problems? Or should I just dump the soda in the Blast Pot tank and forget the conversion kit?
     
  15. The problem is I wanted to use Soda on engine parts to prevent damage to bearings and bearing surfaces from remnants of sand or glass in the parts?
     
    Wallace likes this.
  16. Wallace

    Wallace Member

    Messages:
    6,492
    Location:
    Staines, Middlesex, England.
    On the Clarke pickup tube, try moving the hose and clip out 5 or 6mm and just insert the open end in the media. This will allow air to bleed in from the outer exposed tube and flow around the open end and collect the media. Just doing this in my wee cabinet almost completely eliminated the surging.

    Try a 3mm nozzle @ 90psi, you need more CFM for the bigger nozzles.
     
  17. Ok I’ll try that, not sure if I have a 3mm nozzle, I bought a set of Clarke Cabinet Nozzles, 5mm was the smallest I think?
    I take it a 3mm nozzle will restrict the air flow and increase the velocity.
    Ref pulling the pipe off a bit, someone did mention drilling a hole in the pipe near the connection, this would have the same effect.
     
  18. Wallace

    Wallace Member

    Messages:
    6,492
    Location:
    Staines, Middlesex, England.
    I have not bought any nozzles for a few years, you had to buy a range to get the 3mm included. Being smaller will increase the velocity but also be more suited to your compressor CFM. I ran two 14cfm for a while with a borrowed compressor and used a bigger nozzle.

    It shouldn't need an extra hole as you have a tube within a tube and the air passes down the outer tube to the pickup tube collecting the media as it passes. Sitting fully covered by media causes the surging as the air cannot flow freely without collecting additional media from the hose end. I would check the tube is not blocked with the other media that has been used previosly, this may also contaminate your soda and engine parts in the future.
     
  19. Well had another go today, stripped the cabinet gun down cleaned and re-assembled.

    Put a piece of wood (no rubber available) over the mesh, this did help keep the dust down and aid visibility, but then I couldn't see when the area around the suction tube was void of media.

    I cleared out the suction tube as best I could and moved the hose where it joins the suction pipe to, I also put some smaller diameter PVC tube in the suction pipe. I also took the filter off (as told to do so as its cr%p), but I had not gauze, anyway with not much media in the cabinet I gave it a go. It did seem that media was coming up into the gun but the velocity and amount is rubbish, again it made no difference whatsover - FAIL

    Smallest Nozzle is 4mm, Tried a 3mm nozzle designed for the blast pot but this caused air to be blown down the suction tube - FAIL.

    In exasperation I fired up the Blast pot, it still had some Glass Grit in it (not a lot), this is the effect:
    Had to do it outside into a large cardboard box - very messy!!

    [​IMG]

    Quute aggresive.

    When I thought the Blast pot was empty of media I then put in some Soda (straight into the Pot). Nozzle size was 3mm.
    There was a small amount of glass grit coming out but the effect was a lot smoother - still very very messy.

    [​IMG]
    Apart from possibly having a go a modifying the cabinet to employ a copper pipe pick up under the cabinet, or making a better media pick up tube to insert in a tub of media, I am about done with trying to use the cabinet for Soda.

    The problem with using Soda straight in the blast pot is clogging, which I think it did at the end, no media and no air :-(

    I may try the Soda conversion kit along with a modified suction tube just to see if it works. I definitely don't want to be doing this outside though as it is very messy. I may try and build a large enclosure using the Tumble Dryer carcass I have but I don't want to spend money only to FAIL again.
     
  20. Just re-watched the Soda conversion kit video. The braided hose is an exhaust hose, I thought it was a media pickup tube, so when using the blast pot for Soda you still put the Soda in the pot!! DOH!!

    So, I think I am going to go ahead and try and build a larger enclosure to take the Blast Pot Gun.
    I may also have one last try at modifying the smaller cabinet.
     
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