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Sandblasting Cabinet: Lemon to near bubbly.
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MooiMeisie



Joined: 04 Jan 2010
Posts: 41

PostPosted: Mon Apr 03, 2017 2:50 pm    Post subject: Sandblasting Cabinet: Lemon to near bubbly. Reply with quote

No idea where to post this, so here goes.

All work has ground to a halt over the past two weeks, due to having a bout of this horrible head cold that's doing the rounds

Time to keep everyone updated, and rather than add this to my Ruby thread decided it warranted one of its own.
The Cabinet is one of those ubiquitous bench mounted models, and anyone who has purchased one has either binned it or struggled to get it to do anything.

There are 33 photos covering all the changes I have made, but have not included them in the thread, but will do so if management say so.

Modifications as of 31st, March 2017.

Sandblasting Cabinet.
Link to photos at the end of these details.

I have one of those ubiquitous bench mounting type and have modified it so that it is now doing the job it was supposed to do.

As supplied it is next to useless BUT can be modified to operate as it should.

There are NO quick fixes as the design has too many things that have either been badly designed from the beginning, and/or implemented.

Two of the MAJOR faults are the position of the media pick-up tube and the venting of pressure build-up and dust.

What needs to be done, BUT in no order of preference as they are ALL needed as they work together.

1 - Media Pick-up Pipe:
The design of the tube-in-tube media pick-up pipe is perfect and is used in most commercial cabinets of this type, however, in the position as fitted ex-factory, it will never work properly as no 'free' air can flow down between the two tubes to the suction end, something that's essential for smooth operation instead of 'gulping' up loads of media then stopping, all at regular intervals I've read about.

  a - Unbolt it and place it so that the top, where the suction pipe attaches, is clear of the media.

  b - Leave the pick-up pipe where it is, and run a 'free' air pipe/tube to the suction end, preferably air from outside of the Cabinet

2 - Media Hopper:
  a - Add sloping sides to the left and right hand sides of the hopper, thus assisting the media  to flow back down into the hopper, needing 1a above to be done first. Details in the photos including the template

  b - As supplied you would have to fill that hopper with media in order to keep the pick-up pipe working, and require changes as in 1b above.

3 - Venting:
The filter on the righthand side serves little purpose as is as it relies on pressure inside the cabinet to allow air out.

Major consequence being that dust WILL be blown out of the Cabinet wherever possible.

  a - Connect a vacuum pipe to suck air out, BUT as I soon found out, that filter WILL clog up within a couple of minutes, and needing you to bang it in order to shake the dust and media out that it collects. A right PITA.

  a - Remove the filter altogether and push the vacuum pipe into the 35mm hole as I did, BUT another problem rears its ugly head, and that is that the filter in the vacuum machine will clog up and need cleaning regularly. I would think a bag collector would have the same problem

  c - THE solution is to fit a Cyclone dust trap.

These are available from China now and work very well after being somewhat sceptical at first. Lots of information on the Internet on how they work.

  d - The filter at the rear of the Cabinet is USELESS as it's a loose fit, at least mine was, so easily pushed clear by pressure build up if no suction is used to clear the dust, so remove it altogether

I used that opening to poke the tube through to the outside feeding free air to the media pick-up tube as well as air when gun not operating, but vacuum is.

4 - Lighting:
I never used the Cabinet with that single glow worm lamp supplied, having read all the comments, then all the solutions arrived, from easy to complicated.

  a - I chose my easy method that I found no mention of on the Internet, by attaching a strip of LED lights all round the inside just under the level of the window.

Power was easy as I used the same switch already fitted having removed that glow worm.

  b - Paint the inside white!

Whilst thinking of ways to prevent the media collecting along the side ledges, where the hopper section is secured to the upper section, see photo, I taped white card trimmed to size to all vertical sides to use as templates, as I did for the sloping hopper sides, and the difference they made to visibility inside was astonishing!

  c - I came up with a far more complicated solution but one that cured the lighting issue in one fell swoop, and works an absolute treat.

As good a solution that a and b provided, I still wasn't happy and racked my brain for a way to get concentrated light onto the area the gun was blasting media onto.

The Eureka moment was when I realised that a ring of small LED lights attached to the nozzle of the gun would be perfect, so a search for suitable LEDs ensued.

Many available, and I chose the ones containing two LEDs, then the problem of how to mount them.

Only one solution and that was to fit the LEDs into a ring that fitted over the nozzle, powered from that supplied with the Cabinet, as I did for the LED strip

5 - Seal the Cabinet:
After reading that this type of cabinet leaks like a sieve, I inspected every join and to my surprise found that all had been sealed, except for the four corners of the frame the window fits into.

One person actually went to the trouble of removing the metal Top Hat section strips keeping the top corners together, filling the areas with sealer the putting the metal strips back

One look at that method and it was a "NO WAY" comment I made to myself, and I just squeezed sealer between the joints - ergo, no leaks.

I've also added strips of 'rubber' all round the window opening, in addition to that already glued on the window frame.

6 - Keeping Window clear of dust:
Everyone complains, as I found out, that the plastic window collects dust, be it through static or otherwise, so a solution was needed

  a - I have attached an earthing wire to the main body, window frame and to the window itself.

  b - A few solutions on the Internet in getting clean air to flow under the window, with various ideas going through my mind of ways to achieve this.

Then my epiphany moment: clean air, compressor, regulated supply = use the compressor!

Feed regulated air into a tube, having holes drilled along its length and directed onto the window, and positioned on the side opposite to that of the vacuum outlet.

Pretty easy and quick to do, the pipe being held up against the the window aperture by means of tie-wraps.

Tube MK.II has a slit cut along its length as I'm experimenting.

Although the feed was taken from the regulated side of the output I did later on fit a lever valve for quick and easy flow regulation.

The feed could just as well be from a T-join taken from the main feed into the Cabinet.

7 - Compressor Feed, this being a personal choice only:
After using the Cabinet for a week I changed the compressor feed input to the left hand side of the Cabinet as the less than flexible feed pipe was hindering movement, and proving much better now.

That's it.

Will add updates as and when I do them.

Copy of this page:
http://bit.ly/2nDML9P

Copy of this page

Photos:
http://bit.ly/2n3Nt2W
(http://s1104.photobucket.com/user/Geoff_Halstead/Sandblasting%20Cabinet/story)

Photos

Geoff - Hope this is of help.
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