shoestring blasting setup

[Matchless]

Thought I had better start a thread on my shoestring home blasting cabinet / room, I have only ever had a small bead blasting cabinet before,

one question is where should I extract the air from? it is a tall cabinet, so I can get bike frames or say a Mk2 Jag boot lid in, I am thinking of pulling air from the middle of one side, with the option of top extraction,

The front of the cabinet is made from 10mm foam board with alloy extrusion round the edges for a bit of strength, to keep it light, I intend to hinge it from the top so I can easily open it for loading,

I have the ebay woodwork dust extractor and will be running 70mm rain down pipe to it, I will also carry the drain pipe across the top of the cabinet and into the machine shop next door to provide fume extraction for TIG welding, the pipe across the top could have a cutout with a sliding cover to regulate the extraction,

The rain pipe is just showing the general idea, it will go to the top before turning left,

wish me luck, comments welcome

 

[roofman]

i would pull the air from the back top..The big Guyson i use at the unit has this set-up and i stuffed a load of wire wool in the vent which stopped it picking up the media and pulling it into the filter units but still cleared the cabinet of dust

 

[brightspark]

I take the dust out up the side of cabinet with a fine mesh filter it fits in the bottom base of a gas bottle and is a chip pan filter with the handle cut off everything ready made

 

[Matchless]

little progress today, spent most of it trying to get my new cctv recorder to work...… Grrrrrrrr, I will use a 25mm hole saw to make say four holes in the pipe across the top of the cabinet with a short piece of pipe to slide over to close them when not required, the pipe is on it's way to the other end of the machine shop for welding fume extraction, may put a T in over the doors to the workshop, dust extraction when sanding?

 

[Matchless]

how did this amount of progress take all day yesterday! waiting for an essential piano hinge to be delivered for the front flap, will lift up, hinged from the ceiling,

some white sika and away we go...…..

 

[Matchless]

piano hinge turned up today, attached to a piece of roof tile batten, so I used that to hold the top plastic to the roof! might make the front panel up tomorrow, might not, might go metal detecting around the church grounds, might not, ho hum, sidecar chassis waiting for blasting, two 1920's Matchles model H, one 1914 ww1 stretcher carrier, one? one Matchless number 1,

 

[Matchless]

made and fitted the door today, yes the hand holes are a long way apart, the cabinet is 6' long, I may put another in the middle, anyone got one of those glove hole rings / bezels, I think the came with gloves attached a long time ago!

 

[Matchless]

more or less finished today, blasted the first part, Mk2 Jag rear axle link arm, the blast pot is unmodified at the moment and am using the crushed glass that it came filled with, blasted the arm very quickly, need to route the extraction out of the window somehow, I will use the cabinet for plasma cutting and probably for priming small parts, multi purpose,

 

[Matchless]

just don't tell my wife!

 

[brightspark]

wots up with using a builders bucket

 

[Matchless]

didn't have one to hand and that was sitting in my no.1 shed, in these lockdown times you have to use what is to hand!

 

[Matchless]

ok, so it blasted nicely the first time I used it, kept blocking up yesterday so I have been making a modified grit valve out of bits I have around! I will weld it together as I don't see much of a need to get inside it, and I have a grinder if I do, the top is a round bit of plate that supported my grinding wheel diamond dresser, no longer used as I made a different mount, the bottom is a round stillage foot, have had a box of there for around 20 years, this may be the first one I have ever used, the thick wall tube is a bit cut off a Bradbury four post lift ram tube, have plenty more if any one has a burning desire for some, not looking to get rid but if you have a need, pivot tube for the valve is some very thick wall tube I use for girder fork spindle tube rebuilds etc. just need to sort out a spring and lever,

 

[Morrisman]

A big magnet works to pull rust dust out of your media or extraction route, as rust is still magnetic.

 

[brightspark]

rust isn't the problem damp media is. they probably need opening every 6 month if the media isn't uniform and big ish bits sit in the valve

 

[Dcal]

ok, so it blasted nicely the first time I used it, kept blocking up yesterday so I have been making a modified grit valve out of bits I have around! I will weld it together as I don't see much of a need to get inside it, and I have a grinder if I do, the top is a round bit of plate that supported my grinding wheel diamond dresser, no longer used as I made a different mount, the bottom is a round stillage foot, have had a box of there for around 20 years, this may be the first one I have ever used, the thick wall tube is a bit cut off a Bradbury four post lift ram tube, have plenty more if any one has a burning desire for some, not looking to get rid but if you have a need, pivot tube for the valve is some very thick wall tube I use for girder fork spindle tube rebuilds etc. just need to sort out a spring and lever,

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Great job.
There's always another way of doing things.

Keep the updates coming, you've posted lots of answers to questions that keep being asked on the forum.

Another mod I did on my grit valve was to put an adjustable stop on the lever so you know the last place you set it.
Makes it more likely you turn it off at the end of blasting to stop the blast hose filling.
I must do a proper post on it sometime, but you'll have no need for any more info than the photo below.

 

[Matchless]

yup, thanks, worked out that I would probably need a pair of external stops or just guides or I would not where I was and move the lever the wrong way, mine is welded together but I can unscrew it from the pot and blow it out if required, would need to remove it to dismantle so not much different, and I did not have a big enough bit of steel to machine one with screw holes,

 

[Matchless]

still having problems with blockages, maybe the crushed glass is too large / sharp? I am still using the original blast gun, it has a 3.5mm nozzle, I will try to get a better sieve tomorrow and see what happens after sieving a load of it, not because it is contaminated but to reduce the size I am using,

question, do people with a modified grit valve turn the grit off after a session and run just air through, I have been just turning the main pot supply off and running it down, pictures showing modified dust extractor, waiting for some suitable rubbish bags from ebay, and the main air valve on the front of the cabinet, etc.

 

[brightspark]

just shut mine off at the air supply and that's it. if I haven't used the pot for a month I just tip the whole lot over give it a shake and a quick waggle of the reg valve and that's it. if your using crushed glass and having problems it may be that some of it isn't consistent even from new in the bag. I use the heavy 1.5mm expendable abrasive in my larger pot and have to sieve that theres about half a cupful in a 25kg bag that's 2 big and knackes the job up if I don't are u using a ball valve for the media if so there crap and nothing but trouble the correct size media sieved with a decent reg u can run all day without altering it

 

[Matchless]

I have just fitted my home made grit valve, what grit? and where do you get your grit from?

 

[brightspark]

the heavy 1.5mm stuff I bought 18 bags of localy it uses a 6mm jet and 90cfm comp the smaller pot with the 3mm jet I use use kiln dried and before the forum hse tell me its dangerous silicosis I use an airfed helmet or in then cabinet a woodchip extractor that can suck more air out than the comp can pump in have u tried scangrit superfine