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Shot Blasters / Grit Blasters


Astro_Al

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my local blasters recommended running a bead of silicone sealant round the bead to stop grit getting wedged in the gap where tyre meets rim, you can peel it off after you finish

mike

Good idea. A customer brought some wheels with knock-on hubs, he'd siliconed tennis balls in the hub to protect the splines.

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I like the silicone idea Mike, tennis balls great to RT Barton. Pinny, I have some of the glass beads to try on alloy wheels but have not got that far yet. They are sort of pricey to practice with, need a cabinet thingy. I have been told the medium what ever it is, can be sieved and reused.

Thanks Mark

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I like the silicone idea Mike, tennis balls great to RT Barton. Pinny, I have some of the glass beads to try on alloy wheels but have not got that far yet. They are sort of pricey to practice with, need a cabinet thingy. I have been told the medium what ever it is, can be sieved and reused.

Thanks Mark

I use 801AF 74-149 Glass beads, whatever that means. These are Hodge Clemco part Nos. Like Pinny says these give a nice satin finish on ally. I use very worn out J-Blast Supafine first. You do need to seive to get any big bits out (washers &c) also make sure you have good airflow through the cabinet to remove dust, otherwise the beads will become contaminated.

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How can a good air flow be achieved? I have not got a cabinet yet. And wanted to build my own, I,ve seen some links to sites with cabinets. Just can,t get my head around the air flow issue. I had thought the grit would naturally fall down. Could a false bottom say a mess type area let the grit fall onto the proper botton and not blow the blasted grit about ? It,s time for experimenting.

Mark

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How can a good air flow be achieved? I have not got a cabinet yet. And wanted to build my own, I,ve seen some links to sites with cabinets. Just can,t get my head around the air flow issue. I had thought the grit would naturally fall down. Could a false bottom say a mess type area let the grit fall onto the proper botton and not blow the blasted grit about ? It,s time for experimenting.

Mark

The media does fall pretty quickly, but you always get dust, this forms a fog which is hard to see through. I use a Clarke dust extractor which is fine.

I have a Clarke blast cabinet and it's very poor value for money.

1) It's lit from the back - you can see better if you light from the front & top.

2) It's got a side door which always loses some media when you open it - a top opening is better

3) The door catch on mine fell to bits

4) The syphon blast gun is useless - you're much better off with a pot.

5) The window protectors are fiddly to replace (a top opening would make it easier) I'm experimenting with a roll of cellophane to protect the glass - early results promising

6) The long gloves didn't last 5 minutes. Use elbow length gloves with elasticated holes to put your arms through

I use a plastic baker's tray to rest the work on. Too coarse a mesh will catch studs and bolts.

Line the box with sacrificial panels, I use plastic tops from washing machines

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Great tips thanks.

I plan to build my cabinet from plywood maybe 1/4 or 1/2 inch. I will certainly take your advise and go for a top door/viewing opening panel. Cutting 2 front holes for arms and a hole for the hose. I will have a look at some dust extractors and see what I can come up with. The light I will put as near to the front as possible. It will mainly be for a rim and tire, that,s all I see as the biggest part to go in it being able to lie flat or stand up.

Thanks

Mark

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What about the garden shed for a blast cabinet. Throw out its contents, line the back wall and 1/2 way around 2 sides and floor with metal say tin. Put in the electric a hole for the hose and Bob,s your uncle and Fanny,s your aunt.

Would,nt it be great if it was as easy as this. B)

Mark

Ps I think I,ll go for the ply-box first and see how it goes.

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What about the garden shed for a blast cabinet. Throw out its contents, line the back wall and 1/2 way around 2 sides and floor with metal say tin. Put in the electric a hole for the hose and Bob,s your uncle and Fanny,s your aunt.

Would,nt it be great if it was as easy as this. B)

Mark

Ps I think I,ll go for the ply-box first and see how it goes.

I've done pretty much that - partitioned a corner off in my workshop. It must be airtight, i.e. dust-tight and needs to be fitted with a dust extractot & filter.

You'll need good lighting, I use 12volts in case I clobber a light with a piece of steel. I've actually fitted a bright light to the nozzle to save lighting the whole room. This is better because the dust generated makes it like working in a fog. Paint the inside with white gloss.

You will need a hood to protect your head and a supply of fresh air. For air I use a Metro heater motor feeding a facemask via a vacuum cleaner hose. The motor is sited well away from the dust extractor in the fresh air. You will also need a supply of visor covers, they don't last 10 minutes. I use pieces cut from 2 litre clear plastic pop bottles. The visors for my hood cost 99p a throw, so it's cheaper to buy a bottle of Netto coke & throw the contents away - you get 2 covers from 1 bottle.

Wear wellies with trousers on the outside!

A real luxury would be a mesh floor, so you don't trample the dust outside, with a means of raking the grit into a container, saves shovelling.

The blast pot should be inside next to the bench so you can get at the controls.

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This is what I made out of old gas bottle.

http://community.webshots.com/user/paulhumphries100

Paul Humphries

I was halfway through making one but they started appearing on ebay so I got one of those instead. I'd replace the bottom valve with a gate valve, I find the ball valve is a bit sensitive.

Have you ever had to replace the bottom T-piece at all? my ACE gritblaster eats them at a phenomonal rate.

I like the huge filler hole - the ebay ones are a bit small, at sometime you'll need to get a vacuum cleaner hose in there to remove some foreign object.

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My blast cabinet is made of 12mm MDF (a more dense material than ply) painted with cheap gloss white paint. When the colour gets too dingy it gets another coat of white gloss. The paint is relatively soft and absorbs the impact of the media. I hold the gun in my right hand so I do have a piece of scrap steel plate on the back wall, towards the bottom LH corner, as this is the area that gets the most overspray.

With this slight additional protection, overall the paint is not damaged enough to expose the MDF surface, except where I've 'tested' the flow of grit from the gun!

Initially I used a suction gun, but about 12 months ago changed to a pressure pot, with a spark plug ceramic nozzle. Air delivery is controlled by a foot pedal. I use aluminium oxide as a reusable abrasive. The compressor is a two cylinder device with about 14 CFM free Air Delivery, working on single phase 240v. More air flow, or a larger air storage tank would be better, but with pressure held down to 70 psi at the pot the results are acceptable.

The pressure pot system produces much faster results, but does cost more to set up than a suction gun set-up.

I use a sheet of flat laminated glass as a viewing screen, protected by the type of thin plastic used for making slides on overhead projectors. This lasts for some time, but in turn is protected by standard supermarket cling film, which is a disposable item, as it lasts perhaps an hour before the dust fogging gets too bad. Blasted rust creates a lot of dust.

As regards ventilating the dust out, I suck the air out from each rear top corner (single fan, two pipes), and have found that ensuring a large inlet port made a big difference to the airflow. It's (large) airflow that is important. Don't rely on the air coming in with the blast media. I blow the fan air / dust output through the garage wall at a low level onto waste grass, fortunately well away from any neighbours washing lines.

If I rebuild the cabinet I'll put the air inlet above the viewing glass, so the clean air washes down over the glass, which should reduce the amount of dust sicking to the cling film.

HTH.

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How can a good air flow be achieved? I have not got a cabinet yet. And wanted to build my own, I,ve seen some links to sites with cabinets. Just can,t get my head around the air flow issue. I had thought the grit would naturally fall down. Could a false bottom say a mess type area let the grit fall onto the proper botton and not blow the blasted grit about ? It,s time for experimenting.

Mark

Dyson Vacs are great for the job, easy to clean/empty hopper, and there are loads down your local tip.

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Dyson Vacs are great for the job, easy to clean/empty hopper, and there are loads down your local tip.

Yes and if any grit gets sucked out it tends to collect in the outer chamber of the cyclinder, the fine dust ends up in the centre bit.

Also try Freecycle.org for vacuum cleaners.

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protected by standard supermarket cling film, which is a disposable item, as it lasts perhaps an hour before the dust fogging gets too bad.

Florists cellophane is much better, it's clearer and doesn't stick to itself when you're trying to put it in place. I reckon it lasts a bit longer too.

I bought a roll off ebay, can't remember the seller, but there's quite a few on there.

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protected by standard supermarket cling film, which is a disposable item, as it lasts perhaps an hour before the dust fogging gets too bad.

Florists cellophane is much better, it's clearer and doesn't stick to itself when you're trying to put it in place. I reckon it lasts a bit longer too.

I bought a roll off ebay, can't remember the seller, but there's quite a few on there.

I suppose the fact that I never thought of that reveals how often I buy someone flowers!!!

I have actually bought some of the 'proper stuff' from Anglo Scott Abrasives, but haven't made a mounting for the roll so it can be scrolled across the viewing window / glass pane, so can't report on how good or bad it is.

ASA have no web site, but a call to 01942 270729 gets you an e-mail catalogue by return.

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