My Home built blast cabinet

[Barkychoc]

I bought the blasting cabinet kit from frost a while back, and its finally finished.
If you're in any doubt its quite a lot of work to build, and I upgraded quite a few of the supplied components - the door hinges would have been just about good enough for a cigar box - nevertheless it is still reasonable value.
The plans to build it aren't the greatest - the drawing of how to cut out the plywood sheets is on a sheet of A4 paper, so don't forget your glasses!

I also made the electrics so the main switch you can see turns on the light but also makes live 2 power sockets at the rear which I plug my vacuum cleaner and compressor into.

A few pics.

General Front View

Interior

I'm really pleased with my extraction - just some 40mm waste pipe with a vacuum cleaner - but I guessed at an arrangement with the pipes to try to recover most of the blast media - and its brilliant.
I deliberately made the air go the 'wrong way' round those T joints and it results in it dumping the blast media down into the dead end pipes at the bottom.
I also fitted compression joints for those so they are easy to remove & empty back into the cabinet.

I fitted the upright pipe onto the air inlet as otherwise it whistled like you would not believe!

All the pipe bits were just from B&Q - the ones in the top of the cabinet are sold as a 'tank connector'.

...and yes I did crack the bloody screen

 

[Shox Dr]

Very nice, I built one out of Steel racking I had laying about a few yrs ago. Not as nicely finished off as yours though. Had a hell of a time seeing what I was doing until I picked up a Dyson from the local tip.

I find the suction gun to be a PITA, so Im going to buy a pot to fit underneath, once the pot is empty, I'll pour it straight back in from the cabinet. ALthough looking again at your pictures it doesnt look like your is a suction type?

Have fun

 

[rtbcomp]

That's a suction gun, it's got 2 pipes.

I found the suction gun I got with my Clarke cabinet pretty useles, but I bought a Clarke SB4 suction gun. It has a 6mm nozzle so it uses a fair amount of air, but it handles a wide range of media, from bits larger than granulated sugar to fine powder.

I use it in my blast room to finish off the bits I missed with the pressure pot system and for doing small items.

 

[rtbcomp]

You'd have been better fitting the suction pipe connection low down so that gravity helps to clear the dust and you are not sucking it back up in front of you.

As you've got it most of the air will just fly accross the top of the cabinet from inlet to outlet.

 

[malcolm]

That's a very neat looking job. I've been thinking about doing something similar as my blast cabinet is in a shed with other things, and everything gets covered with dust after blasting. Also visibility is poor. I've found a dust extractor in a shed which might last longer than a vacuum cleaner.

Are you using aluminium oxide grit? The inside of the cabinet looks very white. Mine is made from black plastic. Tempted to cover it in something that's white to improve the light in there.

Also while I'm here, what are you using to protect the screen? Mine doesn't seem to last for long before becoming opaque.

 

[rtbcomp]

I'm thinking of lining mine with steel cut from the inside of dishwashers. I've found that paint rubs off onto the workpiece if you catch the sides whilst manouvering it.

I've used florists cellophane to protect the glass, and am going to try book covering film, which may be stronger

http://www.care4books.com/packaging/page.asp?type=cat&gid=1

I'd like to device a way of mounting a roll outside the cabinet but such that I can draw the film down inside the glass when it becomes opaque.

At the moment I'm only using mine for bead blasting and the glass doesn't need protecting.

 

[Barkychoc]

I have no protection on the perspex at the moment - a little bit annoying actually that frost don't tell you that they don't include this in the kit.

I intend to get some I've only had a little use with it so far using aluminium oxide.

I've found the gun works really well - frost added an air bleed adjustment which allows air into the pipe to draw up the grit (are all cabinets like this?) - you have to fiddle with it but once setup so far at least it seems to work really well.

I have found if it draws up a bit of debris into the gun that really bugers it up - I just bought a food strainer metal mesh seive thing from wilkos and run the grit through it when I drain it out (every time I've finished to keep it dry) which pulls out big bits of rubbish.

I read somewhere to paint the inside white to help vision - and I have absolutely no issues there at all, though I guess that could change as the grit breaks down a bit.

I'm really pleased with how it turned out - though as I've said I thought it would never be finished!

Chris

 

[Barkychoc]

You'd have been better fitting the suction pipe connection low down so that gravity helps to clear the dust and you are not sucking it back up in front of you.

As you've got it most of the air will just fly accross the top of the cabinet from inlet to outlet.

My thought was that I wanted the heavier grit to fall down back into the hopper - and the lighter dust / muck to be extracted out of the top - this way I hoped to keep as much grit as possible inside the cabinet.

I'd have thought you're getting some airflow bottom to top due to the air you're adding from the nozzle?

If I find it becomes an issue I'll cap off the pipe connection(s) and try something else - maybe connecting it lower down as you suggest.

 

[rtbcomp]

Having to sieve the media is normal.

I've not seen the air bleed thing before, although i did experiment with one myself recently by drilling a hole in the ribber pickup pipe, media just spilled out of the hole!

Your gun looks similar to the Clarke SB4, the one that came with my cabinet has exchangeable ceramic nozzles.

 

[graffian]

When I had a cabinet it had a false back and the extractor sucked the air out below the mesh. it worked really well but even with a prorpe rmohair filter everything was sparkley when the light was just right, glass bead on every surface including an engine which cost more than a house!
The sheets of clear plastic we had were whatever the blast companythought they could get away with flogging us, we bought a roll of OHP film, worked
really well.
White inside, sounds good, I was going to make one and line it with black butyl, I have a big sheet of butyl pondliner.

If your looking for ply to make one ask about the ply they wrap pallets of ply in, I happened to see a pallet of ply and it had 12mm ply around it and they said take it if you want it..

 

[Barkychoc]

I went to a lot of trouble to make the cabinet airtight - and have succeeded I think its pretty much there.
You do still drop a bit of media on the floor when you open the door (which was dropping on my compressor till I thought maybe thats not such a hot idea).
I used B&Q own brand frame sealant to seal it - it was the only one I could find that wasn't silicon based - I didn't want the rubbery silicon type as I thought the media would stick to it.
The B&Q one sets fairly hard and so far works well.

 

[rtbcomp]

......You do still drop a bit of media on the floor when you open the door ......

The Machine Mart one does that, there are recesses in the door which hold media until you open it, then it drops out.

I've put a length of guttering under the door to catch it.

 

[rtbcomp]

.......
I've used florists cellophane to protect the glass, and am going to try book covering film, which may be stronger

http://www.care4books.com/packaging/page.asp?type=cat&gid=1

.....

I've now got a sample of Clearcover from the link above (very helpful people). It's perfectly clear and 70 microns, and very strong. OHP is 30 microns.

Cellophane is cheaper but not as strong.

As regards the window in the cabinet, you're better off with some form of safety glass, plastic will attract dust and eventually become scratched as you wipe the dust off.

 

[anscot]

We make these kits and supply them to Frosts, the plans are now A3 so a lot easier to read, the door hinges are small but our demo cabinet fitted with them has been in use now for 13 years and carried from show to show with no problems, the problem with the Clarke cabinet (and most of the others on the market) is not the gun which works fine, but the hopeless method of abrasive pickup which does not work at all.

here is a video of the demo cabinet in use

http://www.youtube.com/watch?v=lq9pboh4vYg

you should be getting this sort of performance using a 3hp compressor, a smaller compressor will do the same job but at a lower speed.

John

 

[brightspark]

heres the pickup pipe i made on my cabinet which i havent any such problem with . the bought ones were either blocking up or not enough media or were pulsing .half the trouble was the pipe dunked into the media and the gun trying to suck it all up at once. heres the simple design which overcame the problem . the hopper is filled with media then a small amount drops through a 20mm hole into a box underneath forming a pyramid . from the side is a sleeve welded to the box with a grubscrew to lock pickup tube /the pickup pipe to gun is inserted through the sleeve till it starts to pickup the media. it can be slid in and out till the right amount of media is sucked up the pipe allowing air in as well which stops pulsing and blockages . there was a lot of experementing but got it right in the end heres a rough picture of it

 

[graffian]

Sometime I am going to have to make a cabinet, I use a big blue drum, have been using it since 1989 and keep saying when i make a cabinet;-) To be honest the blue drum is just as good as the cabinet we had, except you can't get a motorbike frame in it[which is a plus as far as I am concerned].
Wonder if a gun built into the bottom of the cabinet would be any better than the conventional siphon guns? A venturi so the bead is squirted into the air stream? I suppose I could try it out in my cabinet drum.

 

[anscot]

I've now got a sample of Clearcover from the link above (very helpful people). It's perfectly clear and 70 microns, and very strong. OHP is 30 microns.

Cellophane is cheaper but not as strong.

As regards the window in the cabinet, you're better off with some form of safety glass, plastic will attract dust and eventually become scratched as you wipe the dust off.

Try www.angloscotabrasives.co.uk for clear film in 30 or 15 metre rolls 30 microns or 80 microns, doesnt really matter how thick it is as it is the surface which does the work and the film will be opaque long before it wears through.

John

 

[spoiltbrat]

film

I've now got a sample of Clearcover from the link above (very helpful people). It's perfectly clear and 70 microns, and very strong. OHP is 30 microns.

Cellophane is cheaper but not as strong.

As regards the window in the cabinet, you're better off with some form of safety glass, plastic will attract dust and eventually become scratched as you wipe the dust off.

is this film sticky backed or how do you keep it tight to protect the glass ? i,m looking to make my cabinet better

 

[brightspark]

is this film sticky backed or how do you keep it tight to protect the glass ? i,m looking to make my cabinet better

cheapest and quickest method is use scotch double sided tape

 

[atconut]

pick up pipe

heres my pickup pipe. the gate valve allows air to be regulated ie valve open more air=less grit and vise versa. works very well if i'm using the pot i just unscrew the cap at the bottom and the media drops straight into a bucket ready to go back into the pot