Sandblasters & cabinets

[irondarren]

Ratty mine was much simpler than there one.. Just need a 1 1/2 gas barrel nipple and a cap and a few bits of pipe. Need to remove the brass valve from the gas bottle and fill with water and causitic soda for a day or two to ensure all gas is gone. in the bottom of the bottle cut a hole so the nipple can be welded to it, drill a hole in the cap and thread with a 1/4 bsp thread, then screw in a pcl type fitting. the cap is the filler for the bottle, and the pcl connector allows you to pressurise the bottle. At the other end where the valve came out weld a piece of 1/2 internal bore pipe. now make up a T connector from steel pipe. connect using rubber hose (pressure hose) the piece of pipe comming from the gas bottle valve end to the T piece. bearing in mind that the gas bottle should be inverted so as what used to be the top is now the bottom. get a bit of rubber hose to connect to the other end of the T piece and in the other end of the hose insert a piece of round steel about 3 inch long with a hole about 4mm in the centre. then on the last piece of the T connector apply air pressure (will need to fit a PCL type connector), aplly air pressure to the pcl connector at the top. and sand should come out under pressure. Dont have plans for it rusty, very little i do like this is every planned but dont as i go. but it does work. You need some way to turn off the sand but i used a pair of molegrips, on the rubber pipe between the gas bottle and T connector.

I seriously wouldnt recommend any one to try this unless they are 100% sure of the risks and dangers. Any device like this might cause injury or death. (the death part being if ever a HSE inspector saw it, he would have a heart attack) and certainly wouldnt be HSE approved

 

[rtbcomp]

Ratty mine was much simpler than there one.. Just need a 1 1/2 gas barrel nipple and a cap and a few bits of pipe. Need to remove the brass valve from the gas bottle and fill with water and causitic soda for a day or two to ensure all gas is gone. in the bottom of the bottle cut a hole so the nipple can be welded to it, drill a hole in the cap and thread with a 1/4 bsp thread, then screw in a pcl type fitting. the cap is the filler for the bottle, and the pcl connector allows you to pressurise the bottle. At the other end where the valve came out weld a piece of 1/2 internal bore pipe. now make up a T connector from steel pipe. connect using rubber hose (pressure hose) the piece of pipe comming from the gas bottle valve end to the T piece. bearing in mind that the gas bottle should be inverted so as what used to be the top is now the bottom. get a bit of rubber hose to connect to the other end of the T piece and in the other end of the hose insert a piece of round steel about 3 inch long with a hole about 4mm in the centre. then on the last piece of the T connector apply air pressure (will need to fit a PCL type connector), aplly air pressure to the pcl connector at the top. and sand should come out under pressure. Dont have plans for it rusty, very little i do like this is every planned but dont as i go. but it does work. You need some way to turn off the sand but i used a pair of molegrips, on the rubber pipe between the gas bottle and T connector.

I seriously wouldnt recommend any one to try this unless they are 100% sure of the risks and dangers. Any device like this might cause injury or death. (the death part being if ever a HSE inspector saw it, he would have a heart attack) and certainly wouldnt be HSE approved

If I understand you right, that is the same setup as the Ace. It's well worth adding the extra valves to adjust the air/media ratio, this makes a big difference to the efficacy of the blaster and increases the range of media sizes you can use.

You will also need a rubber seal on the cap.

There's no need to weld a piece of pipe into the (new) bottom of the cylinder, simply drill out the old valve and solder some 10mm copper pipe in then use a 10mm compression T to connect this to the air and exit pipes.

The exit pipe wears quite qucikly and will need to be replaced regularly, the copper pipe from the pot to the 'T' shouldn't wear as the grit trickles down slowly.

I've actually made these bits up and have a 2 inch BSP nipple and stopped end ready to convert a cylinder, but given the cost of the Rolson didn't seem worth the bother.

 

[irondarren]

rtb I have to admit its better and safer to buy a professional made one. As i believe i said in a previous post i used to own the sealey version. (until some **** bag nicked it) This had a tungsten end in the exit pipe, which didnt seem to wear, now i know some of the units are provided with ceramic ends which do wear. simple answer to that would be to contact sealey's spares dept and ask them for a new end, that would solve wear problems providing its the same size.

As i also said they are a worth while bit of kit, and if used in car repairs would soon find whats rotten and what isnt.

 

[rtbcomp]

rtb I have to admit its better and safer to buy a professional made one. As i believe i said in a previous post i used to own the sealey version. (until some **** bag nicked it) This had a tungsten end in the exit pipe, which didnt seem to wear, now i know some of the units are provided with ceramic ends which do wear. simple answer to that would be to contact sealey's spares dept and ask them for a new end, that would solve wear problems providing its the same size.

As i also said they are a worth while bit of kit, and if used in car repairs would soon find whats rotten and what isnt.

By exit pipe I meant the exit of the mixer (T-piece at the bottom of the pot). The nozzle on the ACE is tungsten carbide, the Roslon is ceramic. I managed to fit the ACE TC one into the ceramic's holder by squeezing a 10mm olive onto the nozzle and using the 3/8 BSP nut off a 10mm compression fitting on the Rolson's nozzle holder.

The ceramic one lasted 1 pot-full, the TC one has lasted over 88 pots, and then it had already done a few years service on the ACE and is still going strong!

It should be safer buying a commercial unit, but it doesn't look like it! I haven't had a reply from my email to Rolson

 

[Ratty]

I have just rung Rolson tools to ask about the recalled sandblasters, apparently they lack a 'safety pressure test certificate' and were advised to recall them. I rang one of the ebay sellers about this one who assured me that theirs were not Rolson and had no safety issues. Whether they have a 'safety pressure test certificate' is another question, I guess it's just a case of being aware and sensible. Shall probably get this one as it's cheap enough (and even cheaper when the government repay my VAT ) and will do for the limited use I will give it.
It's been interesting to hear different opinions and to learn how these cylinder types actually work - I will know where to look if I get problems but can't imagine there is too much that can go wrong.

 

[rtbcomp]

I have just rung Rolson tools to ask about the recalled sandblasters, apparently they lack a 'safety pressure test certificate' and were advised to recall them. I rang one of the ebay sellers about this one who assured me that theirs were not Rolson and had no safety issues. Whether they have a 'safety pressure test certificate' is another question, I guess it's just a case of being aware and sensible. Shall probably get this one as it's cheap enough (and even cheaper when the government repay my VAT ) and will do for the limited use I will give it.
It's been interesting to hear different opinions and to learn how these cylinder types actually work - I will know where to look if I get problems but can't imagine there is too much that can go wrong.

Thanks Ratty, you saved me a phone call. I've been blasting all day wearing a nuclear fall-out suit I emailed anothe ebay seller who said the issues had been resolved.

Although I think the pressure gauge is duff, it seems to stop at 75 psi.

Things that go wrong

1) air leaks - make sure all joints are tight before using it
2) wet air - get a good regulator/filter
3) nozzle valve wears - make sure it is fully off, a small leak will wear the ball and valve body. I reverse the valve every 5 or 6 pot-fulls
4) blast pipe wears & bursts near the mixer, check for squishyness and cut the iffy section off.
5) blockage - usually opening the bottom valve and closing the bypass valve will clear it. If it doesn't, de-pressurise, remove the cap, open the bottom valve, close the nozzle valve and block the feed into the top of the pot. Open the main valve slowly, this will reverse flush the mixer.

 

[Ratty]

Things that go wrong

1) air leaks - make sure all joints are tight before using it
2) wet air - get a good regulator/filter
3) nozzle valve wears - make sure it is fully off, a small leak will wear the ball and valve body. I reverse the valve every 5 or 6 pot-fulls
4) blast pipe wears & bursts near the mixer, check for squishyness and cut the iffy section off.
5) blockage - usually opening the bottom valve and closing the bypass valve will clear it. If it doesn't, de-pressurise, remove the cap, open the bottom valve, close the nozzle valve and block the feed into the top of the pot. Open the main valve slowly, this will reverse flush the mixer.

Thanks for that rtb, all useful info. I shall print a copy of your list and tape it to the sandblaster. I have good pressure gauge and water trap where I plug in my airline so any extras are just a bonus. If the hose is ridiculously long I have a 'mobile' pressure gauge which I plug in at the end to check the pressure. I don't know why there should be a pressure drop over distance but sometimes there is!

I have some experience of airline fatigue - a tremendous BANG and a screaming hiss when the line coming from the compressor (which is outside my workshop, protected from rain but at the time, not sun). The hose had blown up like a balloon and then burst. No damage but took a few years off my life. It was probably partly exposure to UV and partly because it had a rather sharp bend in it which must have stressed the reinforcement. I now have a steel elbow on it and have built doors to protect from all elements - makes it a lot quieter too!

 

[Drains]

I now have a steel elbow

Crikey Ratty - there's another one for the nasty accidents thread. You have been in the wars.

 

[rtbcomp]

Crikey Ratty - there's another one for the nasty accidents thread. You have been in the wars.

Anyone who mentions threaded nipples gets banned

 

[Ratty]

Crikey Ratty - there's another one for the nasty accidents thread. You have been in the wars.

You are in a better mood Si!

 

[Ratty]

Well I got the cheap one from ebay, paid for Tuesday afternoon, arrived the next morning - so can't fault delivery speed and at under £60 inc. delivery (ex-VAT) ridiculously cheap. Minimal assembly, everything was attached except the hose, wheels and handles and it all seems pretty robust. The reg. seems to work ok and it has a water trap. Also came with 3 spare tips, a nice bright red funnel and protective hood (flimsy but effective). After bolting on the handles & fitting wheels, all I had to do was attach an airline plug - even got a roll of ptfe for this. I have never had to buy ptfe, I always seem to have 2 or 3 part used rolls which appear when I need them, (presumably left behind by various plumbers) I was nearly out (and starting to hyperventilate) but now I have a brand new roll - silly I know but I'd like to go to my grave saying 'never ever bought ptfe tape'
For those who are interested, here is an exploded view of the parts:

Had a quick go with it and it seems to work fine. No sign of any manufacturers name anywhere nor country of origin, not even on the box, but no prizes for guessing .
Until I get around to making a cabinet I'll just use sand as it won't be reclaimable anyway (except by the garden).

 

[MrFluffy]

Just a quick one ratty, while your making your cab might be of use.
My blasting cabinet is a old dishwasher, I gutted out the electrics, sawn out the front of the door and fitted a plexiglass window in its place with two gloves on. Hooked the sand collector to the water filter outlet in the bottom and brought the airlines into the case through what was once the top dishwasher rotator bit thingy head.
I cut in a low voltage spot into the lid, boxed it back up and sat it on a stand. To keep the workpieces off the bottom I used some old pan stands mrs fluffy was discarding. Perfect for the job

Its a bit small but it does the job, and you can just open the door as normal, put the bits in and shut it and voilla instant seal.

 

[Ratty]

Just a quick one ratty, while your making your cab might be of use.
My blasting cabinet is a old dishwasher,.....

Excellent idea Fluffy - and easy enough to get free dead dishwashers. Totally satisfies my re-cycling mentality as well. Thanks for that

 

[MrFluffy]

Its been mentioned already, but if you use the sand more than once (i.e. pick up and reuse in cabinet) , make sure that you have a proper ventilated mask on.
The sand shreds into a fine silica dust which gets into the air. When you inhale this dust, it is so fine it gets drawn down into the lowest part of your lungs, where it cuts and scar's the fine tissues. This is what is known as sillicosis. There is no cure...
Maybe if you finish a cabinet, look into using fine glass beads or other blasting medium in there?
I use something called rungis2000 that was about 15 quid for a big sack from the local diy chain, it is a kind of metalic slag ore ground into tiny shards. Its much more effective than sand but a bit coarse.
You can buy a oxy/aceteylene welding setup in the same supermarket with proper portapak bottles that can be refilled, off the shelf just by taking it the checkout. You might struggle a bit in the uk...

 

[rtbcomp]

Make sure all the hose clips are very tight.

Mr Fluffy is dead right about the sand, in fact the dust I filter out is fine as talcum powder.

You'll get fed up with the hood when you have to replace the piece of perspex! You can make one out of an old flip front welding helmet and a leather jacket. I use pieces cut out of clear pop bottles as lenses.

Save the sleeves off the jacket to protect your arms when using a cabinet.

 

[Ratty]

Thanks for all the tips MrF & rtb - all good stuff, cheers guys (haven't seen fishy for a while so thought I'd pop a couple in)

 

[Ratty]

Gorblimey...was watching a second-hand 'blaster starting at £29 before I decided on the new one...it's just finished..looks identical to the one I got (same name on water filter even) apart from the colour (and mine doesn't have a spare tyre on the gauge) and the stick-on label saying 'Schneider - Germany'. Anyone heard of them? Nothing googled up. Think I'll photograph mine in adjusted light (so it looks yellow rather than orange), stick on a pretty metallic label with a solid German name and see what I get.

 

[marknotgeorge]

I've seen Schneider kit in Asda as one of their own brands, but that was on stuff like vacuum cleaners and the like.

 

[Wozzaaah]

That looks identical to the Rolson one except the colour. I'd imagine they all come out of the same place anyway. You got a bargain there Ratty. I'm gonna get meself one!

 

[Ratty]

I've seen Schneider kit in Asda as one of their own brands.

Oh quality then - d@mn I missed it