Sandblasters & cabinets

[Ratty]

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!

Was it the free roll of ptfe that swung it for you?

 

[MrFluffy]

Oh quality then - d@mn I missed it

Yeah, thats Schneider as in Amstrad-Schneider, none less than the german wing of alan sugar's pile it high and flog it cheap empire of crap...

 

[rtbcomp]

Update on my Rolson machine. Just used over 100 potfulls.

I've had to replace the nozzle valve 5 times, it tends to wear more quickly if you don't shut it completely. Use it as on/off and not to regulate the flow of grit. The ball wore at one edge and on the original the side of the valve wore through. I've tried reversing the valve every few potfulls to even wear, not arrived at an optimum figure yet.

The hose has burst twice near the mixer. Once after 82 pots and again after 104 pots. Closing the nozzle valve makes it more likely to burst.

 

[rtbcomp]

Just tried a roll of cellophane in by blast cabinet to protect the glass. Perfect!

Got to devise a way of sheilding the roll from dust in the room and something to stop dust getting round the edges of the sheet.

 

[philip979]

Hello. I'm new to the forum, and sorry for digging up an old thread! I'd just like to pick peoples brains regarding sand blasters!

I have recently bought a Sealey SB993 blaster. It seemed to work OK, but the gun seemed to clog. I have a new gun on the way, but has anyone had any experience of these? It seems that air is restricted, even if the siphon line is disconnected. Is it likely to be grit in the gun? I have removed the nozzle, and it seems to be blocked in the mechanism somewhere. I have a new gun on the way from the supplier, but is this likely to be a reoccurance?

In the meantime, I have also bought a 10 gallon blaster that has been mentioned frequently on these boards. I was a little dubious as they are very cheap. On inspection, they are obviously from the Far East, but you do seem to get a lot for the money. I did have a few issues using it however. I just wondered whether these were typical experiences and if anyone has any advice?

1) The nozzle kept on blocking frequently. I am using J Blast Supafine.
2) Are you meant to have air pressurising the pot AND have air flowing through bypassing the pot?
3) Flow of grit seemed to run out after a few seconds of blasting. I'm not sure if it was flow of air / pressure reducing, or whether the media was not "falling" through the pot. Shaking the pot after each blast seemed to improve things.
4) The nozzle valve has already worn and is clearly not up to the job. Air is constantly leaking through, meaning the pot doesn't pressurise fully and the compressor is working overtime. Of course shutting off two of the other valves helps, but having to do this after every short blast is impractical. Is there anything I can do / buy that would operate better as a nozzle? I have tried reversing the valve but to no avail. Will I just have to replace the valve every day or so?

I just wondered what peoples opinions on both the Sealey and 10 gallon units were, and if anyone had any tips. It seems to be a bit of a learning curve, but by the time I have arrived at an optimum solution, I will have done all the sandblasting I had lined up!

I am using a 3hp compressor with about 8-10 FAD I think. I know sand blasting using anything but a professional compressor is expecting a lot, but I am only doing small areas at a time. To be honest the Sealey did seem to work fairly well considering the size and cost, and I like the trigger control rather than the valve on the 10 gallon blaster.

Many thanks for reading!!

 

[rtbcomp]

Hi Philip - welcome!

I'm not familiar with the Sealey gun, but I threw my siphon gun away in favour of the type of pot you mention, regarding which,

1 - did you sieve the J-Blast? There are some big bits in there that can cause clogging.

2 - yes, the top valve and bypass valve should be fully open. You can regulate the airflow with the top valve if you need to for very delicate work, though it's best to regulate with a pressure regulator.

3 - Adjust the bottom valve for flow, start with it set at 45 degrees. The adjustment is very fine and can take upto 10 seconds to settle down between adjustments. The optimum flow is when you can just see the media blast, any richer or weaker doesn't work as well.

4 - The nozzle valve should be fully open, and when you operate it do so quickly, most wear occurs when it is partially open. It wears away the casing before the internal ball! I've replaced mine with a standard brass-balled valve. I've tried reversing the valve every so often to even up the wear, but it's not worth the effort. You can get them quite cheaply from Duncan Rogers, let me know if you want part numberrs and contact details. Use this valve as little as possible.

I'm thinking of extending the bottom valve handle so I can operate from the top of the pot, if you close that you still get air through which is good for blowing the dust off so you can inspect your work. It's a real pain having to kneel down and fumble for the valve to adjust it.

My compressor is 3hp (14cfm) and it runs continuously.

I use a tungsten carbide nozzle from ACE Engineering, lasts ages and ages. You need to modify the fitting on the pot nozzle slightly.

Personally I didn't like the gun-type blaster because it was awkward to get into tight corners with it.

I'll try and post details of my nozzle mod later.

 

[philip979]

Thanks for the quick reply!

1) No I didn’t, but I will consider it thanks. Actually, maybe the mix was too rich? Too much media at once?
3) Would this wear the valve here quickly?
4) I have been trying to use the nozzle as quickly and infrequently as possible. Is it the same as any 3/8 ball valve you see at plumbers merchants etc? How much do you normally pay for them?

I have been looking for some sort of “in line” trigger mechanism, as using both hands to operate the valve is a real bind! I have only managed to find one however, and I wasn’t sure about the quality.

I have read about the TC nozzle from ACE. How much modification does the nozzle require?

My compressor is 14.5 cfm, 10.5 max FAD, (8.5 typical IIRC).

 

[rtbcomp]

1) Possibly.

3) Don't know, my valve lasted about 5 potfulls (10 gallon pot)

4) Yes - but be careful some have non-return mechanism in them, you just need the basic type. I get mine from here http://www.airlines-pneumatics.com/webcat/vit.asp?SubCAT=77

I used these part numbers, but they seem to been superceded
Duncan Rogers 106845 3/8 BSP Ball Valve T handle (recommded)
Duncan Rogers 106262 3/8 BSP Ball valve Mini (cheaper but the handle tends to break)

 

[philip979]

Thanks. Would thes valves be OK for either the nozzle or the mixer? Which type would you recommend on the website? The S90 Series or Vienna? Thanks for the link by the way.

If you could post the details of the mod you did for the nozzle that would be very much appreciated. One concern I did have with the 10 gallon pots was (is) the ease of obtaining spares (eg T piece, blast hose etc). How have you found this to be? The good thing about the Sealey is that parts should always be easily obtainable.

Going back to blocking, do you ever find you have to give the pot a shake every so often? Or not? What type of media do you recommend? Many thanks again!

 

[rtbcomp]

Go for the cheapest.

For the mod I replaced the nozzle holder with a 3/8 x 3/8 BSP male/male nipple (The original has an odd thread where the nozzle fits). Got a 10mm straight compression coupler (B&Q, Screwfix) and squeezed the olive on the TC nozzle (it's 10mm OD) about 2mm from one end. I used the nut off the coupler to hold the new nozzle into the nipple.

You may have to open the nut slightly so the TC nozzle slides in.

I haven't needed any other bits yet, and I use the pot on daily basis to earn a living. I've had to trim the blast hose back a couple of times, it tends to wear through where it connects to the mixer.

I reckon the mixer could be made from a 3/8 equal female tee (malleable iron) with hose tails each end. IIRC the blast hose uses a 3/8 x 14mm hose tail.

I've only had to shake the pot using very worn and dusty media, as it tends not to fall down. Are you confusing clogging with the media not falling? If the media sticks then closing the bypass valve will not stop air coming out of the nozzle. If the media has dropped down OK closing the bypass valve will force neat media out of the nozzle. If nothing comes out of the nozzle when you close the bypass valve then there is a blockage at the nozzle or mixer. If you're getting air out of the nozzle with the bypass valve open then it is obviously not blocked.

I've used J-Blast Supafine, G7 chilled iron and Glass beads (801AF 74-149 micron). I usually run the pot at about 80 psi (regulator set with flow cut off) but it works fine down to 20 psi.

 

[rtbcomp]

In an emergency on my old ACE pot I've used heater hose as blast hose. It's about a third the price, so if it only lasts half as long you're in pocket!

 

[rtbcomp]

In an emergency on my old ACE pot I've used heater hose as blast hose. It's about a third the price, so if it only lasts half as long you're in pocket!

Just a point I've thought of. As far as I'm aware proper blast hose will conduct static electricity away, if you use heater hose it may be as well to run an earth wire from the nozzle valve to the workpiece.

 

[JW240]

Hey,

anyone got experience with the (cheap) blast pots?

40 liter tank.

I have a 4 hp compressor and will be making a cabinet myself.

 

[rtbcomp]

Hey,

anyone got experience with the (cheap) blast pots?

40 liter tank.

I have a 4 hp compressor and will be making a cabinet myself.

Yes, me, Ratty and Malcolm at least. Have you trawled through this thread from page 1? There are a few references to it.

A 4hp compressor should be ample.

 

[JW240]

Yes, me, Ratty and Malcolm at least. Have you trawled through this thread from page 1? There are a few references to it.

A 4hp compressor should be ample.

thanks, i'll look around!

and good to hear that the new compressor will be enough..

 

[inchpincher]

I just bought one of the 20 gallon pots, must say I'm pleasantly surprised. Impressed it came with its own water trap too. Unfortunately one of the 3/8" ball valves (the one at the bottom of the pot) had snapped in transit, but found a couple of replacements from the local plumbers merchant which are a bit more substantial.
Got my J-Blast and on rtbcomp's advice a tungston carbide nozzle... itching for the weekend so I can make a mess!!!

 

[philip979]

Go for the cheapest.

For the mod I replaced the nozzle holder with a 3/8 x 3/8 BSP male/male nipple (The original has an odd thread where the nozzle fits). Got a 10mm straight compression coupler (B&Q, Screwfix) and squeezed the olive on the TC nozzle (it's 10mm OD) about 2mm from one end. I used the nut off the coupler to hold the new nozzle into the nipple.

You may have to open the nut slightly so the TC nozzle slides in.

I haven't needed any other bits yet, and I use the pot on daily basis to earn a living. I've had to trim the blast hose back a couple of times, it tends to wear through where it connects to the mixer.

I reckon the mixer could be made from a 3/8 equal female tee (malleable iron) with hose tails each end. IIRC the blast hose uses a 3/8 x 14mm hose tail.

I've only had to shake the pot using very worn and dusty media, as it tends not to fall down. Are you confusing clogging with the media not falling? If the media sticks then closing the bypass valve will not stop air coming out of the nozzle. If the media has dropped down OK closing the bypass valve will force neat media out of the nozzle. If nothing comes out of the nozzle when you close the bypass valve then there is a blockage at the nozzle or mixer. If you're getting air out of the nozzle with the bypass valve open then it is obviously not blocked.

I've used J-Blast Supafine, G7 chilled iron and Glass beads (801AF 74-149 micron). I usually run the pot at about 80 psi (regulator set with flow cut off) but it works fine down to 20 psi.

Hello again. Further to your messages, I have been experimenting with the sandblasters, the 10 gallon type in particular. It is fantastic when it works, but there is a skill in setting the pressure and air/media ratio correctly.

I had two further questions:

1) The hood that is supplied with the 10 gallon type is pretty effective (especially seeing it is thrown in) but frustratingly it mists up very quickly in use. Is there anything I can do to prevent this, or are there any dedicated hoods that people recommend? I have seen this on Northern Tool: http://www.northerntooluk.com/products.asp?partno=1592E. Has anyone had any experience of it. Apparently it is vented, but I suspect it still may mist easily.

2) I am keen on replacing the 3/8 ball valve with this: http://www.northerntooluk.com/products.asp?partno=11303E as I quite like the idea of one-handed operation. Again, has anyone had any experience of this? It uses replacement ceramic valves, varying bores. Any comments or alternative suggestions please?

Many thanks...

 

[rtbcomp]

The mixture is very sensitive, I was thinking of using a gate valve instead.

I use that hood, it has lasted about 9 months of almost daily use. The lens doesn't last long, I'm making my own from pieces cut from the sides of clear 2 litre pop bottles.

I've bought this http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=190208025807&ssPageName=STRK:MEWN:IT&ih=009 for half the price, still waiting for it arrive from Canada.

To stop misting up I'm feeding fresh air into my hood from a Metro heater motor. The motor unit is well away from any dust, and I wear a decent dust mask under the hood.

Not sure about that gun, there's no mention of tungsten carbide internals, given you can get an ordinary ball valve for about £3.00 it may not be viable. Buy one and let us know! Currently I'm using a carbide nozzle fixed straight into a hose tail. For my work I think that nozzle would be a bit bulky.

 

[philip979]

The mixture is very sensitive, I was thinking of using a gate valve instead.

I use that hood, it has lasted about 9 months of almost daily use. The lens doesn't last long, I'm making my own from pieces cut from the sides of clear 2 litre pop bottles.

I've bought this http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=190208025807&ssPageName=STRK:MEWN:IT&ih=009 for half the price, still waiting for it arrive from Canada.

To stop misting up I'm feeding fresh air into my hood from a Metro heater motor. The motor unit is well away from any dust, and I wear a decent dust mask under the hood.

Not sure about that gun, there's no mention of tungsten carbide internals, given you can get an ordinary ball valve for about £3.00 it may not be viable. Buy one and let us know! Currently I'm using a carbide nozzle fixed straight into a hose tail. For my work I think that nozzle would be a bit bulky.

Hello again. I’ve been sandblasting again over the weekend.

For info, the Sealey SB993 does seem pretty effective and I like the trigger design, however the gun does seem to lose pressure sometimes, for no particular reason. The nozzle doesn’t seem to be blocked, so not sure why this is. Also, the rubber hose seems to be perishing prematurely which isn’t good, although the supplier has promised me a new one.

The 10 gallon pot blaster is definitely more effective, but it is a bit of a fiddle with the valves which require constant adjustment. The ball valve on the nozzle needs replacing, but as you have said they are only around £3.

I do find that the 3hp compressor only sustains the blaster for a few seconds at a time. Perhaps a lower pressure would reduce the air used? I’m getting there slowly, however! I’ve nearly done everything I intended, my intention is to sell on one of the blasters when finished! One other thing I find with the pot blaster is it needs a shake every few seconds to dislodge the media. It doesn’t seem to fall naturally, as I have said before. It is dry and has been sieved. Any ideas? Do you think there could be something inside the pot that is restricting the downwards flow of media? I am finding this very problematic.

Thanks again for you input!

 

[rtbcomp]

Strange. I only had to shake mine with very dusty media that had been re-cycled several times, then only every ten minutes or so and when it's nearly empty.

Are you talking about the pot or the Sealey when you say the compressor won't keep up?

You say you adjust the valves - you should only need to adjust the bottom valve and again perhaps a tweak every ten mins. All the other valves should be fully open. With new media my 20 gall pot will go for an hour without adjustment.

As for pressure I've set my regulator for 80psi at the pot with the nozzle valve shut. It works fine down to 20psi. My 3hp compressor sustains 90 psi at the receiver.

Maybe something has got stuck in the bottom of the pot. Next time it's empty turn it upsidedown and give a good shake and see what drops out.