Best gun for media blasting cabinet

[bigdry]

Hello all, i just bought a generic media blasting cabinet off ebay, all is good except the feeble suction of the gun that was provided with the cabinet. It can bearly pull up aluminium oxide media (i wish to derust steel car parts mainly)

Can anyone suggests a decent quality gun that will actually be able to pull up course media such as red garnet. thank you (and yes i have a decent large 18cfm compressor running on this cabinet

Many thanks

 

[brightspark]

u cant expect much from a suction gun. some are slightly better than others . if you want to get there fast buy a pressure pot and still use it with the cabinet

 

[bigdry]

really - surely some guns must work to remove rust from car parts? i wondered if a gun like these would help use of the cabinet ?

https://www.ebay.co.uk/itm/Sand-Bla...m=192446346770&_trksid=p2047675.c100005.m1851

 

[Jlg]

Hello all, i just bought a generic media blasting cabinet off ebay, all is good except the feeble suction of the gun that was provided with the cabinet. It can bearly pull up aluminium oxide media (i wish to derust steel car parts mainly)

Can anyone suggests a decent quality gun that will actually be able to pull up course media such as red garnet. thank you (and yes i have a decent large 18cfm compressor running on this cabinet

Many thanks

Machine mart do a cheap one that I've used a lot and it can suck aluminium oxide up a 6ft pipe no problem

 

[brightspark]

really - surely some guns must work to remove rust from car parts? i wondered if a gun like these would help use of the cabinet ?

https://www.ebay.co.uk/itm/Sand-Blast-Gun-for-Grit-Blast-Cabinet-with-8mm-Tungsten-Carbide-Nozzle-Sandblast/192446346770?_trkparms=aid=222007&algo=SIM.MBE&ao=2&asc=50546&meid=55076008c23c4f65a0d11ec90cd13d50&pid=100005&rk=4&rkt=12&sd=191606522077&itm=192446346770&_trksid=p2047675.c100005.m1851

the one in picture is of good quality and size I have a guyson copy one very similar . there ok for smallish parts but don't expect to be doing rusty wheels with them unless u have all day to spend

 

[rcx132]

I wouldn't go back to a suction gun. Way way way too slow.

 

[brightspark]

I wouldn't go back to a suction gun. Way way way too slow.

but very good using fine sand for cleaning light corrosion and rust of steel and aluminium without damage . the machine mart ones are pants the guyson or professional are decent . pressure pots are the same cheapo are ok but the regulating ball vales aren't up to much

 

[rcx132]

but very good using fine sand for cleaning light corrosion and rust of steel and aluminium without damage . the machine mart ones are pants the guyson or professional are decent . pressure pots are the same cheapo are ok but the regulating ball vales aren't up to much

I have a cheapo pressure pot, you know the 10 gallon one that everyone resells under their own brand. How are the dearer pots better? What's the difference?

The only problems I've found with my cheap pressure pot is that I have to modulate the throttle as the flow of media can change, probably depending on trapped moisture, or obstacles in the media.

I've had much better luck using superfine media. It needs much less modulation, and it blasts almost as well as heavy media. I've totally given up on heavy media now, can't be bothered to keep switching media, I just use superfine for everything now, from body panels to brake drums and 4x4 axles.

I also get pulsing from my tungsten nozzle, never figured out why.

To give you an idea, I think my cheap pressure pot blasts about 5 to 10 times faster than the suction guns I've used.

 

[brightspark]

I make my own regulating valves and pots there copied of the clemco mini pot and are very consistent. once set u can run them for hours without touching the regulator ones got a 3mm jet and runs of a 28cfm comp the others a 6mm jet and runs of a 90cfm comp

 

[brightspark]

I was making the regs from steel but made some patterns up and now made of cast ally . cheaper and quicker to machine

 

[rcx132]

I was making the regs from steel but made some patterns up and now made of cast ally . cheaper and quicker to machine

Great stuff!

 

[carbon]

If it’s the gun with two hoses I removed the brass jet and drilled the hole larger which seemed to increase the media flow. Not sure what size I drilled it out to though

 

[henry Kadzielski]

Good morning gents. Again mt two cents. The pulsation in the line is due to the irregular flow of media. If there is too much media the pulsation or convulsing because the air volume is too low to prevent the grit being suspended in the air stream (penumatic conveyor). The flow of grit should be stable to the grit control valve so that the amount of grit can be set accurately. In a suction pot the grit control is just the suction hose stuck in the grit, but it also need air inlet to control and to stop too much grit getting sucked up into the suction hose. Increasing the air jet will increase the speed, suction of the grit and improve blasting speed. I have a cheap suction pot which increased the air jet to max for that gun and I feed the gun 70cfm at 125psi, it now blasts quite well. There is no substitute for air volume in blasting, the more air volume the quicker you blast, all else being equal. The next step is the go pressure blast. If the suction air pressure and volume is applied to a pressure blast system the resultant blasting rate will be increased by about 3. Three times faster compared suction to pressure. This is what I have noticed it could be more, but there you go, ball park figure. Someone can correct me and be more specific. It is basically down to the abrasive speed hitting the job. The grit used has more kinetic energy

 

[rcx132]

Good morning gents. Again mt two cents. The pulsation in the line is due to the irregular flow of media. If there is too much media the pulsation or convulsing because the air volume is too low to prevent the grit being suspended in the air stream (penumatic conveyor). The flow of grit should be stable to the grit control valve so that the amount of grit can be set accurately. In a suction pot the grit control is just the suction hose stuck in the grit, but it also need air inlet to control and to stop too much grit getting sucked up into the suction hose. Increasing the air jet will increase the speed, suction of the grit and improve blasting speed. I have a cheap suction pot which increased the air jet to max for that gun and I feed the gun 70cfm at 125psi, it now blasts quite well. There is no substitute for air volume in blasting, the more air volume the quicker you blast, all else being equal. The next step is the go pressure blast. If the suction air pressure and volume is applied to a pressure blast system the resultant blasting rate will be increased by about 3. Three times faster compared suction to pressure. This is what I have noticed it could be more, but there you go, ball park figure. Someone can correct me and be more specific. It is basically down to the abrasive speed hitting the job. The grit used has more kinetic energy

So with the pulsing you're saying there's either too much media being released or its released unevenly?

What could be done to steady the release of media? I appreciate @brightspark has done his own valve but I don't understand why his valve is better than the ball valve used to release media on a cheapo blaster?

 

[brightspark]

trouble is with a ball valve any inconsistency in the media drops down in to the valve and lodges there stopping the flow then you have to prat about readjusting it to get it to flow again consistently .the Clemco valves as you can see the media drops down a half inch hole on to the regulating plate which is partially open . the outlet is 3/8 TH of an inch off the base so any larger particles drop through still and fall to one side and don't block the flow of media as a ball valve would do . now and then you just open them up and clean them out . not very often if you use new grit or well sieved used media

 

[henry Kadzielski]

What could be done to steady the release of media? I appreciate @brightspark has done his own valve but I don't understand why his valve is better than the ball valve used to release media on a cheapo blaster?

Yes brightspark has made his own abrasive valve, but you could use a 'Micro valve', you can look it up. It had rotary adjustment of the abrasive flow, so much easier to control and to reset the grit to the correct amount. Grit flow to the grit control valve is very important as it gives consistancy to the blast. Moisture is one huge controlling factor as to grit flow. Also the finer the grit and or the more contaminated if recycled the more it is affected by moisture, all else being equal. Your ball valve system, though seems to be a good idea is not the valve internals don't take wear well, if anything gets caught in the valve to set the grit flow again is difficult. The smaller the compressor feeding the pot / blasting system the smaller the opening in the grit control valve need to be to get the right grit flow down the hose, then it is far easier to get blockages in the grit control valve

 

[rcx132]

So according to Google there's something called a media metering valve which is the proper thing to use. But manufacturers are saying there's a lot more to a blast pot so putting a pro valve on an eBay pot might not fix everything.

My pots been working OK so leaving it as it is for now

 

[8ob]

I make my own regulating valves and pots there copied of the clemco mini pot and are very consistent. once set u can run them for hours without touching the regulator ones got a 3mm jet and runs of a 28cfm comp the others a 6mm jet and runs of a 90cfm comp

Impressive work Mr Sparks, that media regulator is the key component and so much better than a ballafix type valve.

Bob

 

[brightspark]

So according to Google there's something called a media metering valve which is the proper thing to use. But manufacturers are saying there's a lot more to a blast pot so putting a pro valve on an eBay pot might not fix everything.

My pots been working OK so leaving it as it is for now

the only let down on a cheap pot is the metering valve and they need a carbide blast jet. also the filler neck is just a small screw on cap . I made a simple larger quick release one on mine .