Upgraded media valve not working.

[RA Dunk]

Just bought an upgraded media valve from ebay https://www.ebay.co.uk/itm/165968195809

Fitted it over the weekend and no matter how much PSI I use (tried it from 45psi all the way to 90 psi) or how open or closed i have the air valve, it dosent draw any media to my gun?

Thinking it wcould be a problem with my media as it was old I order new stuff. some Draper 40112 shot blasting grit.

I get the whole concept of the venturi affect with the valve and i do hear air coming from the 'air valve' when i open it so the valve seems to be ok and not the problem.

I've got negative pressure in the cabinet when the doors closed and the extractors on, so muc negative pressure that the gauntlets will sit horizontal without my hands being in them.

Compressor seems to be running fine, it fills the tank from empty in 3 or 4 minutes.

Unsure what I should be looking at as this should be a simple set up?

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[JOEPRO]

What gun have you got?

 

[RA Dunk]

Could it be you need to prime that tube with media?

Not sure TBH, but going by the other videos ive seen on You Tube (and ive watched alot) no one else has?

 

[RA Dunk]

What gun have you got?

Just the basic gun that came with the cabinet? had the whole set up 12 years now?

 

[JOEPRO]

Just the basic gun that came with the cabinet? had the whole set up 12 years now?

Others more experienced than me will chime in. What I can say is I have a similar setup with this type of gun now:



It flows MUCH better with this type of gun IMO.

Also - don't over fill the hopper you only need about 8 inches media above the outlet. And ensure the media is dry & sieved too.

Re the neg pressure there is a plastic removal bung in my blast cab. I remove it when blasting and it allows for the intake air for the extraction to work correctly.

 

[voipio]

If the media tube is disconnected from the gun, how much suction from the gun is there when the gun is operated?

Is there any dampness in the bottom of the media hopper? It doesn't take much to completely stop the feed from working.

 

[RA Dunk]

Others more experienced than me will chime in. What I can say is I have a similar setup with this type of gun now:

View attachment 442529

It flows MUCH better with this type of gun IMO.

Also - don't over fill the hopper you only need about 8 inches media above the outlet. And ensure the media is dry & sieved too.

Re the neg pressure there is a plastic removal bung in my blast cab. I remove it when blasting and it allows for the intake air for the extraction to work correctly.

Yea, i was kind of thinking of upgrading the gun too quite soon maybe sooner than i think now lol, I'm guessing that gun works with a foot pedal as i dont see a trigger on it?

I've only a couple of cup fulls in at the moment, maybe I should try adding a bit more? media is brand new im afraid so its not that.

I've one of those plastic bungs too, ive tried removing that already.

 

[RA Dunk]

If the media tube is disconnected from the gun, how much suction from the gun is there when the gun is operated?

Is there any dampness in the bottom of the media hopper? It doesn't take much to completely stop the feed from working.

Not sure what your meaning here buddy, if the media tube is disconnected all the gun will do is blow air unless im mistaken?

Hoppers bone dry too.

 

[dave h 2]

You don't need much air, the small Guyson cabinet pickup had a 3mm breather tube on the pickup. The 13mm ball needs to start closed and open gradually till you get media. I would take the gun out of the cabinet and fire it into a bucket while tweaking the valve. Start low down then lift the gun to working height and fiddle the valve to keep it working.
Voipio is trying to find out if the gun suction is any good

 

[Erie Fred]

Not sure what your meaning here buddy, if the media tube is disconnected all the gun will do is blow air unless im mistaken?

Hoppers bone dry too.

the media tube.
if you disconnect the media tube, and activate the gun, how much suction do you have ?

 

[RA Dunk]

You don't need much air, the small Guyson cabinet pickup had a 3mm breather tube on the pickup. The 13mm ball needs to start closed and open gradually till you get media. I would take the gun out of the cabinet and fire it into a bucket while tweaking the valve. Start low down then lift the gun to working height and fiddle the valve to keep it working.
Voipio is trying to find out if the gun suction is any good

the media tube.
if you disconnect the media tube, and activate the gun, how much suction do you have ?

Eventually managed to work out what you ment lol.

Ok, so just been over to the workshop for a gander, disconnected the media tube and pressed the trigger, what happened was I wasnt getting any suction but it was actually blowing air and not sucking, so obviously the media wont go into the tube if there is air coming down to meet it. I'm guessing my guns ******** then.

Any idea why my gun would start doing this?

 

[dave h 2]

The grit has probably eaten the air jet holder. The answer is inside the gun.

 

[RA Dunk]

The grit has probably eaten the air jet holder. The answer is inside the gun.

yea, ive actually had the good of that gun its lasted years, ohh well, looks like im away to order a new upgraded gun then.

 

[dave h 2]

Might just need a little bzzzzt with the mig

 

[RA Dunk]

Might just need a little bzzzzt with the mig

Havent got a mig, a new gun with better flow was on the cards soon anyway. Ill have a look at that one Joepro mentioned earlier as he said it Flows quite well.

 

[Erie Fred]

Havent got a mig, a new gun with better flow was on the cards soon anyway. Ill have a look at that one Joepro mentioned earlier as he said it Flows quite well.

I just happened to order that same gun from aliexpress 2 months ago, and it works well.

 

[RA Dunk]

I just happened to order that same gun from aliexpress 2 months ago, and it works well.

Just been looking at them on Fleabay, I see no trigger or footpedal mentioned, does the gun just stay on all the time as soon as a compressor is hooked up?

 

[Erie Fred]

Just been looking at them on Fleabay, I see no trigger or footpedal mentioned, does the gun just stay on all the time as soon as a compressor is hooked up?

You rig up a foot pedal.
It's much easier to use rather than pulling a trigger all the time.

 

[JOEPRO]

Yea, i was kind of thinking of upgrading the gun too quite soon maybe sooner than i think now lol, I'm guessing that gun works with a foot pedal as i dont see a trigger on it?

I've only a couple of cup fulls in at the moment, maybe I should try adding a bit more? media is brand new im afraid so its not that.

I've one of those plastic bungs too, ive tried removing that already.

I bought one of tbe generic ebay foot pedals and they are not good. Small / restricted passages inside it so I didn't use it at all.

What I do is load the parts, close the cab. Turn on extractor and connect the air line. The gun is then 100% live until I disconnect the air again. No biggie and works well for me and I am getting the full benefit from the 10mm bore air hoses I use. PCL XF fittings too.

I have a copper pipe and water trap filter at the compressor end. AND another water trap filter on the blast cabinet itself. This second / last in line water trap does pick up water so its very important at least in my application

 

[RA Dunk]

You rig up a foot pedal.
It's much easier to use rather than pulling a trigger all the time.

I bought one of tbe generic ebay foot pedals and they are not good. Small / restricted passages inside it so I didn't use it at all.

What I do is load the parts, close the cab. Turn on extractor and connect the air line. The gun is then 100% live until I disconnect the air again. No biggie and works well for me and I am getting the full benefit from the 10mm bore air hoses I use. PCL XF fittings too.

I have a copper pipe and water trap filter at the compressor end. AND another water trap filter on the blast cabinet itself. This second / last in line water trap does pick up water so its very important at least in my application

oky doky, going to need to nip back to the workshop and measure my nozzle size then as im pretty sure the one i use is smaller than 8mm? I notice the air inlet on this gun you have is much bigger than my current set up as well so maybe with the increased air going to the gun 8mm might be ok? im unsure TBH?