Not picking up media with 3mm nozzle

[Lewis_RX8]

Hello everyone.

I am currently having an issue with my sandblaster it is not as fast as it used to be( Just needing to move slower than i used to) and when I tried to use a 3mm nozzle it would not pick up any media at all and just blow air.

I have changed the whole blast cabinet to brand new dry grade 3 grit from scangrit.

I don't think there is any blockages as it works with a 5mm but then not with a 3mm.

Here is the cabinet - Link

Its still using the original suction and pickup tube.

 

[Lewis_RX8]

I got a few pictures and a video of the gun and cabinet.

https://gyazo.com/8483a194903bd6e29d6d4cc00a3317a8

https://gyazo.com/d4d9391a5c35e281c00f44670eb545f3

https://gyazo.com/c184e25523a4e11cc1cdba57bd2b932e

Video - https://gyazo.com/1c3a30ee8afe7a5572e7bcab1f339902

 

[brightspark]

Hello everyone.

I am currently having an issue with my sandblaster it is not as fast as it used to be( Just needing to move slower than i used to) and when I tried to use a 3mm nozzle it would not pick up any media at all and just blow air.

I have changed the whole blast cabinet to brand new dry grade 3 grit from scangrit.

I don't think there is any blockages as it works with a 5mm but then not with a 3mm.

Here is the cabinet - Link

Its still using the original suction and pickup tube.

the nozzle is your problem 3mm blast jet wont be big enough a 5mm will be there only a suction gun the back cone one is the air jet from comp same as these heres one in bits

 

[MetalMonkey]

I'ts not going to be what you want to hear, but those type of suction style units are dire for blocking and performance in my experience. I would always spend more time messing with the cabinet than I would blasting parts.
Have a look at the SBC420 or 990 units (KMS used to have both styles listed) with the metering valve and foot pedal - these work really well.

I got fed up with my original syphon pick up tube one and built my own using the metering valve/pedal and gun from a 420/990 and it works flawlessly every time.
I upgraded to a carbide nozzle which should last forever.

You should be able to modify your cabinet but you will need some decent air flow to run one, otherwise a pressure pot might be a better route.

 

[Lewis_RX8]

the nozzle is your problem 3mm blast jet wont be big enough a 5mm will be there only a suction gun the back cone one is the air jet from comp same as these heres one in bits

Thanks , Must say that was one of my suspicions from online research but wasn't quite sure.

I'ts not going to be what you want to hear, but those type of suction style units are dire for blocking and performance in my experience. I would always spend more time messing with the cabinet than I would blasting parts.
Have a look at the SBC420 or 990 units (KMS used to have both styles listed) with the metering valve and foot pedal - these work really well.

I got fed up with my original syphon pick up tube one and built my own using the metering valve/pedal and gun from a 420/990 and it works flawlessly every time.
I upgraded to a carbide nozzle which should last forever.

You should be able to modify your cabinet but you will need some decent air flow to run one, otherwise a pressure pot might be a better route.

Yes , Confused how i remember it working better before when it was brand new. How does your gun mix the media and the air hard to make out from the photos.

Did you buy one of those cabinets or just get the gun from it?

Thanks

 

[MetalMonkey]

I just bought the bits I needed and built my own cabinet as I needed to fit it in a specific space.

The gun is a BNP Clemco, mine is a genuine but you can pick up a clone which looks identical:
https://www.ebay.co.uk/itm/Sandblas...-Gun-Kit-for-SBC420-Sand-Blaster/383100235559

The metering valve and foot pedal I bought from KMS as they do spare parts for the 420 if you phone them.
The gun has two inputs, one for the abrasive and one for air, you connect the feed from the metering valve to one and the foot pedal to the other (my gun has no trigger).

The metering valve is the bit that adjusts the flow of media and stops the thing constantly blocking up - you can also tweak it if you change to a finer grit.
It might be worth thinking about swapping just this and try it with your existing gun. There are quite a few videos on youtube that demonstrate how to install it and how it works, I understand it is a common upgrade in the states.
E.g.