Blast Cabinet Sucks - Not!!!

T

TomS

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I have a Harbor Freight bench top siphon type blast cabinet that won't pull the blast media through the gun. I'm using Tractor Supply Black Diamond medium grit coal slag abrasive. It is dry so moisture is not the issue. I've tried four different size ceramic tips supplied with the blast cabinet and varied the air pressure from 80 psi to 135 psi. Also replaced the suction hose with a clear hose and verified that the gun is in fact pulling the abrasive up to the gun. I opened up the internal nozzle size with a drill to increase the amount of air passing over the suction/inlet and still no abrasive passes through the gun. The suction hose has a 3/8" ID by 10" long tube on the end that is buried in the abrasive. I squeezed the open end to reduce the inlet size thinking too much abrasive was being sucked up the tube and blocking the gun inlet. Still no abrasive passes through the gun. What do I need to do to get this thing working?

Thanks,

Tom S
 
I've seen occasions when something in the suction side of the venturi is blocked, and you can simply place your gloved finger over the ceramic nozzle opening and trigger the gun. This forces air to go back down through the suction hose and should clear any blockage. Of course, can't say for sure that is the problem, but it's always the first thing I do when the gun stops and I know I have media and air.
 
If you're using the stock handle that comes with it, take the suction tube off and blow the nozzle down into it. This will clear any obstructions.

NOTE: Those units don't seal up too well and you'll be covering your shop in grit. Get some silicone sealant and go to town.


Ray
 
Tom, I had the same problem with my Harbor Freight blast cabinet. The inlet tube for the abrasive media was blocked and only had about a .03 hole in it, I drilled it out to the same size as the inlet I.D. and it works fine now.

Kevin
 
Tony Wells said:
I've seen occasions when something in the suction side of the venturi is blocked, and you can simply place your gloved finger over the ceramic nozzle opening and trigger the gun. This forces air to go back down through the suction hose and should clear any blockage. Of course, can't say for sure that is the problem, but it's always the first thing I do when the gun stops and I know I have media and air.
Click to expand...

Thanks. Tried it and still no abrasive feed through the gun.
 
How much media is in the cabinet? I have the 50# capable HF unit and found that it works the best about 10# of media in it. It seems the weight of the media would not allow it to get sucked up in the tube. tim
 
I had the same problem with my HF floor model blaster. I found a small piece of metal had gotten sucked into the pickup tube and blocked it. On the other hand it is a HF.
 
Checked the siphon tube and hose for obstructions and they are clear. Put my hand over the nozzle and pulled the trigger to make sure. I'm confident there are no obstructions in the suction side because I have a clear suction hose and you can see the blast media move up the tube when you pull the trigger. I placed the suction tube deep into the abrasive and close to the top. Still pulls the media up the tube then it stops once the tube is full. Could it be there needs to be a larger volume of air moving across the siphon port to pull the abrasive into the gun? I've already opened it up about 3/64".
 
TomS said:
Checked the siphon tube and hose for obstructions and they are clear. Put my hand over the nozzle and pulled the trigger to make sure. I'm confident there are no obstructions in the suction side because I have a clear suction hose and you can see the blast media move up the tube when you pull the trigger. I placed the suction tube deep into the abrasive and close to the top. Still pulls the media up the tube then it stops once the tube is full. Could it be there needs to be a larger volume of air moving across the siphon port to pull the abrasive into the gun? I've already opened it up about 3/64".
Click to expand...

It could be a flow problem and a bit of a worn gun


I think I am going to try the the blast gun from the link above. Mine is not the best either, but it does sorta work. Requires clearing much too often.
 
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