HF sandblaster

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Captainkirk

Captainkirk

Old School Mopar Warrior
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I purchased a barely used Harbor Freight free-standing sandblaster cabinet from my boss here at work. I have it stoked with fresh walnut shell media. Now, this thing, when working, will peel about two square inches of paint or rust in a few seconds. Then it just seems to be blowing air and walnut dust until I pause, wiggle things around, etc. The feed hose feels full of media, and while it does kink a little, seems to be fairly free flowing. If this thing would blast consistently, I'd be done in a flash with the pieces I'm working on. Air pressure is at least 80 psi working pressure minimum so that's not an issue. Anyone else have one of these units and figured out a workaround?
 
Captainkirk said:
I purchased a barely used Harbor Freight free-standing sandblaster cabinet from my boss here at work. I have it stoked with fresh walnut shell media. Now, this thing, when working, will peel about two square inches of paint or rust in a few seconds. Then it just seems to be blowing air and walnut dust until I pause, wiggle things around, etc. The feed hose feels full of media, and while it does kink a little, seems to be fairly free flowing. If this thing would blast consistently, I'd be done in a flash with the pieces I'm working on. Air pressure is at least 80 psi working pressure minimum so that's not an issue. Anyone else have one of these units and figured out a workaround?
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Make sure whatever you're blasting isn't gummy with oil or grease. I've noticed with ours if you use it for a while it will do it too. The only thing I can think of it might be getting some condensate out of the compressor, but I could be wrong.
 
Sandblasters of this kind are a PITA. The media, the tank, and hose all must be dry. You must figure out a way to vibrate or agitate--or at least "hand shake" it at times to keep the media from compacting.

Water in the air line seems to not be helpful, either. Not sure why, as the vacuum should pull the media in anyhow. I've often thought that the sharp 90 the media must make, as opposed to a sweeping elbow, might make the difference.

I've heard/ read about guys applying "some" pressure to the media tank. Remember, the absolute maximum vacuum equates to roughly 15 psi, so if you put 15 psi in the media tank, you've doubled the "supply" pressure
 
If you unscrew the nozzle and remove the ceramic venturi cone you will probably see the inside of the gun packed with media. If so then you need to improve the water trap and place it as close to the blast box(shortest amount of hose)
 
I looked into getting one not long ago. I found a bunch of youtube video's that show how to upgrade and improve your HF blaster.
 
You need to go on the Skat Blast site and get the upgrade kit. I did for mine and it's a night and day difference.
 
Every 5 secs or so cup your hand over the nozel and blow, that will burp the hopper that may have a void.

Alan
 
Cuda Al said:
Every 5 secs or so cup your hand over the nozel and blow, that will burp the hopper that may have a void.

Alan
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Exactly, I do that with my buddies cabinet. Hold the palm of your hand against the nozzle and squeeze the trigger.
 
We have a Trinco blaster at work. I have to cover the nozzle up once in awhile and hit the trigger blowing the media back out if it seems to clog.
 
See post #9. Clear the nozzle if flow stops. Large media has tendency to plug up the gun. Block the nozzle off and pull the trigger will force the air back through the suction. This can also happen if you have excessive moisture in the media or your air.
 
On my glass bead cabinet under the tip is a nozzle that control air flow. It wears out and goes too big. Once I change that out and verify the ceramic cup is with in spec my machine works great. I’ve tried walnut shells and really had bad results. Went back to glass bead. Also make sure the pick up tube does not have any holes in it. They wear out from the inside out. You may be dropping your level and sucking air.
 
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50 psi is lots too. Gets the job done as well as extends the life of the media. May need a desiccant dryer for it to remove moisture.
 
I only have a siphone style blaster, but I had the exact same issue.
I removed the front half of the gun and pulled the venturi - I noticed the clearance from the tip of the venturi to the inside of the Nozzle was very tight. Didn't let media flow very well at all.

So I ground a slight chamfer on the front of the jet and then added a couple washers and an o ring as a spacer to push the venturi back out of the Nozzle a bit. This left more room for media to flow, and flow it did! Was able to get the walnut media to feed consistently. Coal slag was even better than the walnut though, so I'm sticking with that.
 
Phreakish said:
I only have a siphone style blaster, but I had the exact same issue.
I removed the front half of the gun and pulled the venturi - I noticed the clearance from the tip of the venturi to the inside of the Nozzle was very tight. Didn't let media flow very well at all.

So I ground a slight chamfer on the front of the jet and then added a couple washers and an o ring as a spacer to push the venturi back out of the Nozzle a bit. This left more room for media to flow, and flow it did! Was able to get the walnut media to feed consistently. Coal slag was even better than the walnut though, so I'm sticking with that.
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Probably meant copper slag Bud. I say coal all of the time too. lol
 
Burp it...Burp it...Burp it! The Media will cavitate. I started out in the Aviation Industry running a VERY large cabinet blaster. Burping the hose and nozzle was the first thing My trainer taught me.
Norm
 
I have a Hazard Fraught sandblaster, one of those keg shaped ones on a cart. The ONE time I used it, it worked exactly as the OP wrote...It kicked *** for 3-4 seconds at a time but would clog up. I'd tap the nozzle and it would work, then clog again. This was using sand. I ran out of sand and poured in the crushed walnut shells. They were new and in a plastic bag in a box.
The hose clogged instantly and could NOT be cleared out. It was as if the shells all got interlocked all through the 8 foot hose and would not clear out. I hit the hose with hammers to knock it loose, ran a 32" screwdriver through each end but couldn't reach the middle. Now to do anything, I'll need to buy another hose. Hell, maybe I'll buy two so I'll have a spare if this crap happens again.
 
I have a HF cabinet and HF pressure sander. Both work great. My air is really dry.
The pressure blaster did blow the hose off and made a terrible mess. Its double clamped now. Should have known better and added the second clamp before using it. I can see walnut shells having an inherent clogging problem.
 
My garage built, plywood cabinet, with an external 60 Gallon compressor, sucked up moisture from the tank and mixed it with the media. I added the HF water filter from the compressor to the cabinet. End of problem. I can go about 45 minutes before giving the compressor a rest.
 
There is a easy mod you can do to the gun to open it up. Do a google search on it it works great. Post #16 nailed it.
 
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Wait until the light switch goes out and you try to source the parts to fix it. HF stocks nothing for it, so I had to mount a tube shop light inside and ditch the crappy light it had.
 
Same issue with my cabinet. I replaced the 12 dollar gun for a 40 dollar gun, its been awesome.
Next time i will buy the next one up from that. One with interchangeable jets and nozzles is the way to go.
 
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